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Sample records for cultivated rice fields

  1. Effects of Bt-transgenic rice cultivation on planktonic communities in paddy fields and adjacent ditches

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yongbo, E-mail: liuyb@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Liu, Fang [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wang, Chao [Pearl River Fisheries Research Institute, Chinese Academy of Fishery Science, Guangzhou 510380 (China); Quan, Zhanjun [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Li, Junsheng, E-mail: lijsh@creas.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China)

    2016-09-15

    The non-target effects of transgenic plants are issues of concern; however, their impacts in cultivated agricultural fields and adjacent natural aquatic ecosystems are poorly understood. We conducted field experiments during two growing seasons to determine the effects of cultivating Bacillus thuringiensis (Bt)-transgenic rice on the phytoplankton and zooplankton communities in a paddy field and an adjacent ditch. Bt toxin was detected in soil but not in water. Water quality was not significantly different between non-Bt and Bt rice fields, but varied among up-, mid- and downstream locations in the ditch. Cultivation of Bt-transgenic rice had no effects on zooplankton communities. Phytoplankton abundance and biodiversity were not significantly different between transgenic and non-transgenic rice fields in 2013; however, phytoplankton were more abundant in the transgenic rice field than in the non-transgenic rice field in 2014. Water quality and rice type explained 65.9% and 12.8% of this difference in 2014, respectively. Phytoplankton and zooplankton were more abundant in mid- and downstream, than upstream, locations in the ditch, an effect that we attribute to water quality differences. Thus, the release of Bt toxins into field water during the cultivation of transgenic crops had no direct negative effects on plankton community composition, but indirect effects that alter environmental conditions should be taken into account during the processes of management planning and policymaking. - Highlights: • We detect fusion Cry1Ab/1Ac proteins from Bt rice entering into aquatic ecosystems. • Bt-transgenic rice cultivation have no significant effect on zooplankton community. • Bt-transgenic rice cultivation have indirect effect on phytoplankton community. • Water quality explains the difference of plankton communities in adjacent ditches.

  2. Effects of Bt-transgenic rice cultivation on planktonic communities in paddy fields and adjacent ditches

    International Nuclear Information System (INIS)

    Liu, Yongbo; Liu, Fang; Wang, Chao; Quan, Zhanjun; Li, Junsheng

    2016-01-01

    The non-target effects of transgenic plants are issues of concern; however, their impacts in cultivated agricultural fields and adjacent natural aquatic ecosystems are poorly understood. We conducted field experiments during two growing seasons to determine the effects of cultivating Bacillus thuringiensis (Bt)-transgenic rice on the phytoplankton and zooplankton communities in a paddy field and an adjacent ditch. Bt toxin was detected in soil but not in water. Water quality was not significantly different between non-Bt and Bt rice fields, but varied among up-, mid- and downstream locations in the ditch. Cultivation of Bt-transgenic rice had no effects on zooplankton communities. Phytoplankton abundance and biodiversity were not significantly different between transgenic and non-transgenic rice fields in 2013; however, phytoplankton were more abundant in the transgenic rice field than in the non-transgenic rice field in 2014. Water quality and rice type explained 65.9% and 12.8% of this difference in 2014, respectively. Phytoplankton and zooplankton were more abundant in mid- and downstream, than upstream, locations in the ditch, an effect that we attribute to water quality differences. Thus, the release of Bt toxins into field water during the cultivation of transgenic crops had no direct negative effects on plankton community composition, but indirect effects that alter environmental conditions should be taken into account during the processes of management planning and policymaking. - Highlights: • We detect fusion Cry1Ab/1Ac proteins from Bt rice entering into aquatic ecosystems. • Bt-transgenic rice cultivation have no significant effect on zooplankton community. • Bt-transgenic rice cultivation have indirect effect on phytoplankton community. • Water quality explains the difference of plankton communities in adjacent ditches.

  3. Comparison of aquatic macrophyte community structure between natural wetlands and rice fields with different cultivation ages

    OpenAIRE

    Rolon, A. S.; Godoy, R. S.; Maltchik, L.

    2017-01-01

    Abstract Recent studies indicate that rice fields contribute to the conservation of aquatic plants, however, repeated cultivation can reduce the species diversity harbored by rice fields. Repeated tillage, agrochemical application and environmental homogeneity can reduce plant diversity and select for species more tolerant to disturbance. Our hypotheses were: 1) macrophyte richness and biomass decrease with increased rice crop age; and 2) macrophyte species of rice fields are a subsample of n...

  4. Effects of screenhouse cultivation and organic materials incorporation on global warming potential in rice fields.

    Science.gov (United States)

    Xu, Guochun; Liu, Xin; Wang, Qiangsheng; Xiong, Ruiheng; Hang, Yuhao

    2017-03-01

    Global rice production will be increasingly challenged by providing healthy food for a growing population at minimal environmental cost. In this study, a 2-year field experiment was conducted to investigate the effects of a novel rice cultivation mode (screenhouse cultivation, SHC) and organic material (OM) incorporation (wheat straw and wheat straw-based biogas residue) on methane (CH 4 ) and nitrous oxide (N 2 O) emissions and rice yields. In addition, the environmental factors and soil properties were also determined. Relative to the traditional open-field cultivation (OFC), SHC decreased the CH 4 and N 2 O emissions by 6.58-18.73 and 2.51-21.35%, respectively, and the global warming potential (GWP) was reduced by 6.49-18.65%. This trend was mainly because of lower soil temperature and higher soil redox potential in SHC. Although the rice grain yield for SHC were reduced by 2.51-4.98% compared to the OFC, the CH 4 emissions and GWP per unit of grain yield (yield-scaled CH 4 emissions and GWP) under SHC were declined. Compared to use of inorganic fertilizer only (IN), combining inorganic fertilizer with wheat straw (WS) or wheat straw-based biogas residue (BR) improved rice grain yield by 2.12-4.10 and 4.68-5.89%, respectively. However, OM incorporation enhanced CH 4 emissions and GWP, leading to higher yield-scaled CH 4 emissions and GWP in WS treatment. Due to rice yield that is relatively high, there was no obvious effect of BR treatment on them. These findings suggest that apparent environmental benefit can be realized by applying SHC and fermenting straw aerobically before its incorporation.

  5. The land use potential of flood-prone rice fields using floating rice system in Bojonegoro regency in East Java

    Science.gov (United States)

    Irianto, H.; Mujiyo; Riptanti, E. W.; Qonita, A.

    2018-03-01

    Bojonegoro regency occupies the largest flood-prone rice fields of about 14,198 hectares, in East Java province. Floods commonly occur due to Bengawan Solo river over-burst, particularly in rainy season. The fields are potential for cultivating rice, but floods lasting for months causing these areas to be unproductive. The objective of this article is to examine the potential land use of flood prone rice fields in Bojonegoro regency using floating rice system as an effort to maintain productivity in rainy season. The method of this study is referential study about the rice production using floating cultivation system in other regions, which are later compared with the physical condition of the fields in Bojonegoro. The results of analysis show that rice cultivation using floating system can maintain rice production in flood prone areas during rainy season. The potential production of rice is 5-6 tons/ha. However, technical problems for cultivating rice cannot be ignored since farmers are not familiar with cultivating flooded fields. This article also explains alternatives of floating rice cultivation technique, which can be implemented effectively and efficiently. Pioneer work of developing floating rice in Bojonegoro that has been done by the Team of Faculty of Agriculture of UNS, Surakarta, is expected to serve as a medium for accelerating the adoption of cultivation technology innovation to farmers.

  6. Leaf development of cultivated rice and weedy red rice under elevated temperature scenarios

    OpenAIRE

    Streck,Nereu A.; Uhlmann,Lilian O.; Gabriel,Luana F.

    2013-01-01

    The objective of this study was to simulate leaf development of cultivated rice genotypes and weedy red rice biotypes in climate change scenarios at Santa Maria, RS, Brazil. A leaf appearance (LAR) model adapted for rice was used to simulate the accumulated leaf number, represented by the Haun Stage, from crop emergence to flag leaf appearance (EM-FL). Three cultivated rice genotypes and two weedy red rice biotypes in six emergence dates were used. The LAR model was run for each emergence dat...

  7. A comparative study of competitiveness between different genotypes of weedy rice (Oryza sativa) and cultivated rice.

    Science.gov (United States)

    Dai, Lei; Dai, Weimin; Song, Xiaoling; Lu, Baorong; Qiang, Sheng

    2014-01-01

    Competition from weedy rice can cause serious yield losses to cultivated rice. However, key traits that facilitate competitiveness are still not well understood. To explore the mechanisms behind the strong growth and competitive ability, replacement series experiments were established with six genotypes of weedy rice from different regions and one cultivated rice cultivar. (1) Weedy rice from southern China had the greatest impact on growth and yield of cultivated rice throughout the entire growing season. Weedy rice from the northeast was very competitive during the early vegetative stage while the competitive effects of eastern weedy rice were more detrimental at later crop-growth stages. (2) As the proportion of weedy rice increased, plant height, tillers, above-ground biomass, and yield of cultivated rice significantly declined; the crop always being at disadvantage regardless of proportion. (3) Weedy biotypes with greater diversity as estimated by their Shannon indexes were more detrimental to the growth and yield of cultivated rice. Geographic origin (latitude) of weedy rice biotype, its mixture proportion under competition with the crop and its genetic diversity are determinant factors of the outcome of competition and the associated decline in the rice crop yield. © 2013 Society of Chemical Industry. © 2013 Society of Chemical Industry.

  8. Effective Suppression of Methane Emission by 2-Bromoethanesulfonate during Rice Cultivation.

    Science.gov (United States)

    Waghmode, Tatoba R; Haque, Md Mozammel; Kim, Sang Yoon; Kim, Pil Joo

    2015-01-01

    2-bromoethanesulfonate (BES) is a structural analogue of coenzyme M (Co-M) and potent inhibitor of methanogenesis. Several studies confirmed, BES can inhibit CH4 prodcution in rice soil, but the suppressing effectiveness of BES application on CH4 emission under rice cultivation has not been studied. In this pot experiment, different levels of BES (0, 20, 40 and 80 mg kg-1) were applied to study its effect on CH4 emission and plant growth during rice cultivation. Application of BES effectively suppressed CH4 emission when compared with control soil during rice cultivation. The CH4 emission rates were significantly (Price cultivation. A rice plant growth and yield parameters were not affected by BES application. The maximum CH4 reduction (49% reduction over control) was found at 80 mg kg-1 BES application during rice cultivation. It is, therefore, concluded that BES could be a suitable soil amendment for reducing CH4 emission without affecting rice plant growth and productivity during rice cultivation.

  9. Mechanism and capacities of reducing ecological cost through rice-duck cultivation.

    Science.gov (United States)

    Long, Pan; Huang, Huang; Liao, Xiaolan; Fu, Zhiqiang; Zheng, Huabin; Chen, Aiwu; Chen, Can

    2013-09-01

    Rice-duck cultivation is the essence of Chinese traditional agriculture. A scientific assessment of the mechanism and its capacity is of theoretical significance and practical value in improving modern agricultural technology. The duck's secretions, excreta and their treading, pecking and predation decrease the occurrence of plant diseases, pests and weeds, enrich species diversity and improve the field environment. The rice-duck intergrowth system effectively prevents rice planthoppers and rice leafhoppers. The control effects can be up to 98.47% and 100% respectively; it also has effects on the control of Chilo suppressalis, Tryporyza incertulas and the rice leafrollers. Notable control results are found on sheath blight, while the effects on other diseases are about 50%. Harm from weeds is placed under primary control; prevention of weeds is sequenced by broadleaf weeds > sedge weeds > Gramineae weeds. Contents of soil organic matter, N, P and K are improved by the system; nutrient utilization is accelerated, resulting in decreased fertilizer application. Greenhouse gas emissions are reduced by 1-2% and duck fodder is saved in this system. There is also an obvious economic benefit. Compared to conventional rice cultivation, rice-duck cultivation shows great benefits to ecologic cost and economic income. © 2013 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  10. Agriculture and the promotion of insect pests: rice cultivation in river floodplains and malaria vectors in The Gambia

    Directory of Open Access Journals (Sweden)

    Louca Vasilis

    2009-07-01

    Full Text Available Abstract Background Anthropogenic modification of natural habitats can create conditions in which pest species associated with humans can thrive. In order to mitigate for these changes, it is necessary to determine which aspects of human management are associated with the promotion of those pests. Anopheles gambiae, the main Africa malaria vector, often breeds in rice fields. Here the impact of the ancient practice of 'swamp rice' cultivation, on the floodplains of the Gambia River, on the production of anopheline mosquitoes was investigated. Methods Routine surveys were carried out along 500 m transects crossing rice fields from the landward edge of the floodplains to the river during the 2006 rainy season. Aquatic invertebrates were sampled using area samplers and emergence traps and fish sampled using nets. Semi-field experiments were used to investigate whether nutrients used for swamp rice cultivation affected mosquito larval abundance. Results At the beginning of the rainy season rice is grown on the landward edge of the floodplain; the first area to flood with fresh water and one rich in cattle dung. Later, rice plants are transplanted close to the river, the last area to dry out on the floodplain. Nearly all larval and adult stages of malaria vectors were collected 0–100 m from the landward edge of the floodplains, where immature rice plants were grown. These paddies contained stagnant freshwater with high quantities of cattle faeces. Semi-field studies demonstrated that cattle faeces nearly doubled the number of anopheline larvae compared with untreated water. Conclusion Swamp rice cultivation creates ideal breeding sites for malaria vectors. However, only those close to the landward edge harboured vectors. These sites were productive since they were large areas of standing freshwater, rich in nutrients, protected from fish, and situated close to human habitation, where egg-laying mosquitoes from the villages had short distances to

  11. Effective Suppression of Methane Emission by 2-Bromoethanesulfonate during Rice Cultivation.

    Directory of Open Access Journals (Sweden)

    Tatoba R Waghmode

    Full Text Available 2-bromoethanesulfonate (BES is a structural analogue of coenzyme M (Co-M and potent inhibitor of methanogenesis. Several studies confirmed, BES can inhibit CH4 prodcution in rice soil, but the suppressing effectiveness of BES application on CH4 emission under rice cultivation has not been studied. In this pot experiment, different levels of BES (0, 20, 40 and 80 mg kg-1 were applied to study its effect on CH4 emission and plant growth during rice cultivation. Application of BES effectively suppressed CH4 emission when compared with control soil during rice cultivation. The CH4 emission rates were significantly (P<0.001 decreased by BES application possibly due to significant (P<0.001 reduction of methnaogenic biomarkers like Co-M concentration and mcrA gene copy number (i.e. methanogenic abunadance. BES significantly (P<0.001 reduced methanogen activity, while it did not affect soil dehydrogenase activity during rice cultivation. A rice plant growth and yield parameters were not affected by BES application. The maximum CH4 reduction (49% reduction over control was found at 80 mg kg-1 BES application during rice cultivation. It is, therefore, concluded that BES could be a suitable soil amendment for reducing CH4 emission without affecting rice plant growth and productivity during rice cultivation.

  12. Health assessment of Arsenic and Zinc in rice cultivated in Fars province (Case Study: Firoozabad fields

    Directory of Open Access Journals (Sweden)

    M Cheraghi

    2013-11-01

    Full Text Available Food security along with the protection of environment has become a global issue.Accumulation of Arsenic and Zinc in rice is considered as a major problem for South-East Asia, where rice is a staple food. Given that, rice is considered as the highly consumed food in the diet of Iranian people, this study was conducted to estimate the concentrations of Zinc and Arsenic in rice cultivated in Firoozabad fields. For this purpose, 38 rice samples were collected from 22 nearby villages. Samples were digested by Digesdahl device and the concentrations of Arsenic and Zinc were determined by ICP. The results showed that the concentration (mean ± SD of Zinc was 20.87 ± 1.9 mg/kg of dry matter (ranged from 25.26 to 32.97; meanwhile mean value of Arsenic concentration was estimated at 22.89 ± 2.2 mg/kg of dry matter (ranged from 17.61 to 26.77.Comparing the concentrations of Arsenic and Zinc in rice samples with the standard limit set by WHO/FAO it was revealed that Arsenic concentrations in 100% of the samples were higher than standard level, whereas Zinc concentrations in 97.36% of the samples were below the limit.

  13. Can rice field channels contribute to biodiversity conservation in Southern Brazilian wetlands?

    Science.gov (United States)

    Maltchik, Leonardo; Rolon, Ana Silvia; Stenert, Cristina; Machado, Iberê Farina; Rocha, Odete

    2011-12-01

    Conservation of species in agroecosystems has attracted attention. Irrigation channels can improve habitats and offer conditions for freshwater species conservation. Two questions from biodiversity conservation point of view are: 1) Can the irrigated channels maintain a rich diversity of macrophytes, macroinvertebrates and amphibians over the cultivation cycle? 2) Do richness, abundance and composition of aquatic species change over the rice cultivation cycle? For this, a set of four rice field channels was randomly selected in Southern Brazilian wetlands. In each channel, six sample collection events were carried out over the rice cultivation cycle (June 2005 to June 2006). A total of 160 taxa were identified in irrigated channels, including 59 macrophyte species, 91 taxa of macroinvertebrate and 10 amphibian species. The richness and abundance of macrophytes, macroinvertebrates and amphibians did not change significantly over the rice cultivation cycle. However, the species composition of these groups in the irrigation channels varied between uncultivated and cultivated periods. Our results showed that the species diversity found in the irrigation channels, together with the permanence of water enables these man-made aquatic networks to function as important systems that can contribute to the conservation of biodiversity in regions where the wetlands were converted into rice fields. The conservation of the species in agriculture, such as rice field channels, may be an important alternative for biodiversity conservation in Southern Brazil, where more than 90% of wetland systems have already been lost and the remaining ones are still at high risk due to the expansion of rice production.

  14. 7 CFR 457.170 - Cultivated wild rice crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ... reinsured policies: Cultivated Wild Rice Crop Provisions. 1. Definitions Approved laboratory. A testing.... Cultivated Wild Rice. A member of the grass family Zizania Palustris L., adapted for growing in man-made... for the crop year. Planted acreage. In addition to the definition contained in the Basic Provisions...

  15. Implications of Water Use and Water Scarcity Footprint for Sustainable Rice Cultivation

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    Thapat Silalertruksa

    2017-12-01

    Full Text Available Rice cultivation is a vital economic sector of many countries in Asia, including Thailand, with the well-being of people relying significantly on selling rice commodities. Water-intensive rice cultivation is facing the challenge of water scarcity. The study assessed the volumetric freshwater use and water scarcity footprint of the major and second rice cultivation systems in the Chao Phraya, Tha Chin, Mun, and Chi watersheds of Thailand. The results revealed that a wide range of freshwater use, i.e., 0.9–3.0 m3/kg of major rice and 0.9–2.3 m3/kg of second rice, and a high water use of rice was found among the watersheds in the northeastern region, like the Mun and Chi watersheds. However, the water scarcity footprint results showed that the second rice cultivation in watersheds, like in Chao Phraya and Tha Chin in the central region, need to be focused for improving the irrigation water use efficiency. The alternate wetting and drying (AWD method was found to be a promising approach for substituting the pre-germinated seed broadcasting system to enhance the water use efficiency of second rice cultivation in the central region. Recommendations vis-à-vis the use of the water stress index as a tool for agricultural zoning policy were also discussed.

  16. Motivation of farmers to cultivate organic rice in Central Java

    Science.gov (United States)

    Dalmiyatun, T.; Eddy, B. T.; Sumekar, W.; Mardiningsih, D.

    2018-01-01

    The consumer’s need for organic agricultural products increases sharply along with awareness of health, lifestyle and environmental concern. This research was intended to determine the relationship between social factors and the motivation of farmers for cultivating organic rice in Central Java. The research has been done by survey to farmers groups at three regions i.e. Semarang, Sragen and Demak. The determination of the location was carried out by means of purposive i.e. farmer groups that conduct organic rice cultivation (not semi organic). The determination of the sample was conducted purposively for a number of 50 people each regencies. Data were analyzed descriptive analysis and rank Spearman correlation analysis. The results showed that social factors include age, cultivated area, education, farming experience have correlation with motivation. education and cultivated area of land has a fairly close relation with correlation value 0,463% and 0,242%. Based on the motivation level, 33% of farmers have high motivation, motivation of farmers varied but most of them, 54% of total farmers stated that the motivation to cultivate organic rice is the quality of organic rice products and high income.

  17. Significance, progress and prospects for research in simplified cultivation technologies for rice in China.

    Science.gov (United States)

    Huang, M; Ibrahim, Md; Xia, B; Zou, Y

    2011-08-01

    Simplified cultivation technologies for rice have become increasingly attractive in recent years in China because of their social, economical and environmental benefits. To date, several simplified cultivation technologies, such as conventional tillage and seedling throwing (CTST), conventional tillage and direct seeding (CTDS), no-tillage and seedling throwing (NTST), no-tillage and direct seeding (NTDS) and no-tillage and transplanting (NTTP), have been developed in China. Most studies have shown that rice grown under each of these simplified cultivation technologies can produce a grain yield equal to or higher than traditional cultivation (conventional tillage and transplanting). Studies that have described the influences of agronomic practices on yield formation of rice under simplified cultivation have demonstrated that optimizing agronomy practices would increase the efficiencies of simplified cultivation systems. Further research is needed to optimize the management strategies for CTST, CTDS and NTST rice which have developed quickly in recent years, to strengthen basic research for those simplified cultivation technologies that are rarely used at present (such as NTTP and NTDS), to select and breed cultivars suitable for simplified cultivation and to compare the practicability and effectiveness of different simplified cultivation technologies in different rice production regions.

  18. Energy and environmental impact analysis of rice cultivation and straw management in northern Thailand.

    Science.gov (United States)

    Yodkhum, Sanwasan; Sampattagul, Sate; Gheewala, Shabbir H

    2018-04-17

    Rice cultivation and energy use for rice production can produce the environmental impacts, especially related to greenhouse gas (GHG) emissions. Also, rice straw open burning by farmers generally practiced after harvesting stage in Thailand for removing the residues in the rice field is associated with emissions of air pollutants, especially particulate matter formation that affects human health and global climate. This study assessed the environmental burdens, consisting of GHG emissions, energy use, and particulate matter formation (PM10), from rice cultivation in Thailand by life cycle assessment (LCA) and compared the environmental burdens of rice straw management scenarios: open burning, incorporation into soil, and direct combustion for electricity generation. The data were collected from the rice production cooperative in Chiang Mai province, northern Thailand, via onsite records and face-to-face questionnaires in 2016. The environmental impacts were evaluated from cradle-to-farm gate. The results showed that the total GHG emissions were 0.64 kg CO 2 -eq per kilogram of paddy rice, the total energy use was 1.80 MJ per kilogram of paddy rice and the PM10 emissions were 0.42 g PM10-eq per kilogram of paddy rice. The results of rice straw management scenarios showed that rice straw open burning had the highest GHG and PM10 emissions. However, rice straw utilization by incorporation into soil and direct combustion for electricity generation could reduce these impacts substantially.

  19. Improving Yield of Transplanted Aman and Boro Rice Through Tegra Package of Cultivation

    Directory of Open Access Journals (Sweden)

    MA Kader, MSR Mia, MA Kafi, MS Hossain, N Islam

    2015-12-01

    Full Text Available The study investigated the yield performance of transplant aman rice cv. BRRI dhan49 and boro rice cv. BRRI dhan29 under improved package of cultivation (TEGRA as compared to farmers’ practice. TEGRA is a rice farming practice which includes use of quality seeds and healthy seedlings, transplanting with rice transplanter, use of herbicide, use of balanced fertilization and micronutrients, and preventive plant protection measures. The study during transplant aman season included two treatments on rice cultivation method viz. TEGRA package and farmers’ practice while in boro rice four treatments viz. TEGRA package, farmers’ practice with high inputs, farmers’ practice with medium inputs and farmers’ practice with low inputs. The yield and plant characters of both transplant aman and boro rice were significantly influenced by the TEGRA package of cultivation as compared to farmers’ practice. TEGRA package of cultivation as compared to farmers’ practice increased the grain yield by 18.3% in transplant aman rice and by 80% in boro rice with less cost of production as compared to farmers’ practice, which eventually resulted 23% increase in gross return and 400% in net return. As a result, the benefit cost ratio of TEGRA package was much higher (1.35 and 2.20 during transplant aman rice and boro rice, respectively compared to that of farmers’ practice (1.07 and 1.30.

  20. Phosphorus critical levels and availability in lowland soils cultivated with flooded rice

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    Mariano Isabela Orlando dos Santos

    2002-01-01

    Full Text Available Lowland soils present a great potential for the flooded rice crop. This work aimed to estimate critical levels of P in waterlogged soils cultivated with rice using Mehlich 1 and anion exchange resin as soil-P extractors, compare the performance of these extractors as for the evaluation of the P availability, and study the soil-P fractions involved in the P nutrition of the rice crop. Studied soils consisted of four Histosols: Low Humic Gley (GP, Aluvial (A, Humic Gley (GH and Bog Soil (O which were previously cultivated with beans. The experimental design was completely randomized, in a factorial scheme, using four soils, five P rates (75, 150, 300, 500 and 800 mg dm-3 and two liming treatments (with and without liming, with three replicates. After 60 days of flooding, soil samples were submitted to P extraction by Mehlich 1 and resin, and phosphorous fractionation. Two rice plants were cultivated in pots containing 3 dm³ of waterlogged soils. The labile P and the moderately labile P of the soils contributed for rice nutrition. The two tested extractors presented efficiency in the evaluation of P availability for the rice cultivated in lowland waterlogged soils.

  1. Modified rice cultivation in Tamil Nadu, India: Yield gains and farmers' (lack of) acceptance

    NARCIS (Netherlands)

    Senthilkumar, K.; Bindraban, P.S.; Thiyagarajan, T.M.; Ridder, de N.; Giller, K.E.

    2008-01-01

    The looming water crisis and water-intensive nature of rice cultivation are driving the search for alternative management methods to increase water productivity in rice cultivation. Experiments were conducted under on-station and on-farm conditions to compare rice production using modified methods

  2. Submergence rice cultivation in southern Bangladesh: farmers opinion and adaptations practices

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    AKM Abdul Ahad Biswas

    2015-12-01

    Full Text Available Rice productivity in coastal Bangladesh is lower than the national average and total coastal area is considered to be submergence-prone and higher vulnerable in July to January cropping season. The selected study areas are Kalapara and Patuakhali Sadar Upazila that are too vulnerable to agriculture practices. Field survey was conducted during 01st June to 30th July, 2015 to investigate the impact of submergence on Aman rice cultivation (ARC, existing adopted local adaptation practices with impacts and options to address the submergence problem. Primary data was collected through Focus Group Discussion (FGD, Individual Interview and Key Informant Interview methods and secondary data was collected from different secondary sources. A well-structured pretested questionnaire schedule was developed keeping in mind the objectives and variables under this study. After cyclone SIDR and AILA devastation, the rate of traditional ARC is decreasing every year and in 2015 it was 26.51%. Recently farmers have adopted new cropping practices and strategies like modern ARC in Aman season as single crop; Boro-Aus-Aman season as triple crop and Aus-Aman season as double crop are practicing. Approximately all farmers have adopted to grow stress tolerant rice varieties (STRV; farmer’s curiosities to familiar with and to have the STRV are encouraging. Farmers were fully adopted BRRIdhan52 rice cultivation with positive perceptions of higher yield and lower production cost. Therefore it can be concluded that the intensity of adoption of adaptation and mitigation measures are significantly influenced positively by the STRV yield capability; farmer’s participation in intervention programs; livelihood diversification; frequency of extension personnel contact; submergence and inundation characteristics; tolerance attributes of STRV and availability of STRV cultivation information.International Journal of Environment Vol.4(4 2015: 100-113

  3. AN INTERACTION MODEL BETWEEN ENVIRONMENTAL FACTORS AND BLACK RICE GROWTH IN IRRIGATED ORGANIC PADDY FIELD

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    Budiman

    2015-02-01

    Full Text Available Black rice production in organic farming system does not meet the demand of local customers because of its low productivity. This research aimed to set an interaction model using multivariate analysis via smartPLS to identify environmental factors which simultaneously affects the growth of black rice. The growth of black rice in two irrigated organic paddy field in Malang, Indonesia was observed during planting period from November 2011 to March 2012. In each rice field, the growth was periodically recorded during planting periods: 19-29 days after planting (dap, 41-45 dap, 62-66 dap, 77-81 dap, 90-94 dap and 104-106 dap. Environmental factors such as water quantities, soil conditions, weed communities and cultivation system around the black rice population were also measured. Black rice growth was influenced simultaneously by water quantities, soil, weed communities and cultivating systems with predictive-relevance value reaching 92.83%. Based on the model, water quantities in paddy field is a key factor which directly and indirectly determined the growth and productivity of black rice.

  4. Deciphering the Environmental Impacts on Rice Quality for Different Rice Cultivated Areas.

    Science.gov (United States)

    Li, Xiukun; Wu, Lian; Geng, Xin; Xia, Xiuhong; Wang, Xuhong; Xu, Zhengjin; Xu, Quan

    2018-01-19

    Rice (Oryza sativa L.) is cultivated in a wide range of climatic conditions, and is one of mankind's major staple foods. The interaction of environmental factors with genotype effects major agronomic traits such as yield, quality, and resistance in rice. However, studies on the environmental factors affecting agronomic traits are often difficult to conduct because most environmental factors are dynamic and constantly changing. A series of recombinant inbred lines (RILs) derived from an indica/japonica cross were planted into four typical rice cultivated areas arranging from latitude N22° to N42°. The environmental data from the heading to mature (45 days) stages were recorded for each RIL in the four areas. We determined that light, temperature, and humidity significantly affected the milling quality and cooking quality overall the four areas. Within each area, these environmental factors mainly affected the head rice ratio, grain length, alkali consumption, and amylose and protein content. Moreover, the effect of these environmental factors dynamically changed from heading to mature stage. Compared to light and humidity, temperature was more stable and predictable, and night temperature showed a stronger correlation efficiency to cooking quality than day temperature, and the daily temperature range had contrary effects compared to day and night temperature on grain quality. The present study evaluated the critical phase during the grain filling stage by calculating the dynamic changes of correlation efficiency between the quality traits and climate parameters. Our findings suggest that the sowing date could be adjusted to improve rice quality so as to adjust for environmental changes.

  5. Oyster mushroom cultivation with rice and wheat straw.

    Science.gov (United States)

    Zhang, Ruihong; Li, Xiujin; Fadel, J G

    2002-05-01

    Cultivation of the oyster mushroom, Pleurotus sajor-caju, on rice and wheat straw without nutrient supplementation was investigated. The effects of straw size reduction method and particle size, spawn inoculation level, and type of substrate (rice straw versus wheat straw) on mushroom yield, biological efficiency, bioconversion efficiency, and substrate degradation were determined. Two size reduction methods, grinding and chopping, were compared. The ground straw yielded higher mushroom growth rate and yield than the chopped straw. The growth cycles of mushrooms with the ground substrate were five days shorter than with the chopped straw for a similar particle size. However, it was found that when the straw was ground into particles that were too small, the mushroom yield decreased. With the three spawn levels tested (12%, 16% and 18%), the 12% level resulted in significantly lower mushroom yield than the other two levels. Comparing rice straw with wheat straw, rice straw yielded about 10% more mushrooms than wheat straw under the same cultivation conditions. The dry matter loss of the substrate after mushroom growth varied from 30.1% to 44.3%. The straw fiber remaining after fungal utilization was not as degradable as the original straw fiber, indicating that the fungal fermentation did not improve the feed value of the straw.

  6. Massive gene losses in Asian cultivated rice unveiled by comparative genome analysis

    Directory of Open Access Journals (Sweden)

    Itoh Takeshi

    2010-02-01

    Full Text Available Abstract Background Rice is one of the most important food crops in the world. With increasing world demand for food crops, there is an urgent need to develop new cultivars that have enhanced performance with regard to yield, disease resistance, and so on. Wild rice is expected to provide useful genetic resources that could improve the present cultivated species. However, the quantity and quality of these unexplored resources remain unclear. Recent accumulation of the genomic information of both cultivated and wild rice species allows for their comparison at the molecular level. Here, we compared the genome sequence of Oryza sativa ssp. japonica with sets of bacterial artificial chromosome end sequences (BESs from two wild rice species, O. rufipogon and O. nivara, and an African rice species, O. glaberrima. Results We found that about four to five percent of the BESs of the two wild rice species and about seven percent of the African rice could not be mapped to the japonica genome, suggesting that a substantial number of genes have been lost in the japonica rice lineage; however, their close relatives still possess their counterpart genes. We estimated that during evolution, O. sativa has lost at least one thousand genes that are still preserved in the genomes of the other species. In addition, our BLASTX searches against the non-redundant protein sequence database showed that disease resistance-related proteins were significantly overrepresented in the close relative-specific genomic portions. In total, 235 unmapped BESs of the three relatives matched 83 non-redundant proteins that contained a disease resistance protein domain, most of which corresponded to an NBS-LRR domain. Conclusion We found that the O. sativa lineage appears to have recently experienced massive gene losses following divergence from its wild ancestor. Our results imply that the domestication process accelerated large-scale genomic deletions in the lineage of Asian

  7. Farmers' perception of risk in cultivating hybrid rice in Bangladesh ...

    African Journals Online (AJOL)

    Although there is an enormous potential for improving adoption of hybrid rice in Bangladesh, it is going through some difficulties in practice. Understanding farmers' perception about difficulties is critical to successful promotion. The present study was conducted to analyze farmers' perception of risk in cultivating hybrid rice ...

  8. Effective Suppression of Methane Emission by 2-Bromoethanesulfonate during Rice Cultivation

    NARCIS (Netherlands)

    Waghmode, Tatoba R.; Haque, Md Mozammel; Kim, Sang Yoon; Kim, Pil Joo

    2015-01-01

    2-bromoethanesulfonate (BES) is a structural analogue of coenzyme M (Co-M) and potent inhibitor of methanogenesis. Several studies confirmed, BES can inhibit CH4 prodcution in rice soil, but the suppressing effectiveness of BES application on CH4 emission under rice cultivation has not been studied.

  9. Evaluation of nutrients status of soils under rice cultivation in cross ...

    African Journals Online (AJOL)

    Nutrients status of soils under rice cultivation in Cross River State Nigeria was evaluated to ascertain the present status and suggest management practices needed for an increased rice production. A reconnaissance survey of the entire State was undertaken. A total number of eight Local Government Areas, namely ...

  10. Greenhouse gas budget from a rice paddy field in the Albufera of Valencia, Spain.

    Science.gov (United States)

    Meijide, Ana; López-Ballesteros, Ana; Calvo-Roselló, Esperanza; López-Jiménez, Ramón; Recio-Huetos, Jaime; Calatayud, Vicent; Carrara, Arnaud; Serrano-Ortiz, Penelope

    2017-04-01

    Rice paddy fields are large sources of anthropogenic methane (CH4) and therefore many studies have assessed CH4 fluxes from rice paddy fields, mainly in Asia where most of the rice cultivation takes place. However, rice is also cultivated in the Mediterranean, where climatic and management conditions greatly differ. In the Albufera of Valencia, the largest freshwater lagoon in Spain, rice paddy fields have the particularity of being flooded not only while the rice grows, but also after the harvest during the winter. These flooding conditions might result in emissions which are very specific of this ecosystem, and cannot be extrapolated from other studies. We studied CH4 fluxes in a rice paddy field in the Albufera of Valencia at different stages of rice cultivation using the eddy covariance technique and static chambers. We additionally measured carbon dioxide (CO2), water fluxes and nitrous oxide (N2O) fluxes with eddy covariance and chamber methods respectively, in order to obtain a full greenhouse gas (GHG) budget. Our study also aimed at providing a mechanistic understanding of GHG emissions at different stages of rice cultivation, and therefore we also used the Enhanced and Normalized Vegetation Indexes (EVI and NDVI, respectively), derived from remote sensing images. The general ecosystem functioning encompasses three different phases. The first one, over the autumn and the winter, a biological dormancy period causes low CO2 emissions (ca. 1-5 µmol m-2 s-1), which coincides with the EVI and NDVI. The intermittent flooding taking place during this period is expected to cause CH4 emissions. Then, during the spring months (March-May), larger CO2 respiratory emissions take place during the daytime (> 5 µmol m-2 s-1) due to an increase in air temperature, which turn to neutral at the end of spring due to the start of photosynthesis by the rice. The third phase corresponds to the vegetation growth, when the net CO2 uptake increases gradually up to maximum CO2

  11. Concentration of radiocesium in rice, vegetables, and fruits cultivated in the evacuation area in Okuma Town, Fukushima

    International Nuclear Information System (INIS)

    Kenji Ohse; Kyo Kitayama; Akira Kanno; Chika Suzuki; Kencho Kawatsu; Hirofumi Tsukada

    2015-01-01

    Radiocesium concentration in the crops cultivated in contaminated and decontaminated soils in the evacuation area were measured. The radiocesium concentration in the decontaminated soil decreased approximately one-quarter to that in the contaminated soil. The radiocesium concentration in the rice and vegetables cultivated in the decontaminated soil decreased to one-half to tenth of that in the contaminated soil. Except for eggplant and pumpkin cultivated in the decontaminated field, the radiocesium concentration in crops was higher than the standard limit in foods in Japan. The obtained transfer factors of most crops were within the reported values. (author)

  12. Testing climate-smart irrigation strategies to reduce methane emissions from rice fields

    Science.gov (United States)

    Runkle, B.; Suvocarev, K.; Reba, M. L.

    2017-12-01

    Approximately 11% of the global 308 Tg CH4 anthropogenic emissions are currently attributed to rice cultivation. In this study, the impact of water conservation practices on rice field CH4 emissions was evaluated in Arkansas, the leading state in US rice cultivation. While conserving water, the Alternate Wetting and Drying (AWD) irrigation practice can also reduce CH4 emissions through the deliberate, periodic introduction of aerobic conditions. Seasonal CH4emissions from a pair of adjacent, production-sized rice fields were estimated and compared during the 2015 to 2017 growing seasons using the eddy covariance method on each field. The fields were alternately treated with continuous flood (CF) and AWD irrigation. In 2015, the seasonal cumulative carbon losses by CH4 emission were 30.3 ± 6.3 and 141.9 ± 8.6 kg CH4-C ha-1 for the AWD and CF treatments, respectively. Data from 2016 and 2017 will be analyzed and shown within this presentation; an initial view demonstrates consistent findings to 2015. When accounting for differences in field conditions and soils, the AWD practice is attributable to a 36-51% reduction in seasonal emissions. The substantial decrease in CH4 emissions by AWD supports previous chamber-based research and offers strong evidence for the efficacy of AWD in reducing CH4 emissions in Arkansas rice production. The AWD practice has enabled the sale of credits for carbon offsets trading and this new market could encourage CH4 emissions reductions on a national scale. These eddy covariance towers are being placed into a regional perspective including crop and forest land in the three states comprising the Mississippi Delta: Arkansas, Mississippi, and Louisiana.

  13. Concentration of radiocesium in rice, vegetables, and fruits cultivated in evacuation area at Okuma town, Fukushima

    International Nuclear Information System (INIS)

    Ohse, Kenji; Kitayama, Kyo; Kanno, Akira; Suzuki, Chika; Kawatsu, Kencho; Tsukada, Hirofumi; Suenaga, Seiichi; Matsumoto, Kiyoyuki

    2013-01-01

    Rice, vegetables, and fruits were cultivated in the evacuation area at Okuma town, and the radiocesium concentration of the crop samples cultivated in contaminated and decontaminated soil was compared. Decrease of the concentration in every crop by decontamination was observed. The TF of brown rice was higher than previous reports. (author)

  14. Rice and foxtail millet cultivation reconstructed from weed seed assemblages in the Chengtoushan site, central China

    International Nuclear Information System (INIS)

    Nasu, H.; Yasuda, Y.; Momohara, A.; Jiejun, H.

    2005-01-01

    Full text: Crop weeds have been successfully used for evaluation of farming practices in archaeological sites and reconstruction of the environmental condition. In rice agricultural sites in East Asia, however, a few studies of crop remains have been attempted. We evaluated the crop husbandry based on plant macrofossils including crop grains and weed seeds in the Chengtoushan site, Hunan Province, central China, which is one of the oldest rice agricultural site around the Yangtze River Basin. In the moat surrounding the site that is located on a loess plateau that juts out into the alluvial plain, we recognized three cultural layers during the Daxi Culture. Plant macrofossils in silty clay deposits in the moat consist of abundant rice and foxtail millet grains with many weed seeds. Radiocarbon age of these fossils shows that rice and foxtail millet cultivation dated back to 6400 cal. years B.P. The weed seed composition characterizes farmland and ruderal environments in the site surrounded by the moat. We assumed foxtail millet and rice cultivation practiced within the site on loess plateau, along with a paddy style rice cultivation in the alluvial lowland outside of the site. (author)

  15. Mapping regional risks from climate change for rainfed rice cultivation in India.

    Science.gov (United States)

    Singh, Kuntal; McClean, Colin J; Büker, Patrick; Hartley, Sue E; Hill, Jane K

    2017-09-01

    Global warming is predicted to increase in the future, with detrimental consequences for rainfed crops that are dependent on natural rainfall (i.e. non-irrigated). Given that many crops grown under rainfed conditions support the livelihoods of low-income farmers, it is important to highlight the vulnerability of rainfed areas to climate change in order to anticipate potential risks to food security. In this paper, we focus on India, where ~ 50% of rice is grown under rainfed conditions, and we employ statistical models (climate envelope models (CEMs) and boosted regression trees (BRTs)) to map changes in climate suitability for rainfed rice cultivation at a regional level (~ 18 × 18 km cell resolution) under projected future (2050) climate change (IPCC RCPs 2.6 and 8.5, using three GCMs: BCC-CSM1.1, MIROC-ESM-CHEM, and HadGEM2-ES). We quantify the occurrence of rice (whether or not rainfed rice is commonly grown, using CEMs) and rice extent (area under cultivation, using BRTs) during the summer monsoon in relation to four climate variables that affect rice growth and yield namely ratio of precipitation to evapotranspiration ( PER ), maximum and minimum temperatures ( T max and T min ), and total rainfall during harvesting. Our models described the occurrence and extent of rice very well (CEMs for occurrence, ensemble AUC = 0.92; BRTs for extent, Pearson's r = 0.87). PER was the most important predictor of rainfed rice occurrence, and it was positively related to rainfed rice area, but all four climate variables were important for determining the extent of rice cultivation. Our models project that 15%-40% of current rainfed rice growing areas will be at risk (i.e. decline in climate suitability or become completely unsuitable). However, our models project considerable variation across India in the impact of future climate change: eastern and northern India are the locations most at risk, but parts of central and western India may benefit from increased

  16. To What Extent Do Improved Practices Increase Productivity of Small-Scale Rice Cultivation in A Rain-fed Area? : Evidence from Tanzania

    OpenAIRE

    Yuko Nakano; Yuki Tanaka; Keijiro Otsuka

    2014-01-01

    This paper investigates the impact of training provided by a large-scale private farm on the performance of surrounding small-scale rice farmers in a rain-fed area in Tanzania. We found that the training effectively enhances the adoption of improved rice cultivation practices, paddy yield, and profit of rice cultivation by small-holder farmers. In fact, the trainees achieve paddy yield of 5 tons per hectare on average, which is remarkably high for rain-fed rice cultivation. Our results sugges...

  17. evaluation of nutrients status of soils under rice cultivation in cross ...

    African Journals Online (AJOL)

    CULTIVATION IN CROSS RIVER STATE, NIGERIA. I. N. ONYEKWERE, A. G. ... KEYWORDS: Evaluation, Nutrient status, Soils, Cross River. ... countries like India, Japan, Taiwan and South Korea. ... which the rice culture can be established.

  18. Single-base resolution maps of cultivated and wild rice methylomes and regulatory roles of DNA methylation in plant gene expression

    Directory of Open Access Journals (Sweden)

    Li Xin

    2012-07-01

    Full Text Available Abstract Background DNA methylation plays important biological roles in plants and animals. To examine the rice genomic methylation landscape and assess its functional significance, we generated single-base resolution DNA methylome maps for Asian cultivated rice Oryza sativa ssp. japonica, indica and their wild relatives, Oryza rufipogon and Oryza nivara. Results The overall methylation level of rice genomes is four times higher than that of Arabidopsis. Consistent with the results reported for Arabidopsis, methylation in promoters represses gene expression while gene-body methylation generally appears to be positively associated with gene expression. Interestingly, we discovered that methylation in gene transcriptional termination regions (TTRs can significantly repress gene expression, and the effect is even stronger than that of promoter methylation. Through integrated analysis of genomic, DNA methylomic and transcriptomic differences between cultivated and wild rice, we found that primary DNA sequence divergence is the major determinant of methylational differences at the whole genome level, but DNA methylational difference alone can only account for limited gene expression variation between the cultivated and wild rice. Furthermore, we identified a number of genes with significant difference in methylation level between the wild and cultivated rice. Conclusions The single-base resolution methylomes of rice obtained in this study have not only broadened our understanding of the mechanism and function of DNA methylation in plant genomes, but also provided valuable data for future studies of rice epigenetics and the epigenetic differentiation between wild and cultivated rice.

  19. Development of labor saving operation technique by making large scale paddy field and direct seeding cultivation of rice in Tohoku district [Japan], 2: Development of technique for automatic precision laser-levelling system

    International Nuclear Information System (INIS)

    Kimura, S.; Imazono, S.; Yaji, Y.

    1999-01-01

    1) Preparation for large large paddy fields and utilization of direct rice seeding cultivation are expected to be the key technologies for the low cost and labor saving large farm rice cultivation. To achieve this, the technique of land leveling for field operations have to be developed. A precise land leveling operation by a wheel tractor with laser-beam emitter and recover in a wet paddy field are developed. 2) The automatic measurement system of a rice paddy field surface level by a tractor that we developed was highly practical. After measured data ate stored in a memory of hand-held computer the standard deviation of a field height value is shown on the display. Also, measured data are exported to the personal computer and by RC232C, the contour map of the paddy field is draw quickly, which is useful for the land leveling work. 3) Considering the relation between rice seed germination and water depth in the field, the preciseness of the field leveling for direct rice seeding is required to be under 1.5cm of standard deviation (s.d.). To realize this preciseness, a prototype leveling aparatus consisting a laser emitter, a laser receiver and dry land leveler pulled by a tracter, was developed and was tested the performance. The results of land leveling test at a field of 1 ha indicated that the elevation difference of the field of 16cm was improved to that of 92% of +- 2.5cm (1.58cm s.d.) after leveling work. The working efficiency was 0.57hour/10a. For a precise leveling work, the of the soil water content should be under the plastic limitation, under which less amount of soil adoheres to the blade of the leveler. The performance tests of the laser assisted leveling apparatus for a paddy harrowing work revealed that for an accurate operation only a blade should be controlled by a hydraulic cylinder according to a laser beam. Since large amount of soil can not be handled by the apparatus, the leveling for a paddy harrowing work is recommended for a fine leveling

  20. Resequencing 50 accessions of cultivated and wild rice yields markers for identifying agronomically important genes

    DEFF Research Database (Denmark)

    Xu, Xun; Liu, Xin; Ge, Song

    2012-01-01

    Rice is a staple crop that has undergone substantial phenotypic and physiological changes during domestication. Here we resequenced the genomes of 40 cultivated accessions selected from the major groups of rice and 10 accessions of their wild progenitors (Oryza rufipogon and Oryza nivara) to >15 x...... diversity in cultivated but not wild rice, which represent candidate regions selected during domestication. Some of these variants are associated with important biological features, whereas others have yet to be functionally characterized. The molecular markers we have identified should be valuable...... raw data coverage. We investigated genome-wide variation patterns in rice and obtained 6.5 million high-quality single nucleotide polymorphisms (SNPs) after excluding sites with missing data in any accession. Using these population SNP data, we identified thousands of genes with significantly lower...

  1. Microbial activity promoted with organic carbon accumulation in macroaggregates of paddy soils under long-term rice cultivation

    Science.gov (United States)

    Liu, Yalong; Wang, Ping; Ding, Yuanjun; Lu, Haifei; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Filley, Timothy; Zhang, Xuhui; Zheng, Jinwei; Pan, Genxing

    2016-12-01

    metabolic quotient was lower in coarse-sand-sized fractions than in other fractions. Soil respiration was higher in the silt fraction than in other fractions for the rice soils. For the size fractions other than the clay fraction, enzyme activity was increased with prolonged rice cultivation, whereas soil respiration appeared to have a decreasing trend. Only in the coarse-sand fraction was both microbial gene abundance and enzyme activity well correlated to SOC and LOC content, although the chemical stability and respiratory of SOC were similar between coarse-sand and clay fractions. Thus, biological activity was generally promoted with LOC accumulation in the coarse-sand-sized macroaggregates of the rice soils, positively responding to prolonged rice cultivation management. The finding here provides a mechanistic understanding of soil organic carbon turnover and microbial community succession at fine scale of soil aggregates that have evolved along with anthropogenic activity of rice cultivation in the field.

  2. Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence

    Science.gov (United States)

    Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

    2015-01-01

    Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist. PMID:26503629

  3. Loss of function at RAE2, a previously unidentified EPFL, is required for awnlessness in cultivated Asian rice.

    Science.gov (United States)

    Bessho-Uehara, Kanako; Wang, Diane R; Furuta, Tomoyuki; Minami, Anzu; Nagai, Keisuke; Gamuyao, Rico; Asano, Kenji; Angeles-Shim, Rosalyn B; Shimizu, Yoshihiro; Ayano, Madoka; Komeda, Norio; Doi, Kazuyuki; Miura, Kotaro; Toda, Yosuke; Kinoshita, Toshinori; Okuda, Satohiro; Higashiyama, Tetsuya; Nomoto, Mika; Tada, Yasuomi; Shinohara, Hidefumi; Matsubayashi, Yoshikatsu; Greenberg, Anthony; Wu, Jianzhong; Yasui, Hideshi; Yoshimura, Atsushi; Mori, Hitoshi; McCouch, Susan R; Ashikari, Motoyuki

    2016-08-09

    Domestication of crops based on artificial selection has contributed numerous beneficial traits for agriculture. Wild characteristics such as red pericarp and seed shattering were lost in both Asian (Oryza sativa) and African (Oryza glaberrima) cultivated rice species as a result of human selection on common genes. Awnedness, in contrast, is a trait that has been lost in both cultivated species due to selection on different sets of genes. In a previous report, we revealed that at least three loci regulate awn development in rice; however, the molecular mechanism underlying awnlessness remains unknown. Here we isolate and characterize a previously unidentified EPIDERMAL PATTERNING FACTOR-LIKE (EPFL) family member named REGULATOR OF AWN ELONGATION 2 (RAE2) and identify one of its requisite processing enzymes, SUBTILISIN-LIKE PROTEASE 1 (SLP1). The RAE2 precursor is specifically cleaved by SLP1 in the rice spikelet, where the mature RAE2 peptide subsequently induces awn elongation. Analysis of RAE2 sequence diversity identified a highly variable GC-rich region harboring multiple independent mutations underlying protein-length variation that disrupt the function of the RAE2 protein and condition the awnless phenotype in Asian rice. Cultivated African rice, on the other hand, retained the functional RAE2 allele despite its awnless phenotype. Our findings illuminate the molecular function of RAE2 in awn development and shed light on the independent domestication histories of Asian and African cultivated rice.

  4. Untapped Endophytic Colonization and Plant Growth-Promoting Potential of the Genus Novosphingobium to Optimize Rice Cultivation

    OpenAIRE

    Rangjaroen, Chakrapong; Sungthong, Rungroch; Rerkasem, Benjavan; Teaumroong, Neung; Noisangiam, Rujirek; Lumyong, Saisamorn

    2017-01-01

    With the aim of searching for potent diazotrophic bacteria that are free of public health concerns and optimize rice cultivation, the endophytic colonization and plant growth-promoting activities of some endophytic diazotrophic bacteria isolated from rice were evaluated. Among these bacteria, the emerging diazotrophic strains of the genus Novosphingobium effectively associated with rice plant interiors and consequently promoted the growth of rice, even with the lack of a nitrogen source. Thes...

  5. Characterising rice-based farming systems to identify opportunities for adopting water efficient cultivation methods in Tamil Nadu, India

    NARCIS (Netherlands)

    Senthilkumar, K.; Bindraban, P.S.; Boer, de W.J.; Ridder, de N.; Thiyagarajan, T.M.; Giller, K.E.

    2009-01-01

    Efficient water use in rice cultivation is a prerequisite for sustaining food security for the rice consuming population of India. Novel rice production practices, including water-saving techniques, modifications in transplanting, spacing, weeding and nutrient management, have been developed and

  6. Water management practices affect arsenic and cadmium accumulation in rice grains.

    Science.gov (United States)

    Sun, Liming; Zheng, Manman; Liu, Hongyan; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

    2014-01-01

    Cadmium (Cd) and arsenic (As) accumulation in rice grains is a great threat to its productivity, grain quality, and thus human health. Pot and field studies were carried out to unravel the effect of different water management practices (aerobic, aerobic-flooded, and flooded) on Cd and As accumulation in rice grains of two different varieties. In pot experiment, Cd or As was also added into the soil as treatment. Pots without Cd or As addition were maintained as control. Results indicated that water management practices significantly influenced the Cd and As concentration in rice grains and aerobic cultivation of rice furnished less As concentration in its grains. Nonetheless, Cd concentration in this treatment was higher than the grains of flooded rice. Likewise, in field study, aerobic and flooded rice cultivation recorded higher Cd and As concentration, respectively. However, growing of rice in aerobic-flooded conditions decreased the Cd concentration by 9.38 times on average basis as compared to aerobic rice. Furthermore, this treatment showed 28% less As concentration than that recorded in flooded rice cultivation. The results suggested that aerobic-flooded cultivation may be a promising strategy to reduce the Cd and As accumulations in rice grains simultaneously.

  7. Introgression from cultivated rice alters genetic structures of wild relative populations: implications for in situ conservation

    Science.gov (United States)

    Jin, Xin; Chen, Yu; Liu, Ping; Li, Chen; Cai, Xingxing; Rong, Jun

    2018-01-01

    Abstract Maintaining genetic integrity is essential for in situ and ex situ conservation of crop wild relative (CWR) species. However, introgression of crop alleles into CWR species/populations may change their genetic structure and diversity, resulting in more invasive weeds or, in contrast, the extinction of endangered populations. To determine crop-wild introgression and its consequences, we examined the genetic structure and diversity of six wild rice (Oryza rufipogon) populations under in situ conservation in China. Thirty-four simple sequence repeat (SSR) and 34 insertion/deletion markers were used to genotype the wild rice populations and two sets of rice cultivars (O. sativa), corresponding to the two types of molecular markers. Shared alleles and STRUCTURE analyses suggested a variable level of crop-wild introgression and admixture. Principal coordinates and cluster analyses indicated differentiation of wild rice populations, which was associated with the spatial distances to cultivated rice fields. The level of overall genetic diversity was comparable between wild rice populations and rice cultivars, but a great number of wild-specific alleles was detected in the wild populations. We conclude based on the results that crop-wild introgression can considerably alter the pattern of genetic structure and relationships of CWR populations. Appropriate measures should be taken for effective in situ conservation of CWR species under the scenario of crop-wild introgression. PMID:29308123

  8. The carbon count of 2000 years of rice cultivation.

    Science.gov (United States)

    Kalbitz, Karsten; Kaiser, Klaus; Fiedler, Sabine; Kölbl, Angelika; Amelung, Wulf; Bräuer, Tino; Cao, Zhihong; Don, Axel; Grootes, Piet; Jahn, Reinhold; Schwark, Lorenz; Vogelsang, Vanessa; Wissing, Livia; Kögel-Knabner, Ingrid

    2013-04-01

    More than 50% of the world's population feeds on rice. Soils used for rice production are mostly managed under submerged conditions (paddy soils). This management, which favors carbon sequestration, potentially decouples surface from subsurface carbon cycling. The objective of this study was to elucidate the long-term rates of carbon accrual in surface and subsurface soil horizons relative to those of soils under nonpaddy management. We assessed changes in total soil organic as well as of inorganic carbon stocks along a 2000-year chronosequence of soils under paddy and adjacent nonpaddy management in the Yangtze delta, China. The initial organic carbon accumulation phase lasts much longer and is more intensive than previously assumed, e.g., by the Intergovernmental Panel on Climate Change (IPCC). Paddy topsoils accumulated 170-178 kg organic carbon ha(-1) a(-1) in the first 300 years; subsoils lost 29-84 kg organic carbon ha(-1) a(-1) during this period of time. Subsoil carbon losses were largest during the first 50 years after land embankment and again large beyond 700 years of cultivation, due to inorganic carbonate weathering and the lack of organic carbon replenishment. Carbon losses in subsoils may therefore offset soil carbon gains or losses in the surface soils. We strongly recommend including subsoils into global carbon accounting schemes, particularly for paddy fields. © 2012 Blackwell Publishing Ltd.

  9. Local mat-forming cyanobacteria effectively facilitate decontamination of radioactive cesium in rice fields

    International Nuclear Information System (INIS)

    Yamamoto, Atsushi; Yoshida, Shigeru; Okumura, Hiroshi; Inagaki, Masayo; Yamanishi, Hirokuni; Ito, Tetsuo; Furukawa, Michio

    2015-01-01

    The most effective and widespread method to decontaminate radioactive cesium from the Fukushima Daiichi Nuclear Power Plant Disaster was peeling topsoil. But the method had problems, such as large amounts of discarded soil and large-scale work. In nature, cyanobacteria formed biomats on the ground surface and facilitated peeling topsoil when the biomats dried. The cyanobacteria-facilitating peeling decontamination method utilized these cyanobacterial properties. Cyanobacteria are located all over Japan and 'local' cyanobacteria could be used for decontamination without introducing new species. Utilizing cyanobacteria could decrease the amount of discarded soil to about 30% and downsize the execution-scale to individual locations. Cyanobacterial biomats were easily cultivated, especially in rice fields, by maintaining wet conditions and exposure to 100 - 83% solar radiation. Shading by a thin net was helpful in maintaining an environment suitable for cyanobacteria. Nowadays, to prevent uptake of radioactive cesium into rice, K + is usually added to fertilizer in rice fields. The K + fertilization in rice fields might also enhance cyanobacterial capture of radioactive cesium, because high concentrations of K + enhanced cyanobacterial uptake of Cs + . Cyanobacteria could also mitigate the risk of radioactive cesium moving away from a decontaminating rice field. Therefore, the cyanobacteria-facilitating peeling decontamination method was proposed as an easy and safe 'D.I.Y.' method for both farmers and the environment. Besides, plowing rice fields with water before peeling improved the efficiency of this method, because plowing increased the radioactive cesium concentration in the topsoil. (author)

  10. International tourist preference of Lodok Rice Field natural elements, the cultural rice field from Manggarai - Indonesia

    Science.gov (United States)

    March Syahadat, Ray; Trie Putra, Priambudi; Nuraini; Nailufar, Balqis; Fatmala Makhmud, Desy

    2017-10-01

    Lodok Rice Field or usually known as spiderweb rice field is a system of land division. It cultural rice field only found on Manggarai, Province of East Nusa Tenggara, Indonesia. The landscape of Lodok Rice Field was aesthetic and it has big potential for tourism development. The aim of this study was to know the perception of natural elements of Lodok Rice Field landscape that could influence international tourist to visited Lodok Rice Field. If we know the elements that could influenced the international tourist, we could used the landscape image for tourism media promotion. The methods of this study used scenic beauty estimation (SBE) by 85 respondents from 34 countries and Kruskal Wallis H test. The countries grouped by five continents (Asia, America, Europe, Africa, and Oceania). The result showed that the Asian respondents liked the elements of sky, mountain, and the rice field. Then, the other respondent from another continent liked the elements of sunshine, mountain, and the rice field. Although the Asian had different perception about landscape elements of rice field’s good view, it’s not differ significantly by Kruskal Wallis H test.

  11. Delay-tolerant mobile network protocol for rice field monitoring using wireless sensor networks

    Science.gov (United States)

    Guitton, Alexandre; Andres, Frédéric; Cardoso, Jarbas Lopes; Kawtrakul, Asanee; Barbin, Silvio E.

    2015-10-01

    The monitoring of rice fields can improve productivity by helping farmers throughout the rice cultivation cycle, on various issues: when to harvest, when to treat the crops against disease, when to increase the water level, how to share observations and decisions made in a collaborative way, etc. In this paper, we propose an architecture to monitor a rice field by a wireless sensor network. Our architecture is based on static sensor nodes forming a disconnected network, and mobile nodes communicating with the sensor nodes in a delay-tolerant manner. The data collected by the static sensor nodes are transmitted to mobile nodes, which in turn transmit them to a gateway, connected to a database, for further analysis. We focus on the related architecture, as well as on the energy-efficient protocols intended to perform the data collection.

  12. Studies on mosquitoes (Diptera: Culicidae and anthropicenvironment: 5- Breeding of Anopheles albitarsis in flooded rice fields in South-Eastern Brazil

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1994-10-01

    Full Text Available Studies on breeding Anopheles albitarsis and association with rice growth in irrigated paddy fields were carried out during the rice cultivation cycle from December 1993 to March 1994. This period corresponded to the length of time of permanent paddy flooding. Breeding occurred in the early stage up until five weeks after transplantation when rice plant height was small. That inverse correlation may give potential direction to control measures.

  13. Population Dynamics Among six Major Groups of the Oryza rufipogon Species Complex, Wild Relative of Cultivated Asian Rice.

    Science.gov (United States)

    Kim, HyunJung; Jung, Janelle; Singh, Namrata; Greenberg, Anthony; Doyle, Jeff J; Tyagi, Wricha; Chung, Jong-Wook; Kimball, Jennifer; Hamilton, Ruaraidh Sackville; McCouch, Susan R

    2016-12-01

    Understanding population structure of the wild progenitor of Asian cultivated rice (O. sativa), the Oryza rufipogon species complex (ORSC), is of interest to plant breeders and contributes to our understanding of rice domestication. A collection of 286 diverse ORSC accessions was evaluated for nuclear variation using genotyping-by-sequencing (113,739 SNPs) and for chloroplast variation using Sanger sequencing (25 polymorphic sites). Six wild subpopulations were identified, with 25 % of accessions classified as admixed. Three of the wild groups were genetically and geographically closely related to the O. sativa subpopulations, indica, aus and japonica, and carried O. sativa introgressions; the other three wild groups were genetically divergent, had unique chloroplast haplotypes, and were located at the geographical extremes of the species range. The genetic subpopulations were significantly correlated (r 2  = 0.562) with traditional species designations, O. rufipogon (perennial) and O. nivara (annual), differentiated based on morphology and life history. A wild diversity panel of 95 purified (inbred) accessions was developed for future genetic studies. Our results suggest that the cultivated aus subpopulation is most closely related to an annual wild relative, japonica to a perennial wild relative, and indica to an admixed population of diverse annual and perennial wild ancestors. Gene flow between ORSC and O. sativa is common in regions where rice is cultivated, threatening the identity and diversity of wild ORSC populations. The three geographically isolated ORSC populations harbor variation rarely seen in cultivated rice and provide a unique window into the genetic composition of ancient rice subpopulations.

  14. A Study on Land Suitability for Rice Cultivation in Khordha District of Odisha (India) Using Remote Sensing and GIS

    Science.gov (United States)

    Rath, Sudhansu S.; Panda, Jagabandhu; Annadurai, R.; Nanda, Sachikanta

    2018-05-01

    With the global population on the rise, it is important to address the increasing demand for food. According to FAO (Food and Agriculture Organization, United Nations), by 2050, the developing countries must double their food production to meet the growing demand. Proper land utilization can be one of the solutions for this problem. In view of this, the current study focussed on land suitability analysis for Khordha district of Odisha (India) for rice crop. This study estimated that the amount of land suitable for rice cropping was 195,731 ha against the currently cultivated land of 122,183.38 ha. Therefore, there was a possibility of more amount of land that could be available for rice cultivation in Khordha district than the currently cultivated area. In order to perform this exercise, the land use and land cover data from IRS (Indian remote sensing satellite), soil nutrient parameters like pH values and nitrogen, potassium, phosphorous and organic carbon contents were considered. In addition, the climatic parameters such as near surface temperature, rainfall and number of rainy days were taken into account. The unused land identified in Khordha district in this study might be utilized for cultivating rice crop in this region.

  15. A Study on Land Suitability for Rice Cultivation in Khordha District of Odisha (India) Using Remote Sensing and GIS

    Science.gov (United States)

    Rath, Sudhansu S.; Panda, Jagabandhu; Annadurai, R.; Nanda, Sachikanta

    2018-02-01

    With the global population on the rise, it is important to address the increasing demand for food. According to FAO (Food and Agriculture Organization, United Nations), by 2050, the developing countries must double their food production to meet the growing demand. Proper land utilization can be one of the solutions for this problem. In view of this, the current study focussed on land suitability analysis for Khordha district of Odisha (India) for rice crop. This study estimated that the amount of land suitable for rice cropping was 195,731 ha against the currently cultivated land of 122,183.38 ha. Therefore, there was a possibility of more amount of land that could be available for rice cultivation in Khordha district than the currently cultivated area. In order to perform this exercise, the land use and land cover data from IRS (Indian remote sensing satellite), soil nutrient parameters like pH values and nitrogen, potassium, phosphorous and organic carbon contents were considered. In addition, the climatic parameters such as near surface temperature, rainfall and number of rainy days were taken into account. The unused land identified in Khordha district in this study might be utilized for cultivating rice crop in this region.

  16. Molecular evolution of shattering loci in U.S. weedy rice.

    Science.gov (United States)

    Thurber, Carrie S; Reagon, Michael; Gross, Briana L; Olsen, Kenneth M; Jia, Yulin; Caicedo, Ana L

    2010-08-01

    Cultivated rice fields worldwide are plagued with weedy rice, a conspecific weed of cultivated rice (Oryza sativa L.). The persistence of weedy rice has been attributed, in part, to its ability to shatter (disperse) seed prior to crop harvesting. In the United States, separately evolved weedy rice groups have been shown to share genomic identity with exotic domesticated cultivars. Here, we investigate the shattering phenotype in a collection of U.S. weedy rice accessions, as well as wild and cultivated relatives. We find that all U.S. weedy rice groups shatter seeds easily, despite multiple origins, and in contrast to a decrease in shattering ability seen in cultivated groups. We assessed allelic identity and diversity at the major shattering locus, sh4, in weedy rice; we find that all cultivated and weedy rice, regardless of population, share similar haplotypes at sh4, and all contain a single derived mutation associated with decreased seed shattering. Our data constitute the strongest evidence to date of an evolution of weeds from domesticated backgrounds. The combination of a shared cultivar sh4 allele and a highly shattering phenotype, suggests that U.S. weedy rice have re-acquired the shattering trait after divergence from their progenitors through alternative genetic mechanisms.

  17. Rice methylmercury exposure and mitigation: a comprehensive review.

    Science.gov (United States)

    Rothenberg, Sarah E; Windham-Myers, Lisamarie; Creswell, Joel E

    2014-08-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Rice improvement through radiation-induced mutation for cultivation in South Vietnam

    International Nuclear Information System (INIS)

    Do Khac Thinh; Hung Phi Oanh; Nguyen Thi Cuc; Nguyen Ngoc Quynh

    2001-01-01

    For past years, rice varieties cultivated in South Vietnam originated from domestic hybridisation or from IRRI. Rice mutation breeding has been initiated for recent years. To meet the requirement of rice production diversification in different agro-ecological areas and rice genetic resources, from 1993 Institute of Agricultural Science of South Vietnam has carried out rice improvement by induced mutation of radiation. The mutagen was gamma rays of 60 Co. The goal is to create inherited variations, which cannot be obtained from other breeding methods, specially important characters of rice varieties (high tolerance to acid sulfate soil, lodging resistance combined with early maturity), which were difficult to gain by hybridisation. With 60 Co gamma rays, doses of 10-20 krad, dose rate of 280 krad/h, dry and germinated seeds of introduced and local rice varieties (IR 64, IR 9729, IR 50404, IR 59606, Jasmine 85, Nang Huong, Tam Xoan) were irradiated. The irradiated seeds were immediately sown within 24 and 94 hrs for wet seeds and dry seeds after treatment, respectively. Population of 10,000-15,000 plants were established and evaluated by IRRI evaluation standard from M2-M7 generations. 365 lines, varieties were selected with better behaviours than original varieties as lodging resistance, earliness, potential yield, leaf characters, tolerant ability to adverse conditions etc. Some good varieties (VND95-19, VND95-20) have been approved as leading national varieties and released for large-scale production in South Vietnam. (author)

  19. Rice improvement through radiation-induced mutation for cultivation in South Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Do Khac Thinh; Hung Phi Oanh; Nguyen Thi Cuc; Nguyen Ngoc Quynh [Institute of Agricultural Science of South Vietnam, Ho Chi Minh (Viet Nam)

    2001-03-01

    For past years, rice varieties cultivated in South Vietnam originated from domestic hybridisation or from IRRI. Rice mutation breeding has been initiated for recent years. To meet the requirement of rice production diversification in different agro-ecological areas and rice genetic resources, from 1993 Institute of Agricultural Science of South Vietnam has carried out rice improvement by induced mutation of radiation. The mutagen was gamma rays of {sup 60}Co. The goal is to create inherited variations, which cannot be obtained from other breeding methods, specially important characters of rice varieties (high tolerance to acid sulfate soil, lodging resistance combined with early maturity), which were difficult to gain by hybridisation. With {sup 60}Co gamma rays, doses of 10-20 krad, dose rate of 280 krad/h, dry and germinated seeds of introduced and local rice varieties (IR 64, IR 9729, IR 50404, IR 59606, Jasmine 85, Nang Huong, Tam Xoan) were irradiated. The irradiated seeds were immediately sown within 24 and 94 hrs for wet seeds and dry seeds after treatment, respectively. Population of 10,000-15,000 plants were established and evaluated by IRRI evaluation standard from M2-M7 generations. 365 lines, varieties were selected with better behaviours than original varieties as lodging resistance, earliness, potential yield, leaf characters, tolerant ability to adverse conditions etc. Some good varieties (VND95-19, VND95-20) have been approved as leading national varieties and released for large-scale production in South Vietnam. (author)

  20. Rice methylmercury exposure and mitigation: a comprehensive review

    Science.gov (United States)

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, price percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.

  1. Changes in carbon stability and microbial activity in size fractions of micro-aggregates in a rice soil chronosequence under long term rice cultivation

    Science.gov (United States)

    Pan, Genxing; Liu, Yalong; Wang, Ping; Li, Lianqinfg; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Bian, Rongjun; Ding, Yuanjun; Ma, Chong

    2016-04-01

    Recent studies have shown soil carbon sequestration through physical protection of relative labile carbon intra micro-aggregates with formation of large sized macro-aggregates under good management of soil and agricultural systems. While carbon stabilization had been increasingly concerned as ecosystem properties, the mechanisms underspin bioactivity of soil carbon with increased carbon stability has been still poorly understood. In this study, topsoil samples were collected from rice soils derived from salt marsh under different length of rice cultivation up to 700 years from eastern China. Particle size fractions (PSF) of soil aggregates were separated using a low energy dispersion protocol. Carbon fractions in the PSFs were analyzed either with FTIR spectroscopy. Soil microbial community of bacterial, fungal and archaeal were analyzed with molecular fingerprinting using specific gene primers. Soil respiration and carbon gain from amended maize as well as enzyme activities were measured using lab incubation protocols. While the PSFs were dominated by the fine sand (200-20μm) and silt fraction (20-2μm), the mass proportion both of sand (2000-200μm) and clay (soil aggregates (also referred to aggregate stability). Soil organic carbon was found most enriched in coarse sand fraction (40-60g/kg), followed by the clay fraction (20-24.5g/kg), but depleted in the silt fraction (~10g/kg). Phenolic and aromatic carbon as recalcitrant pool were high (33-40% of total SOC) in both coarse sand and clay fractions than in both fine sand and silt fractions (20-29% of total SOC). However, the ratio of LOC/total SOC showed a weak decreasing trend with decreasing size of the aggregate fractions. Total gene content in the size fractions followed a similar trend to that of SOC. Bacterial and archaeal gene abundance was concentrated in both sand and clay fractions but that of fungi in sand fraction, and sharply decreased with the decreasing size of aggregate fraction. Gene abundance

  2. Can rice field channels contribute to biodiversity conservation in Southern Brazilian wetlands?

    Directory of Open Access Journals (Sweden)

    Leonardo Maltchik

    2011-12-01

    species in agroecosystems has attracted attention. Irrigation channels can improve habitats and offer conditions for freshwater species conservation. Two questions from biodiversity conservation point of view are: 1 Can the irrigated channels maintain a rich diversity of macrophytes, macroinvertebrates and amphibians over the cultivation cycle? 2 Do richness, abundance and composition of aquatic species change over the rice cultivation cycle? For this, a set of four rice field channels was randomly selected in Southern Brazilian wetlands. In each channel, six sample collection events were carried out over the rice cultivation cycle (June 2005 to June 2006. A total of 160 taxa were identified in irrigated channels, including 59 macrophyte species, 91 taxa of macroinvertebrate and 10 amphibian species. The richness and abundance of macrophytes, macroinvertebrates and amphibians did not change significantly over the rice cultivation cycle. However, the species composition of these groups in the irrigation channels varied between uncultivated and cultivated periods. Our results showed that the species diversity found in the irrigation channels, together with the permanence of water enables these man-made aquatic networks to function as important systems that can contribute to the conservation of biodiversity in regions where the wetlands were converted into rice fields. The conservation of the species in agriculture, such as rice field channels, may be an important alternative for biodiversity conservation in Southern Brazil, where more than 90% of wetland systems have already been lost and the remaining ones are still at high risk due to the expansion of rice production. Rev. Biol. Trop. 59 (4: 1895-1914. Epub 2011 December 01.

  3. Water Productivity of Irrigated Rice under Transplanting, Wet Seeding and Dry Seeding Methods of Cultivation

    Directory of Open Access Journals (Sweden)

    Murali, NS.

    1997-01-01

    Full Text Available Water productivity (WP of irrigated lowland rice was determined during the 1994 dry (January to May and wet (August to December seasons on a heavy clay acid sulphate soil. Treatments consisted of three cultivation methods : transplanted rice, pregerminated seeds broadcasted on puddled soil (wet seeding and dry seeds broadcasted on unpuddled soil (dry seeding. In wet and dry seeded plots, continuous standing water condition was initiated 17 days after sowing. Total water requirement for rice production was highest in transplanted plots (755 mm in wet season and 1154 mm in dry season and was lowest in dry seeded plots (505 mm in wet season and 1040 mm in dry season. Dry seeding required no water for land preparation but transplanting and wet seeding methods required 18 - 20 % of total water requirement in dry season and 27 - 29 % in wet season. Total percolation was maximum (99 mm in wet season and 215 mm in dry season in dry seeding method and was minimum (62 mm in wet season and 94 mm in dry season in transplanting method. In dry and wet seeding methods, daily percolation gradually decreased with the age of the crop. Total seepage loss did not show any significant difference between the cultivation methods in the two seasons. Grain yield was not affected by the three cultivation methods in both seasons. Water productivity (the ratio between grain yield and total amount of water used in production was 3.5 - 4.1 kg ha-1 mm-1, 3.8 - 4.4 kg ha-1 mm-1 and 4.1 - 5.5 kg ha-1 mm-1 in transplanted, wet seeded and dry seeded rice, respectively. Labour requirement for land preparation and sowing was maximum in transplanted (219 - 226 man-hours ha-1 followed by wet (104 -112 man-hours ha-1 and dry seeded (94 - 99 man-hours ha-1 methods. However, in wet season extra labour (77 man-hours ha-1 was required for weeding after crop establishment in dry and wet seeding methods. Crop maturity was 20 days earlier in wet and dry seeding methods compared to

  4. Influence of transgenic rice expressing a fused Cry1Ab/1Ac protein on frogs in paddy fields.

    Science.gov (United States)

    Wang, Jia-Mei; Chen, Xiu-Ping; Liang, Yu-Yong; Zhu, Hao-Jun; Ding, Jia-Tong; Peng, Yu-Fa

    2014-11-01

    As genetic engineering in plants is increasingly used to control agricultural pests, it is important to determine whether such transgenic plants adversely affect non-target organisms within and around cultivated fields. The cry1Ab/1Ac fusion gene from Bacillus thuringiensis (Bt) has insecticidal activity and has been introduced into rice line Minghui 63 (MH63). We evaluated the effect of transgenic cry1Ab/1Ac rice (Huahui 1, HH1) on paddy frogs by comparing HH1 and MH63 rice paddies with and without pesticide treatment. The density of tadpoles in rice fields was surveyed at regular intervals, and Cry1Ab/1Ac protein levels were determined in tissues of tadpoles and froglets collected from the paddy fields. In addition, Rana nigromaculata froglets were raised in purse nets placed within these experimental plots. The survival, body weight, feeding habits, and histological characteristics of the digestive tract of these froglets were analyzed. We found that the tadpole density was significantly decreased immediately after pesticide application, and the weight of R. nigromaculata froglets of pesticide groups was significantly reduced compared with no pesticide treatment, but we found no differences between Bt and non-Bt rice groups. Moreover, no Cry1Ab/1Ac protein was detected in tissue samples collected from 192 tadpoles and froglets representing all four experimental groups. In addition, R. nigromaculata froglets raised in purse seines fed primarily on stem borer and non-target insects, and showed no obvious abnormality in the microstructure of their digestive tracts. Based on these results, we conclude that cultivation of transgenic cry1Ab/1Ac rice does not adversely affect paddy frogs.

  5. Both Hd1 and Ehd1 are important for artificial selection of flowering time in cultivated rice.

    Science.gov (United States)

    Wei, Fu-Jin; Tsai, Yuan-Ching; Wu, Hshin-Ping; Huang, Lin-Tzu; Chen, Yu-Chi; Chen, Yi-Fang; Wu, Cheng-Chieh; Tseng, Yi-Tzu; Hsing, Yue-Ie C

    2016-01-01

    Rice is a facultative short-day plant, and it requires a photoperiod shorter than the critical day length to get flowering. Sensitivity to photoperiod has been suggested as a major selection target in cultivated or weedy rice. The modern rice varieties in Taiwan may be cultivated twice a year. These varieties contain loss-of-function of two important flowering-time related genes, Heading date 1 (Hd1) and Early heading date 1 (Ehd1), and are mainly from a mega variety, Taichung 65. However, the parental lines of this variety were sensitive to photoperiod, thus, how Taichung 65 loss its sensitivity is a mystery. In this study, we used accession-specific single nucleotide polymorphism analysis to reveal the gene flow that occurred between different rice accessions decades ago and demonstrate that two landraces introgressed during the breeding process, which led to the loss of photoperiod sensitivity. Both Hd1 and Ehd1 may be important during artificial selection for flowering time, especially in a subtropical region such as Taiwan. This is a good example of introgression playing important roles during rice domestication. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Different farming and water regimes in Italian rice fields affect arbuscular mycorrhizal fungal soil communities.

    Science.gov (United States)

    Lumini, Erica; Vallino, Marta; Alguacil, Maria M; Romani, Marco; Bianciotto, Valeria

    2011-07-01

    Arbuscular mycorrhizal fungi (AMF) comprise one of the main components of soil microbiota in most agroecosystems. These obligate mutualistic symbionts colonize the roots of most plants, including crop plants. Many papers have indicated that different crop management practices could affect AMF communities and their root colonization. However, there is little knowledge available on the influence of conventional and low-input agriculture on root colonization and AMF molecular diversity in rice fields. Two different agroecosystems (continuous conventional high-input rice monocropping and organic farming with a five-year crop rotation) and two different water management regimes have been considered in this study. Both morphological and molecular analyses were performed. The soil mycorrhizal potential, estimated using clover trap cultures, was high and similar in the two agroecosystems. The diversity of the AMF community in the soil, calculated by means of PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and 18S rDNA sequencing on clover trap cultures roots, was higher for the organic cultivation. The rice roots cultivated in the conventional agrosystem or under permanent flooding showed no AMF colonization, while the rice plants grown under the organic agriculture system showed typical mycorrhization patterns. Considered together, our data suggest that a high-input cropping system and conventional flooding depress AMF colonization in rice roots and that organic managements could help maintain a higher diversity of AMF communities in soil.

  7. Physiological and molecular characterization of Si uptake in wild rice species.

    Science.gov (United States)

    Mitani-Ueno, Namiki; Ogai, Hisao; Yamaji, Naoki; Ma, Jian Feng

    2014-07-01

    Cultivated rice (Oryza sativa) accumulates high concentration of silicon (Si), which is required for its high and sustainable production. High Si accumulation in cultivated rice is achieved by a high expression of both influx (Lsi1) and efflux (Lsi2) Si transporters in roots. Herein, we physiologically investigated Si uptake, isolated and functionally characterized Si transporters in six wild rice species with different genome types. Si uptake by the roots was lower in Oryza rufipogon, Oryza barthii (AA genome), Oryza australiensis (EE genome) and Oryza punctata (BB genome), but similar in Oryza glumaepatula and Oryza meridionalis (AA genome) compared with the cultivated rice (cv. Nipponbare). However, all wild rice species and the cultivated rice showed similar concentration of Si in the shoots when grown in a field. All species with AA genome showed the same amino acid sequence of both Lsi1 and Lsi2 as O. sativa, whereas species with EE and BB genome showed several nucleotide differences in both Lsi1 and Lsi2. However, proteins encoded by these genes also showed transport activity for Si in Xenopus oocyte. The mRNA expression of Lsi1 in all wild rice species was lower than that in the cultivated rice, whereas the expression of Lsi2 was lower in O. rufipogon and O. barthii but similar in other species. Similar cellular localization of Lsi1 and Lsi2 was observed in all wild rice as the cultivated rice. These results indicate that superior Si uptake, the important trait for rice growth, is basically conserved in wild and cultivated rice species. © 2013 Scandinavian Plant Physiology Society.

  8. Experimental studies on the injurious effect of sulfur dioxide upon the rice cultivation

    Energy Technology Data Exchange (ETDEWEB)

    Teshima, T; Takahashi, T

    1952-01-01

    From experimental studies on the injurious effect of sulfur dioxide upon the cultivation of rice it was ascertained that SO2 strongly affects the pollen and the ovary. The pollen and the matured grain showed a decrease in fertility when the plant is fumigated at the flowering and boot stage.

  9. Benthic macroinvertebrates in Italian rice fields

    Directory of Open Access Journals (Sweden)

    Daniela Lupi

    2013-02-01

    Full Text Available Rice fields can be considered man-managed temporary wetlands. Five rice fields handled with different management strategies, their adjacent channels, and a spring were analysed by their benthic macroinvertebrate community to i evaluate the role of rice agroe- cosystem in biodiversity conservation; ii find indicator species which can be used to compare the ecological status of natural wetlands with rice agroecosystems; and iii find the influence of environmental variables on biodiversity. Different methods of data analysis with increasing degree of complexity – from diversity index up to sophisticated multivariate analysis – were used. The investigation provided a picture of benthic macroinvertebrates inhabiting rice agroecosystems where 173 taxa were identified, 89 of which detected in rice paddies. Among them, 4 phyla (Mollusca, Annelida, Nematomorpha, and Arthropoda, 8 classes (Bivalvia, Gastropoda, Oligochaeta, Hirudinea, Gordioida, Insecta, Branchiopoda, and Malacostraca, 24 orders, 68 families, 127 genera and 159 species have been found. Ten threatened and 3 invasive species were detected in the habitats examined. The information obtained by the different methods of data analysis allowed a more comprehensive view on the value of the components of rice agroecosystems. Data analyses highlighted significant differences between habitats (feeding channel and rice field, with higher diversity observed in channels, and emphasised the role of the water chemical-physical parameters. The period of water permanence in rice fields resulted to be only one of the factors influencing the community of benthic macroinvertebrates. The presence of rare/endangered species allowed characterising some stations, but it was less informative about management strategies in rice paddies because most of these species were absent in rice fields.

  10. All roads lead to weediness: patterns of genomic divergence reveal extensive recurrent weedy rice origins from South Asian Oryza

    Science.gov (United States)

    Weedy rice (Oryza spp.), a weedy relative of cultivated rice (O. sativa), invades and persists in cultivated rice fields worldwide. Many weedy rice populations have evolved similar adaptive traits, considered part of the “agricultural weed syndrome,” making this an ideal model to study the genetic b...

  11. Yield gap analysis in long-term experiments with intensive rice cultivation

    International Nuclear Information System (INIS)

    Laureles, E.V.; Correa, T. Jr.; Buresh, R.J.

    2007-01-01

    The long-term continuous cropping experiment at IRRI is cultivated with three rice crops in a year, making it the world's most intensively cropped long-term rice experiment. The availability of comprehensive rice production records, compiled weather data, and tested crop models provides a means to evaluate long-term trends in measured and potential yields and yield gaps in this rice production system. Yield trends were assessed using the highest yielding cultivar in each cropping season from 1979 to 2005. Potential yield of the highest yielding cultivar in each season was determined using three rice models (ORYZA, TERM, and CERES) run with the actual transplanting and harvest dates for the cultivar. The yield gap was determined from the difference between the simulated potential grain yield and the measured grain yield. Measured and potential yields and the yield gap varied across seasons and years. Measured yields were higher in the dry season than in the early and late wet seasons. The yield gap tended to be higher in the wet season than in the dry season. Climatic parameters, particularly solar radiation, influenced the performance of rice cultivars. The relatively larger yield gaps in the late wet season than in the dry season were associated with increased spikelet sterility. The cumulative measured yield for the three annual rice crop was near 80 percent of the annual yield potential in years with best practices for fertilizer N and crop management. The long term trends suggest that effective timing and rates of N fertilization and effective control of diseases were critical in achieving 80 percent of the annual yield potential

  12. Analysis of Stress-Responsive Gene Expression in Cultivated and Weedy Rice Differing in Cold Stress Tolerance.

    Directory of Open Access Journals (Sweden)

    Caroline Borges Bevilacqua

    Full Text Available Rice (Oryza sativa L. cultivars show impairment of growth in response to environmental stresses such as cold at the early seedling stage. Locally adapted weedy rice is able to survive under adverse environmental conditions, and can emerge in fields from greater soil depth. Cold-tolerant weedy rice can be a good genetic source for developing cold-tolerant, weed-competitive rice cultivars. An in-depth analysis is presented here of diverse indica and japonica rice genotypes, mostly weedy rice, for cold stress response to provide an understanding of different stress adaptive mechanisms towards improvement of the rice crop performance in the field. We have tested a collection of weedy rice genotypes to: 1 classify the subspecies (ssp. grouping (japonica or indica of 21 accessions; 2 evaluate their sensitivity to cold stress; and 3 analyze the expression of stress-responsive genes under cold stress and a combination of cold and depth stress. Seeds were germinated at 25°C at 1.5- and 10-cm sowing depth for 10d. Seedlings were then exposed to cold stress at 10°C for 6, 24 and 96h, and the expression of cold-, anoxia-, and submergence-inducible genes was analyzed. Control plants were seeded at 1.5cm depth and kept at 25°C. The analysis revealed that cold stress signaling in indica genotypes is more complex than that of japonica as it operates via both the CBF-dependent and CBF-independent pathways, implicated through induction of transcription factors including OsNAC2, OsMYB46 and OsF-BOX28. When plants were exposed to cold + sowing depth stress, a complex signaling network was induced that involved cross talk between stresses mediated by CBF-dependent and CBF-independent pathways to circumvent the detrimental effects of stresses. The experiments revealed the importance of the CBF regulon for tolerance to both stresses in japonica and indica ssp. The mechanisms for cold tolerance differed among weedy indica genotypes and also between weedy indica and

  13. [Effects of fish on field resource utilization and rice growth in rice-fish coculture].

    Science.gov (United States)

    Zhang, Jian; Hu, Liang Liang; Ren, Wei Zheng; Guo, Liang; Wu, Min Fang; Tang, Jian Jun; Chen, Xin

    2017-01-01

    Rice field can provide habitat for fish and other aquatic animals. Rice-fish coculture can increase rice yield and simultaneously reduce the use of chemicals through reducing rice pest occurrence and nutrient complementary use. However, how fish uses food sources (e.g. phytoplankton, weeds, duckweed, macro-algal and snail) from rice field, and whether the nutrients releasing from those food sources due to fish transforming can improve rice growth are still unknown. Here, we conducted two field experiments to address these questions. One was to investigate the pattern of fish activity in the field using the method of video recording. The other was to examine the utilization of field resources by fish using stable isotope technology. Rice growth and rice yield were also exa-mined. Results showed that fish tended to be more active and significantly expanded the activity range in the rice-fish coculture compared to fish monoculture (fish not living together with rice plants). The contributions of 3 potential aquatic organisms (duckweed, phytoplankton and snail) to fish dietary were 22.7%, 34.8% and 30.0% respectively under rice-fish coculture without feed. Under the treatment with feed, however, the contributions of these 3 aquatic organisms to the fish die-tary were 8.9%, 5.9% and 1.6% respectively. The feed contribution was 71.0%. Rice-fish coculture significantly increased the nitrogen concentration in rice leaves, prolonged tillering stage by 10-12 days and increased rice spike rate and yield. The results suggested that raising fish in paddy field may transform the nutrients contained in field resources to bioavailable for rice plants through fish feeding activity, which can improve rice growth and rice yield.

  14. Investigating differences in light stable isotopes between Thai jasmine rice and Sungyod rice

    Science.gov (United States)

    Kukusamude, C.; Kongsri, S.

    2017-10-01

    We report the differences in light stable isotopes between two kinds of Thai rice (Thai jasmine and Sungyod rice). Thai jasmine rice and Sungyod rice were cultivated in the northeast and the south of Thailand. Light isotopes including 13C, 15N and 18O of Thai jasmine rice and Sungyod rice samples were carried out using isotope ratio mass spectrometry (IRMS). Thai jasmine rice (Khao Dawk Mali 105) was cultivated from Thung Kula Rong Hai area, whereas Sungyod rice was cultivated from Phathalung province. Hypothesis testing of difference of each isotope between Thai jasmine rice and Sungyod rice was also studied. The study was the feasibility test whether the light stable isotopes can be the variables to identify Thai jasmine rice and Sungyod rice. The result shows that there was difference in the isotope patterns of Thai jasmine rice and Sungyod rice. Our results may provide the useful information in term of stable isotope profiles of Thai rice.

  15. Rice field agroecosystem investigation : environmental and toxicological assessment; Indagine su una risaia campione: analisi ambientali e chimico-tossicologiche

    Energy Technology Data Exchange (ETDEWEB)

    Bari, A; Minciardi, M; Rossi, G [ENEA, Centro Ricerche Saluggia, Vercelli (Italy). Dip. Ambiente; Bonotto, F; Paonessa, F; Troiani, F [ENEA, Centro Ricerche Saluggia, Vercelli (Italy). Dip. Energia; Rosa, S [ENEA, Centro Ricrche Casaccia, Rome (Italy). Dip. Ambiente; Cormegna, M [Ente Nazionale Risi, Centro Ricerche sul Riso, Castello d` Agogna, Pavia (Italy)

    1995-10-01

    The rice-field agroecosystem, even if deeply anthropically determined, can be considered substitute of the plain wet lands, now almost all disappeared in the part of the territory has been considering. The aim of the research we started was the analysis and the ecological characterization of this environment and the assessment of the effects of the different agronomical practices, relating to the conservation of the biodiversity in a plain wetland. The ENEA Environmental Biology and Nature Conservation Division of Saluggia (VC) and Casaccia (Roma), in co-operation with ENEA ERG-RAD-LAB Division of Saluggia and the Rice Research Center of Castello d`Agogna (PV) associated to Rice National Society, started a preliminary research on a sample rice field, aiming to evaluate, using different methodologies, the destiny of the chemical substances (herbicides, fungicidals, heavy metals and other chemical compounds) introduced through cultivation practices or arrived by irrigation systems.

  16. Single-base resolution maps of cultivated and wild rice methylomes and regulatory roles of DNA methylation in plant gene expression

    DEFF Research Database (Denmark)

    Li, Xin; Zhu, Jingde; Hu, Fengyi

    2012-01-01

    DNA methylation plays important biological roles in plants and animals. To examine the rice genomic methylation landscape and assess its functional significance, we generated single-base resolution DNA methylome maps for Asian cultivated rice Oryza sativa ssp. japonica, indica and their wild rela...

  17. The relationship between Anopheles gambiae density and rice cultivation in the savannah zone and forest zone of Côte d'Ivoire.

    Science.gov (United States)

    Briët, Olivier J T; Dossou-Yovo, Joel; Akodo, Elena; van de Giesen, Nick; Teuscher, Thomas M

    2003-05-01

    In 13 villages in the savannah zone and 21 villages in the forest zone of Côte d'Ivoire, the biting density of the principal malaria vector, Anopheles gambiae, was studied as a function of rice cultivation in the inland valleys in a 2-km radius around each village. In the savannah villages, during the main season cropping period, surface water on rice-cultivated and to a lesser extent on uncultivated inland valleys seems to contribute strongly to the A. gambiae population density. For the off-season cropping period (which starts after the first light rains in the savannah zone), correlations were weaker. Breeding sites other than in inland valleys may play an important role in the savannah zone. In the forest zone, however, the A. gambiae population density was strongly correlated with the surface water availability (SWA) in the rice-cultivated inland valleys, whereas the correlation with the SWA in other (uncultivated) inland valleys was weak. The requirement of sunlit breeding sites for A. gambiae might explain this difference between zones. In the forest zone, only inland valleys cleared for rice cultivation meet this requirement, whereas all other inland valleys are covered with dense vegetation. In the savannah zone, however, most undergrowth is burnt during the dry season, which permits sunlight to reach puddles resulting from the first rains.

  18. Rice agroecosystem and the maintenance of biodiversity

    International Nuclear Information System (INIS)

    Ahyaudin Ali

    2002-01-01

    Rice fields are a special type of wetland. They are shallow, constantly disturbed and experience extremes in temperature and dissolved oxygen content. They receive nutrients in the form of fertilizers during rice cultivation. Rice fields; support a variety of flora and fauna that have adapted and adjusted themselves to the extreme conditions. Since rice fields also support populations of wild fish, rice?fish integration should be done in order to optimize land use and provide supplementary income to farmers. Rice?fish farming encourages farmers to judiciously apply pesticides and herbicides in their fields thus helping to control excessive and unwarranted use of these chemicals. Rice fields also support many migratory and nonmigratory bird species and provides habitat for small mammals. Thus the rice agroecosystem helps to maintain aquatic biodiversity. The Muda rice agroecosystem consists of a troika of interconnected ecosystems. The troika consisting of reservoirs, the connecting network of canals and the rice fields; should be investigated further. This data is needed for informed decision-making concerning development and management of the system so that productivity and biodiversity can be maintained and sustained. (Author)

  19. Utilizing NASA Earth Observations to Monitor Land Management Practices and the Development of Marshlands to Rice Fields in Rwanda

    Science.gov (United States)

    Dusabimana, M. R.; Blach, D.; Mwiza, F.; Muzungu, E.; Swaminathan, R.; Tate, Z.

    2014-12-01

    Rwanda, a small country with the highest population density in Sub-Saharan Africa, is one of the world's poorest countries. Although agriculture is the backbone of Rwandan economy, agricultural productivity is extremely low. Over 90 % of the population is engaged in subsistence farming and only 52 % of the total land surface area is arable. Of this land, approximately 165,000 hectares are marshlands, of which only 57 % has been cultivated. Rwandan government has invested in the advancement of agriculture with activities such as irrigation, marshland reclamation, and crop regionalization. In 2001, Ministry of Agriculture and Animal Resources (MINAGRI) released the Rural Sector Support Program (RSSP), which aimed at converting marshlands into rice fields at various development sites across the country. The focus of this project was to monitor rice fields in Rwanda utilizing NASA Earth observations such as Landsat 5 Thematic Mapper and Landsat 8 Operational Land Imager. Modified Normalized Difference Water Index (MNDWI) was used to depict the progress of marshland to rice field conversion as it highlights the presence of irrigated rice fields from the surrounding area. Additionally, Decision Support System for Agrotechnology Transfer (DSSAT) was used to estimate rice yield at RSSP sites. Various simulations were run to find perfect conditions for cultivating the highest yield for a given farm. Furthermore, soil erosion susceptibility masks were created by combining factors derived from ASTER, MERRA, and ground truth data using Revised Universal Soil Loss Equation (RUSLE). The end results, maps, and tutorials were delivered to the partners and policy makers in Rwanda to help make informed decisions. It can be clearly seen that Earth observations can be successfully used to monitor agricultural and land management practices as a cost effective method that will enable farmers to improve crop yield production and food security.

  20. Ethanol production from rice on radioactively contaminated field toward sustainable rice farming

    International Nuclear Information System (INIS)

    Yokoyama, Shinya; Izumi, Bintaro; Oki, Kazuo

    2011-01-01

    Radioactive species such as 137 Cs were discharged from Fukushima Daiichi Nuclear Power Plant which was severely damaged by the enormous earthquake and tsunami. Cropland has been radioactively contaminated by 137 Cs etc. and it seems impossible to plant rice due to the non-suitability for food. According to the reports, 137 Cs transferred into the rice from soil is less than 1% on the average. Therefore, it is expected that the concentration of 137 Cs in bioethanol will be well below the tentative restriction value even if bioethanol could be produced from the rice. It is proposed that the rice field should be filled with water to avoid the flow of runoff contaminated by radioactive cesium compounds because they are insoluble in aqueous phase and that bioethanol should be produced from the rice in order to maintain the multifunction of rice field and to continue the agriculture. If rice farming is halted and neglected, agricultural function of rice field as well as local community will be permanently destroyed. (author)

  1. Determination of Cadmium and Lead levels in high consumed rice (Oryza Sativa L. cultivated in Lorestan province and its comparison with national standards

    Directory of Open Access Journals (Sweden)

    roshanak Hedayatifar

    2011-03-01

    Full Text Available Rice is the main food of people in Iran and about 2.4 billion of the world population. Although its cultivation areas are less than wheat but 85% of the total product is used by people. Consumption of rice per person is estimated 42.5 kg in Iran. So it is the second high consumed agricultural product. The aim of this study was determination amount of toxic and heavy metals in high consumed rice varites cultivated in different areas of Lorestan province. Materials and Methods: In this study 99 rice samples (Tarem and Domsiah cultivated in three areas of Lorestan( khorramabad, Dorud and Borujerd province were collected. Amount of Lead and Cadmium were analyzed by atomic absorption model BRAIC WFX 130. Data were gathered and analyzed by SPSS software and compared with national standards. Results: The results for Cd and Pb were 0.037±0.06 and 0.077±0.08 mg/kg respectively. Conclusion: Cadmium and Lead levels in rice samples caltivated in Lorestan province were less than Permissible limit, so there is no risk for human health.

  2. Effects of alkaline and bioorganic amendments on cadmium, lead, zinc, and nutrient accumulation in brown rice and grain yield in acidic paddy fields contaminated with a mixture of heavy metals.

    Science.gov (United States)

    He, Huaidong; Tam, Nora F Y; Yao, Aijun; Qiu, Rongliang; Li, Wai Chin; Ye, Zhihong

    2016-12-01

    Paddy soils and rice (Oryza sativa L.) contaminated by mixed heavy metals have given rise to great concern. Field experiments were conducted over two cultivation seasons to study the effects of steel slag (SS), fly ash (FA), limestone (LS), bioorganic fertilizer (BF), and the combination of SS and BF (SSBF) on rice grain yield, Cd, Pb, and Zn and nutrient accumulation in brown rice, bioavailability of Cd, Pb, and Zn in soil as well as soil properties (pH and catalase), at two acidic paddy fields contaminated with mixed heavy metals (Cd, Pb, and Zn). Compared to the controls, SS, LS, and SSBF at both low and high additions significantly elevated soil pH over both cultivation seasons. The high treatments of SS and SSBF markedly increased grain yields, the accumulation of P and Ca in brown rice and soil catalase activities in the first cultivation season. The most striking result was from SS application (4.0 t ha -1 ) that consistently and significantly reduced the soil bioavailability of Cd, Pb, and Zn by 38.5-91.2 % and the concentrations of Cd and Pb in brown rice by 20.9-50.9 % in the two soils over both cultivation seasons. LS addition (4.0 t ha -1 ) also markedly reduced the bioavailable Cd, Pb, and Zn in soil and the Cd concentrations in brown rice. BF remobilized soil Cd and Pb leading to more accumulation of these metals in brown rice. The results showed that steel slag was most effective in the remediation of acidic paddy soils contaminated with mixed heavy metals.

  3. Richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides in rice paddy fields

    Directory of Open Access Journals (Sweden)

    ALANA C.D. WANDSCHEER

    Full Text Available ABSTRACT The objective of this study was to verify the richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides of the rice paddy fields. In the crop seasons of 2012/13 and 2013/14, field experiments were performed, which consisted of single-dose applications of the fungicides trifloxystrobin + tebuconazole and tricyclazole, and the insecticides lambda-cyhalothrin + thiamethoxam and diflubenzuron, in 10 m2 experimental plots, over rice plants in the R3 stage. Control plots with and without rice plants were maintained in order to simulate a natural environment. Soil samples were collected during rice cultivation for assessment of the macroinvertebrate fauna. Chemical-physical parameters assessed in the experiments included temperature, pH and oxygen dissolved in the water and pesticide persistence in the water and in the soil. The application of a single dose of the pesticides and fungicides in the recommended period does not cause significant negative effects over the richness and density of the macroinvertebrates. Tebuconazole, tricyclazole and thiamethoxam showed high persistence in the irrigation water of rice paddy fields. Thus, the doses and number of applications of these products in crops should be carefully handled in order to avoid contamination of the environment.

  4. Richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides in rice paddy fields.

    Science.gov (United States)

    Wandscheer, Alana C D; Marchesan, Enio; Santos, Sandro; Zanella, Renato; Silva, Marília F; Londero, Guilherme P; Donato, Gabriel

    2017-01-01

    The objective of this study was to verify the richness and density of aquatic benthic macroinvertebrates after exposure to fungicides and insecticides of the rice paddy fields. In the crop seasons of 2012/13 and 2013/14, field experiments were performed, which consisted of single-dose applications of the fungicides trifloxystrobin + tebuconazole and tricyclazole, and the insecticides lambda-cyhalothrin + thiamethoxam and diflubenzuron, in 10 m2 experimental plots, over rice plants in the R3 stage. Control plots with and without rice plants were maintained in order to simulate a natural environment. Soil samples were collected during rice cultivation for assessment of the macroinvertebrate fauna. Chemical-physical parameters assessed in the experiments included temperature, pH and oxygen dissolved in the water and pesticide persistence in the water and in the soil. The application of a single dose of the pesticides and fungicides in the recommended period does not cause significant negative effects over the richness and density of the macroinvertebrates. Tebuconazole, tricyclazole and thiamethoxam showed high persistence in the irrigation water of rice paddy fields. Thus, the doses and number of applications of these products in crops should be carefully handled in order to avoid contamination of the environment.

  5. Focal species candidates for pesticide risk assessment in European rice fields: A review.

    Science.gov (United States)

    Vallon, Martin; Dietzen, Christian; Laucht, Silke; Ludwigs, Jan-Dieter

    2018-04-25

    An assessment of potential risks of pesticides on wildlife is required during the process of product registration within Europe because of the importance of agricultural landscapes as wildlife habitats. Despite their peculiarity and their specific role as artificial wetlands, rice paddies are to date pooled with cereals in guidance documents on how to conduct risk assessments for birds and mammals in Europe. Hence, the focal species currently considered in risk assessments for rice paddies are those known from cereal fields and can therefore be expected to differ significantly from the species actually occurring in the wet environments of rice paddies. We present results of a comprehensive review on bird and mammal species regularly occurring in rice paddies during a time of potential pesticide exposure to identify appropriate focal species candidates for ecotoxicological pesticide risk assessment according to the European Food Safety Authority (EFSA). In addition, we present data on rice cultivation areas and agricultural practices in Europe to give background information supporting the species selection process. Our literature search identified a general scarcity of relevant data, particularly for mammals, which highlights the need for crop-specific focal species studies. However, our results clearly indicate that the relevant bird and mammal species in rice fields indeed differ strongly from the focal species used for the cereal risk assessment. They can thus be used as a baseline for more realistic wildlife risk assessments specific to rice and the development of a revised guidance document to bridge the gap for regulatory decision makers. Integr Environ Assess Manag 2018;00:000-000. © 2018 SETAC. © 2018 SETAC.

  6. The Emissions of Carbon Dioxide, Methane, and Nitrous Oxide during Winter without Cultivation in Local Saline-Alkali Rice and Maize Fields in Northeast China

    Directory of Open Access Journals (Sweden)

    Hao Zhang

    2017-10-01

    Full Text Available Agricultural ecosystems are important contributors to atmospheric greenhouse gasses (GHGs; however, in situ winter emission data in saline-alkali fields are scarce. Gas samples were collected during different periods, from three rice (R1–R3 and three maize (M1–M3 fields with different soil pH levels and salinity conditions. Carbon dioxide (CO2 emissions in the rice and maize fields decreased with decreasing temperature during the freezing period and increased with the rising temperature during the thawing period, with the majority of winter CO2 emissions occurring during these two periods. Peaks in methane (CH4 emissions were observed during the freezing period in the rice fields and during the snow-melting period in the rice and maize fields. CH4 emissions in the rice fields and CH4 uptake rates in the maize fields were significantly (P < 0.05 related to surface soil temperature. Nitrous oxide (N2O emissions remained relatively low, except for during the peaks observed during the snow-melting period in both the rice and maize fields, leading to the high GHG contribution of the snow-melting period throughout the winter. Higher pH and salinity conditions consistently resulted in lower CO2, CH4, and N2O emissions, CH4 uptake, and lower global warming potential (GWP. These results can contribute to the assessment of the GWP during winter in saline-alkali regions.

  7. Beneficial effect of compost utilization on reducing greenhouse gas emissions in a rice cultivation system through the overall management chain.

    Science.gov (United States)

    Jeong, Seung Tak; Kim, Gil Won; Hwang, Hyun Young; Kim, Pil Joo; Kim, Sang Yoon

    2018-02-01

    Livestock manure application can stimulate greenhouse gas (GHG) emissions, especially methane (CH 4 ) in rice paddy. The stabilized organic matter (OM) is recommended to suppress CH 4 emission without counting the additional GHG emission during the composting process. To evaluate the effect of compost utilization on the net global warming potential (GWP) of a rice cropping system, the fluxes of GHGs from composting to land application were calculated by a life cycle assessment (LCA) method. The model framework was composed of GHG fluxes from industrial activities and biogenic GHG fluxes from the composting and rice cultivation processes. Fresh manure emitted 30MgCO 2 -eq.ha -1 , 90% and 10% of which were contributed by CH 4 and nitrous oxide (N 2 O) fluxes, respectively, during rice cultivation. Compost utilization decreased net GWP by 25% over that of the fresh manure during the whole process. The composting process increased the GWP of the industrial processes by 35%, but the 60% reduction in CH 4 emissions from the rice paddy mainly influenced the reduction of GWP during the overall process. Therefore, compost application could be a good management strategy to reduce GHG emissions from rice paddy systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Cultivation of different strains of king oyster mushroom (Pleurotus eryngii) on saw dust and rice straw in Bangladesh.

    Science.gov (United States)

    Moonmoon, Mahbuba; Uddin, Md Nazim; Ahmed, Saleh; Shelly, Nasrat Jahan; Khan, Md Asaduzzaman

    2010-10-01

    Pleurotus eryngii is a popular mushroom due to its excellent consistency of cap and stem, culinary qualities and longer shelf life. In Bangladesh, where Pleurotus mushrooms are very popular, P. eryngii may take position among the consumers, but currently this mushroom is not cultivated in large scale there. In this study, 3 strains of P. eryngii such as Pe-1 (native to Bangladesh), Pe-2 (germplasm collected from China) and Pe-3 (germplasm collected from Japan) were cultivated on saw dust and rice straw and their growth and yield parameters were investigated. Pe-1 on saw dust showed the highest biological yield and efficiency (73.5%) than other strains. Also, the mycelium run rate and number of fruiting bodies were higher in Pe-1 than other two strains. The quality of mushroom strains was near about similar. On saw dust, the yield and efficiency were better than those cultivated on rice straw, however, on straw; the mushroom fruiting bodies were larger in size. This study shows the prospects of P. eryngii cultivation in Bangladesh and suggests further study in controlled environment for higher yield and production.

  9. Acetylcholinesterase inhibition and gill lesions in Rasbora caverii, an indigenous fish inhabiting rice field associated waterbodies in Sri Lanka.

    Science.gov (United States)

    Wijeyaratne, W M D N; Pathiratne, Asoka

    2006-10-01

    The present study was aimed at applying condition factor (CF), brain acetylcholinesterase (AChE) and gill histology as biomarkers for detecting possible exposure/effect induced by pesticides in fish residing rice field associated waterbodies in Sri Lanka. Biomarkers of an indigenous fish, Rasbora caverii collected from five sampling sites including canals near rice fields, a river and a reservoir (the reference site) were evaluated at four sampling stages covering pesticide application periods during rice cultivation season in 2004. Results indicated that CF of the fish did not show significant alterations regardless of the sampling sites or sampling stages. Site specific differences in AChE activities of the fish were not evident either prior to application of pesticides or at 7 days after Paraquat application to the rice fields. Two days after the application of a mixture of Fenthion and Phenthoate to the rice fields, AChE activity of the fish collected from canals near rice fields was significantly depressed (65-75%) compared to the fish in the reference site. The activities remain depressed to 50-56% even at 65 days after the insecticides application. Laboratory studies showed that prior exposure of R. caverii to Paraquat (2 microg l(-1), 7 days) enhanced the extent of inhibition of brain AChE activity induced by Fenthion (3 microg l(-1)) or a mixture of Fenthion (3 microg l(-1)) and Phenthoate (5 microg l(-1)). Gills of fish collected from canals near rice fields exhibited abnormal multiple divisions at the tips of some secondary lamellae in addition to hyperplasia, hypertrophy and club shaped deformities. Results indicate that application of pesticides in rice culture could manifest a threat to native fish populations residing rice field associated waterbodies. The response of brain AChE and histological changes in the gills of R. caverii allowed differentiating sampling sites after insecticide applications to the rice fields. Hence, R. caverii may be

  10. An economic evaluation comparison of solar water pumping system with engine pumping system for rice cultivation

    Science.gov (United States)

    Treephak, Kasem; Thongpron, Jutturit; Somsak, Dhirasak; Saelao, Jeerawan; Patcharaprakiti, Nopporn

    2015-08-01

    In this paper we propose the design and economic evaluation of the water pumping systems for rice cultivation using solar energy, gasoline fuel and compare both systems. The design of the water and gasoline engine pumping system were evaluated. The gasoline fuel cost used in rice cultivation in an area of 1.6 acres. Under same conditions of water pumping system is replaced by the photovoltaic system which is composed of a solar panel, a converter and an electric motor pump which is compose of a direct current (DC) motor or an alternating current (AC) motor with an inverter. In addition, the battery is installed to increase the efficiency and productivity of rice cultivation. In order to verify, the simulation and economic evaluation of the storage energy battery system with batteries and without batteries are carried out. Finally the cost of four solar pumping systems was evaluated and compared with that of the gasoline pump. The results showed that the solar pumping system can be used to replace the gasoline water pumping system and DC solar pump has a payback less than 10 years. The systems that can payback the fastest is the DC solar pumping system without batteries storage system. The system the can payback the slowest is AC solar pumping system with batteries storage system. However, VAC motor pump of 220 V can be more easily maintained than the motor pump of 24 VDC and batteries back up system can supply a more stable power to the pump system.

  11. Genetic variation for traits associated with domestication identified in a cultivated rice, Nipponbare (Oryza sativa ssp. japonica) x ancestral rice, O. nivara, mapping population

    Science.gov (United States)

    Oryza nivara, the progenitor of cultivated rice, O. sativa, has been the source of novel alleles for resistance to biotic and abiotic stresses, as well as for yield improvement. Many of these alleles were lost during the domestication process. To determine the molecular changes that occurred during ...

  12. Greenhouse Gas Emissions and Global Warming Potential of Traditional and Diversified Tropical Rice Rotation Systems including Impacts of Upland Crop Management Practices i.e. Mulching and Inter-crop Cultivation

    Science.gov (United States)

    Janz, Baldur; Weller, Sebastian; Kraus, David; Wassmann, Reiner; Butterbach-Bahl, Klaus; Kiese, Ralf

    2016-04-01

    was returned to the field and incorporated into soil as mulch treatment and ii) mungbean was grown as a cover-crop between dry and wet season in addition to the rice straw application. The input of organic material led to higher methanogenic substrate availability during the following wet season. GHG measurements for upland cropping systems (R-M and R-A) indicate increased CH4 and N2O emissions with mulching and inter-crop cultivation when compared to a control treatment. Subsequent measurements will be necessary to further quantify and assess the mitigation potentials or risks of new management practices. Nevertheless, regarding a future increase of water scarcity it can be expected that mixed lowland-upland systems will expand in SE Asia as water requirements were cut by more than half in both rotation systems with upland crops.

  13. Basic approaches for the handling of illnesses of the cultivation of the rice

    International Nuclear Information System (INIS)

    Tapiero Ortiz, A.L.

    2001-01-01

    Some basic concepts are exposed for the handling of illnesses in the cultivation of the rice, beginning with the illness definition in the plants, integrating the concept in a system plant-pathogen-environment that in turn would have the subsystem it plants, subsystem pathogen and subsystem environmental conditions. It discusses each one of these subsystems and their influence in the development of the infection. The illnesses of the rice are described taken place by the mushrooms Pyricularia oryzae and Rizoctonia solani and the resistance and receptivity to the pathogens on the part of genetic materials, as well as it influences of the environment and indications are given for their handling. The spotted of the grain of the rice like an illness is described caused by a complex of mushrooms, bacteria and nutritional and climatic factors that cause decrease in the yield and they reduce the quality of the grain and the seed. They are related the pathogens organisms causing the illness, the influence of the environment in their development and instructions are given for their handling

  14. Genome-wide analysis of Dongxiang wild rice (Oryza rufipogon Griff.) to investigate lost/acquired genes during rice domestication.

    Science.gov (United States)

    Zhang, Fantao; Xu, Tao; Mao, Linyong; Yan, Shuangyong; Chen, Xiwen; Wu, Zhenfeng; Chen, Rui; Luo, Xiangdong; Xie, Jiankun; Gao, Shan

    2016-04-26

    It is widely accepted that cultivated rice (Oryza sativa L.) was domesticated from common wild rice (Oryza rufipogon Griff.). Compared to other studies which concentrate on rice origin, this study is to genetically elucidate the substantially phenotypic and physiological changes from wild rice to cultivated rice at the whole genome level. Instead of comparing two assembled genomes, this study directly compared the Dongxiang wild rice (DXWR) Illumina sequencing reads with the Nipponbare (O. sativa) complete genome without assembly of the DXWR genome. Based on the results from the comparative genomics analysis, structural variations (SVs) between DXWR and Nipponbare were determined to locate deleted genes which could have been acquired by Nipponbare during rice domestication. To overcome the limit of the SV detection, the DXWR transcriptome was also sequenced and compared with the Nipponbare transcriptome to discover the genes which could have been lost in DXWR during domestication. Both 1591 Nipponbare-acquired genes and 206 DXWR-lost transcripts were further analyzed using annotations from multiple sources. The NGS data are available in the NCBI SRA database with ID SRP070627. These results help better understanding the domestication from wild rice to cultivated rice at the whole genome level and provide a genomic data resource for rice genetic research or breeding. One finding confirmed transposable elements contribute greatly to the genome evolution from wild rice to cultivated rice. Another finding suggested the photophosphorylation and oxidative phosphorylation system in cultivated rice could have adapted to environmental changes simultaneously during domestication.

  15. The Interactive Effect of Diversification and Farming Scale on Productivity of Family Farm:Taking Rice Cultivation as An Example

    Science.gov (United States)

    Wei, Zhou

    2017-05-01

    Based on the diversification and cultivation scale, the rice cropping data of rural fixed observation points in 2011 were selected and the effect of diversification degree on rice productivity was analyzed by the Tobit model. The empirical results of the model show that diversification of sample farm will lead to loss of rice production efficiency. With the increase of rice planting scale, the loss of rice production efficiency will need to be further increased by diversification. Thus, we should stick to the family farm of specialized production operation. The transfer of land, the price and quantity of leasing, respecting the law of the market; the raising of funds can be considered non-subsidized capital market financing to help, while maintaining a certain degree of diversification, to avoid idle assets, low resource efficiency loss.

  16. Australian wild rice reveals pre-domestication origin of polymorphism deserts in rice genome.

    Science.gov (United States)

    Krishnan S, Gopala; Waters, Daniel L E; Henry, Robert J

    2014-01-01

    Rice is a major source of human food with a predominantly Asian production base. Domestication involved selection of traits that are desirable for agriculture and to human consumers. Wild relatives of crop plants are a source of useful variation which is of immense value for crop improvement. Australian wild rices have been isolated from the impacts of domestication in Asia and represents a source of novel diversity for global rice improvement. Oryza rufipogon is a perennial wild progenitor of cultivated rice. Oryza meridionalis is a related annual species in Australia. We have examined the sequence of the genomes of AA genome wild rices from Australia that are close relatives of cultivated rice through whole genome re-sequencing. Assembly of the resequencing data to the O. sativa ssp. japonica cv. Nipponbare shows that Australian wild rices possess 2.5 times more single nucleotide polymorphisms than in the Asian wild rice and cultivated O. sativa ssp. indica. Analysis of the genome of domesticated rice reveals regions of low diversity that show very little variation (polymorphism deserts). Both the perennial and annual wild rice from Australia show a high degree of conservation of sequence with that found in cultivated rice in the same 4.58 Mbp region on chromosome 5, which suggests that some of the 'polymorphism deserts' in this and other parts of the rice genome may have originated prior to domestication due to natural selection. Analysis of genes in the 'polymorphism deserts' indicates that this selection may have been due to biotic or abiotic stress in the environment of early rice relatives. Despite having closely related sequences in these genome regions, the Australian wild populations represent an invaluable source of diversity supporting rice food security.

  17. Australian wild rice reveals pre-domestication origin of polymorphism deserts in rice genome.

    Directory of Open Access Journals (Sweden)

    Gopala Krishnan S

    Full Text Available BACKGROUND: Rice is a major source of human food with a predominantly Asian production base. Domestication involved selection of traits that are desirable for agriculture and to human consumers. Wild relatives of crop plants are a source of useful variation which is of immense value for crop improvement. Australian wild rices have been isolated from the impacts of domestication in Asia and represents a source of novel diversity for global rice improvement. Oryza rufipogon is a perennial wild progenitor of cultivated rice. Oryza meridionalis is a related annual species in Australia. RESULTS: We have examined the sequence of the genomes of AA genome wild rices from Australia that are close relatives of cultivated rice through whole genome re-sequencing. Assembly of the resequencing data to the O. sativa ssp. japonica cv. Nipponbare shows that Australian wild rices possess 2.5 times more single nucleotide polymorphisms than in the Asian wild rice and cultivated O. sativa ssp. indica. Analysis of the genome of domesticated rice reveals regions of low diversity that show very little variation (polymorphism deserts. Both the perennial and annual wild rice from Australia show a high degree of conservation of sequence with that found in cultivated rice in the same 4.58 Mbp region on chromosome 5, which suggests that some of the 'polymorphism deserts' in this and other parts of the rice genome may have originated prior to domestication due to natural selection. CONCLUSIONS: Analysis of genes in the 'polymorphism deserts' indicates that this selection may have been due to biotic or abiotic stress in the environment of early rice relatives. Despite having closely related sequences in these genome regions, the Australian wild populations represent an invaluable source of diversity supporting rice food security.

  18. Population genomics identifies the origin and signatures of selection of Korean weedy rice

    OpenAIRE

    He, Qiang; Kim, Kyu?Won; Park, Yong?Jin

    2016-01-01

    Summary Weedy rice is the same biological species as cultivated rice (Oryza sativa); it is also a noxious weed infesting rice fields worldwide. Its formation and population?selective or ?adaptive signatures are poorly understood. In this study, we investigated the phylogenetics, population structure and signatures of selection of Korean weedy rice by determining the whole genomes of 30 weedy rice, 30 landrace rice and ten wild rice samples. The phylogenetic tree and results of ancestry infere...

  19. Rice cultivation in the farming systems of Sukumaland, Tanzania : a quest for sustainable production under structural adjustment programmes

    NARCIS (Netherlands)

    Meertens, H.C.C.

    1999-01-01

    This thesis investigates options for sustainable rice cultivation and general agricultural development in the Mwanza and Shinyanga regions in northwestern Tanzania, often called Sukumaland due to the predominance of Wasukuma people. Generally Sukumaland has a semi-arid climate; agriculture

  20. Influence of nitrogen loading and plant nitrogen assimilation on nitrogen leaching and N₂O emission in forage rice paddy fields fertilized with liquid cattle waste.

    Science.gov (United States)

    Riya, Shohei; Zhou, Sheng; Kobara, Yuso; Sagehashi, Masaki; Terada, Akihiko; Hosomi, Masaaki

    2015-04-01

    Livestock wastewater disposal onto rice paddy fields is a cost- and labor-effective way to treat wastewater and cultivate rice crops. We evaluated the influence of nitrogen loading rates on nitrogen assimilation by rice plants and on nitrogen losses (leaching and N2O emission) in forage rice fields receiving liquid cattle waste (LCW). Four forage rice fields were subjected to nitrogen loads of 107, 258, 522, and 786 kg N ha(-1) (N100, N250, N500, and N750, respectively) using basal fertilizer (chemical fertilizer) (50 kg N ha(-1)) and three LCW topdressings (each 57-284 kg N ha(-1)). Nitrogen assimilated by rice plants increased over time. However, after the third topdressing, the nitrogen content of the biomass did not increase in any treatment. Harvested aboveground biomass contained 93, 60, 33, and 31 % of applied nitrogen in N100, N250, N500, and N750, respectively. The NH4 (+) concentration in the pore water at a depth of 20 cm was less than 1 mg N L(-1) in N100, N250, and N500 throughout the cultivation period, while the NH4 (+) concentration in N750 increased to 3 mg N L(-1) after the third topdressing. Cumulative N2O emissions ranged from -0.042 to 2.39 kg N ha(-1); the highest value was observed in N750, followed by N500. In N750, N2O emitted during the final drainage accounted for 80 % of cumulative N2O emissions. This study suggested that 100-258 kg N ha(-1) is a recommended nitrogen loading rate for nitrogen recovery by rice plants without negative environmental impacts such as groundwater pollution and N2O emission.

  1. Little white lies: pericarp color provides insights into the origins and evolution of Southeast Asian weedy rice

    Science.gov (United States)

    Weedy rice is a conspecific form of cultivated rice (Oryza sativa L.) that infests rice fields and results in severe crop losses. Weed strains in different world regions appear to have originated multiple times from different domesticated and/or wild rice progenitors. In the case of Malaysian weedy ...

  2. The impact of Rhizopus oryzae cultivation on rice bran: Gamma-oryzanol recovery and its antioxidant properties.

    Science.gov (United States)

    Massarolo, Kelly Cristina; Denardi de Souza, Taiana; Collazzo, Carolina Carvalho; Badiale Furlong, Eliana; Souza Soares, Leonor Almeida de

    2017-08-01

    This study evaluated the effect of the solid state cultivation (SSC) time of rice bran by Rhizopus oryzae on γ-oryzanol recovery and its antioxidant properties. Gamma-oryzanol was extracted with organic solvents and its extracts were characterized by GC-FID and HPLC-UV. The antioxidant capacity was assessed by DPPH and ABTS + assays, β-carotene/linoleic acid system, and reduction of oxidation in lipid system. The biomass showed the γ-oryzanol recovery increased by 51.5% (20.52mg/g), and 5.7% in polyunsaturated fatty acids. The γ-oryzanol major components changing in their profile. The γ-oryzanol extract from biomass (72h) showed the greatest DPPH inhibition (59.0%), while 90.5% inhibition of oxidation of β-carotene/linoleic acid system, and 30% reduction of the indicators of oxidation in olive oil was observed in the one cultivated at 96h, these behaviors were confirmed by PCA analyses. SSC provides an increase in the γ-oryzanol recovery followed by improving of the functional properties of rice bran. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Genomic dissection of small RNAs in wild rice (Oryza rufipogon): lessons for rice domestication.

    Science.gov (United States)

    Wang, Yu; Bai, Xuefei; Yan, Chenghai; Gui, Yiejie; Wei, Xinghua; Zhu, Qian-Hao; Guo, Longbiao; Fan, Longjiang

    2012-11-01

    The lack of a MIRNA set and genome sequence of wild rice (Oryza rufipogon) has prevented us from determining the role of MIRNA genes in rice domestication. In this study, a genome, three small RNA populations and a degradome of O. rufipogon were sequenced by Illumina platform and the expression levels of microRNAs (miRNAs) were investigated by miRNA chips. A de novo O. rufipogon genome was assembled using c. 55× coverage of raw sequencing data and a total of 387 MIRNAs were identified in the O. rufipogon genome based on c. 5.2 million unique small RNA reads from three different tissues of O. rufipogon. Of these, O. rufipogon MIRNAs, 259 were not found in the cultivated rice, suggesting a loss of these MIRNAs in the cultivated rice. We also found that 48 MIRNAs were novel in the cultivated rice, suggesting that they were potential targets of domestication selection. Some miRNAs showed significant expression differences between wild and cultivated rice, suggesting that expression of miRNA could also be a target of domestication, as demonstrated for the miR164 family. Our results illustrated that MIRNA genes, like protein-coding genes, might have been significantly shaped during rice domestication and could be one of the driving forces that contributed to rice domestication. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  4. Rice production with minimal irrigation and no nitrogen fertilizer by intensive use of treated municipal wastewater.

    Science.gov (United States)

    Muramatsu, Ayumi; Watanabe, Toru; Sasaki, Atsushi; Ito, Hiroaki; Kajihara, Akihiko

    2014-01-01

    We designed a new cultivation system of rice with circulated irrigation to remove nitrogen from treated municipal wastewater effectively and assessed the possibility of nitrogen removal in the new system without any adverse effects on rice production through bench-scale experiments through two seasons. Overgrowth of the rice plant, which can lead to lodging and tasteless rice, was found in the first season probably because nitrogen supply based on standard practice in normal paddy fields was too much in the closed irrigation system. In the second season, therefore, the amount of treated wastewater initially applied to the system was reduced but this resulted in a considerably decreased yield. On the other hand, the taste of the rice was significantly improved. The two-season experiments revealed that the new system enabled rice production with minimal irrigation (approximately 50% on the yield base compared to normal paddy fields) and no nitrogen fertilizer. The system also achieved >95% removal of nitrogen from the treated wastewater used for circulated irrigation. The accumulation of harmful metals in the rice was not observed after one season of cultivation in the new system. The accumulation after cultivation using the same soil repeatedly for a longer time should be examined by further studies.

  5. Lead in rice: analysis of baseline lead levels in market and field collected rice grains.

    Science.gov (United States)

    Norton, Gareth J; Williams, Paul N; Adomako, Eureka E; Price, Adam H; Zhu, Yongguan; Zhao, Fang-Jie; McGrath, Steve; Deacon, Claire M; Villada, Antia; Sommella, Alessia; Lu, Ying; Ming, Lei; De Silva, P Mangala C S; Brammer, Hugh; Dasgupta, Tapash; Islam, M Rafiqul; Meharg, Andrew A

    2014-07-01

    In a large scale survey of rice grains from markets (13 countries) and fields (6 countries), a total of 1578 rice grain samples were analysed for lead. From the market collected samples, only 0.6% of the samples exceeded the Chinese and EU limit of 0.2 μg g(-1) lead in rice (when excluding samples collected from known contaminated/mine impacted regions). When evaluating the rice grain samples against the Food and Drug Administration's (FDA) provisional total tolerable intake (PTTI) values for children and pregnant women, it was found that only people consuming large quantities of rice were at risk of exceeding the PTTI from rice alone. Furthermore, 6 field experiments were conducted to evaluate the proportion of the variation in lead concentration in rice grains due to genetics. A total of 4 of the 6 field experiments had significant differences between genotypes, but when the genotypes common across all six field sites were assessed, only 4% of the variation was explained by genotype, with 9.5% and 11% of the variation explained by the environment and genotype by environment interaction respectively. Further work is needed to identify the sources of lead contamination in rice, with detailed information obtained on the locations and environments where the rice is sampled, so that specific risk assessments can be performed. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. KAJIAN INPUT ENERGI PADA BUDIDAYA PADI METODE SYSTEM OF RICE INTENSIFICATION Studies on Energy Input in System of Rice Intensification Method of Rice Cultivation

    Directory of Open Access Journals (Sweden)

    Bambang Purwantana

    2012-05-01

    Full Text Available System of Rice Intensification (SRI is a rice cultivation method that intensively control and manage macro and micro nutrients as well as irrigation. This paper quantifies and compares the energy uses of SRI and conventional rice cultiva- tion systems. The study was conducted at some SRI’s experimental plots in the districts of Sleman, Kulonprogo, and Bantul, the province of Yogyakarta. The calculation of the energy was based on the farmers’ work schedule, the time required for each operation, the number of laborers, machines, tools, fuel, and all materials and inputs used. The result shows that SRI method consumed 35% less energy to conventional rice cultivation. Energy inputs from seed, water, fertilizer and pesticide were significantly reduces. However, there was higher input of human energy due to compost- ing, land preparation and weeding operations. The specific energy of SRI method was 1.96 MJ ha-1 lower than conven- tional method of 4.43 MJ ha-1. In the SRI method, 56.2 % of energy consumed was classified as direct energy and 43.8% was indirect energy. The SRI method used 61.9 % of renewable energy and 38.1 % of non-renewable energy. The working efficiency in composting and weeding operations should be improved in perspective of machine and tools to reduce the use of human energy. ABSTRAK System of Rice Intensification (SRI, merupakan suatu metode budidaya padi secara intensif dengan pengendalian unsur-unsur hara makro dan mikro disertai pengendalian dan pengaturan kebutuhan air. Penelitian ini bertujuan untuk menganalisis penggunaan energi dan mengidentifikasi kemungkinan penghematan energi pada budidaya padi SRI. Pe- nelitian dilakukan di Kabupaten Sleman, Kulonprogo, dan Bantul, Propinsi Daerah Istimewa Yogyakarta. Pengamatan dilakukan pada plot-plot percobaan budidaya padi SRI dengan melakukan audit seluruh input energi selama proses budidaya dan dikomparasikan dengan input energi pada budidaya padi cara konvensional. Hasil

  7. Aerobic rice mechanization: techniques for crop establishment

    Science.gov (United States)

    Khusairy, K. M.; Ayob, H.; Chan, C. S.; Fauzi, M. I. Mohamed; Mohamad Fakhrul, Z. O.; Shahril Shah, G. S. M.; Azlan, O.; Rasad, M. A.; Hashim, A. M.; Arshad, Z.; E, E. Ibrahim; Saifulizan, M. N.

    2015-12-01

    Rice being the staple food crops, hundreds of land races in it makes the diversity of rice crops. Aerobic rice production was introduced which requires much less water input to safeguard and sustain the rice production and conserve water due to decreasing water resources, climatic changes and competition from urban and industrial users. Mechanization system plays an important role for the success of aerobic rice cultivation. All farming activities for aerobic rice production are run on aerobic soil conditions. Row seeder mechanization system is developed to replace conventional seeding technique on the aerobic rice field. It is targeted for small and the large scale aerobic rice farmers. The aero - seeder machine is used for the small scale aerobic rice field, while the accord - seeder is used for the large scale aerobic rice field. The use of this mechanization machine can eliminate the tedious and inaccurate seeding operations reduce labour costs and increases work rate. The machine is easy to operate and it can increase crop establishment rate. It reduce missing hill, increasing planting and crop with high yield can be produce. This machine is designed for low costs maintenance and it is easy to dismantle and assemble during maintenance and it is safe to be used.

  8. Rice Cluster I, an Important Group of Archaea Producing Methane in Rice Fields

    Science.gov (United States)

    Conrad, R.

    2006-12-01

    Rice fields are an important source for the greenhouse gas methane. Methane is a major degradation product of organic matter in the anoxic soil, is partially oxidized in the rhizosphere and is emitted into the atmosphere through the aerenchyma system of the plants. Anaerobic degradation of organic matter by fermenting bacteria eventually results in the production of acetate and hydrogen, the two major substrates for microbial methanogenesis. The community of methanogenic archaea consists of several major orders or families including hydrogen-utilizing Rice Cluster-I (RC-I). Environmental conditions affect the methanogenic degradation process and the community structure of the methanogenic archaea in soil and rhizosphere. For example, populations of acetoclastic Methanosaetaceae and Methanosarcinaceae are enhanced by low and high acetate concentrations, respectively. Stable isotope probing of 16S rRNA showed that RC-I methanogens are mainly active on rice roots and at low H2 concentrations. Growth and population size is largely consistent with energetic conditions. RC-I methanogens on roots seem to be responsible for methane production from plant photosynthates that account for a major part of the emitted methane. Populations of RC-I methanogens in rice field soil are also enhanced at elevated temperatures (40-50°C). Moderately thermophilic members of RC-I methanogens or other methanogenic families were found to be ubiquitously present in soils from rice fields and river marshes. The genome of a RC-I methanogen was completely sequenced out of an enrichment culture using a metagenome approach. Genes found are consistent with life in the rhizosphere and in temporarily drained, oxic soil. We found that the methanogenic community structure on the rice roots is mainly determined by the respective community structure of the soil, but is in addition affected by the rice cultivar. Rice microcosms in which soil and rice roots are mainly colonized by RC-I methanogens produce

  9. Enhancing the fertility of an acid sulfate soil for rice cultivation using lime in combination with bio-organic fertilizer

    International Nuclear Information System (INIS)

    Farhana, A.; Shamshuddin, J.; Fauziah, C.I.; Panhwar, Q.A.

    2017-01-01

    The acid sulfate soils contain pyrite (FeS/sub 2/) which is due to oxidation results in the production of high amount of acidity, aluminum and iron significantly affecting rice growth. A glasshouse study was arranged to determine the effect of ground magnesium limestone (GML) in combination with bio-organic fertilizer (JITUTM) application on the chemical properties of soils and rice yield. Three rice seedlings were transplanted in pots which were previously amended with 0, 2, 4, 6 and 8 t/ha GML with or without bio-organic fertilizer. The common rice varieties (MR 219 and MR 253) were cultivated for two seasons in the same pots. The critical Fe2+ and Al3+ activities for MR 219 were 14.45 and 4.23 mu M, while for MR 253 were 7.45 and 5.53 mu M, respectively. However, without applying the amendments, rice grown on the soils was affected severely by the high acidity (Fe2+ and Al3+ toxicity). The soil pH increased to 5 and the higher grain yield of MR 219 (99.77 and 121.38 g/pot) and MR253 (98.63 and 112.60 g/pot) was in first and second season with the application of 2 t GML application combined with 0.25 t JITUTM/ha respectively. In addition, 1000 grain weight, number of panicle, number of spikelets panicle-1 and the percentage of filled spikelet, were also higher than without the soil amendments. Hence, the infertility of acid sulfate soils for sustainable rice cultivation in Malaysia can be improved by applying 2 t GML/ha combined with 0.25 t JITUTM/ha for two seasons in long run. (author)

  10. Mitigation options for methane emissions from rice fields in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Lantin, R.S.; Buendia, L.V.; Wassmann, R. [International Rice Research Institute, Laguna (Philippines)] [and others

    1996-12-31

    The contribution of Philippine rice production to global methane emission and breakthroughs in methane emission studies conducted in the country are presented in this paper. A significant impact in the reduction of GHG emissions from agriculture can be achieved if methane emissions from ricefields can be abated. This study presents the contribution of Philippine rice cultivation to global methane emission and breakthroughs in methane emission studies in the country which address the issue of mitigation. Using the derived emission factors from local measurements, rice cultivation contributes 566.6 Gg of methane emission in the Philippines. This value is 62% of the total methane emitted from the agriculture sector. The emission factors employed which are 78% of the IPCC value for irrigated rice and 95% for rainfed rice were derived from measurements with an automatic system taken during the growth duration in the respective ecosystems. Plots drained for 2 weeks at midtillering and before harvest gave a significant reduction in methane emission as opposed to continuously flooded plots and plots drained before harvest. The cultivar Magat reduced methane emission by 50% as compared to the check variety IR72. The application of ammonium sulfate instead of urea reduced methane emission by 10% to 34%. Addition of 6 t ha{sup {minus}1} phosphogypsum in combination with urea reduced emission by 74% as opposed to plots applied with urea alone. It is also from the results of such measurements that abatement strategies are based as regards to modifying treatments such as water management, fertilization, and choice of rice variety. It is not easy to identify and recommend mitigation strategies that will fit a particular cropping system. However, the identified mitigation options provide focus for the abatement of methane emission from ricefields.

  11. Genetic Diversity of Wild Rice Species in Yunnan Province of China

    OpenAIRE

    Zai-quan CHENG; Fu-you YING; Ding-qing LI; Teng-qiong YU; Jian FU; Hui-jun YAN; Qiao-fang ZHONG; Dun-yu ZHANG; Wei-jiao LI; Xing-qi HUANG

    2012-01-01

    Yunnan Province of China is one of the important centers for origin and evolution of cultivated rice worldwide. Wild rice is the ancestor of the cultivated rice. Many elite traits of wild rice have widened the genetic basis in cultivated rice. However, many populations of wild rice species have disappeared in the past few years. Therefore, the current status of wild rice resources should be updated and the genetic diversity of wild rice species should be examined for further germplasm preserv...

  12. Little White Lies: Pericarp Color Provides Insights into the Origins and Evolution of Southeast Asian Weedy Rice

    Science.gov (United States)

    Cui, Yongxia; Song, Beng Kah; Li, Lin-Feng; Li, Ya-Ling; Huang, Zhongyun; Caicedo, Ana L.; Jia, Yulin; Olsen, Kenneth M.

    2016-01-01

    Weedy rice is a conspecific form of cultivated rice (Oryza sativa L.) that infests rice fields and results in severe crop losses. Weed strains in different world regions appear to have originated multiple times from different domesticated and/or wild rice progenitors. In the case of Malaysian weedy rice, a multiple-origin model has been proposed based on neutral markers and analyses of domestication genes for hull color and seed shattering. Here, we examined variation in pericarp (bran) color and its molecular basis to address how this trait evolved in Malaysian weeds and its possible role in weed adaptation. Functional alleles of the Rc gene confer proanthocyanidin pigmentation of the pericarp, a trait found in most wild and weedy Oryzas and associated with seed dormancy; nonfunctional rc alleles were strongly favored during rice domestication, and most cultivated varieties have nonpigmented pericarps. Phenotypic characterizations of 52 Malaysian weeds revealed that most strains are characterized by the pigmented pericarp; however, some weeds have white pericarps, suggesting close relationships to cultivated rice. Phylogenetic analyses indicate that the Rc haplotypes present in Malaysian weeds likely have at least three distinct origins: wild O. rufipogon, white-pericarp cultivated rice, and red-pericarp cultivated rice. These diverse origins contribute to high Rc nucleotide diversity in the Malaysian weeds. Comparison of Rc allelic distributions with other rice domestication genes suggests that functional Rc alleles may confer particular fitness benefits in weedy rice populations, for example, by conferring seed dormancy. This may promote functional Rc introgression from local wild Oryza populations. PMID:27729434

  13. Mosquitoes and other aquatic insects in fallow field biotopes and rice paddy fields.

    Science.gov (United States)

    Ohba, S Y; Matsuo, T; Takagi, M

    2013-03-01

    Fallow field biotopes that develop from abandoned rice fields are man-made wetlands that provide new habitats for various aquatic animals. Although consideration of such biotopes generally focuses on their positive aspects, this study evaluated the negative aspects of establishing fallow field biotopes with regard to mosquito breeding sites. To determine whether fallow field biotopes become breeding habitats for vector mosquitoes, we evaluated mosquito fauna in fallow field biotopes and adjacent rice fields. We found larvae of Anopheles lesteri, Anopheles sinensis and Culex tritaeniorhynchus (all: Diptera: Culicidae) in the biotopes. Although abundances of mosquito larvae in the biotopes and rice fields were statistically similar, mosquito abundances in rice fields increased dramatically in August when the water level reduced after the rainy season. The abundance and variety of the mosquitoes' natural predators were greater in biotopes than in rice fields because the former are a permanent and stable aquatic environment. A generalized linear mixed model showed a negative effect of predator diversity on mosquito larvae abundance in both habitats. Although fallow field biotopes become breeding habitats for vector mosquitoes, establishing biotopes from fallow fields in order to protect various aquatic animals, including mosquito insect predators, may help to control mosquito breeding. © 2012 The Royal Entomological Society.

  14. The effect of motor vehicle emission towards lead (Pb content of rice field soil with different clay content

    Directory of Open Access Journals (Sweden)

    C.C.Wati

    2015-10-01

    Full Text Available Motor vehicle gas emission contains lead (Pb which is a hazardous and toxic substance. Agricultural land, especially rice field, which is located nearby roads passed by many motor vehicle, are susceptible to the accumulation of Pb. If Pb is permeated by plants cultivated in the rice field, it will be very hazardous for humans as they are the final consumers. Hence, it is essential to identify Pb content of rice-field soil initiated by motor vehicle gas emission. This study was aimed to identify the effects of motor vehicle density, the distance between rice-field and road, and the clay content of soil towards Pb content of soils in Blitar and Ngawi Regencies of East Java. The method used for the study was survey method managed by using three-factor nested design with three replicates. The results of this study showed that motor vehicle density and the distance of rice field to road provide significant affected the total of Pb content of soil. However, the dissemination pattern of Pb in the soil was irregular due to the factors of climate and environment. Before Pb reached soil surface, Pb was spread out in the air due to the effect of temperature, wind velocity, vehicle velocity, size of vehicle, and road density. Consequently, the location with low motor vehicle density and positioned faraway to the road had higher total rate of Pb than the location with high motor vehicle density and positioned nearby the road. Clay content affected the total rate of Pb content as much as 37%, every 1% increase of clay content increased the total rate of Pb as much as 0.08 mg/kg.

  15. Runoff of pesticides from rice fields in the Ile de Camargue (Rhone river delta, France): Field study and modeling

    International Nuclear Information System (INIS)

    Comoretto, Laetitia; Arfib, Bruno; Talva, Romain; Chauvelon, Philippe; Pichaud, Marc; Chiron, Serge; Hoehener, Patrick

    2008-01-01

    A field study on the runoff of pesticides was conducted during the cultivation period in 2004 on a hydraulically isolated rice farm of 120 ha surface with one central water outlet. Four pesticides were studied: Alphamethrin, MCPA, Oxadiazon, and Pretilachlor. Alphamethrin concentrations in runoff never exceeded 0.001 μg L -1 . The three other pesticides were found in concentrations between 5.2 and 28.2 μg L -1 in the runoff water shortly after the application and decreased thereafter. The data for MCPA compared reasonably well with predictions by an analytical runoff model, accounting for volatilization, degradation, leaching to groundwater, and sorption to soil. The runoff model estimated that runoff accounted for as much as 18-42% of mass loss for MCPA. Less runoff is observed and predicted for Oxadiazon and Pretilachlor. It was concluded that runoff from rice paddies carries important loads of dissolved pesticides to the wetlands in the Ile de Camargue, and that the model can be used to predict this runoff. - Runoff of dissolved pesticides was measured on a rice farm in the Camargue (France) and modeled with an analytical model

  16. Improved stress tolerance and productivity in transgenic rice plants constitutively expressing the Oryza sativa glutathione synthetase OsGS under paddy field conditions.

    Science.gov (United States)

    Park, Seong-Im; Kim, Young-Saeng; Kim, Jin-Ju; Mok, Ji-Eun; Kim, Yul-Ho; Park, Hyang-Mi; Kim, Il-Sup; Yoon, Ho-Sung

    2017-08-01

    Reactive oxygen species, which increase under various environmental stresses, have deleterious effects on plants. An important antioxidant, glutathione, is used to detoxify reactive oxygen species in plant cells and is mainly produced by two enzymes: gamma-glutamylcysteine synthetase (γ-ECS) and glutathione synthetase (GS). To evaluate the functional roles of the glutathione synthetase gene (OsGS) in rice, we generated four independent transgenic rice plants (TG1-TG4) that overexpressed OsGS under the control of the constitutively expressed OsCc1 promoter. When grown under natural paddy field conditions, the TG rice plants exhibited greater growth development, higher chlorophyll content, and higher GSH/GSSH ratios than control wild-type (WT) rice plants. Subsequently, the TG rice plants enhanced redox homeostasis by preventing hydroperoxide-mediated membrane damage, which improved their adaptation to environmental stresses. As a result, TG rice plants improved rice grain yield and total biomass following increases in panicle number and number of spikelets per panicle, despite differences in climate during the cultivation periods of 2014 and 2015. Overall, our results indicate that OsGS overexpression improved redox homeostasis by enhancing the glutathione pool, which resulted in greater tolerance to environmental stresses in the paddy fields. Copyright © 2017. Published by Elsevier GmbH.

  17. Research Advances in High-Yielding Cultivation and Physiology of Super Rice

    Directory of Open Access Journals (Sweden)

    Jing FU

    2012-09-01

    Full Text Available In 1996, China launched a program to breed super rice or super hybrid rice by combining intersubspecific heterosis with ideal plant types. Today, approximately 80 super rice varieties have been released and some of them show high grain yields of 12–21 t/hm2 in field experiments. The main reasons for the high yields of super rice varieties, compared with those of conventional varieties, can be summarized as follows: more spikelets per panicle and larger sink size (number of spikelets per square meter; larger leaf area index, longer duration of green leaf, greater photosynthetic rate, higher lodging resistance, greater dry matter accumulation before the heading stage, greater remobilization of pre-stored carbohydrates from stems and leaves to grains during the grain-filling period; and larger root system and greater root activity. However, there are two main problems in super rice production: poor grain-filling of the later-flowering inferior spikelets (in contrast to earlier-flowering superior spikelets, and low and unstable seed-setting rate. Here, we review recent research advances in the crop physiology of super rice, focusing on biological features, formation of yield components, and population quality. Finally, we suggest further research on crop physiology of super rice.

  18. Nitrogen Dynamic Study on Rice Mutant Lines Using 15N Isotope Techniques

    International Nuclear Information System (INIS)

    Ahmad Nazrul Abd Wahid; Shyful Azizi Abdul Rahman; Abdul Rahim Harun

    2015-01-01

    Malaysian Nuclear Agency in collaboration with UPM and MARDI has produced two types of rice mutant lines of MR219, viz. MR219-4 and MR219-9 developed under rice radiation mutagenenesis programme for adaptability to aerobic conditions. Aerobic cultivating is rice cultivation system on well drained soil and using minimal water input. At Malaysian Nuclear Agency, a nitrogen fertilization study in aerobic condition for the rice mutant lines was carried out in the shade house and field. The study is intended to examine and assess the dynamics of nitrogen by rice mutant lines through the different soil water management and nitrogen levels. Direct 15 N isotopic tracer method was used in this study, whereby the 15 N labeled urea fertilizer was utilized as a tracer for nitrogen nutrient uptake by the test crops. This paper is intended to highlight the progress that has been made in the study of the nitrogen dynamics on MR219-4 and MR219-9 rice mutant lines. (author)

  19. Epiphytic Cyanobacteria on Chara vulgaris Are the Main Contributors to N2 Fixation in Rice Fields

    Science.gov (United States)

    Ariosa, Yoanna; Quesada, Antonio; Aburto, Juan; Carrasco, David; Carreres, Ramón; Leganés, Francisco; Fernández Valiente, Eduardo

    2004-01-01

    The distribution of nitrogenase activity in the rice-soil system and the possible contribution of epiphytic cyanobacteria on rice plants and other macrophytes to this activity were studied in two locations in the rice fields of Valencia, Spain, in two consecutive crop seasons. The largest proportion of photodependent N2 fixation was associated with the macrophyte Chara vulgaris in both years and at both locations. The nitrogen fixation rate associated with Chara always represented more than 45% of the global nitrogenase activity measured in the rice field. The estimated average N2 fixation rate associated with Chara was 27.53 kg of N ha−1 crop−1. The mean estimated N2 fixation rates for the other parts of the system for all sampling periods were as follows: soil, 4.07 kg of N ha−1 crop−1; submerged parts of rice plants, 3.93 kg of N ha−1 crop−1; and roots, 0.28 kg of N ha−1 crop−1. Micrographic studies revealed the presence of epiphytic cyanobacteria on the surface of Chara. Three-dimensional reconstructions by confocal scanning laser microscopy revealed no cyanobacterial cells inside the Chara structures. Quantification of epiphytic cyanobacteria by image analysis revealed that cyanobacteria were more abundant in nodes than in internodes (on average, cyanobacteria covered 8.4% ± 4.4% and 6.2% ± 5.0% of the surface area in the nodes and internodes, respectively). Epiphytic cyanobacteria were also quantified by using a fluorometer. This made it possible to discriminate which algal groups were the source of chlorophyll a. Chlorophyll a measurements confirmed that cyanobacteria were more abundant in nodes than in internodes (on average, the chlorophyll a concentrations were 17.2 ± 28.0 and 4.0 ± 3.8 μg mg [dry weight] of Chara−1 in the nodes and internodes, respectively). These results indicate that this macrophyte, which is usually considered a weed in the context of rice cultivation, may help maintain soil N fertility in the rice field

  20. Molecular evolution of the rice blast resistance gene Pi-ta in invasive weedy rice in the USA.

    Directory of Open Access Journals (Sweden)

    Seonghee Lee

    Full Text Available The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus, which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH, suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta, not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing.

  1. Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA

    Science.gov (United States)

    Lee, Seonghee; Jia, Yulin; Jia, Melissa; Gealy, David R.; Olsen, Kenneth M.; Caicedo, Ana L.

    2011-01-01

    The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta) found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH), suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s) required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta), not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing. PMID:22043312

  2. Rice Production without Insecticide in Smallholder Farmer's Field

    Directory of Open Access Journals (Sweden)

    M. P. Ali

    2017-05-01

    Full Text Available Highlights:Use of perching, sweeping, and need based insecticide (IPM technique useage produce at par yields compared to prophylactic insecticide useage in rice fields.There exists a technique that can reduce 75% of insecticide useage in rice field.The results were obtained in cooperation between smallholder rice farmers and researchers of Bangladesh.Currently rice protection from insect pests solely depends on chemical pesticides which have tremendous impact on biodiversity, environment, animal, and human health. To reduce their impact from our society we need to cut pesticide use from agricultural practices. To address this issue, we did an experiment to identify realistic solutions that could help farmers build sustainable crop protection systems and minimize useage of insecticides and thus reduce the impact of pesticides in the environment. Innovations developed jointly by farmers and researchers and evaluated for their potential to be adopted by more farmers. In this paper we tested four management practices jointly with smallholder farmer fields in order to select the best one. Four management practices were used namely, T1 = Prophylactic use of insecticide where insecticide was applied in rice field at every 15 days interval without judging the infestation level; T2 = Perching (that is, placing roosting (perching sites for insectivorous birds within the rice field and concurrent sweep net samples along with need-based insecticide application; T3 = Perching only; and T4 = Farmer's own practices. The results revealed that routine application of insecticides for crop protection is not mandatory which is commonly found at use in rice farmers. In our experiment, where prophylactic method or farmers used 3–4 times insecticides without judging the insect pests infestation level, the similar pest population was found when compared to the field where insecticide was not applied. Our management system reduced by 75% the use of insecticides even

  3. Avian foods, foraging and habitat conservation in world rice fields

    Science.gov (United States)

    Stafford, J.D.; Kaminski, R.M.; Reinecke, K.J.

    2010-01-01

    Worldwide, rice (Oryza sativa) agriculture typically involves seasonal flooding and soil tillage, which provides a variety of microhabitats and potential food for birds. Water management in rice fields creates conditions ranging from saturated mud flats to shallow (seed mass from North America ranging from 66672 kg/ha. Although initially abundant after harvest, waste rice availability can be temporally limited. Few abundance estimates for other foods, such as vertebrate prey or forage vegetation, exist for rice fields. Outside North America, Europe and Japan, little is known about abundance and importance of any avian food in rice fields. Currently, flooding rice fields after harvest is the best known management practice to attract and benefit birds. Studies from North America indicate specific agricultural practices (e.g. burning stubble) may increase use and improve access to food resources. Evaluating and implementing management practices that are ecologically sustainable, increase food for birds and are agronomically beneficial should be global priorities to integrate rice production and avian conservation. Finally, land area devoted to rice agriculture appears to be stable in the USA, declining in China, and largely unquantified in many regions. Monitoring trends in riceland area may provide information to guide avian conservation planning in rice-agriculture ecosystems.

  4. Adapting rice production to climate change for sustainable blue water consumption: an economic and virtual water analysis

    Science.gov (United States)

    Darzi-Naftchali, Abdullah; Karandish, Fatemeh

    2017-12-01

    Sustainable utilization of blue water resources under climate change is of great significance especially for producing high water-consuming crops in water-scarce regions. Based on the virtual water concept, we carried out a comprehensive field-modeling research to find the optimal agricultural practices regarding rice blue water consumption under prospective climate change. The DSSAT-CERES-Rice model was used in combination with 20 GCMs under three Representative Concentration Pathways of low (RCP2.6), intermediate (RCP4.6), and very high (RCP8.5) greenhouse concentrations to predict rice yield and water requirement and related virtual water and economic return for the base and future periods. The crop model was calibrated and validated based on the 2-year field data obtained from consolidated paddy fields of the Sari Agricultural Sciences and Natural Resources University during 2011 and 2012 rice cropping cycles. Climate change imposes an increase of 0.02-0.04 °C in air temperature which consequently shifts rice growing seasons to winter season, and shorten the length of rice physiological maturity period by 2-15 days. While rice virtual water reduces by 0.1-20.6% during 2011-2070, reduced rice yield by 3.8-22.6% over the late twenty-first century results in a considerable increase in rice virtual water. By increasing the contribution of green water in supplying crop water requirement, earlier cropping could diminish blue water consumption for rice production in the region while cultivation postponement increases irrigation water requirement by 2-195 m3 ha-1. Forty days delay in rice cultivation in future will result in 29.9-40.6% yield reduction and 43.9-60% increase in rice virtual water under different scenarios. Earlier cropping during the 2011-2040 and 2041-2070 periods would increase water productivity, unit value of water, and economic value of blue water compared to the base period. Based on the results, management of rice cultivation calendar is a

  5. Formation of Guaiacol by Spoilage Bacteria from Vanillic Acid, a Product of Rice Koji Cultivation, in Japanese Sake Brewing.

    Science.gov (United States)

    Ito, Toshihiko; Konno, Mahito; Shimura, Yoichiro; Watanabe, Seiei; Takahashi, Hitoshi; Hashizume, Katsumi

    2016-06-08

    The formation of guaiacol, a potent phenolic off-odor compound in the Japanese sake brewing process, was investigated. Eight rice koji samples were analyzed, and one contained guaiacol and 4-vinylguaiacol (4-VG) at extraordinarily high levels: 374 and 2433 μg/kg dry mass koji, respectively. All samples contained ferulic and vanillic acids at concentrations of mg/kg dry mass koji. Guaiacol forming microorganisms were isolated from four rice koji samples. They were identified as Bacillus subtilis, B. amyloliquefaciens/subtilis, and Staphylococcus gallinarum using 16S rRNA gene sequence. These spoilage bacteria convert vanillic acid to guaiacol and ferulic acid to 4-VG. However, they convert very little ferulic acid or 4-VG to guaiacol. Nine strains of koji fungi tested produced vanillic acid at the mg/kg dry mass koji level after cultivation. These results indicated that spoilage bacteria form guaiacol from vanillic acid, which is a product of koji cultivation in the sake brewing process.

  6. Photodegradation of clothianidin under simulated California rice field conditions.

    Science.gov (United States)

    Mulligan, Rebecca A; Redman, Zachary C; Keener, Megan R; Ball, David B; Tjeerdema, Ronald S

    2016-07-01

    Photodegradation can be a major route of dissipation for pesticides applied to shallow rice field water, leading to diminished persistence and reducing the risk of offsite transport. The objective of this study was to characterize the aqueous-phase photodegradation of clothianidin under simulated California rice field conditions. Photodegradation of clothianidin was characterized in deionized, Sacramento River and rice field water samples. Pseudo-first-order rate constants and DT50 values in rice field water (mean k = 0.0158 min(-1) ; mean DT50 = 18.0 equivalent days) were significantly slower than in deionized water (k = 0.0167 min(-1) ; DT50 = 14.7 equivalent days) and river water (k = 0.0146 min(-1) ; DT50 = 16.6 equivalent days) samples. Quantum yield ϕc values demonstrate that approximately 1 and 0.5% of the light energy absorbed results in photochemical transformation in pure and field water respectively. Concentrations of the photodegradation product thiazolymethylurea in aqueous photolysis samples were determined using liquid chromatography-tandem mass spectrometry and accounted for ≤17% in deionized water and ≤8% in natural water. Photodegradation rates of clothianidin in flooded rice fields will be controlled by turbidity and light attenuation. Aqueous-phase photodegradation may reduce the risk of offsite transport of clothianidin from flooded rice fields (via drainage) and mitigate exposure to non-target organisms. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  7. Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice

    Science.gov (United States)

    Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E.; Qiang, Sheng

    2015-01-01

    Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China. PMID:26012494

  8. Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice.

    Science.gov (United States)

    Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E; Qiang, Sheng

    2015-05-27

    Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China.

  9. Modelagem da emissão de folhas em arroz cultivado e em arroz-vermelho Modeling leaf appearance in cultivated rice and red rice

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    2008-05-01

    Full Text Available O objetivo deste trabalho foi simular o aparecimento de folhas em genótipos de arroz cultivados e em biótipos de arroz-vermelho por meio da adaptação do modelo de Wang e Engel, modificado por Streck et al. Dois experimentos foram conduzidos em Santa Maria, RS, em 2004/2005 e 2005/2006. Foram utilizadas as cultivares IRGA 417 e EEA 406, um híbrido e dois biótipos de arroz-vermelho. O modelo de aparecimento de folhas foi ajustado para os genótipos usando-se dados de estágio de Haun (HS, de cinco épocas de semeadura, em 2004/2005, e a avaliação do modelo foi feita com dados de HS medidos em três épocas de semeadura, em 2005/2006. Realizou-se também um experimento numérico utilizando-se dados de temperatura de 2003/2004 e de 2006/2007, e comparou-se o HS simulado dos genótipos cultivados em relação aos biótipos de arroz-vermelho. O modelo apresentou bom desempenho para simular o HS com raiz do quadrado médio do erro geralmente menor do que uma folha. A emissão de folhas na haste principal foi maior nos genótipos modernos - IRGA 417 e híbrido - do que no genótipo tradicional EEA 406. A emissão de folhas é diferente em distintos biótipos de arroz-vermelho.The objective of this work was to simulate leaf appearance in cultivated rice genotypes and in red rice biotypes, by adapting the Wang and Engel model modified by Streck et al. Two experiments were conducted in Santa Maria, Rio Grande do Sul State, Brazil, during 2004/2005 and 2005/2006 growing seasons. Cultivars IRGA 417 and EEA 406, one hybrid, and two red rice biotypes were used. The leaf appearance model was adjusted, using Haun Stage (HS data from five sowing dates of 2004/2005 growing season, and the model evaluation was performed using HS data from three sowing dates of 2005/2006 growing season. A numerical experiment was also carried out using temperature data occurred during 2003/2004 and 2006/2007 growing seasons, and simulated HS of the cultivated rice genotypes

  10. Influence of Crop Nutrition on Grain Yield, Seed Quality and Water Productivity under Two Rice Cultivation Systems

    Directory of Open Access Journals (Sweden)

    Y.V. SINGH

    2013-03-01

    Full Text Available The system of rice intensification (SRI is reported to have advantages like lower seed requirement, less pest attack, shorter crop duration, higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation. With this background, SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute, New Delhi, India during two wet seasons (2009–2011. In the experiment laid out in a factorial randomized block design, two methods of rice cultivation [conventional transplanting (CT and SRI] and two rice varieties (Pusa Basmati 1 and Pusa 44 were used under seven crop nutrition treatments, viz. T1, 120 kg/hm2 N, 26.2 kg/hm2 P and 33 kg/hm2 K; T2, 20 t/hm2 farmyard manure (FYM; T3, 10 t/hm2 FYM + 60 kg/hm2 N; T4, 5 t/hm2 FYM + 90 kg/hm2 N; T5, 5 t/hm2 FYM + 60 kg/hm2 N + 1.5 kg/hm2 blue green algae (BGA; T6, 5 t/hm2 FYM + 60 kg/hm2 N + 1.0 t/hm2 Azolla, and T7, N0P0K0 (control, no NPK application to study the effect on seed quality, yield and water use. In SRI, soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water (2–3 cm was maintained during the reproductive phase of rice, however, in CT, standing water was maintained in crop growing season. Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI. Seed quality was superior in SRI as compared to CT. Integrated nutrient management (INM resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties. Grain yield attributes such as number of effective tillers per hill, panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone. Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer. The grain yield

  11. Study of the influence of stable cadmium on the transfer of zinc-65 in an ecosystem irrigated by submersion (irrigated rice field)

    International Nuclear Information System (INIS)

    Myttenaere, C.; Merlini, M.; Dabin, P.; Mousny, J.M.; Pozzi, G.; Bittel, R.

    1975-01-01

    Irrigation water contains varying amounts of stable cadmium from industrial disposal. The presence of this element is capable of modifying the transfer of and affecting the mechanisms of absorption of zinc-65, a radionuclide which is discharged into water by nuclear power stations. This type of interaction between a nuclear contaminant and a conventional contaminant was studied in a rice-field irrigated by submersion. This ecosystem was reproduced under controlled 'mini-rice-field' conditions: the water was enriched in stable zinc (1 ppm) and in stable cadmium (2,5x10 -3 ; 50x10 -3 ppm) so as to reproduce the actual conditions; the stable zinc was traced by means of zinc-65. Fish (20 Carassius auratus L.) were introduced into each compartment of the ecosystem. Samples of irrigation water and surface water were taken during cultivation, and at the end of cultivation the content of stable zinc, radioactive zinc and stable cadmium was determined in each component of the ecosystem. The results show the important influence of a conventional contaminant on the transfer of a radionuclide and justify the use of the term 'associate contaminant' to describe it. (author)

  12. African rice (Oryza glaberrima) cultivation in the Togo Hills: ecological and socio-cultural cues in farmer seed selection and development

    NARCIS (Netherlands)

    Teeken, B.W.E.

    2015-01-01

    Abstract

    Teeken B (2015). African rice (Oryza glaberrima) cultivation in the Togo Hills: ecological and socio-cultural cues in farmer seed selection and development. PhD thesis, Wageningen University, The Netherlands, 306 pp. The low adoption rates of

  13. Fungicide sensitivity in the wild rice pathogen Bipolaris oryzae

    Science.gov (United States)

    In recent years the occurrence of fungal brown spot, caused by Bipolaris oryzae has increased in cultivated wild rice (Zizania palustris) paddies in spite of the use of fungicides. To implement an efficient integrated disease management system, we are exploring whether field isolates have developed ...

  14. Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 6 - Breeding in empty conditions of rice fields in South-Eastern Brazil

    OpenAIRE

    Forattini,Oswaldo Paulo; Kakitani,Iná; Massad,Eduardo; Marucci,Daniel

    1994-01-01

    Studies on culicid breeding in empty rice fields were carried out during the cultivation cycle from May to November 1993. This period corresponded to stages 1 and 2, when empty conditions prevailed. Breeding occurred in stage 1 and the first part of stage 2, corresponding respectively to fallow uncultivated and ploughing situations. No breeding was found to take place during the second part of stage 2 when transient floods and harrowing occurred. The predominant species were Aedes scapularis,...

  15. Abiotic partitioning of clothianidin under simulated rice field conditions.

    Science.gov (United States)

    Mulligan, Rebecca A; Parikh, Sanjai J; Tjeerdema, Ronald S

    2015-10-01

    Clothianidin is registered for pre- and post-flood application in Californian rice fields for control of the rice seed midge, Cricotopus sylvestris, and the rice water weevil, Lissorhoptrus oryzophilus. The objective was to characterize air-water and soil-water partitioning of clothianidin under simulated Californian rice field conditions. Clothianidin was confirmed to be non-volatile (from water) via the gas purge method, as no loss from the aqueous phase was observed at 22 and 37 °C; an upper-limit KH value was calculated at 2.9 × 10(-11) Pa m(3) mol(-1) (20 °C). Soil-water partitioning was determined by the batch equilibrium method using four soils collected from rice fields in the Sacramento Valley, and sorption affinity (Kd ), sorbent capacity, desorption and organic-carbon-normalized distribution (Koc ) were determined. Values for pH, cation exchange capacity and organic matter content ranged from 4.5 to 6.6, from 5.9 to 37.9 and from 1.25 to 1.97% respectively. The log Koc values (22 and 37 °C) ranged from 2.6 to 2.7, while sorption capacity was low at 22 °C and decreased further at 37 °C. Hysteresis was observed in soils at both temperatures, suggesting that bound residues do not readily desorb. Soil-water and air-water partitioning will not significantly reduce offsite transport of clothianidin from flooded rice fields via drainage. © 2014 Society of Chemical Industry.

  16. Rice field for the treatment of pond aquaculture effluents | Wang ...

    African Journals Online (AJOL)

    We conducted an experiment to evaluate the efficiency of rice fields in treating pond aquaculture effluent and its responses to different fertilizer treatments. Four treatments was considered in the experiment: no rice planted as the control (CT); rice planted and no fertilizer input (RE); rice planted and a rate of approximately ...

  17. Transfer of radioactive and chemical pollutants into irrigated rice fields

    International Nuclear Information System (INIS)

    Myttenaere, C.; Mousny, J.-M.; Dabin, P.; Bittel, R.

    1975-01-01

    In a general study on the consequences of radioactive and chemical releases in continental waters, flooded rice fields must be considered as a very important ecosystem due to the very large quantities of water used. In order to approach as much as possible to the natural conditions (irrigated rice fields of Northern Italy) ''mini-rice fields'' were built and local practices were respected. The behavior of activation and fission products ( 137 Cs, 60 Co, 65 Zn, 51 Cr...) and heavy metals pollutants (Cd, Cr, Sn) was studied and the transfer from water to soil and plant was followed. Concentration factors were calculated for the different organs of the plant and the impact of rice ingested to the dose delivered to man was evaluated [fr

  18. Weed populations and their buried seeds in rice fields of the MUDA area

    International Nuclear Information System (INIS)

    Ismail Sahid; Noor Faezah Zainuddin; Ho Nai Kin

    2002-01-01

    A total of 25 weed species belonging to 15 families were found in rice fields near Kampung Tandop, in the Muda Irrigation Scheme, Kedah, Malaysia. The dominant weeds in dry-seeded rice were Utricularia aurea Lour., Fimbristylis miliacea (L.) vahl., Echinochloa crusgalli (L.) Beauv., Monochoria vaginalis (Burm. Q Presl. and Najas graminea (Del.) Redl. In wet-seeded rice, the dominant species were N. graminea, Lemna minor L., Sphenoclea zeylanica Gaertn., U. aured, and Sagittaria guayanensis H. B. K., while in volunteer seedling rice fields, the dominant species were Echinochloa colonum (L.) Link., Fimbristylis alboviridis C. B. Clarke, E miliacea, Cyperus babakan Steud. and Fuirena umbellata Rottb. Dry-seeded rice fields contained the highest number of weed seeds (930 910/m 2 in the top 15 cm of soil); volunteer seedling rice fields contained 793.162/m 2 and wet-seeded rice fields 712 228/m 2 . In general, the seed numbers declined with increasing soil depth. At 1015 cm depth, seeds of U aurea and S. zeylanica were the most abundant in dry and wet-seeded rice fields, whilst seeds of Scirpusjuncoides Roxb. and E miliacea were most abundant in volunteer seedling fields. (Author)

  19. Distribution, genetic diversity and potential spatiotemporal scale of alien gene flow in crop wild relatives of rice (Oryza spp.) in Colombia.

    Science.gov (United States)

    Thomas, Evert; Tovar, Eduardo; Villafañe, Carolina; Bocanegra, José Leonardo; Moreno, Rodrigo

    2017-12-01

    Crop wild relatives (CWRs) of rice hold important traits that can contribute to enhancing the ability of cultivated rice (Oryza sativa and O. glaberrima) to produce higher yields, cope with the effects of climate change, and resist attacks of pests and diseases, among others. However, the genetic resources of these species remain dramatically understudied, putting at risk their future availability from in situ and ex situ sources. Here we assess the distribution of genetic diversity of the four rice CWRs known to occur in Colombia (O. glumaepatula, O. alta, O. grandiglumis, and O. latifolia). Furthermore, we estimated the degree of overlap between areas with suitable habitat for cultivated and wild rice, both under current and predicted future climate conditions to assess the potential spatiotemporal scale of potential gene flow from GM rice to its CWRs. Our findings suggest that part of the observed genetic diversity and structure, at least of the most exhaustively sampled species, may be explained by their glacial and post-glacial range dynamics. Furthermore, in assessing the expected impact of climate change and the potential spatiotemporal scale of gene flow between populations of CWRs and GM rice we find significant overlap between present and future suitable areas for cultivated rice and its four CWRs. Climate change is expected to have relatively limited negative effects on the rice CWRs, with three species showing opportunities to expand their distribution ranges in the future. Given (i) the sparse presence of CWR populations in protected areas (ii) the strong suitability overlap between cultivated rice and its four CWRs; and (iii) the complexity of managing and regulating areas to prevent alien gene flow, the first priority should be to establish representative ex situ collections for all CWR species, which currently do not exist. In the absence of studies under field conditions on the scale and extent of gene flow between cultivated rice and its Colombian

  20. An Investigation of Factors Affecting the Management of Risk for the Rice Cultivating Women in Sari Town with LISREL Application

    Directory of Open Access Journals (Sweden)

    M. charmchian Langerodi

    2016-03-01

    . To determine the validity of the questionnaire, copies were distributed to experts in the field and their comments were recorded and relevant corrections were made. Corrected content validity was determined by experts at the Agricultural Organization of Mazandaran province, then reliability of the questionnaire was assessed by random completion of 30 questionnaires by women rice farmers in Qaem Shahr by interview and survey. Cronbach’s alpha and ordinal theta were 0.84 and 0.89, respectively. The questionnaire contained questions about age, work experience, area of owned land, extent of financial difficulty related to rice farming, and educational level of the women rice farmers. The questionnaire contained questions about risk management approaches (17 questions, sources of information for women rice farmers in Sari (12 questions and sources for borrowing funds (7 questions. The Likert scale was: none (0, very low (1, low (2, moderate (3, high (4, and very high (5. Results and Discussion: The average age range of women in the study was 46.68 years and their relative work experience was 26.17 years. The average financial difficulty for the women was high. The woman rice farmers were most likely to obtain loans from friends and neighbors and also to obtain financing from winning lottery. There was a significant positive relationship between information resources, borrowing resources, extent of financial difficulty, rice cultivation experience, and educational level with risk management methods. Tabatabaee et al. (30 stated that the extent of borrowing affected risk management. Tiraee (31 pointed to agricultural experience affecting risk management. Monfared (21, Torkamani and Ezatabadi (33 and Garavandi and Alibige (10 believe that the level of education affects risk management,which is consistent with the results of this study. Structural equation modeling showed that information sources influenced the use of risk management methods.Structural equation modeling

  1. Life cycle GHG evaluation of organic rice production in northern Thailand.

    Science.gov (United States)

    Yodkhum, Sanwasan; Gheewala, Shabbir H; Sampattagul, Sate

    2017-07-01

    Greenhouse gas (GHG) emission is one of the serious international environmental issues that can lead to severe damages such as climate change, sea level rise, emerging disease and many other impacts. Rice cultivation is associated with emissions of potent GHGs such as methane and nitrous oxide. Thai rice has been massively exported worldwide however the markets are becoming more competitive than ever since the green market has been hugely promoted. In order to maintain the same level or enhance of competitiveness, Thai rice needs to be considered for environmentally conscious products to meet the international environmental standards. Therefore, it is necessary to evaluate the greenhouse gas emissions throughout the life cycle of rice production in order to identify the major emission sources and possible reduction strategies. In this research, the rice variety considered is Khao Dawk Mali 105 (KDML 105) cultivated by organic practices. The data sources were Don-Chiang Organic Agricultural Cooperative (DCOAC), Mae-teang district, Chiang Mai province, Thailand and the Office of Agricultural Economics (OAE) of Thailand with onsite records and interviews of farmers in 2013. The GHG emissions were calculated from cradle-to-farm by using the Life Cycle Assessment (LCA) approach and the 2006 IPCC Guideline for National Greenhouse Gas Inventories. The functional unit is defined as 1 kg of paddy rice at farm gate. Results showed that the total GHG emissions of organic rice production were 0.58 kg CO 2 -eq per kg of paddy rice. The major source of GHG emission was from the field emissions accounting for 0.48 kg CO 2 -eq per kg of paddy rice, about 83% of total, followed by land preparation, harvesting and other stages (planting, cultivation and transport of raw materials) were 9, 5 and 3% of total, respectively. The comparative results clearly showed that the GHG emissions of organic paddy rice were considerably lower than conventional rice production due to the

  2. Rice cultivation in the farming systems of Sukumaland, Tanzania : a quest for sustainable production under structural adjustment programmes

    OpenAIRE

    Meertens, H.C.C.

    1999-01-01

    This thesis investigates options for sustainable rice cultivation and general agricultural development in the Mwanza and Shinyanga regions in northwestern Tanzania, often called Sukumaland due to the predominance of Wasukuma people. Generally Sukumaland has a semi-arid climate; agriculture is constrained by unreliable and low rainfall. In the past fifty years the population density has doubled in most parts. This has triggered several changes in farming systems. One important change ...

  3. Study on residues of 14C-Fenitrothion in a model rice-fish ecosystem and in a field rice-fish ecosystem

    International Nuclear Information System (INIS)

    Zhang Zhongliang; Wang Huaxin; Guo Dazhi; Chen Zhiyu; Wu Suchueng

    1993-01-01

    Residues of 14 C-fenitrothion in a model rice-fish ecosystem and field rice-fish ecosystem were studied. When equal amounts of the pesticide were applied, the extractable residues in brown rice (equivalent to 34.3±1.9 μg/kg fenitrothion) and rice stems and leaves (20.9±1.5 μg/kg) of the model rice-fish ecosystem were 10-15 times higher than that of the field rice-fish ecosystem (4.48±0.13 μg/kg and 1.27±0.34 μg/kg respectively). Residues in upper part of the soil (6.50±0.1--8.10±0.2 μg/kg) and lower part of the soil (1.30±0.1--1.50±0.1 μg/kg) of the model rice-fish ecosystem were 10-40 times higher than that of the field rice-fish ecosystem (0.17±0.01 μg/kg). The extractable residues in paddy water of the model ecosystem (0.30 ± 0.01 μg/kg) were similar to that of the field ecosystem (0.20±0.02 μg/kg). When the fenitrothion was sprayed on the rice plants, residues in brown rice, fish body, soil and paddy water were lower than those when the pesticide was spread on the surface of the soil. (author). 4 refs, 2 tabs

  4. Sustainable gasification–biochar systems? A case-study of rice-husk gasification in Cambodia, Part II: Field trial results, carbon abatement, economic assessment and conclusions

    International Nuclear Information System (INIS)

    Shackley, Simon; Carter, Sarah; Knowles, Tony; Middelink, Erik; Haefele, Stephan; Haszeldine, Stuart

    2012-01-01

    In part I we described the gasification technology and characterised the physio-chemical properties and environmental impacts of the rice husk char (RHC) by-product. In part II we present summary results from field trials using the RHC, and provide an estimate of the carbon abatement and economic evaluation of the system. Statistically significant yield increases are demonstrated for RHC addition in irrigated rice cultivation (33% increase in paddy rice yield for a 41.5 t (dry weight) RHC application per hectare). The carbon abatement from the RHC addition is approximately 0.42 t CO 2 t −1 rice husk; including energy generation from gasification this increases to ca. 0.86 tCO 2 t −1 . Assuming a carbon value of $5 t CO 2 t −1 , and agronomic value of $3 t −1 RHC based on the field trials, the economic value of the RHC varies from $9 t −1 (including only recalcitrant carbon) to $15 t −1 (including avoided emissions from energy production). We summarise results from parts I and II, concluding that the gasification–biochar system meets many of the criteria of sustainability, but requires better waste water management and more field trials to demonstrate repeatable agronomic efficacy of RHC application. - Highlights: ► Field trials show statistically significant rice yield increases using rice husk char (RHC). ► Carbon abatement of 0.42 t CO 2 t −1 rice husk from RHC production. ► Bioenergy generation via gasification gives carbon abatement of 0.44 t CO 2 t −1 husk. ► Total carbon abatement is therefore ca. 0.86 t CO 2 t −1 husk. ► Agronomic value from trials is $3 t −1 char; assuming $5 CO 2 t −1 , the total value of RHC is $9–$15 t −1 .

  5. Succession of methanogenic archaea in rice straw incorporated into a Japanese rice field: estimation by PCR-DGGE and sequence analyses

    Directory of Open Access Journals (Sweden)

    Atsuo Sugano

    2005-01-01

    Full Text Available The succession and phylogenetic profiles of methanogenic archaeal communities associated with rice straw decomposition in rice-field soil were studied by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE analysis followed by 16S rDNA sequencing. Nylon bags containing either leaf sheaths or blades were buried in the plowed layer of a Japanese rice field under drained conditions during the off-crop season and under flooded conditions after transplanting. In addition, rice straw samples that had been buried in the rice field under drained conditions during the off-crop season were temporarily removed during spring plowing and then re-buried in the same rice field under flooded conditions at transplanting. Populations of methanogenic archaea were examined by amplification of the 16S rRNA genes in the DNA extracted from the rice straw samples. No PCR product was produced for samples of leaf sheath or blade prior to burial or after burial under drained conditions, indicating that the methanogen population was very small during decomposition of rice straw under oxic conditions. Many common bands were observed in rice straw samples of leaf sheath and blade during decomposition of rice straw under flooded conditions. Cluster analysis based on DGGE patterns divided methanogenic archaeal communities into two groups before and after the mid-season drainage. Sequence analysis of DGGE bands that were commonly present were closely related to Methanomicrobiales and Rice cluster I. Methanomicrobiales, Rice cluster I and Methanosarcinales were major members before the mid-season drainage, whereas the DGGE bands that characterized methanogenic archaeal communities after the mid-season drainage were closely related to Methanomicrobiales. These results indicate that mid-season drainage affected the methanogenic archaeal communities irrespective of their location on rice straw (sheath and blade and the previous history of decomposition

  6. Azolla planting reduces methane emission and nitrogen fertilizer application in double rice cropping system in southern China

    DEFF Research Database (Denmark)

    Xu, Heshui; Zhu, Bo; Liu, Jingna

    2017-01-01

    Rice paddies are a major source of methane. How to reduce the methane emission in the paddy field without decreasing the yield has become a major concern of scientists, environmental groups, and agricultural policymakers worldwide. Azolla, used as a dual crop in rice cultivation, has multiple agr...

  7. Rapid assessment of rice seed availability for wildlife in harvested fields

    Science.gov (United States)

    Halstead, B.J.; Miller, M.R.; Casazza, Michael L.; Coates, P.S.; Farinha, M.A.; Benjamin, Gustafson K.; Yee, J.L.; Fleskes, J.P.

    2011-01-01

    Rice seed remaining in commercial fields after harvest (waste rice) is a critical food resource for wintering waterfowl in rice-growing regions of North America. Accurate and precise estimates of the seed mass density of waste rice are essential for planning waterfowl wintering habitat extents and management. In the Sacramento Valley of California, USA, the existing method for obtaining estimates of availability of waste rice in harvested fields produces relatively precise estimates, but the labor-, time-, and machineryintensive process is not practical for routine assessments needed to examine long-term trends in waste rice availability. We tested several experimental methods designed to rapidly derive estimates that would not be burdened with disadvantages of the existing method. We first conducted a simulation study of the efficiency of each method and then conducted field tests. For each approach, methods did not vary in root mean squared error, although some methods did exhibit bias for both simulations and field tests. Methods also varied substantially in the time to conduct each sample and in the number of samples required to detect a standard trend. Overall, modified line-intercept methods performed well for estimating the density of rice seeds. Waste rice in the straw, although not measured directly, can be accounted for by a positive relationship with density of rice on the ground. Rapid assessment of food availability is a useful tool to help waterfowl managers establish and implement wetland restoration and agricultural habitat-enhancement goals for wintering waterfowl. ?? 2011 The Wildlife Society.

  8. Spot-5 multispectral image for 60-75 days of rice mapping

    International Nuclear Information System (INIS)

    Ramli, Mohd Amiruddin; Shariff, Abdul Rashid Mohamed; Bejo, Siti Khairunniza

    2014-01-01

    The objective of this study is to investigate the potential application of Spot-5 multispectral satellite data in monitoring rice cultivation areas in IADA (Integrated Agriculture Development Area) located at Kerian District, Perak Malaysia. Information of the rice cultivation areas is a global economic and environmental significance. Multi-spectral images acquired at high spatial resolution are an important tool, especially in agricultural applications. This paper addresses the relationship between normalize difference vegetation index (NDVI) and ancillary data acquired from Farmers Organization Authority (PPK) for 217 farmer's field in IADA Kerian. The results indicated that NDVI range 0.62 – 0.75 has a strong positive relationship with the ground survey area estimation with (r = 0.85; p <0.01) (r 2 = 0.722). The r 2 value of 0.722 indicated a statistically significant linear relationship between the rice area estimate using NDVI range 0.62 – 0.75 and on the ground surveyed data for 217 farmers' fields. The equation of unstandardized distribution can be described as Ŷ=0.0197+0.852x. The equation for standardized regression formula for this distribution is Ŷ= 0.850x. Thus, the results indicate that 60-75 days of rice area can be estimated from the following equation Ŷ=0.197+0.852x, where Ŷ is the predicted rice area and x is area calculated using NDVI range 0.62-0.75 in IADA Kerian Perak Malaysia. The results appear promising and rice mapping operations using SPOT-5 multispectral image data can be foreseen

  9. Fate of Fertilizer-Derived N Applied to Enhance Rice Straw Decomposition in a Paddy Field during the Fallow Season under Cool Temperature Conditions

    Directory of Open Access Journals (Sweden)

    Fumiaki Takakai

    2018-03-01

    Full Text Available A field experiment was conducted to evaluate the fate of nitrogen (N derived from fertilizer (fertilizer-derived N applied to a paddy field after rice harvesting to promote rice straw decomposition during the fallow season, and to determine its effect on soil N fertility in northern Japan. A frame containing soil mixed with rice straw and 15N-labeled fertilizer (4.3 g N m−2 ammonium sulfate [AS] or lime-nitrogen [LN] was placed into a paddy field on a gray lowland soil during the fallow season (October–April, and the following rice-growing season (May–September. Before cultivation (April, the percentages of fertilizer-derived N in soil + straw were higher for LN (55–72% than for AS (41–63%. At the harvesting stage (September, the percentages of fertilizer-derived N in plants were significantly higher for LN (4.9–6.2% than for AS (3.4–5.3%, and the percentages in soil were also significantly higher for LN (42–61% than for AS (31–38%. This could be attributed to the nitrification inhibitory effect of LN and result in the suppression of N losses via leaching. Consequently, fertilizer-derived N could contribute to the maintenance of soil N fertility, and this effect could be higher for LN than AS.

  10. A Built-In Mechanism to Mitigate the Spread of Insect-Resistance and Herbicide-Tolerance Transgenes into Weedy Rice Populations

    Science.gov (United States)

    Liu, Chengyi; Li, Jingjing; Gao, Jianhua; Shen, Zhicheng; Lu, Bao-Rong; Lin, Chaoyang

    2012-01-01

    Background The major challenge of cultivating genetically modified (GM) rice (Oryza sativa) at the commercial scale is to prevent the spread of transgenes from GM cultivated rice to its coexisting weedy rice (O. sativa f. spontanea). The strategic development of GM rice with a built-in control mechanism can mitigate transgene spread in weedy rice populations. Methodology/Principal Findings An RNAi cassette suppressing the expression of the bentazon detoxifying enzyme CYP81A6 was constructed into the T-DNA which contained two tightly linked transgenes expressing the Bt insecticidal protein Cry1Ab and the glyphosate tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), respectively. GM rice plants developed from this T-DNA were resistant to lepidopteran pests and tolerant to glyphosate, but sensitive to bentazon. The application of bentazon of 2000 mg/L at the rate of 40 mL/m2, which is approximately the recommended dose for the field application to control common rice weeds, killed all F2 plants containing the transgenes generated from the Crop-weed hybrids between a GM rice line (CGH-13) and two weedy rice strains (PI-63 and PI-1401). Conclusions/Significance Weedy rice plants containing transgenes from GM rice through gene flow can be selectively killed by the spray of bentazon when a non-GM rice variety is cultivated alternately in a few-year interval. The built-in control mechanism in combination of cropping management is likely to mitigate the spread of transgenes into weedy rice populations. PMID:22359609

  11. A built-in mechanism to mitigate the spread of insect-resistance and herbicide-tolerance transgenes into weedy rice populations.

    Directory of Open Access Journals (Sweden)

    Chengyi Liu

    Full Text Available BACKGROUND: The major challenge of cultivating genetically modified (GM rice (Oryza sativa at the commercial scale is to prevent the spread of transgenes from GM cultivated rice to its coexisting weedy rice (O. sativa f. spontanea. The strategic development of GM rice with a built-in control mechanism can mitigate transgene spread in weedy rice populations. METHODOLOGY/PRINCIPAL FINDINGS: An RNAi cassette suppressing the expression of the bentazon detoxifying enzyme CYP81A6 was constructed into the T-DNA which contained two tightly linked transgenes expressing the Bt insecticidal protein Cry1Ab and the glyphosate tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS, respectively. GM rice plants developed from this T-DNA were resistant to lepidopteran pests and tolerant to glyphosate, but sensitive to bentazon. The application of bentazon of 2000 mg/L at the rate of 40 mL/m(2, which is approximately the recommended dose for the field application to control common rice weeds, killed all F(2 plants containing the transgenes generated from the Crop-weed hybrids between a GM rice line (CGH-13 and two weedy rice strains (PI-63 and PI-1401. CONCLUSIONS/SIGNIFICANCE: Weedy rice plants containing transgenes from GM rice through gene flow can be selectively killed by the spray of bentazon when a non-GM rice variety is cultivated alternately in a few-year interval. The built-in control mechanism in combination of cropping management is likely to mitigate the spread of transgenes into weedy rice populations.

  12. Studies on the Ecological Adaptability of Growing Rice with Floating Bed on the Dilute Biogas Slurry

    Science.gov (United States)

    Du, Qi; Cheng, Bowen; Liao, Zhiqi; Sun, Chengcheng

    2016-01-01

    This study aimed to explore the ecological adaptability and the possibility of growing rice with floating bed on the dilute biogas slurry. The results of the experiments show that the growth stage, rice plant height, and rice yield and quality were significantly affected by multiple dilutions; rice plants cultivated with 45 multiple dilutions had better ecological adaptability than others. In the 45 multiple dilutions' group, the yield of rice was 13.3 g/bucket (8 rice plants), milled rice rate was 63.1%, and the content of crude protein in the rice was 6.3%. The concentrations of heavy metals in the rice cultivated with 30 multiple dilutions' slurry, such as total lead, cadmium, mercury, chromium, and arsenic, were all below the national standard. The study shows that it is possible and safe to cultivate rice plants with no soil but diluted biogas slurry. In the experiments, the yield, milled rice rate, and crude protein of the rice cultivated with slurry were not as much as those of rice cultivated with regular way in soil. This study provides the basic theoretical support for the development of biogas projects and the potential achievement of organic farming in special agricultural facilities and circular economy. PMID:27882324

  13. Studies on the Ecological Adaptability of Growing Rice with Floating Bed on the Dilute Biogas Slurry.

    Science.gov (United States)

    Kang, Qun; Li, Rui; Du, Qi; Cheng, Bowen; Liao, Zhiqi; Sun, Chengcheng; Li, Zhaohua

    2016-01-01

    This study aimed to explore the ecological adaptability and the possibility of growing rice with floating bed on the dilute biogas slurry. The results of the experiments show that the growth stage, rice plant height, and rice yield and quality were significantly affected by multiple dilutions; rice plants cultivated with 45 multiple dilutions had better ecological adaptability than others. In the 45 multiple dilutions' group, the yield of rice was 13.3 g/bucket (8 rice plants), milled rice rate was 63.1%, and the content of crude protein in the rice was 6.3%. The concentrations of heavy metals in the rice cultivated with 30 multiple dilutions' slurry, such as total lead, cadmium, mercury, chromium, and arsenic, were all below the national standard. The study shows that it is possible and safe to cultivate rice plants with no soil but diluted biogas slurry. In the experiments, the yield, milled rice rate, and crude protein of the rice cultivated with slurry were not as much as those of rice cultivated with regular way in soil. This study provides the basic theoretical support for the development of biogas projects and the potential achievement of organic farming in special agricultural facilities and circular economy.

  14. Utilization of organic fertilizer to increase paddy growth and productivity using System of Rice Intensification (SRI method in saline soil

    Directory of Open Access Journals (Sweden)

    V . O . Subardja

    2016-01-01

    Full Text Available Soil salinity has negative effect on soil biodiversity as well as microbial activities. Hence, rice growth also effected by salinity. Application of organic fertilizer and adoption of System of Rice Intensification (SRI cultivation might improve the (biological soil properties and increase rice yield. The aim of this study was to evaluate the effect of two different rice cultivation methods namely conventional rice cultivation method and System of Rice Intensification (SRI rice cultivation method and two kinds organic fertilizer on improvement of soil biological properties and rice yield. In this study, a split plot experimental design was applied where rice cultivation method (conventional and SRI was the main plot and two kinds of organic fertilizer (market waste and rice straw was the sub plot. The treatments had four replicates. The results showed that SRI cultivation with market waste organic fertilizer could increase soil biological properties (population of microbe, fungi and soil respiration. The same treatment also increased rice growth and production. Combination of SRI and market waste organic fertilizer yielded the highest rice production (7.21 t/ha.

  15. Life cycle GHG analysis of rice straw bio-DME production and application in Thailand

    International Nuclear Information System (INIS)

    Silalertruksa, Thapat; Gheewala, Shabbir H.; Sagisaka, Masayuki; Yamaguchi, Katsunobu

    2013-01-01

    Highlights: • Life cycle GHG emissions of rice straw bio-DME production in Thailand are assessed. • Bio-DME replaces diesel in engines and supplements LPG for household application. • Rice straw bio-DME in both cases of substitution helps reduce GHG emissions. - Abstract: Thailand is one of the leading countries in rice production and export; an abundance of rice straw, therefore, is left in the field nowadays and is commonly burnt to facilitate quick planting of the next crop. The study assesses the life cycle greenhouse gas (GHG) emissions of using rice straw for bio-DME production in Thailand. The analysis is divided into two scenarios of rice straw bio-DME utilization i.e. used as automotive fuel for diesel engines and used as LPG supplement for household application. The results reveal that that utilization of rice straw for bio-DME in the two scenarios could help reduce GHG emissions by around 14–70% and 2–66%, respectively as compared to the diesel fuel and LPG substituted. In case rice straw is considered as a by-product of rice cultivation, the cultivation of rice straw will be the major source of GHG emission contributing around 50% of the total GHG emissions of rice straw bio-DME production. Several factors that can affect the GHG performance of rice straw bio-DME production are discussed along with measures to enhance GHG performance of rice straw bio-DME production and utilization

  16. Rice Combine Harvester: Its Effects to the Livelihood of Rice-Field Tenants in a Second Class Municipality

    Directory of Open Access Journals (Sweden)

    Jesrael Medrano

    2016-11-01

    Full Text Available Over the past few years, the advancement of modern technology has intensely overhauled society. People use and benefit from modern technology, and the tremendous opportunities it provides play a significant role in almost all aspects of human life. However, too much usage of this has its repercussions as well. Technological and mechanical change in agricultural sector and its impact on the work force have already become one of the neglected concerns of farmers in Amulung, a second class municipality of Cagayan. The newly introduced rice combine harvesters are already dominating the rice fields in Amulung during harvesting seasons. Thus, it replaces the conventional system of harvesting using human labor and sickles. This study is conducted to determine the effects of rice combine harvesters to the livelihood of rice field tenants in Amulung, Cagayan. Using purposive sampling through site selection approach and networking, 25 rice field tenants were selected as participants of this study. In–depth conversations and guided interview had served as the main instruments used by the researchers to gather the needed data. The results showed that rice combine harvesters cause unemployment and migration among the participants and degrade their sense of solidarity and camaraderie. As a result, the participants sought alternative activities which they can be paid off. Also, they engage themselves in livestock and poultry production, and even in informal sector economy just to cope with the prevalence of rice combine harvesters.

  17. Evaluation of the Effects of Iron Oxides on Soil Reducing Conditions and Methane Generation in Cambodian Wetland Rice Fields

    Science.gov (United States)

    Weaver, M.; Benner, S.; Fendorf, S.; Sampson, M.; Leng, M.

    2007-12-01

    Atmospheric concentrations of methane have been steadily increasing over the last 100 years, which has given rise to research of wetland rice fields, recently identified as a major anthropomorphic source of methane. Establishment of experimental soil pots, cultivating an aromatic early variety rice strain in the Kean Svay District of Cambodia, have recently been carried out to evaluate methods to minimize methane release by promoting redox buffering by iron oxides. In the first series of experiments, iron oxides were added to the soils and the rate of change in reducing conditions and methanogenesis onset was monitored. In the second series of experiments, plots are subject to periodic drying cycles to promote rejuvenation of buffering iron oxides. Initial results indicate a delay in the onset of methanogenesis, and overall methane generation, in plots where initial iron oxides concentrations are elevated.

  18. Chloroplast DNA polymorphism and evolutional relationships between Asian cultivated rice (Oryza sativa) and its wild relatives (O. rufipogon).

    Science.gov (United States)

    Li, W J; Zhang, B; Huang, G W; Kang, G P; Liang, M Z; Chen, L B

    2012-12-17

    We analyzed chloroplast DNA (cpDNA) polymorphism and phylogenic relationships between 6 typical indica rice, 4 japonica rice, 8 javanica rice, and 12 Asian common wild rice (Oryza rufipogon) strains collected from different latitudes in China by comparing polymorphism at 9 highly variable regions. One hundred and forty-four polymorphic bases were detected. The O. rufipogon samples had 117 polymorphic bases, showing rich genetic diversity. One hundred and thirty-one bases at 13 sites were identified with indica/japonica characteristics; they showed differences between the indica and japonica subspecies at these sites. The javanica strains and japonica shared similar bases at these 131 polymorphic sites, suggesting that javanica is closely related to japonica. On the basis of length analyses of the open reading frame (ORF)100 and (ORF)29-tRNA-Cys(GCA) (TrnC(GCA)) fragments, the O. rufipogon strains were classified into indica/japonica subgroups, which was consistent with the results of the phylogenic tree assay based on concatenated datasets. These results indicated that differences in indica and japonica also exist in the cpDNA genome of the O. rufipogon strains. However, these differences demonstrated a certain degree of primitiveness and incompleteness, as an O. rufipogon line may show different indica/ japonica attributes at different sites. Consequently, O. rufipogon cannot be simply classified into the indica/japonica types as O. sativa. Our data support the hypothesis that Asian cultivated rice, O. indica and O. japonica, separately evolved from Asian common wild rice (O. rufipogon) strains, which have different indica-japonica differentiation trends.

  19. All roads lead to weediness: Patterns of genomic divergence reveal extensive recurrent weedy rice origins from South Asian Oryza.

    Science.gov (United States)

    Huang, Zhongyun; Young, Nelson D; Reagon, Michael; Hyma, Katie E; Olsen, Kenneth M; Jia, Yulin; Caicedo, Ana L

    2017-06-01

    Weedy rice (Oryza spp.), a weedy relative of cultivated rice (O. sativa), infests and persists in cultivated rice fields worldwide. Many weedy rice populations have evolved similar adaptive traits, considered part of the 'agricultural weed syndrome', making this an ideal model to study the genetic basis of parallel evolution. Understanding parallel evolution hinges on accurate knowledge of the genetic background and origins of existing weedy rice groups. Using population structure analyses of South Asian and US weedy rice, we show that weeds in South Asia have highly heterogeneous genetic backgrounds, with ancestry contributions both from cultivated varieties (aus and indica) and wild rice. Moreover, the two main groups of weedy rice in the USA, which are also related to aus and indica cultivars, constitute a separate origin from that of Asian weeds. Weedy rice populations in South Asia largely converge on presence of red pericarps and awns and on ease of shattering. Genomewide divergence scans between weed groups from the USA and South Asia, and their crop relatives are enriched for loci involved in metabolic processes. Some candidate genes related to iconic weedy traits and competitiveness are highly divergent between some weed-crop pairs, but are not shared among all weed-crop comparisons. Our results show that weedy rice is an extreme example of recurrent evolution, and suggest that most populations are evolving their weedy traits through different genetic mechanisms. © 2017 John Wiley & Sons Ltd.

  20. Effects of field high temperature on grain yield and quality of a subtropical type japonica rice—Pon-Lai rice

    Directory of Open Access Journals (Sweden)

    Yi-Chien Wu

    2016-01-01

    Full Text Available Typical japonica type rice is sensitive to high temperature. Pon-Lai rice is a special japonica type with adaptation to the subtropical climate in Taiwan. Facing climate change, rising temperatures would damage the yield and quality of rice production. This research was conducted using Pon-Lai rice in the field of a subtropical climate. We conducted 2 experiments, including a year-round experiment and collection of samples from different districts for building different temperature conditions. We analyzed the correlation between rising temperature and rice yield or quality. In our results, the critical period of temperature effect is 0–15 days after heading (H15. The threshold of high temperature damage in yield and appearance quality was 25–27 °C. Grain weight decreased about 2–6%, while the temperature of H15 was raised 1 °C above the thresholds. Perfect grain ratio and chalky grain ratio decreased and increased, respectively, while the temperature of H15 was raised above the thresholds. However, the high temperature in H15 affected the physicochemical characteristics. In addition, we found positive correlation between grain length to width ratio and perfect grain ratio. Grain length to width ratio could be an index of temperature effects for grain quality. In our study, when the temperature was below 30 °C, a rising temperature of H15 could damage rice yield and appearance quality, and change grain shape. Our results could provide reference for dealing with the warming future in other temperate rice-cultivated countries.

  1. Agent-based modelling of shifting cultivation field patterns, Vietnam

    DEFF Research Database (Denmark)

    Jepsen, Martin Rudbeck; Leisz, S.; Rasmussen, K.

    2006-01-01

    Shifting cultivation in the Nghe An Province of Vietnam's Northern Mountain Region produces a characteristic land-cover pattern of small and larger fields. The pattern is the result of farmers cultivating either individually or in spatially clustered groups. Using spatially explicit agent...

  2. Genetic analysis of rice blast disease resistance genes using USDA rice mini-core and a mapping population

    Science.gov (United States)

    Rice blast disease caused by the fungal pathogen Magnaporthe oryzae (M. oryzae) is one of the most destructive diseases of cultivated rice, resulting in significant yield loss each year all over the world. Developing and utilizing blast resistant rice varieties is the most economical and effective m...

  3. The Dynamics Of Rice Field Conversion Into Settlement In The District Of Bandung

    Directory of Open Access Journals (Sweden)

    Ivan Chofyan

    2016-12-01

    Full Text Available Bandung District as one of the rice-producing areas in West Java has a strong interest in maintaining rice field. However, the land conversion of rice field in the Bandung District continues to occur with various factors. This study aims to identify the elements that make up the structure of the phenomenon and the linkages between these elements which lead to the conversion of rice fields and recommend some policy alternatives that are useful for efforts to control the conversion of rice field. In order to achieve the stated goals, this study uses system dynamics which is one method of thinking system that could see the various aspects of integral and structurally enable to explain the phenomenon of land conversion happens. On this study determines 4 scenarios consists of a basic scenario, rice field cropping intensity scenarios (RFCI, necessity standard of land settlement scenarios (NSLS, and food diversification scenarios (FD. The final result of this study states that the necessity standard of land settlement scenarios result in a decrease in the rate of land conversion is smaller and the rice stock inventory is more stable compared to other scenarios. Under these conditions, policies that support the above scenario should be established, namely the policy of land-saving settlement development and establishment of sustainable rice field.

  4. C and N accumulations in soil aggregates determine nitrous oxide emissions from cover crop treated rice paddy soils during fallow season

    International Nuclear Information System (INIS)

    Pramanik, Prabhat; Haque, Md. Mozammel; Kim, Sang Yoon; Kim, Pil Joo

    2014-01-01

    Combination of leguminous and non-leguminous plant residues are preferably applied in rice paddy soils to increase the rate of organic matter mineralization and to improve plant growth. However, organic matter addition facilitates methane (CH 4 ) emission from rice paddy soil. Mineralization of organic nitrogen (N) increases NO 3 –N concentrations in soil, which are precursors for the formation of nitrous oxide (N 2 O). However, N 2 O is a minor greenhouse gas emitted from submerged rice field and hence is not often considered during calculation of total global warming potential (GWP) during rice cultivation. The hypothesis of this study was that fluxes of N 2 O emissions might be changed after removal of flooded water from rice field and the effect of cover crops on N 2 O emissions in the fallow season might be interesting. However, the effects of N-rich plant residues on N 2 O emission rates in the fallow season and its effect on annual GWP were not studied before. In this experiment, combination of barley (non-leguminous) and hairy vetch (leguminous) biomasses were applied at 9 Mg ha −1 and 27 Mg ha −1 rates in rice paddy soil. Cover crop application significantly increased CH 4 emission flux while decreased N 2 O emissions during rice cultivation. The lowest N 2 O emission was observed in 27 Mg ha −1 cover crop treated plots. Cover crop applications increased N contents in soil aggregates especially in smaller aggregates (< 250 μm), and that proportionately increased the N 2 O emission potentials of these soil aggregates. Fluxes of N 2 O emissions in the fallow season were influenced by the N 2 O emission potentials of soil aggregates and followed opposite trends as those observed during rice cultivation. Therefore, it could be concluded that the doses of cover crop applications for rice cultivation should not be optimized considering only CH 4 , but N 2 O should also be considered especially for fallow season to calculate total GWP. - Highlights:

  5. Effect of seed treatment with static magnetic field (SMF) and low dose gamma radiation (GR) on grain yield of aerobic rice

    International Nuclear Information System (INIS)

    Kumar, Dinesh; Anand, Anjali; Singh, Bhupinder

    2014-01-01

    Aerobic rice cultivation is gaining popularity as it demands less water. However, poor germination of rice is an important issue in this situation. Seed pretreatment with static magnetic field (SMF) and gamma radiation (GR) at prescribed dose is known to influence the germination, seedling vigour and and yield of many crops. There is a possibility to improve the crop establishment under aerobic situation by physical seed treatment with static-magnetic field (SMF) and gamma radiation (GR) prior to sowing. Hence, a field experiment was conducted at the Indian Agricultural Research Institute, New Delhi during kharif 2012 and 2013 to study the effect of SMF and GR-treated seeds on growth and yield of aerobic rice. The five seed treatments were: SMF 50 mT for 2 hrs, SMF 100 mT for 2 hrs, GR 0.0025 kGy, GR 0.10 kGy and an untreated control. The experiment was laid out in a Randomized Block Design with four replications. Crop (variety 'Pusa Basmati-1121') was direct seeded on 25 th and 24 th June during 2012 and 2013, respectively at a spacing of 25 cm. Treatments GR 0.0025 kGy, SMF (50 mT) and SMF (100 mT) resulted in a significant improvement in grain yield of rice over control and GR dose (0.10 kGy) during both the years. Averaged across two years the grain yield increase by treating the rice seeds with GR 0.0025 kGy, SMF (50 mT) and SMF (100 mT) was 20.1, 17.6 and 14.5%, respectively over the control. Increase in GR dose (0.10 kGy ) was not effective in improving the yield, and was found to be similar to control. It is therefore concluded that treatment of rice seeds either with GR (0.0025 kGy) or SMF (50 mT) holds a great promise in increasing the grain yield of aerobic rice. (author)

  6. THE EFFECT OF RICE CULTIVARS ON METHANE EMISSION FROM IRRIGATED RICE FIELD

    Directory of Open Access Journals (Sweden)

    P. Setyanto

    2016-10-01

    Full Text Available Rice plants have been reported to affect methane (CH4 emission from rice fields. The objectives of this study were to determine the effect of rice cultivars on CH4 emission from flooded rice and to develop crop management strategies with low emitting rice cultivars while sustaining high yield. The four rice cultivars studied were Memberamo, Cisadane, IR64, and Way Apoburu. The CH4 emissions were determined in the wet season of 2001/2002 (November-February using an automated closed chamber technique in an irrigated field condition. Farmyard manure at the rate of 5 t ha-1 was given to the plots to ensure carbon was not limited. Root weight, root length, biomass, and number of tillers were determined at 17, 36, and 57 days after transplanting (DAT. The results showed that the mean CH4 emission was highest in the plot planted with Cisadane (94.8 kg CH4 ha-1, and the lowest with IR64 (37.7 kg CH4 ha-1. The plots treated with emberamo and Way Apoburu resulted an intermediate CH4 emission at the average of 61.1 and 58.9 kg CH4 ha-1, respectively. There was no significant difference in yield between the cultivars tested. The yield of Memberamo, Cisadane, IR64, and Way Apoburu were 5.882, 5.764, 5.873 and 6.065 t ha-1, respectively. Statistical analysis showed that there were no significant differences in the root weight and root length among cultivars. However, Cisadane gave the highest dry matter weight (222 g hill-1 at 57 DAT compared to the other cultivars (175-190 g hill-1. Plant tillers did not show significant differences between the cultivars. Regression analysis showed that CH4 flux was significantly related with root weight, root length, aboveground biomass, and number of plant tillers. This finding shows that the use of selected cultivars, such as IR64, can potentially lower CH4 emission without scarifying yield.

  7. Remotely Sensing Larval Population Dynamics of Rice Field Anophelines

    Science.gov (United States)

    Beck, Louisa R.; Dister, Sheri W.; Wood, Byron L.; Washino, Robert K.

    1997-01-01

    The primary objective of both studies was to determine if RS and GIS techniques could be used to distinguish between high and low larval-producing rice fields in California. Results of the first study suggested that early-season green-up and proximity to livestock pastures were positively correlated with high larval abundance. Based on the early-season spectral differences between high and low larval-producing fields, it appeared that canopy development and tillering influenced mosquito habitat quality. At that time, rice fields consisted of a mixture of plants and water, a combination that allowed An. freeborni females to lay eggs in partial sunlight, protected from both predators and wind. This established a population earlier in the season than in other, 'less-green' fields where tillering and plant emergence was too minimal for ovipositioning. The study also indicated the importance of the distance that a mosquito would have to fly in order to take a bloodmeal prior to ovipositing. These associations were fully explored in an expanded study two years later. The second study confirmed the positive relationship between early season canopy development and larval abundance, and also demonstrated the relationship between abundance and distance-to-pasture. The association between greenness (as measured using NDVI), distance-to-pasture, and abundance is illustrated. The second study also indicated the siginificance of the landscape context of rice fields for larval production. Fields that included opportunities for feeding and resting within the flight range of the mosquito had higher abundances than did fields that were in a homogeneous rice area.

  8. PRELIMINARY STUDIES FOR PRODUCING CRUDE LIPASE FROM TEMPE’S MOULD CULTIVATED IN RICE-HUSK-BASED SOLID MEDIA

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    Teuku Beuna Bardant

    2010-06-01

    Full Text Available The goal of these preliminary studies is to support Indonesian program for increasing palm oil added value through independent production technology based on Indonesian natural resources. Various palm oil derivatives could be synthesized enzymatically using lipase from microbes that available in Indonesia. Tempe's mould is available in abundance in Indonesia and had already been proved for producing lipase. This paper provides information about producing crude lipase from Tempe's mould cultivated in rice-husk-based solid media using palm oil as carbon source. Observed variables include solid media composition, optimum fermentation time, extraction and enriching process of crude lipase. The crude lipase was analyzed its hydrolysis activity on coconut oil and palm oil. The result of these preliminary studies shows that this production process is a simple and tough process and very potential to be developed.   Keywords: lipase, Tempe's mould, palm oil, solid fermentation, rice husk

  9. Managing flood prone ecosystem for rice production in Bihar plains

    International Nuclear Information System (INIS)

    Khan, A.R.; Singh, S.S.

    2002-06-01

    A large area of the eastern region especially Bihar (0.5 million hectare) faces flood submergence and/or drought every year which creates an unfavorable environment for crop production. In this ecosystem only flood prone rice is grown whose cultivation is entirely different than normal rice crop. Managing the flood prone ecosystem for rice production needs to evaluate the reasons and a comprehensive appropriate technology through research efforts for better rice production under such harsh ecology. An attempt was made to develop a suitable agronomic package for rice cultivation during and after flooding in flood prone plains of Bihar. (author)

  10. Modeling methane emission from rice paddies with various agricultural practices

    Science.gov (United States)

    Huang, Yao; Zhang, Wen; Zheng, Xunhua; Li, Jin; Yu, Yongqiang

    2004-04-01

    Several models have been developed over the past decade to estimate CH4 emission from rice paddies. However, few models have been validated against field measurements with various parameters of soil, climate and agricultural practice. Thus reliability of the model's performance remains questionable particularly when extrapolating the model from site microscale to regional scale. In this paper, modification to the original model focuses on the effect of water regime on CH4 production/emission and the CH4 transport via bubbles. The modified model, named as CH4MOD, was then validated against a total of 94 field observations. These observations covered main rice cultivation regions from northern (Beijing, 40°30'N, 116°25'E) to southern China (Guangzhou, 23°08'N, 113°20'E), and from eastern (Hangzhou, 30°19'N, 120°12'E) to southwestern (Tuzu, 29°40'N, 103°50'E) China. Both single rice and double rice cultivations are distributed in these regions with different irrigation patterns and various types of organic matter incorporation. The observed seasonal amount of CH4 emission ranged from 3.1 to 761.7 kg C ha-1 with an average of 199.4 ± 187.3 kg C ha-1. In consonance with the observations, model simulations resulted in an average value of 224.6 ± 187.0 kg C ha-1, ranging from 13.9 to 824.3 kg C ha-1. Comparison between the computed and the observed seasonal CH4 emission yielded a correlation coefficient r2 of 0.84 with a slope of 0.92 and an intercept of 41.1 (n = 94, p < 0.001). It was concluded that the CH4MOD can reasonably simulate CH4 emissions from irrigated rice fields with a minimal number of inputs and parameters.

  11. Rice Field Geochemistry and Hydrology: An Explanation for Why Groundwater Irrigated Fields in Bangladesh are Net Sinks of Arsenic from Groundwater

    Science.gov (United States)

    Neumann, Rebecca B.; St. Vincent, Allison P.; Roberts, Linda C.; Badruzzaman, A. Borhan M.; Ali, M. Ashraf; Harvey, Charles F.

    2011-01-01

    Irrigation of rice fields in Bangladesh with arsenic-contaminated groundwater transfers tens of cubic kilometers of water and thousands of tons of arsenic from aquifers to rice fields each year. Here we combine observations of infiltration patterns with measurements of porewater chemical composition from our field site in Munshiganj Bangladesh to characterize the mobility of arsenic in soils beneath rice fields. We find that very little arsenic delivered by irrigation returns to the aquifer, and that recharging water mobilizes little, if any, arsenic from rice field subsoils. Arsenic from irrigation water is deposited on surface soils and sequestered along flow paths that pass through bunds, the raised soil boundaries around fields. Additionally, timing of flow into bunds limits the transport of biologically available organic carbon from rice fields into the subsurface where it could stimulate reduction processes that mobilize arsenic from soils and sediments. Together, these results explain why groundwater irrigated rice fields act as net sinks of arsenic from groundwater. PMID:21332196

  12. Prompt Proxy Mapping of Flood Damaged Rice Fields Using MODIS-Derived Indices

    Directory of Open Access Journals (Sweden)

    Youngjoo Kwak

    2015-11-01

    Full Text Available Flood mapping, particularly hazard and risk mapping, is an imperative process and a fundamental part of emergency response and risk management. This paper aims to produce a flood risk proxy map of damaged rice fields over the whole of Bangladesh, where monsoon river floods are dominant and frequent, affecting over 80% of the total population. This proxy risk map was developed to meet the request of the government on a national level. This study represents a rapid, straightforward methodology for estimating rice-crop damage in flood areas of Bangladesh during the large flood from July to September 2007, despite the lack of primary data. We improved a water detection algorithm to achieve a better discrimination capacity to discern flood areas by using a modified land surface water index (MLSWI. Then, rice fields were estimated utilizing a hybrid rice field map from land-cover classification and MODIS-derived indices, such as the normalized difference vegetation index (NDVI and enhanced vegetation index (EVI. The results showed that the developed method is capable of providing instant, comprehensive, nationwide mapping of flood risks, such as rice field damage. The detected flood areas and damaged rice fields during the 2007 flood were verified by comparing them with the Advanced Land Observing Satellite (ALOS AVNIR-2 images (a 10 m spatial resolution and in situ field survey data with moderate agreement (K = 0.57.

  13. ANALYSIS ON THE DYNAMICS OF SPATIAL DISTRIBUTION PATTERN OF MIXED SPIDER POPULATION IN RICE FIELD

    Institute of Scientific and Technical Information of China (English)

    ZhiWang; Zhe-mingYuan; Da-xiangSong; Ming-shengZhu

    2004-01-01

    The results make it clear that there are total 11 families, 29 genera and 43 species of spiders in the rice field of Dong Fang Hong Farm. Among them, there are 8 families, 19 genera and 28 species in the early rice field, and 10 families, 27 genera and 36 species in the late rice field. The spatial distribution pattern of mixed spider populations in rice fields was different during different development stages of rice plant. During the prophase, metaphase and anaphase of early rice plant development, the spatial distribution pattern of mixed spider populations was aggregative, random and aggregative respectively. During the prophase, metaphase and anaphase of late rice plant development, the spatial distribution pattern was uniform, aggregative and uniform respectively.

  14. Diversity and population dynamics of pests and predators in irrigated rice fields with treated and untreated pesticide.

    Science.gov (United States)

    Rattanapun, W

    2012-01-01

    The monitoring of rice pests and their predators in pesticide untreated and treated rice fields was conducted at the southern of Thailand. Twenty-two species in 15 families and 6 orders of rice pests were sampled from untreated rice field. For treated rice field, 22 species in 14 families and 5 orders of rice pest were collected. Regardless of treatment type, dominant species and individual number of rice pest varied to physiological stage of rice. Lepidopteran pests had highest infestation during the vegetative stage of rice growth, while hemipteran pests composed of hopper species (Hemipetra: Auchenorrhyncha) and heteropteran species (Hemiptera: Heteroptera) were dominant groups during the reproductive stage and grain formation and ripening stage of rice growth. In contrast, dominant species of predator did not change throughout rice growing season. There were 35 species in 25 families and seven orders and 40 species in 29 families and seven orders of predators collected from untreated and treated rice field, respectively. Major predators of both rice fields were Micraspis discolor (Fabricius) (Coleoptera: Coccinellidae), Tetragnatha sp. (Araneae: Tetragnathidae) and Agriocnemis pygmaea Rambur (Odonata: Agrionidae). The population dynamic of predators were not related with rice pest population in both treatments. However, the fluctuation of population pattern of rice pests in the untreated treatment were more distinctly synchronized with their predators than that of the treated treatment. There were no significant differences in the total number of rice pest and predator between two treatments at vegetative and reproductive stages of rice growth. Untreated rice field had a higher population number of predator and a lower population number of rice pest than that of treated rice field during grain formation and ripening stages. These results indicated the ago-ecosystem balance in rice fields could be produced through minimal pesticide application, in order to allow

  15. Testing of Rice Stocks for Their Survival of Winter Cold

    Directory of Open Access Journals (Sweden)

    Hiroshi Ikehashi

    2018-03-01

    Full Text Available Rice cultivation is considered to be initiated by vegetative propagation of sprout from wild perennial stocks. To test whether any presently cultivated rice cultivar can survive the winter cold or not, rice stocks of several cultivars including indica and japonica types were placed in a shallow pool from October to April in 2015–2016 and 2016–2017. During the coldest period of the winter, the bases of the stocks were placed 5–6 cm below the surface of water, where temperatures ranged from 3 °C to 5 °C, while the surface was frozen for two or three times and covered with snow for a day. Only one cultivar, Nipponbare, a japonica type, survived the winter cold and regenerated sprouts in the end of April or early May. A possibility to develop perennial cultivation of rice or perennial hybrid rice is discussed.

  16. Diversity and activity of nitrogen fixing archaea and bacteria associated with micro-environments of wetland rice

    Science.gov (United States)

    Schmidt, Hannes; Woebken, Dagmar

    2017-04-01

    Wetland rice is one of the world's most important crop plants. The cultivation on waterlogged paddy soils is strongly limited by nitrogen (N), which is typically supplied by industrial fertilizers that are not only costly but also exhibit hazardous effects on the environment. It has been reported that "Biological Nitrogen Fixation" through N2-fixing bacteria and archaea (diazotrophs) can alleviate the N-shortage in rice cultivation, thus carrying out an important ecosystem function. However, our understanding of the diversity and in situ N2 fixation activity of diazotrophs in flooded rice fields is still rudimentary. Moreover, knowledge on the impact of biochemical gradients established by root activity (i.e. exudation, radial oxygen loss) on the functioning of N-fixing microorganisms in paddy soil ecosystems is limited. We aimed at studying underlying processes on biologically relevant scales. Greenhouse studies were performed to identify key factors that control rice-diazotroph association and related N2 fixation activities. Paddy soils of different geographical origin were cultivated with two commercially used genotypes of wetland rice. Samples were separated into bulk soil, rhizosphere soil, rhizoplane, and roots at flowering stage of rice plant development. These samples were subjected to functional assays and various molecular biological techniques in order to analyze the associated diazotroph communities. Based on Illumina amplicon sequencing of nifH genes and transcripts, we show that the diversity and potential activity of diazotroph communities varies according to micro-environments. We will comparatively discuss the influence of (a) the soil microbial "seed bank" and (b) plant genotype in shaping the respective microbiomes and selecting for potentially active diazotrophs. Actual N2 fixation activities of soil-genotype combinations and micro-environments will be shown on the basis of incubation assays using 15N2-containing atmospheres. Areas of potential

  17. Methane emission from wetland rice fields

    NARCIS (Netherlands)

    Denier van der Gon, H.A.C.

    1996-01-01


    Methane (CH 4 ) is an important greenhouse gas and plays a key role in tropospheric and stratospheric chemistry. Wetland rice fields are an important source of methane, accounting for approximately 20% of the global anthropogenic

  18. The competitiveness of domestic rice production in East Africa: A domestic resource cost approach in Uganda

    Directory of Open Access Journals (Sweden)

    Masao Kikuchi

    2016-03-01

    Full Text Available The rapid increase of rice imports in sub-Saharan Africa under the unstable situation in the world rice market during the 2000s has made it an important policy target for the countries in the region to increase self-sufficiency in rice in order to enhance food security. Whether domestic rice production can be competitive with imported rice is a serious question in East African countries that lie close, just across the Arabian Sea, to major rice exporting countries in South Asia. This study investigates the international competitiveness of domestic rice production in Uganda in terms of the domestic resource cost ratio. The results show that rainfed rice cultivation, which accounts for 95% of domestic rice production, does not have a comparative advantage with respect to rice imported from Pakistan, the largest supplier of imported rice to Uganda. However, the degree of non-competitiveness is not serious, and a high possibility exists for Uganda’s rainfed rice cultivation to become internationally competitive by improving yield levels by applying more modern inputs and enhancing labour productivity. Irrigated rice cultivation, though very limited in area, is competitive even under the present input-output structure when the cost of irrigation infrastructure is treated as a sunk cost. If the cost of installing irrigation infrastructure and its operation and maintenance is taken into account, the types of irrigation development that are economically feasible are not large-scale irrigation projects, but are small- and microscale projects for lowland rice cultivation and rain-water harvesting for upland rice cultivation.

  19. Statistical analysis of fallout radionuclides transfer to paddy-field rice

    International Nuclear Information System (INIS)

    Takahashi, T.; Morisawa, S.; Inoue, Y.

    1996-01-01

    Radionuclides released from nuclear facilities to atmosphere are transported through various pathways in biosphere and cause human exposure. Among these radionuclides transfer pathways, an ingestion of crops containing radionuclides is one of the dominant pathway for human exposure. For the safety assessment of nuclear facilities, it is important to understand the behavior of radionuclides in agricultural environment and to describe them in a mathematical model. In this paper, a statistical model is proposed for estimating the concentration of fallout radionuclides in paddy-field rice, the staple food for Japanese people. For describing behavior of fallout radionuclides in a paddy-field, a dynamic model and a statistical model have been proposed respectively. The model used in this study has been developed assuming that the amount of radionuclides transfer to brown rice (hulled rice) or polished rice through direct deposition of airborne radionuclides (the direct deposition pathway) and root uptake from a paddy soil (the root uptake pathway) are proportional to the deposition flux of radionuclides and concentration of radionuclides in paddy soil respectively. That is, the model has two independent variables; the deposition flux of radionuclides and the concentration of radionuclides in the paddy soil, and has single dependent variable; the concentration of radionuclides in brown rice or polished rice. The regression analysis is applied by using environmental monitoring data. Then the distribution of radionuclides between rice-bran (skin part of rice crop) and polished rice (core part) through both the direct deposition pathway and the root uptake pathway are evaluated by the model. (author)

  20. Signatures of adaptation in the weedy rice genome

    Science.gov (United States)

    Weedy rice is a common problem of by product of domestication that has evolved multiple times from cultivated and wild rice relatives. Here we use whole genome sequences to examine the origin and adaptation of the two major US weedy red rice strains, with a comparison to Chinese weedy red rice. We f...

  1. Rice production in relation to soil quality under different rice-based cropping systems

    Science.gov (United States)

    Tran Ba, Linh; Sleutel, Steven; Nguyen Van, Qui; Thi, Guong Vo; Le Van, Khoa; Cornelis, Wim

    2016-04-01

    Soil quality of shallow paddy soils may be improved by introducing upland crops and thus a more diverse crop cultivation pattern. Yet, the causal relationship between crop performance and enhanced soil traits in rice-upland crop rotations remains elusive. The objectives of this study were to (i) find correlations among soil properties under different rice-upland crop systems and link selected soil properties to rice growth and yield, (ii) present appropriate values of soil parameters for sustainable rice productivity in heavy clay soil, (iii) evaluate the effect of rotating rice with upland crops on rice yield and economic benefit in a long-term experiment. A rice-upland crop rotational field experiment in the Vietnamese Mekong delta was conducted for 10 years using a randomized complete block design with four treatments and four replications. Treatments were: (i) rice-rice-rice (control - conventional system as farmers' practice), (ii) rice-maize-rice, (iii) rice-mung bean-rice, and (iv) rice-mung bean-maize. Soil and plant sampling were performed after harvest of the rice crop at the end of the final winter-spring cropping season (i.e. year 10). Results show differences in rice growth and yield, and economic benefit as an effect of the crop rotation system. These differences were linked with changes in bulk density, soil porosity, soil aggregate stability index, soil penetration resistance, soil macro-porosity, soil organic carbon, acid hydrolysable soil C and soil nutrient elements, especially at soil depth of 20-30 cm. This is evidenced by the strong correlation (P < 0.01) between rice plant parameters, rice yield and soil properties such as bulk density, porosity, penetration resistance, soil organic carbon and Chydrolysable. It turned out that good rice root growth and rice yield corresponded to bulk density values lower than 1.3 Mg m-3, soil porosity higher than 50%, penetration resistance below 1.0 MPa, and soil organic carbon above 25 g kg-1. The optimal

  2. [Introduction of upland rice cultivars to eastern Keerqin sandy land and their biological characteristics].

    Science.gov (United States)

    Zeng, Dehui; Zhang, Chunxing; Wang, Guirong; Fan, Zhiping

    2004-10-01

    Developing water-saving rice cultivation is one important strategy for food security in China. This paper reported the experimental results of introducing six upland rice cultivars to eastern Keerqin sandy land. The field experiment results showed that under the condition of 60% water-saving, the yield of cultivars XH 95-13 and XH 95-13-6 was 10.2% and 5.5% higher than the control, respectively, while other four cultivars decreased by 6.7%-18.6%. Economically, all the cultivars except JP 121 had a higher income than the control, and the profitability of cultivars XH 95-13 and XH 95-13-6 reached 24.0% and 19.3%, respectively. The water productivity of all the six cultivars was over 0.566 kg x m(-3), increased by 59.89%-116.38%. Pot experiment showed that 12.1%-16.3% of soil moisture in 0-15 cm layer was beneficial to the growth of upland rice. In eastern Keerqin sandy land, effective tillers occurred before July 18. In brief, upland rice production could be extensively applicable in eastern Keerqin sandy land to gradually alternate the traditional lowland rice cultivation with continuous flooding, and save much underground water.

  3. Field trial of GABA-fortified rice plants and oral administration of milled rice in spontaneously hypertensive rats.

    Science.gov (United States)

    Kowaka, Emi; Shimajiri, Yasuka; Kawakami, Kouhei; Tongu, Miki; Akama, Kazuhito

    2015-06-01

    Hypertension is one of the most critical risk factors accompanying cardiovascular diseases. γ-Aminobutyric acid (GABA) is a non-protein amino acid that functions as a major neurotransmitter in mammals and also as a blood-pressure lowering agent. We previously produced GABA-fortified rice lines of a popular Japonica rice cultivar 'Koshihikari' by genetic manipulation of GABA shunt-related genes. In the study reported here, we grew these same novel rice lines in a field trial and administered the milled rice orally to rats. The yield parameters of the transgenic rice plants were almost unchanged compared to those of untransformed cv. 'Koshihikari' plants, while the rice grains of the transgenic plants contained a high GABA content (3.5 g GABA/kg brown rice; 0.75-0.85 GABA g/kg milled rice) in a greenhouse trial. Oral administration of a diet containing 2.5% GABA-fortified rice, with a daily intake for 8 weeks, had an approximately 20 mmHg anti-hypertensive effect in spontaneous hypertensive rats but not in normotensive Wistar-Kyoto rats. These results suggest that GABA-fortified rice may be applicable as a staple food to control or prevent hypertension.

  4. A comparison of spider communities in Bt and non-Bt rice fields.

    Science.gov (United States)

    Lee, Sue Yeon; Kim, Seung Tae; Jung, Jong Kook; Lee, Joon-Ho

    2014-06-01

    To assess the potential adverse effects of a Bt rice line (Japonica rice cultivar, Nakdong) expressing a synthetic cry1Ac1 gene, C7-1-9-1-B, which was highly active against all larval stages of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Crambidae), we investigated the community structure of spiders in Bt and non-Bt rice fields during the rice-growing season in 2007 and 2008 in Chungcheongnam-do, Korea. Spiders were surveyed with a sweep net and suction device. Suction sampling captured more spiders, measured in terms of species level and abundance, than sweeping. Araneidae and Thomisidae were captured more by sweeping, and certain species were captured only by sweeping. These findings show that both suction and sweep sampling methods should be used because these methods are most likely complementary. In total, 29 species in 23 genera and nine families were identified from the 4,937 spiders collected, and both Bt and non-Bt rice fields showed a typical Korean spider assemblage. The temporal patterns of spider species richness and spider abundance were very similar between Bt and non-Bt rice, although significant differences in species richness were observed on a few occasions. Overall, spider community structure, including diversity, the dominant species, and abundance did not differ between Bt and non-Bt rice. The results of the study indicated that the transgenic Cry1Ac rice lines tested in this study had no adverse effects on the spider community structure of the rice fields.

  5. Cultivation of Schizophyllum commune mushroom on different wood substrates

    Directory of Open Access Journals (Sweden)

    P.N. Dasanayaka

    2017-07-01

    Full Text Available Schizophyllum commune is an edible mushroom grown on wood under natural conditions. Present study focused on cultivation of S.commune on different wood substrates since it is not commercially cultivated. A pure culture of S. commune was obtained by growing a tissue of the mushroom on Potato Dextrose Agar (PDA medium. Spawns were produced by growing the mycelium on paddy grains. Mushroom was cultivated on sawdust of seven different wood substrates. The maximum yield was observed in sawdust of jackfruit (Artocarpusheterophyllus followed by sawdust of rambutan (Nepheliumlappaceum and country almond (Terminaliacatappa. A significant difference was not observed when mango (Mangiferaindica elephant apple (Dilleniaindica, tulip wood tree (Harpulliaarborea and thungfaa (Alstoniamacrophylla sawdust used as substrate. The lowest yield was observed in thungfaa (Alstoniamacrophylla sawdust. Effect of some additives on the yield was studied and significant difference in yield was observed when rice bran and used-tea leaves used as additives. Effect of rice bran on yield was studied using different ratios of sawdust to rice bran and the highest was observed in 2:1 ratio of sawdust to rice bran. The best incubating temperature for mycelial growth on the substrate was 350C. The composition of the mushroom on a dry weight basis was; 71.4% moisture, 23.35% crude protein and 6% ash. Tested wood species are promising substrates for cultivation of S.communeas cottage industry.

  6. Design, Fabrication and Performance Evaluation of an Inter-Row Cultivator for Sugarcane Fields

    Directory of Open Access Journals (Sweden)

    Yuttana Khaehanchanpong

    2017-09-01

    Full Text Available The aims of this research were to design and fabricate an inter-row cultivator for mounting on a medium-sized tractor (25.3 or 37.3 kW for sugarcane fields, and to assess the performance of the cultivator when harvesting is conducted either by hand or with a sugarcane harvester. Moreover, this study was also designed to assess the performance of the cultivator in mixing sugarcane residues in the field. The inter-row cultivator has a working width of 80 cm, a rotor shaft speed of 500 rpm, and a total weight of 518 kg. The cultivator comprises 18 European C-type blades attached to three disk holder flanges arranged in a spiral formation. Two notch-cutting discs were mounted on the front to cut and press the sugarcane leaves before they were chopped and mixed by the inter-row cultivator. The working performance test was conducted for different thicknesses of trash blankets while using the inter-row cultivator mounted on 25.3 kW- and 37.3 kW-size tractors. The effective field capacity for trash incorporation of the inter-row cultivator was 0.30 ha·h−1 when trash was left through harvesting by hand. On the other hand, effective field capacity was 0.31 ha·h−1 when a sugarcane harvester was used. Moreover, the field efficiency exceeded 90% in all tested fields, with greater soil inversion. The results also showed that the fuel consumption of both tractors was higher when harvesting by hand compared with harvesting using a harvester.

  7. Improvement of traditional local rice varieties through induced mutations using nuclear techniques

    International Nuclear Information System (INIS)

    Pham Van Ro; Do Huu At

    2001-01-01

    'Improvement of local rice varieties for high yield, resistance to disease and insect pests (brown plant hopper and rice blast) and export quality through induced mutations for the Mekong Delta' started in 1993. After six years, it showed effecting on the field in the MD as well as at the south of Vietnam. TNDB-100 manifest very wide adaptation and yield stable variety. THDB is suitable for deepwater rice region, coastal area, where rice cultivation effected by acid sulphate and salinity conditions. Both varieties are good example for the method. Thank to good Co-operation from extension center from provinces, hundred classes of extension were organized to recommend to the farmers. And thank to the strongly supporting from IAEA so that nearly 400,000 ha of TNDB-100 occupied at the south of Vietnam as well as nearly 15,000 ha of THDB grown in the coastal as well as rainfed lowland rice areas at the South of Vietnam. To continue the rice improvement by this technique, seeds of six traditional local varieties were exposed under different dose of gamma rays to create new mutants. At present day hundred improved breeding lines were selected, a dozen of uniform lines were isolated and entranced the yield trail as well as regional testing program. From these improved varieties would be selected to contribute to the rice cultivation at the south of Vietnam in the next years. (author)

  8. Improvement of traditional local rice varieties through induced mutations using nuclear techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pham Van Ro; Do Huu At [Cuu Long Delta Rice Research Institute (Viet Nam)

    2001-03-01

    'Improvement of local rice varieties for high yield, resistance to disease and insect pests (brown plant hopper and rice blast) and export quality through induced mutations for the Mekong Delta' started in 1993. After six years, it showed effecting on the field in the MD as well as at the south of Vietnam. TNDB-100 manifest very wide adaptation and yield stable variety. THDB is suitable for deepwater rice region, coastal area, where rice cultivation effected by acid sulphate and salinity conditions. Both varieties are good example for the method. Thank to good Co-operation from extension center from provinces, hundred classes of extension were organized to recommend to the farmers. And thank to the strongly supporting from IAEA so that nearly 400,000 ha of TNDB-100 occupied at the south of Vietnam as well as nearly 15,000 ha of THDB grown in the coastal as well as rainfed lowland rice areas at the South of Vietnam. To continue the rice improvement by this technique, seeds of six traditional local varieties were exposed under different dose of gamma rays to create new mutants. At present day hundred improved breeding lines were selected, a dozen of uniform lines were isolated and entranced the yield trail as well as regional testing program. From these improved varieties would be selected to contribute to the rice cultivation at the south of Vietnam in the next years. (author)

  9. C and N accumulations in soil aggregates determine nitrous oxide emissions from cover crop treated rice paddy soils during fallow season

    Energy Technology Data Exchange (ETDEWEB)

    Pramanik, Prabhat, E-mail: prabhat2003@gmail.com; Haque, Md. Mozammel; Kim, Sang Yoon; Kim, Pil Joo, E-mail: pjkim@gnu.ac.kr

    2014-08-15

    Combination of leguminous and non-leguminous plant residues are preferably applied in rice paddy soils to increase the rate of organic matter mineralization and to improve plant growth. However, organic matter addition facilitates methane (CH{sub 4}) emission from rice paddy soil. Mineralization of organic nitrogen (N) increases NO{sub 3}–N concentrations in soil, which are precursors for the formation of nitrous oxide (N{sub 2}O). However, N{sub 2}O is a minor greenhouse gas emitted from submerged rice field and hence is not often considered during calculation of total global warming potential (GWP) during rice cultivation. The hypothesis of this study was that fluxes of N{sub 2}O emissions might be changed after removal of flooded water from rice field and the effect of cover crops on N{sub 2}O emissions in the fallow season might be interesting. However, the effects of N-rich plant residues on N{sub 2}O emission rates in the fallow season and its effect on annual GWP were not studied before. In this experiment, combination of barley (non-leguminous) and hairy vetch (leguminous) biomasses were applied at 9 Mg ha{sup −1} and 27 Mg ha{sup −1} rates in rice paddy soil. Cover crop application significantly increased CH{sub 4} emission flux while decreased N{sub 2}O emissions during rice cultivation. The lowest N{sub 2}O emission was observed in 27 Mg ha{sup −1} cover crop treated plots. Cover crop applications increased N contents in soil aggregates especially in smaller aggregates (< 250 μm), and that proportionately increased the N{sub 2}O emission potentials of these soil aggregates. Fluxes of N{sub 2}O emissions in the fallow season were influenced by the N{sub 2}O emission potentials of soil aggregates and followed opposite trends as those observed during rice cultivation. Therefore, it could be concluded that the doses of cover crop applications for rice cultivation should not be optimized considering only CH{sub 4}, but N{sub 2}O should also be

  10. Changing cultural landscape in post-productivism of rice field in Nyuh Kuning Village Bali

    Science.gov (United States)

    Maulidi, C.; Wulandari, L. D.

    2017-06-01

    Natural landscape in developing countries is facing a challenge due to economic growth, a cultural shift, and population dynamics. Farm land where is close to urban areas tending to be converted into more economically valuable spaces. Watershed Pakerisan listed as World Heritage of UNESCO, rich of cultural value on its landscape, especially the Subak, a traditional irrigation system, has a close relationship to the philosophy of Hindu-Bali culture. Nyuh Kuning, a village (local terms is Banjar) located adjacent to the Pakerisan Watershed, and has a spatial pattern in synergic ally connected with tradition, culture, and their religion. Rice field not only for economical but also its place to worship the Goddess (Dewi Sri). Rice Field in Nyuh Kuning declined significantly along past 10 years. The changing landscape of Nyuh Kuning traced through serial of aerial photographs from 2005 until 2015. Along with the broad decline of rice field, villager’s attachment on their cultural space is also changing. An economic motive pronounces a winner in the bargaining between the motives of economic value and cultural value in the Nyuh Kuning. Villagers revealed arguments that necessities nowadays prosecute high consumption, both for household and for education. Therefore conversion of rice fields to become more economical is understandable among communities. Villagers rent the rice fields to foreigners (migrants), and then foreigners take rice-fields as personal assets, not for the villagers (ritual activities and the cultural traditions) any longer. In theoritical term, villager’s emotional bond to the cultural landscape in post—productivism of rice field, is weakened. Wawedangan Desa and its complex cultural values are not part of their identity anymore. However, place dependence become the reason why the shifting place attachment is happening. Functional economic bond is mentioned as place dependence dominats in villager’s attachment. Certainly it’s not a

  11. Natural variation of rice blast resistance gene Pi-d2

    Science.gov (United States)

    Studying natural variation of rice resistance (R) genes in cultivated and wild rice relatives can predict resistance stability to rice blast fungus. In the present study, the protein coding regions of rice R gene Pi-d2 in 35 rice accessions of subgroups, aus (AUS), indica (IND), temperate japonica (...

  12. Reverse-transcriptional gene expression of anammox and ammonia-oxidizing archaea and bacteria in soybean and rice paddy soils of Northeast China.

    Science.gov (United States)

    Wang, Jing; Dong, Hailiang; Wang, Weidong; Gu, Ji-Dong

    2014-03-01

    The relative gene expression of hydrazine oxidoreductase encoding gene (hzo) for anaerobic ammonium oxidizing bacteria (anammox) and ammonia monooxygenase encoding gene (amoA) for both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in Sanjiang Plain soybean and rice paddy soils of Northeast China was investigated by using real-time reverse-transcriptional quantitative PCR. Metabolically active populations of anammox, AOA, and AOB in rice paddy soils were evident by the presence and successful quantification of hzo mRNA and amoA mRNA genes. The expression ratio of amoA gene for both AOA and AOB varied between soybean soils and different rice paddy soils while the expression of hzo gene for anammox was detectable only in rice paddy soils by showing a diverse relative expression ratio in each soil sample. Gene expression of both archaeal and bacterial amoA genes in rice paddy soils differed among the three sampling depths, but that of hzo was not. Both archaeal and bacterial amoA genes showed an increase trend of expression level with continuation of rice paddy cultivation, but the low expression ratio of hzo gene indicated a relatively small contribution of anammox in overall removal of inorganic nitrogen through N2 even under anoxic and high nitrogen input in agriculture. Bacterial amoA gene from two soybean fields and three rice paddy fields were also analyzed for community composition by denaturing gradient gel electrophoresis fingerprint. Community shift was observed between soybean and paddy fields and within each of them. The consistent occurrence of three bands 5, 6, and 7 in all samples showed their high adaptability for both arid cultivation and continuous rice paddy cultivation. Our data suggest that AOA and AOB are playing a more important role in nitrogen transformation in agricultural soils in oxic or anoxic environment and anammox bacteria may also contribute but in a less extent to N transformation in these agricultural soils

  13. Anopheles larval abundance and diversity in three rice agro-village complexes Mwea irrigation scheme, central Kenya

    Directory of Open Access Journals (Sweden)

    Mwangangi Joseph M

    2010-08-01

    Full Text Available Abstract Background The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. Methods Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru, unplanned rice cultivation (Kiamachiri and non-irrigated (Murinduko agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. Records of distance to the nearest homestead, vegetation coverage, surface debris, turbidity, habitat stability, habitat type, rice growth stage, number of rice tillers and percent Azolla cover were taken for each habitat. Results Captures of early, late instars and pupae accounted for 78.2%, 10.9% and 10.8% of the total Anopheles immatures sampled (n = 29,252, respectively. There were significant differences in larval abundance between 3 agro-ecosystems. The village with 'planned' rice cultivation had relatively lower Anopheles larval densities compared to the villages where 'unplanned' or non-irrigated. Similarly, species composition and richness was higher in the two villages with either 'unplanned' or limited rice cultivation, an indication of the importance of land use patterns on diversity of larval habitat types. Rice fields and associated canals were the most productive habitat types while water pools and puddles were important for short periods during the rainy season. Multiple logistic regression analysis showed that presence of other invertebrates, percentage Azolla cover, distance to nearest homestead, depth and water turbidity were the best predictors for Anopheles mosquito larval

  14. Dissipation and Residue Level of Thifluzamide in Rice Field Ecosystem

    Directory of Open Access Journals (Sweden)

    Weitao Chen

    2015-01-01

    Full Text Available An efficient modified QuEChERS method combined with high performance liquid chromatography-tandem mass spectrometry detection (HPLC-MS/MS was established and evaluated for the residue analysis of thifluzamide in rice grain, husk, straw, seedling, paddy water, and soil. Thifluzamide residues were extracted with acetonitrile, cleaned up with primary secondary amine (PSA, and then determined by HPLC-MS/MS. The fortified recoveries were 76%–106% with RSDs of 3%–13%. The results of the supervised field trials at two experiment sites showed that thifluzamide dissipated rapidly in paddy fields, and the half-lives in paddy water, soil, and rice seedling were 0.3–0.6 d, 1.8–3.6 d, and 4.3–13.9 d, respectively. At harvest time, when the preharvest interval (PHI was set as 21 d, the final residues of thifluzamide in rice grains were below the maximum residue limit (MRL of 0.5 mg/kg set by Japan, whereas the final residues in rice husk and straw were still high (the highest value reached 1.36 mg/kg in rice husk and 0.83 mg/kg in rice straw. The results indicated that the highest residue in rice grain was 0.23 mg/kg when PHI was 21 d, and only 6.9–11.0% of acute risk quotient of thifluzamide was occupied by the dietary daily intake in Chinese population consuming rice.

  15. The impact of herbicide-resistant rice technology on phenotypic diversity and population structure of United States weedy rice.

    Science.gov (United States)

    Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D; Huang, Zhongyun; Hyma, Katie E; Gealy, David R; Caicedo, Ana L

    2014-11-01

    The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. © 2014 American Society of Plant Biologists. All Rights Reserved.

  16. Damage by Tibraca limbativentris Stål (Pentatomidae) to Upland Rice Cultivated in Amazon Rainforest Region (Brazil) at Different Growth Stages.

    Science.gov (United States)

    Krinski, D; Foerster, L A

    2017-02-01

    In this study, we evaluated the damage caused in the field by Tibraca limbativentris Stål adults at different levels of infestation (0, 1, 2, and 4 stink bugs) per three rice plants during three growth stages (V8, V13, and R4 stages) of upland rice cultivated in southwestern of Pará State, Amazon Rainforest region, Brazil. Heading time (panicle exertion) was affected by T. limbativentris infestations mainly in the vegetative stage and the whiteheads percentage in treatments ranged from 18.2 to 38%. The dead hearts percentages varied between 0 and 21.5%, and the mean number of primary branches (ramifications) ranged from 5.9 ± 0.4 to 12.3 ± 0.2. The number of empty spikelets was only affected in infestations with four insects/three plants, while the quantity of filled grains per panicle was affected only when infestations occurred during the vegetative stage. The total number of spikelets (filled + empty) per panicle decreased significantly in all phenological stages, and the percentage of damage ranged from 17 to 44% among treatments. Based on the proportion of damage observed, we suggest doubling the number of insects presently used as action threshold to 2 and 4 stink bugs per 15 stalks sampled for the vegetative stage, and of 1 or 2 stink bugs per 15 stalks sampled at the beginning of reproductive stage (R3/R4). Also, the field should be monitored during the entire vegetative stage, since most damage was observed in this phenological stage.

  17. Genome wide association mapping of grain arsenic, copper, molybdenum and zinc in rice (Oryza sativa L. grown at four international field sites.

    Directory of Open Access Journals (Sweden)

    Gareth J Norton

    Full Text Available The mineral concentrations in cereals are important for human health, especially for individuals who consume a cereal subsistence diet. A number of elements, such as zinc, are required within the diet, while some elements are toxic to humans, for example arsenic. In this study we carry out genome-wide association (GWA mapping of grain concentrations of arsenic, copper, molybdenum and zinc in brown rice using an established rice diversity panel of ∼ 300 accessions and 36.9 k single nucleotide polymorphisms (SNPs. The study was performed across five environments: one field site in Bangladesh, one in China and two in the US, with one of the US sites repeated over two years. GWA mapping on the whole dataset and on separate subpopulations of rice revealed a large number of loci significantly associated with variation in grain arsenic, copper, molybdenum and zinc. Seventeen of these loci were detected in data obtained from grain cultivated in more than one field location, and six co-localise with previously identified quantitative trait loci. Additionally, a number of candidate genes for the uptake or transport of these elements were located near significantly associated SNPs (within 200 kb, the estimated global linkage disequilibrium previously employed in this rice panel. This analysis highlights a number of genomic regions and candidate genes for further analysis as well as the challenges faced when mapping environmentally-variable traits in a highly genetically structured diversity panel.

  18. Understanding the social and economic aspects of upland rice farming

    Science.gov (United States)

    Taridala, S. A. A.; Abdullah, W. G.; Suaib; Wahyuni, S.; Wianti, N. I.; Zani, M.; Jabuddin, L. O.; Yusria, W. O.; Limi, M. A.; Ekaputri, A. S.

    2018-02-01

    The objectives of this study were to (1) analyze the socio-economic characteristics of upland rice farmers, and (2) to analyze the productivity of farming in South Konawe Regency of Southeast Sulawesi Province, Indonesia. The analysis used in this research was combine economic research through quantitative and qualitative analysis. This research was conducted by survey method. The results showed that (1) farmers are generally in productive age, dominated by men, with low formal education level, and moderate family members, (2) upland rice farming is cultivated in medium land area, with fixed costs higher than variable cost, productivity that has been increased but still lower than rice paddy, and the price of rice production is relatively higher than rice paddy production price, and (3) feasible to cultivate dryland rice, and has a high efficiency value.

  19. Seasonal variation of carbon dioxide and methane exchange between rice paddy fields and atmosphere in Japan

    Science.gov (United States)

    Kokubo, R.

    2017-12-01

    Rice paddy fields spread throughout Asia and play an important role in terms of regulating greenhouse gases on the ground. Rice paddies have the potential to either increase or decrease the net balance of greenhouse gases in the atmosphere. In the rice growth period, rice paddy fields are sources of CH4, whereas they generally act as a sink of CO2. However, the behavior of greenhouse gases during fallow periods has not been well understood. A field experiment was conducted at a rice paddy field in Fuchu, central Japan in 2014. We evaluated CO2 and CH4 fluxes in the rice paddy field using the eddy covariance method. Except for 20 days after transplanting (DAT), temporal CO2 fluxes showed negative values during a rice growth period whereas they showed positive values throughout a fallow period. The positive CO2 fluxes at 2 emissions by respiration of rice plants and soil microorganisms than CO2 uptake by photosynthesis of rice plants. In the middle of the growing season at around DAT=50, CO2 emission became dominant again because flooded water was temporarily drained in the rice paddy field. Seasonal CH4 fluxes during a growth period were regulated by water management and plant growth stages. During a fallow period, however, the field was kept a non-flooded condition that resulted in an aerobic soil condition and thus very low CH4 emission.

  20. Saving water? : analysis of options for rice-based farms in Tamil Nadu, India

    NARCIS (Netherlands)

    Senthilkumar, K.

    2008-01-01

    Keywords: Modified rice cultivation, Water-saving, Farm typology, Technology adoption, Policy interventions, Farmers livelihoods, Resource use efficiency and Linear programming.

    The looming water crisis and water-intensive nature of rice cultivation are driving the search for alternative

  1. Model development for nutrient loading estimates from paddy rice fields in Korea.

    Science.gov (United States)

    Jeon, Ji-Hong; Yoon, Chun G; Ham, Jong-Hwa; Jung, Kwang-Wook

    2004-01-01

    A field experiment was performed to evaluate water and nutrient balances in paddy rice culture operations during 2001-2002. The water balance analysis indicated that about half (50-60%) of the total outflow was lost by surface drainage, with the remainder occurring by evapotranspiration (490-530 mm). The surface drainage from paddy fields was mainly caused by rainfall and forced-drainage, and in particular, the runoff during early rice culture periods depends more on the forced-drainage due to fertilization practices. Most of the total phosphorus (T-P) inflow was supplied by fertilization at transplanting, while the total nitrogen (T-N) inflow was supplied by the three fertilizations, precipitation. and from the upper paddy field, which comprised 13-33% of the total inflow. Although most of the nutrient outflow was attributed to plant uptake. nutrient loss by surface drainage was substantial, comprising 20% for T-N and 10% for T-P. Water and nutrient balances indicate that reduction of surface drainage from paddy rice fields is imperative for nonpoint source pollution control. The simplified computer model, PADDIMOD, was developed to simulate water and nutrient (T-N and T-P) behavior in the paddy rice field. The model predicts daily ponded water depth, surface drainage, and nutrient concentrations. It was formulated with a few equations and simplified assumptions, but its application and a model fitness test indicated that the simulation results reasonably matched the observed data. It is a simple and convenient planning model that could be used to evaluate BMPs of paddy rice fields alone or in combination with other complex watershed models. Application of the PADDIMOD to other paddy rice fields with different agricultural environments might require further calibration and validation.

  2. Waste rice seed in conventional and stripper-head harvested fields in California: Implications for wintering waterfowl

    Science.gov (United States)

    Fleskes, Joseph P.; Halstead, Brian J.; Casazza, Michael L.; Coates, Peter S.; Kohl, Jeffrey D.; Skalos, Daniel A.

    2012-01-01

    Waste rice seed is an important food for wintering waterfowl and current estimates of its availability are needed to determine the carrying capacity of rice fields and guide habitat conservation. We used a line-intercept method to estimate mass-density of rice seed remaining after harvest during 2010 in the Sacramento Valley (SACV) of California and compared results with estimates from previous studies in the SACV and Mississippi Alluvial Valley (MAV). Posterior mean (95% credible interval) estimates of total waste rice seed mass-density for the SACV in 2010 were 388 (336–449) kg/ha in conventionally harvested fields and 245 (198–307) kg/ha in stripper-head harvested fields; the 2010 mass-density is nearly identical to the mid-1980s estimate for conventionally harvested fields but 36% lower than the mid-1990s estimate for stripped fields. About 18% of SACV fields were stripper-head harvested in 2010 vs. 9–15% in the mid-1990s and 0% in the mid-1980s; but due to a 50% increase in planted rice area, total mass of waste rice seed in SACV remaining after harvest in 2010 was 43% greater than in the mid-1980s. However, total mass of seed-eating waterfowl also increased 82%, and the ratio of waste rice seed to seed-eating waterfowl mass was 21% smaller in 2010 than in the mid-1980s. Mass-densities of waste rice remaining after harvest in SACV fields are within the range reported for MAV fields. However, because there is a lag between harvest and waterfowl use in the MAV but not in the SACV, seed loss is greater in the MAV and estimated waste seed mass-density available to wintering waterfowl in SACV fields is about 5–30 times recent MAV estimates. Waste rice seed remains an abundant food source for waterfowl wintering in the SACV, but increased use of stripper-head harvesters would reduce this food. To provide accurate data on carrying capacities of rice fields necessary for conservation planning, trends in planted rice area, harvest method, and postharvest field

  3. Genomic patterns of nucleotide diversity in divergent populations of U.S. weedy rice

    Directory of Open Access Journals (Sweden)

    Olsen Kenneth M

    2010-06-01

    Full Text Available Abstract Background Weedy rice (red rice, a conspecific weed of cultivated rice (Oryza sativa L., is a significant problem throughout the world and an emerging threat in regions where it was previously absent. Despite belonging to the same species complex as domesticated rice and its wild relatives, the evolutionary origins of weedy rice remain unclear. We use genome-wide patterns of single nucleotide polymorphism (SNP variation in a broad geographic sample of weedy, domesticated, and wild Oryza samples to infer the origin and demographic processes influencing U.S. weedy rice evolution. Results We find greater population structure than has been previously reported for U.S. weedy rice, and that the multiple, genetically divergent populations have separate origins. The two main U.S. weedy rice populations share genetic backgrounds with cultivated O. sativa varietal groups not grown commercially in the U.S., suggesting weed origins from domesticated ancestors. Hybridization between weedy groups and between weedy rice and local crops has also led to the evolution of distinct U.S. weedy rice populations. Demographic simulations indicate differences among the main weedy groups in the impact of bottlenecks on their establishment in the U.S., and in the timing of divergence from their cultivated relatives. Conclusions Unlike prior research, we did not find unambiguous evidence for U.S. weedy rice originating via hybridization between cultivated and wild Oryza species. Our results demonstrate the potential for weedy life-histories to evolve directly from within domesticated lineages. The diverse origins of U.S. weedy rice populations demonstrate the multiplicity of evolutionary forces that can influence the emergence of weeds from a single species complex.

  4. Use of rice seedlings to estimate uptake of radiocesium from soil to plants in Fukushima Prefecture

    International Nuclear Information System (INIS)

    Fujimura, Shigeto; Suzuki, Yasukazu; Ohno, Takeshi

    2013-01-01

    The uptake of radiocesium to plants from the soil is affected by many environmental factors, and it is difficult to determine the contribution of uptake among these factors. In addition, these environmental factors should be investigated independently for each field. The aim of this study was to develop a practical and simple method for the estimate of uptake of radiocesium from soil to plants. Rice seedlings were used to estimate the root uptake of radiocesium from seven different soils. To confirm that the seedlings were the effective indicator, the concentration of "1"3"7Cs in the seedlings was compared with that in brown rice and sunflower. The seedlings were cultivated for a week from germination in a phytotron and the concentrations of "1"3"7Cs in the seedlings above ground were determined. To obtain brown rice and sunflower, rice and sunflower were cultivated either in a pot (1/5000 a Wagner pot, 4000 cm"3) placed in a glasshouse or in a paddy field in Fukushima prefecture for two to four months. The concentration of "1"3"7Cs in the rice seedlings ranged from 150 to 1900 Bq kg"-"1, and that in brown rice and sunflower ranged from 2 to 880 Bq kg"-"1 and from 580 to 3900 Bq kg"-"1, respectively. The Spearman's rank correlation coefficient between the measured concentration of "1"3"7Cs in rice seedlings and the measured concentration of "1"3"7Cs in brown rice and sunflower was 1.0 (p < 0.001 and p = 0.09, respectively). This suggests that the use of rice seedlings in this experiment over a period of two weeks provides an effective indicator for the uptake of "1"3"7Cs from soil to plants over a longer period of time. (author)

  5. Use of rice seedlings to estimate uptake of radiocesium from soil to plants in Fukushima Prefecture

    International Nuclear Information System (INIS)

    Fujimura, Shigeto; Suzuki, Yasukazu; Ohno, Takeshi

    2012-01-01

    The uptake of radiocesium to plants from the soil is affected by many environmental factors, and it is difficult to determine the contribution of uptake among these factors. In addition, these environmental factors should be investigated independently for each field. The aim of this study was to develop a practical and simple method for the estimate of uptake of radiocesium from soil to plants. Rice seedlings were used to estimate the root uptake of radiocesium from seven different soils. To confirm that the seedlings were the effective indicator, the concentration of 137 Cs in the seedlings was compared with that in brown rice and sunflower. The seedlings were cultivated for a week from germination in a phytotron and the concentrations of 137 Cs in the seedlings above ground were determined. To obtain brown rice and sunflower, rice and sunflower were cultivated either in a pot (1/5000 a Wagner pot, 4000 cm 3 ) placed in a glasshouse or in a paddy field in Fukushima prefecture for two to four months. The concentration of 137 Cs in the rice seedlings ranged from 150 to 1900 Bq kg -1 , and that in brown rice and sunflower ranged from 2 to 880 Bq kg -1 and from 580 to 3900 Bq kg -1 , respectively. The Spearman's rank correlation coefficient between the measured concentration of 137 Cs in rice seedlings and the measured concentration of 137 Cs in brown rice and sunflower was 1.0 (p < 0.001 and p = 0.09, respectively). This suggests that the use of rice seedlings in this experiment over a period of two weeks provides an effective indicator for the uptake of 137 Cs from soil to plants over a longer period of time. (author)

  6. Effect of Interplanting with Zero Tillage and Straw Manure on Rice Growth and Rice Quality

    Directory of Open Access Journals (Sweden)

    Shi-ping LIU

    2007-09-01

    Full Text Available The interplanting with zero-tillage of rice, i.e. direct sowing rice 10–20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS (Zero-tillage, straw manure and rice interplanting, ZI (Zero-tillage, no straw manure and rice interplanting, PTS (Plowing tillage, straw manure and rice transplanting, and PT (Plowing tillage, no straw manure and rice transplanting, were used. ZIS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year (2002, there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year (2003. Compared with the transplanting treatments, the number of filled grains per panicle decreased but 1000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield. Interplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments

  7. Mapping paddy rice distribution using multi-temporal Landsat imagery in the Sanjiang Plain, northeast China

    Science.gov (United States)

    XIAO, Xiangming; DONG, Jinwei; QIN, Yuanwei; WANG, Zongming

    2016-01-01

    Information of paddy rice distribution is essential for food production and methane emission calculation. Phenology-based algorithms have been utilized in the mapping of paddy rice fields by identifying the unique flooding and seedling transplanting phases using multi-temporal moderate resolution (500 m to 1 km) images. In this study, we developed simple algorithms to identify paddy rice at a fine resolution at the regional scale using multi-temporal Landsat imagery. Sixteen Landsat images from 2010–2012 were used to generate the 30 m paddy rice map in the Sanjiang Plain, northeast China—one of the major paddy rice cultivation regions in China. Three vegetation indices, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Land Surface Water Index (LSWI), were used to identify rice fields during the flooding/transplanting and ripening phases. The user and producer accuracies of paddy rice on the resultant Landsat-based paddy rice map were 90% and 94%, respectively. The Landsat-based paddy rice map was an improvement over the paddy rice layer on the National Land Cover Dataset, which was generated through visual interpretation and digitalization on the fine-resolution images. The agricultural census data substantially underreported paddy rice area, raising serious concern about its use for studies on food security. PMID:27695637

  8. Proteomic analysis of seed storage proteins in wild rice species of the Oryza genus.

    Science.gov (United States)

    Jiang, Chunmiao; Cheng, Zaiquan; Zhang, Cheng; Yu, Tengqiong; Zhong, Qiaofang; Shen, J Qingxi; Huang, Xingqi

    2014-01-01

    The total protein contents of rice seeds are significantly higher in the three wild rice species (Oryza rufipogon Grill., Oryza officinalis Wall. and Oryza meyeriana Baill.) than in the cultivated rice (Oryza sativa L.). However, there is still no report regarding a systematic proteomic analysis of seed proteins in the wild rice species. Also, the relationship between the contents of seed total proteins and rice nutritional quality has not been thoroughly investigated. The total seed protein contents, especially the glutelin contents, of the three wild rice species were higher than those of the two cultivated rice materials. Based on the protein banding patterns of SDS-PAGE, O. rufipogon was similar to the two cultivated rice materials, followed by O. officinalis, while O. meyeriana exhibited notable differences. Interestingly, O. meyeriana had high contents of glutelin and low contents of prolamine, and lacked 26 kDa globulin band and appeared a new 28 kDa protein band. However, for O. officinali a 16 kDa protein band was absent and a row of unique 32 kDa proteins appeared. In addition, we found that 13 kDa prolamine band disappeared while special 14 kDa and 12 kDa protein bands were present in O. officinalis. Two-dimensional gel electrophoresis (2-DE) analysis revealed remarkable differences in protein profiles of the wild rice species and the two cultivated rice materials. Also, the numbers of detected protein spots of the three wild rice species were significantly higher than those of two cultivated rice. A total of 35 differential protein spots were found for glutelin acidic subunits, glutelin precursors and glutelin basic subunits in wild rice species. Among those, 18 protein spots were specific and 17 major spots were elevated. Six differential protein spots for glutelin acidic subunits were identified, including a glutelin type-A 2 precursor and five hypothetical proteins. This was the first report on proteomic analysis of the three wild rice species

  9. The Impact of Herbicide-Resistant Rice Technology on Phenotypic Diversity and Population Structure of United States Weedy Rice1[W][OPEN

    Science.gov (United States)

    Burgos, Nilda Roma; Singh, Vijay; Tseng, Te Ming; Black, Howard; Young, Nelson D.; Huang, Zhongyun; Hyma, Katie E.; Gealy, David R.; Caicedo, Ana L.

    2014-01-01

    The use of herbicide-resistant (HR) Clearfield rice (Oryza sativa) to control weedy rice has increased in the past 12 years to constitute about 60% of rice acreage in Arkansas, where most U.S. rice is grown. To assess the impact of HR cultivated rice on the herbicide resistance and population structure of weedy rice, weedy samples were collected from commercial fields with a history of Clearfield rice. Panicles from each weedy type were harvested and tested for resistance to imazethapyr. The majority of plants sampled had at least 20% resistant offspring. These resistant weeds were 97 to 199 cm tall and initiated flowering from 78 to 128 d, generally later than recorded for accessions collected prior to the widespread use of Clearfield rice (i.e. historical accessions). Whereas the majority (70%) of historical accessions had straw-colored hulls, only 30% of contemporary HR weedy rice had straw-colored hulls. Analysis of genotyping-by-sequencing data showed that HR weeds were not genetically structured according to hull color, whereas historical weedy rice was separated into straw-hull and black-hull populations. A significant portion of the local rice crop genome was introgressed into HR weedy rice, which was rare in historical weedy accessions. Admixture analyses showed that HR weeds tend to possess crop haplotypes in the portion of chromosome 2 containing the ACETOLACTATE SYNTHASE gene, which confers herbicide resistance to Clearfield rice. Thus, U.S. HR weedy rice is a distinct population relative to historical weedy rice and shows modifications in morphology and phenology that are relevant to weed management. PMID:25122473

  10. Establishment of a rice-duck integrated farming system and its effects on soil fertility and rice disease control

    Science.gov (United States)

    Teng, Qing; Hu, Xue-Feng; Cheng, Chang; Luo, Zhi-Qing; Luo, Fan

    2015-04-01

    Rice-duck integrated farming is an ecological farming system newly established in some areas of southern China . It was reported that the ducks walking around the paddy fields is beneficial to control weed hazards and reduce rice pests and diseases. To study and evaluate the effects of the rice-duck integrated farming on soil fertility and rice disease control, a field experiment of rice cultivation was carried out in the suburb of Shanghai in 2014. It includes a treatment of raising ducks in the fields and a control without ducks. The treatment was implemented by building a duck coop nearby the experimental fields and driving 15 ducks into a plot at daytime since the early stage of rice growth. Each plot is 667 m2 in area. The treatment and control were replicated for three times. No any herbicides, pesticides, fungicides and chemical fertilizers were applied during the experiment to prevent any disturbance to duck growing and rice weed hazards and disease incidences from agrochemicals. The results are as follows: (1) The incidences of rice leaf rollers (Cnaphalocrocis medinalis) and stem borers treated with ducks, 0.45%and 1.18% on average, respectively, are lower than those of the control, 0.74% and 1.44% on average, respectively. At the late stage of rice growth, the incidence of rice sheath blight treated with ducks, 13.15% on average, is significantly lower than that of the control, 16.9% on average; and the incidence of rice planthoppers treated with ducks, 11.3 per hill on average, is also significantly lower than that of the control, 47.4 per hill on average. (2) The number of weeds in the plots treated with ducks, 8.3 per m2 on average, is significantly lower than that of the control, 87.5 m2 on average. (3) Raising ducks in the fields could also enhance soil enzyme activity and nutrient status. At the late stage of rice growth, the activities of urease, phosphatase, sucrase and catalase in the soils treated with ducks are 1.39 times, 1.40 times, 1

  11. Analysis of hyperspectral field radiometric data for monitoring nitrogen concentration in rice crops

    Science.gov (United States)

    Stroppiana, D.; Boschetti, M.; Confalonieri, R.; Bocchi, S.; Brivio, P. A.

    2005-10-01

    Monitoring crop conditions and assessing nutrition requirements is fundamental for implementing sustainable agriculture. Rational nitrogen fertilization is of particular importance in rice crops in order to guarantee high production levels while minimising the impact on the environment. In fact, the typical flooded condition of rice fields can be a significant source of greenhouse gasses. Information on plant nitrogen concentration can be used, coupled with information about the phenological stage, to plan strategies for a rational and spatially differentiated fertilization schedule. A field experiment was carried out in a rice field Northern Italy, in order to evaluate the potential of field radiometric measurements for the prediction of rice nitrogen concentration. The results indicate that rice reflectance is influenced by nitrogen supply at certain wavelengths although N concentration cannot be accurately predicted based on the reflectance measured at a given wavelength. Regression analysis highlighted that the visible region of the spectrum is most sensitive to plant nitrogen concentration when reflectance measures are combined into a spectral index. An automated procedure allowed the analysis of all the possible combinations into a Normalized Difference Index (NDI) of the narrow spectral bands derived by spectral resampling of field measurements. The derived index appeared to be least influenced by plant biomass and Leaf Area Index (LAI) providing a useful approach to detect rice nutritional status. The validation of the regressive model showed that the model is able to predict rice N concentration (R2=0.55 [p<0.01] RRMSE=29.4; modelling efficiency close to the optimum value).

  12. Mapping rice areas of South Asia using MODIS multitemporal data

    Science.gov (United States)

    Gumma, Murali Krishna; Nelson, Andrew; Thenkabail, Prasad S.; Singh, Amrendra N.

    2011-01-01

    Our goal is to map the rice areas of six South Asian countries using moderate-resolution imaging spectroradiometer (MODIS) time-series data for the time period 2000 to 2001. South Asia accounts for almost 40% of the world's harvested rice area and is also home to 74% of the population that lives on less than $2.00 a day. The population of the region is growing faster than its ability to produce rice. Thus, accurate and timely assessment of where and how rice is cultivated is important to craft food security and poverty alleviation strategies. We used a time series of eight-day, 500-m spatial resolution composite images from the MODIS sensor to produce rice maps and rice characteristics (e.g., intensity of cropping, cropping calendar) taking data for the years 2000 to 2001 and by adopting a suite of methods that include spectral matching techniques, decision trees, and ideal temporal profile data banks to rapidly identify and classify rice areas over large spatial extents. These methods are used in conjunction with ancillary spatial data sets (e.g., elevation, precipitation), national statistics, and maps, and a large volume of field-plot data. The resulting rice maps and statistics are compared against a subset of independent field-plot points and the best available subnational statistics on rice areas for the main crop growing season (kharif season). A fuzzy classification accuracy assessment for the 2000 to 2001 rice-map product, based on field-plot data, demonstrated accuracies from 67% to 100% for individual rice classes, with an overall accuracy of 80% for all classes. Most of the mixing was within rice classes. The derived physical rice area was highly correlated with the subnational statistics with R2 values of 97% at the district level and 99% at the state level for 2000 to 2001. These results suggest that the methods, approaches, algorithms, and data sets we used are ideal for rapid, accurate, and large-scale mapping of paddy rice as well as for generating

  13. A System Designed for Rice? Materiality and the Invention/Discovery of the System of Rice Intensification

    NARCIS (Netherlands)

    Glover, D.

    2011-01-01

    The System of Rice Intensification (SRI) is a novel approach to rice cultivation that is claimed to be both more productive and more sustainable than conventional methods. It is said to have been discovered by a French Jesuit missionary working in Madagascar during the 1970s and 1980s. The system

  14. Reducing Potential Disaster Impacts in Irrigated Rice Fields in West Java

    NARCIS (Netherlands)

    Sianturi, R.S.

    2018-01-01

    The increasing global population inevitably demands for stable food production. As an important food crop, rice plays a major role in maintaining food security. However, irrigated rice fields are increasingly suffered from natural hazard occurrences worldwide, disrupting livelihoods of millions of

  15. Global Rice Atlas: Disaggregated seasonal crop calendar and production

    NARCIS (Netherlands)

    Balanza, Jane Girly; Gutierrez, Mary Anne; Villano, Lorena; Nelson, A.D.; Zwart, S.J.; Boschetti, Mirco; Koo, Jawoo; Reinke, Russell; Murty, M. V.R.; Laborte, Alice G.

    2014-01-01

    Purpose: Rice is an important staple crop cultivated in more than 163 million ha globally. Although information on the distribution of global rice production is available by country and, at times, at subnational level, information on its distribution within a year is often lacking in different rice

  16. Rice status and microwave characteristics: Analysis of rice paddy fields at Kojima Bay [Okayama, Japan] using multi-frequency and polarimetric Pi-SAR radar data images

    International Nuclear Information System (INIS)

    Ishitsuka, N.; Saito, G.; Ouchi, K.; Davidson, G.; Mohri, K.; Uratsuka, S.

    2003-01-01

    Abstract South-east Asia has a rainy-season at the crop growing period, and it is difficult to observe agricultural land in this season using optical remote sensing. Synthetic Aperture Radar (SAR) can observe the earth's surface without being influenced by of clouds. However, it is less useful for observing agricultural land, because satellite SAR has only one data band. Recently, SAR is able to provide multi band and multi polarimetric data. Pi-SAR, an airborne SAR developed by NASDA and CRL, can provide L and X bands and fully polarimetric data. Rice is the main crop in Asia, and we studied the characteristic microwave scatter on rice paddy fields using Pi-SAR data. Our study area was the rice paddy fields in Kojima reclaimed land in Japan. We had two fully polarimetric data sets from 13 July 1999 and 4 October 2000. First, we processed the color polarimetric composite image. Next we calibrated the phase of each polarimetric data using river area by the Kimura method. After that we performed decomposition analysis and drew polarimetric signatures for understanding the status of rice paddy fields. At the rice planting period, rice paddy fields are filled with water and rice plants are very small. The SAR microwave scatters on water surfaces like a mirror, called 'mirror (or specular) reflection'. This phenomenon makes backscatter a small value at the water-covered area. The image from July is about one month after trans-planting and rice plants are 20-40 cm in height. X-band microwave scatters on the rice surface, but L-band microwave passes through rice bodies and shows mirror refraction on water surfaces. Some strong backscatter occur on rice paddy fields especially VV polarization because of bragg scattering. The fields where bragg scattering returns strong VV scatter because the space between rice stems cause resonation in the L-band wavelength. We can easily understand bragg scatter by using polarimetric data. Using the image from October at

  17. Effects of Position of Rainfed Rice Field in a Toposequence on Water Availability and Rice Yield in Central Java, Indonesia

    OpenAIRE

    SUGANDA, HUSEIN; PANINGBATAN, E.P; GUERRA, L.C; TUONG, T.P

    2003-01-01

    The productivity of rainfed rice needs to be increased in order to support the Indonesian Food Security programs, especially rice. Rainfall is one of the main sources of the water availability on the rainfed rice field. This research was conducted from October 2000 to February 2001 at four sites in Central Java Province. The objectives of this research were to study thevariability of water availability that influenced by toposequen's position and to analyze the rice yields due to treatments o...

  18. Liquid chromatographic-diode-array detection multiresidue determination of rice herbicides in drinking and paddy-field water.

    Science.gov (United States)

    Roehrs, Rafael; Zanella, Renato; Pizzuti, Ionara; Adaime, Martha B; Pareja, Lucía; Niell, Silvina; Cesio, María V; Heinzen, Horacio

    2009-01-01

    A sensitive, rapid, and simple multiresidue method for the simultaneous determination of six postemergence herbicides currently used in rice cultivation--metsulfuron methyl, bensulfuron methyl, pyrazosulfuron ethyl, bentazone, bispyribac sodium, and cyhalofop butyl--in drinking and paddy-field water is presented. Water samples were extracted with solid-phase extraction cartridges. Final determination was made by LC with diode-array detection. The extraction efficiencies of C18 and HLB cartridges were compared. The average recovery obtained for these compounds for the lowest spiked level (0.1 microg/L) varied from 70 to 122% for C18 and 75-119% for HLB, with RSDs of 11 and 8.3%, respectively. The method had good linearity, and the lower detection limit for the pesticides studied varied from 0.03 to 0.04 microg/L. The proposed method was also tested in paddy-field water, with recovery studies giving good results with low RSDs at 1.0 microg/L.

  19. Evaluation of Protocols for Measuring Leaf Photosynthetic Properties of Field-Grown Rice

    Directory of Open Access Journals (Sweden)

    Chang Tian-gen

    2017-01-01

    Full Text Available Largely due to the heterogeneity of environmental parameters and the logistical difficulty of moving photosynthetic equipment in the paddy fields, effective measurement of lowland rice photosynthesis is still a challenge. In this study, we showed that measuring detached rice leaves in the laboratory can not effectively represent the parameters measured in situ. We further described a new indoor facility, high-efficiency all-weather photosynthetic measurement system (HAPS, and the associated measurement protocol to enable whole-weather measurement of photosynthetic parameters of rice grown in the paddy fields. Using HAPS, we can conduct photosynthetic measurements with a time span much longer than that appropriate for the outdoor measurements. Comparative study shows that photosynthetic parameters obtained with the new protocol can effectively represent the parameters in the fields. There was much less standard deviation for measurements using HAPS compared to the outdoor measurements, no matter for technical replications of each recording or for biological replications of each leaf position. This new facility and protocol enables rice photosynthetic physiology studies to be less tough but more efficient, and provides a potential option for large scale studies of rice leaf photosynthesis.

  20. From Early Domesticated Rice of the Middle Yangtze Basin to Millet, Rice and Wheat Agriculture: Archaeobotanical Macro-Remains from Baligang, Nanyang Basin, Central China (6700-500 BC.

    Directory of Open Access Journals (Sweden)

    Zhenhua Deng

    Full Text Available Baligang is a Neolithic site on a northern tributary of the middle Yangtze and provides a long archaeobotanical sequence from the Seventh Millennium BC upto the First Millennium BC. It provides evidence for developments in rice and millet agriculture influenced by shifting cultural affiliation with the north (Yangshao and Longshan and south (Qujialing and Shijiahe between 4300 and 1800 BC. This paper reports on plant macro-remains (seeds, from systematic flotation of 123 samples (1700 litres, producing more than 10,000 identifiable remains. The earliest Pre-Yangshao occupation of the sites provide evidence for cultivation of rice (Oryza sativa between 6300-6700 BC. This rice appears already domesticated in on the basis of a dominance of non-shattering spikelet bases. However, in terms of grain size changes has not yet finished, as grains are still thinner than more recent domesaticated rice and are closer in grain shape to wild rices. This early rice was cultivated alongside collection of wild staple foods, especially acorns (Quercus/Lithicarpus sensu lato. In later periods the sites has evidence for mixed farming of both rice and millets (Setaria italica and Panicum miliaceum. Soybean appears on the site in the Shijiahe period (ca.2500 BC and wheat (Triticum cf. aestivum in the Late Longshan levels (2200-1800 BC. Weed flora suggests an intensification of rice agriculture over time with increasing evidence of wetland weeds. We interpret these data as indicating early opportunistic cultivation of alluvial floodplains and some rainfed rice, developing into more systematic and probably irrigated cultivation starting in the Yangshao period, which intensified in the Qujialing and Shijiahe period, before a shift back to an emphasis on millets with the Late Longshan cultural influence from the north.

  1. Rice evapotranspiration at the field and canopy scales under water-saving irrigation

    Science.gov (United States)

    Liu, Xiaoyin; Xu, Junzeng; Yang, Shihong; Zhang, Jiangang

    2018-04-01

    Evapotranspiration (ET) is an important process of land surface water and thermal cycling, with large temporal and spatial variability. To reveal the effect of water-saving irrigation (WSI) on rice ET at different spatial scales and understand the cross spatial scale difference, rice ET under WSI condition at canopy (ETCML) and field scale (ETEC) were measured simultaneously by mini-lysimeter and eddy covariance (EC) in the rice season of 2014. To overcome the shortage of energy balance deficit by EC system, and evaluate the influence of energy balance closure degree on ETEC, ETEC was corrected as {ET}_{EC}^{*} by energy balance closure correction according to the evaporative fraction. Seasonal average daily ETEC, {ET}_{EC}^{*} and ETCML of rice under WSI practice were estimated as 3.12, 4.03 and 4.35 mm day-1, smaller than the values reported in flooded paddy fields. Daily ETEC, {ET}_{EC}^{*} and ETCML varied in a similar trends and reached the maximum in late tillering, then decreased along with the crop growth in late season. The value of ETEC was much lower than ETCML, and was frequently 1-2 h lagged behind ETCML. It indicated that the energy balance deficit resulted in underestimation of crop ET by EC system. The corrected value of {ET}_{EC}^{*} matched ETCML much better than ETEC, with a smaller RMSE (0.086 mm h-1) and higher R 2 (0.843) and IOA (0.961). The time lapse between {ET}_{EC}^{*} and ETCML was mostly shortened to less than 0.5 h. The multiple stepwise regression analysis indicated that net radiation ( R n) is the dominant factor for rice ET, and soil moisture ( θ) is another significant factor ( p rice fields. The difference between ETCML and {ET}_{EC}^{*} ({ET}_{CML} - {ET}_{EC}^{*}) were significantly ( p rice ET in WSI fields, and for its cross scale conversion.

  2. Understanding the evolution of rice technology in China - from traditional agriculture to GM rice today.

    Science.gov (United States)

    Shen, Xiaobai

    2010-01-01

    This paper provides an historical survey of the evolution of rice technology in China, from the traditional farming system to genetically modified rice today. Using sociotechnological analytical framework, it analyses rice technology as a socio-technical ensemble - a complex interaction of material and social elements, and discusses the specificity of technology development and its socio-technical outcomes. It points to two imperatives in rice variety development: wholesale transporting agricultural technology and social mechanism to developing countries are likely lead to negative consequences; indigenous innovation including deploying GM technology for seed varietal development and capturing/cultivating local knowledge will provide better solutions.

  3. Translocations of 2,4-D-14C Herbicides In Weed And Rice Plant On Irrigated Rice Field System

    International Nuclear Information System (INIS)

    Chairul, Sofnie M.; Idawati; Mulyadi

    2000-01-01

    The investigation of translocation 2,4-D herbicides using 14 C as tracer on irradiated rice plant system. Condition of the soil was two kinds, that is normal soil and soil 30% up normal. The soil of rice field was spray with 1μCi of 2,4-D non labelled, one week after planting. A part of rice plant and weed was determined the radioactivity after 0, 2, 4, 8, and 10 weeks after spraying. The result showed that radioactivity maximum after zero week was in root and leaf of weeds, the second weeks in root of rice, the forth weeks in rice stick, and eighth weeks in leaf of rice. This result occur at normal condition soil of solid 30 % up normal soil. The residues of 2.4-D in rice was 4,24x10 -3 ppb at normal soil and 3.16x10 -3 ppb at solid 30% up normal soil. This result still lower than rate of WHO/FAO, that is 0,05 ppm

  4. Effect of potassium application on root uptake of radiocesium in rice

    International Nuclear Information System (INIS)

    Saito, Takashi; Ohkoshi, Satoru; Fujimura, Shigeto

    2013-01-01

    After the Fukushima Daiichi Nuclear Power Plant accident that occurred in March 2011, the concentration of radiocesium in brown rice that has been produced in some area has exceeded the provisional regulation value. In order to decrease the concentration of radiocesium in brown rice, we investigated the effect of the application of potassium fertilizer in rice paddy fields on the root uptake of radiocesium. The observed concentration ratio of "1"3"4Cs to "1"3"7Cs was 0.81 at the time of sample collection, and the mean concentrations of radiocesium in the soils at depths of 0-5, 5-10, and 10-15 cm were 5879 Bq kg"-"1 DW, 3223 Bq kg"-"1 DW and 1835 Bq kg"-"1 DW, respectively. The results showed that the vertical distribution of radiocesium was not uniform, although the rice paddy fields had been plowed. The concentration of radiocesium at a depth of 0-5 cm in soil collected from the 5 different rice paddy fields was in the range of 2465-7823Bq kg"-"1 DW, showing an approximately 3-fold variation between the upper and lower limits of the range. The concentration of radiocesium in brown rice cultivated in 5 different fields, was in the range of 52-485 Bq kg"-"1. The concentration of radiocesium in brown rice was found to be not correlated with that in the soil, and the soil-to-brown rice transfer factor was found to lie in the range of 0.0075-0.11. However, the radiocesium in brown rice decreased with an increase in exchangeable potassium in the soil. The concentration of radiocesium in brown rice also decreased from 370 to 138 Bq kg"-"1 upon the application of a top dressing of potassium fertilizer. Thus, the application of potassium fertilizer is shown to reduce the concentration of radiocesium in brown rice. (author)

  5. Studying the Impacts of Environmental Factors and Agricultural Management on Methane Emissions from Rice Paddies Using a Land Surface Model

    Science.gov (United States)

    Lin, T. S.; Gahlot, S.; Shu, S.; Jain, A. K.; Kheshgi, H. S.

    2017-12-01

    Continued growth in population is projected to drive increased future demand for rice and the methane emissions associated with its production. However, observational studies of methane emissions from rice have reported seemingly conflicting results and do not all support this projection. In this study we couple an ecophysiological process-based rice paddy module and a methane emission module with a land surface model, Integrated Science Assessment Model (ISAM), to study the impacts of various environmental factors and agricultural management practices on rice production and methane emissions from rice fields. This coupled modeling framework accounts for dynamic rice growth processes with adaptation of photosynthesis, rice-specific phenology, biomass accumulation, leaf area development and structures responses to water, temperature, light and nutrient stresses. The coupled model is calibrated and validated with observations from various rice cultivation fields. We find that the differing results of observational studies can be caused by the interactions of environmental factors, including climate, atmospheric CO2 concentration, and N deposition, and agricultural management practices, such as irrigation and N fertilizer applications, with rice production at spatial and temporal scales.

  6. Effects of straw incorporation along with microbial inoculant on methane and nitrous oxide emissions from rice fields

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gang; Yu, Haiyang [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ma, Jing [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008 (China); Xu, Hua, E-mail: hxu@issas.ac.cn [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71 East Beijing Road, Nanjing 210008 (China); Wu, Qinyan; Yang, Jinghui; Zhuang, Yiqing [Zhenjiang Institute of Agricultural Science of Hilly Regions in Jiangsu, Jurong 212400 (China)

    2015-06-15

    Incorporation of straw together with microbial inoculant (a microorganism agent, accelerating straw decomposition) is being increasingly adopted in rice cultivation, thus its effect on greenhouse gas (GHG) emissions merits serious attention. A 3-year field experiment was conducted from 2010 to 2012 to investigate combined effect of straw and microbial inoculant on methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) emissions, global warming potential (GWP) and greenhouse gas intensity (GHGI) in a rice field in Jurong, Jiangsu Province, China. The experiment was designed to have treatment NPK (N, P and K fertilizers only), treatment NPKS (NPK plus wheat straw), treatment NPKSR (NPKS plus Ruilaite microbial inoculant) and treatment NPKSJ (NPKS plus Jinkuizi microbial inoculant). Results show that compared to NPK, NPKS increased seasonal CH{sub 4} emission by 280–1370%, while decreasing N{sub 2}O emission by 7–13%. When compared with NPKS, NPKSR and NPKSJ increased seasonal CH{sub 4} emission by 7–13% and 6–12%, respectively, whereas reduced N{sub 2}O emission by 10–27% and 9–24%, respectively. The higher CH{sub 4} emission could be attributed to the higher soil CH{sub 4} production potential triggered by the combined application of straw and microbial inoculant, and the lower N{sub 2}O emission to the decreased inorganic N content. As a whole, the benefit of lower N{sub 2}O emission was completely offset by increased CH{sub 4} emission, resulting in a higher GWP for NPKSR (5–12%) and NPKSJ (5–11%) relative to NPKS. Due to NPKSR and NPKSJ increased rice grain yield by 3–6% and 2–4% compared to NPKS, the GHGI values for NPKS, NPKSR and NPKSJ were comparable. These findings suggest that incorporating straw together with microbial inoculant would not influence the radiative forcing of rice production in the terms of per unit of rice grain yield relative to the incorporation of straw alone. - Highlights: • This paper presents 3-year measurements of CH

  7. From Early Domesticated Rice of the Middle Yangtze Basin to Millet, Rice and Wheat Agriculture: Archaeobotanical Macro-Remains from Baligang, Nanyang Basin, Central China (6700–500 BC)

    Science.gov (United States)

    Deng, Zhenhua; Qin, Ling; Gao, Yu; Weisskopf, Alison Ruth; Zhang, Chi; Fuller, Dorian Q.

    2015-01-01

    Baligang is a Neolithic site on a northern tributary of the middle Yangtze and provides a long archaeobotanical sequence from the Seventh Millennium BC upto the First Millennium BC. It provides evidence for developments in rice and millet agriculture influenced by shifting cultural affiliation with the north (Yangshao and Longshan) and south (Qujialing and Shijiahe) between 4300 and 1800 BC. This paper reports on plant macro-remains (seeds), from systematic flotation of 123 samples (1700 litres), producing more than 10,000 identifiable remains. The earliest Pre-Yangshao occupation of the sites provide evidence for cultivation of rice (Oryza sativa) between 6300–6700 BC. This rice appears already domesticated in on the basis of a dominance of non-shattering spikelet bases. However, in terms of grain size changes has not yet finished, as grains are still thinner than more recent domesaticated rice and are closer in grain shape to wild rices. This early rice was cultivated alongside collection of wild staple foods, especially acorns (Quercus/Lithicarpus sensu lato). In later periods the sites has evidence for mixed farming of both rice and millets (Setaria italica and Panicum miliaceum). Soybean appears on the site in the Shijiahe period (ca.2500 BC) and wheat (Triticum cf. aestivum) in the Late Longshan levels (2200–1800 BC). Weed flora suggests an intensification of rice agriculture over time with increasing evidence of wetland weeds. We interpret these data as indicating early opportunistic cultivation of alluvial floodplains and some rainfed rice, developing into more systematic and probably irrigated cultivation starting in the Yangshao period, which intensified in the Qujialing and Shijiahe period, before a shift back to an emphasis on millets with the Late Longshan cultural influence from the north. PMID:26460975

  8. LABA1, a Domestication Gene Associated with Long, Barbed Awns in Wild Rice.

    Science.gov (United States)

    Hua, Lei; Wang, Diane R; Tan, Lubin; Fu, Yongcai; Liu, Fengxia; Xiao, Langtao; Zhu, Zuofeng; Fu, Qiang; Sun, Xianyou; Gu, Ping; Cai, Hongwei; McCouch, Susan R; Sun, Chuanqing

    2015-07-01

    Common wild rice (Oryza rufipogon), the wild relative of Asian cultivated rice (Oryza sativa), flaunts long, barbed awns, which are necessary for efficient propagation and dissemination of seeds. By contrast, O. sativa cultivars have been selected to be awnless or to harbor short, barbless awns, which facilitate seed processing and storage. The transition from long, barbed awns to short, barbless awns was a crucial event in rice domestication. Here, we show that the presence of long, barbed awns in wild rice is controlled by a major gene on chromosome 4, LONG AND BARBED AWN1 (LABA1), which encodes a cytokinin-activating enzyme. A frame-shift deletion in LABA1 of cultivated rice reduces the cytokinin concentration in awn primordia, disrupting barb formation and awn elongation. Sequencing analysis demonstrated low nucleotide diversity and a selective sweep encompassing an ∼800-kb region around the derived laba1 allele in cultivated rice. Haplotype analysis revealed that the laba1 allele originated in the japonica subspecies and moved into the indica gene pool via introgression, suggesting that humans selected for this locus in early rice domestication. Identification of LABA1 provides new insights into rice domestication and also sheds light on the molecular mechanism underlying awn development. © 2015 American Society of Plant Biologists. All rights reserved.

  9. Tolerance to zinc deficiency in rice correlates with zinc uptake and translocation

    NARCIS (Netherlands)

    Gao, X.; Zou, C.Q.; Zee, van der S.E.A.T.M.; Hoffland, E.

    2005-01-01

    To study variation in zinc efficiency (ZE) among current Chinese rice genotypes, a pot experiment was conducted with 15 aerobic and 8 lowland rice genotypes. Aerobic rice is currently bred by crossing lowland with upland rice genotypes, for growth in an aerobic cultivation system, which is saving

  10. Cultivation of oyster mushroom ( Pleurotus spp.) on palm oil ...

    African Journals Online (AJOL)

    Oyster mushroom is a popular mushroom due to its nutritional, medicinal and potential commercial value. In Malaysia, the fungus is currently cultivated on sawdust and rice husk. In this study, the efficiency of cultivating oyster mushroom was assessed using palm oil mesocarp fibre as a substrate. The experiment consisted ...

  11. Effects of ridge tillage on photosynthesis and root characters of rice

    Directory of Open Access Journals (Sweden)

    Yao Yuan-zhi

    2015-03-01

    Full Text Available Rice (Oryza sativa L. is an important crop and breeding has not been able to improve yield. Root characteristics of hybrid rice 'Zhuliangyou 02' under conventional tillage and ridge tillage were studied in a Calcisols in Huaihua, China, from 2011 to 2013 to find better tillage methods to resolve massive water consumption, improve yield, and enhance productivity of agricultural labor for rice cultivation. Results showed ridge tillage increased photosynthetic parameters such as photosynthetic rate (P N, stomatal conductance (g s, and water use efficiency (WUE. It also significantly enhanced rice root number, root activity, and antioxidant enzyme activities; it also increased effective panicle number and actual yield by 22.12% and 15.18%, respectively, and enhanced aerenchymae during the early growth stage. Overall, ridge tillage could promote hybrid rice yields by enhancing root absorption, gas exchange, and reducing water consumption. It could be widely used in rice cultivation.

  12. Mapping rice areas of South Asia using MODIS multitemporal data

    Science.gov (United States)

    Gumma, M.K.; Nelson, A.; Thenkabail, P.S.; Singh, A.N.

    2011-01-01

    Our goal is to map the rice areas of six South Asian countries using moderate-resolution imaging spectroradiometer (MODIS) time-series data for the time period 2000 to 2001. South Asia accounts for almost 40% of the world's harvested rice area and is also home to 74% of the population that lives on less than $2.00 a day. The population of the region is growing faster than its ability to produce rice. Thus, accurate and timely assessment of where and how rice is cultivated is important to craft food security and poverty alleviation strategies. We used a time series of eight-day, 500-m spatial resolution composite images from the MODIS sensor to produce rice maps and rice characteristics (e.g., intensity of cropping, cropping calendar) taking data for the years 2000 to 2001 and by adopting a suite of methods that include spectral matching techniques, decision trees, and ideal temporal profile data banks to rapidly identify and classify rice areas over large spatial extents. These methods are used in conjunction with ancillary spatial data sets (e.g., elevation, precipitation), national statistics, and maps, and a large volume of field-plot data. The resulting rice maps and statistics are compared against a subset of independent field-plot points and the best available subnational statistics on rice areas for the main crop growing season (kharif season). A fuzzy classification accuracy assessment for the 2000 to 2001 rice-map product, based on field-plot data, demonstrated accuracies from 67% to 100% for individual rice classes, with an overall accuracy of 80% for all classes. Most of the mixing was within rice classes. The derived physical rice area was highly correlated with the subnational statistics with R2 values of 97% at the district level and 99% at the state level for 2000 to 2001. These results suggest that the methods, approaches, algorithms, and data sets we used are ideal for rapid, accurate, and large-scale mapping of paddy rice as well as for generating

  13. Rice-planted area extraction by time series analysis of ENVISAT ASAR WS data using a phenology-based classification approach: A case study for Red River Delta, Vietnam

    Science.gov (United States)

    Nguyen, D.; Wagner, W.; Naeimi, V.; Cao, S.

    2015-04-01

    Recent studies have shown the potential of Synthetic Aperture Radars (SAR) for mapping of rice fields and some other vegetation types. For rice field classification, conventional classification techniques have been mostly used including manual threshold-based and supervised classification approaches. The challenge of the threshold-based approach is to find acceptable thresholds to be used for each individual SAR scene. Furthermore, the influence of local incidence angle on backscatter hinders using a single threshold for the entire scene. Similarly, the supervised classification approach requires different training samples for different output classes. In case of rice crop, supervised classification using temporal data requires different training datasets to perform classification procedure which might lead to inconsistent mapping results. In this study we present an automatic method to identify rice crop areas by extracting phonological parameters after performing an empirical regression-based normalization of the backscatter to a reference incidence angle. The method is evaluated in the Red River Delta (RRD), Vietnam using the time series of ENVISAT Advanced SAR (ASAR) Wide Swath (WS) mode data. The results of rice mapping algorithm compared to the reference data indicate the Completeness (User accuracy), Correctness (Producer accuracy) and Quality (Overall accuracies) of 88.8%, 92.5 % and 83.9 % respectively. The total area of the classified rice fields corresponds to the total rice cultivation areas given by the official statistics in Vietnam (R2  0.96). The results indicates that applying a phenology-based classification approach using backscatter time series in optimal incidence angle normalization can achieve high classification accuracies. In addition, the method is not only useful for large scale early mapping of rice fields in the Red River Delta using the current and future C-band Sentinal-1A&B backscatter data but also might be applied for other rice

  14. Relative availability of crop residue-N in rice cultivation

    International Nuclear Information System (INIS)

    Sirwando, H; Abdullah, N.

    1988-01-01

    The use of plant residues for soil amendment will reduce the use of chemical fertilizers. The experiment to study the uptake of N from various plant residues by rice crop. Three kinds of plant residue of soybean labelled with 15-N. Four levels of urea (0, 15, 30, 40 kg N/ha) were applied to aluvial soil from Pusakanegara. The factorial experiment was conducted in fully randomize design, with plant residues as the main treatment, and rate of urea as substreatment. The results obtained from this experiment showed that plant dry weight, N content of grain, straw, and the whole plant of Atomita I rice treated with soybean strow seens to be higher than those treated with the straw of rice or corn. (author). 6 refs.; 7 tabs

  15. Spatial Field Variability Mapping of Rice Crop using Clustering Technique from Space Borne Hyperspectral Data

    Science.gov (United States)

    Moharana, S.; Dutta, S.

    2015-12-01

    Precision farming refers to field-specific management of an agricultural crop at a spatial scale with an aim to get the highest achievable yield and to achieve this spatial information on field variability is essential. The difficulty in mapping of spatial variability occurring within an agriculture field can be revealed by employing spectral techniques in hyperspectral imagery rather than multispectral imagery. However an advanced algorithm needs to be developed to fully make use of the rich information content in hyperspectral data. In the present study, potential of hyperspectral data acquired from space platform was examined to map the field variation of paddy crop and its species discrimination. This high dimensional data comprising 242 spectral narrow bands with 30m ground resolution Hyperion L1R product acquired for Assam, India (30th Sept and 3rd Oct, 2014) were allowed for necessary pre-processing steps followed by geometric correction using Hyperion L1GST product. Finally an atmospherically corrected and spatially deduced image consisting of 112 band was obtained. By employing an advanced clustering algorithm, 12 different clusters of spectral waveforms of the crop were generated from six paddy fields for each images. The findings showed that, some clusters were well discriminated representing specific rice genotypes and some clusters were mixed treating as a single rice genotype. As vegetation index (VI) is the best indicator of vegetation mapping, three ratio based VI maps were also generated and unsupervised classification was performed for it. The so obtained 12 clusters of paddy crop were mapped spatially to the derived VI maps. From these findings, the existence of heterogeneity was clearly captured in one of the 6 rice plots (rice plot no. 1) while heterogeneity was observed in rest of the 5 rice plots. The degree of heterogeneous was found more in rice plot no.6 as compared to other plots. Subsequently, spatial variability of paddy field was

  16. Biological control of golden apple snail, Pomacea canaliculata by Chinese soft-shelled turtle, Pelodiscus sinensis in the wild rice, Zizania latifolia field

    Directory of Open Access Journals (Sweden)

    Shengzhang Dong

    2012-04-01

    Full Text Available The wild rice, Zizania latifolia Turcz, used to be one of the important aquatic vegetables cultivated in China. Recently, the golden apple snail - GAS (Pomacea canaliculata (Lamarck was found to be a major invasive pest attacking Z. latifolia. To control efficiently GAS, predation by the Chinese soft-shelled turtles (Pelodiscus sinensis on GAS was evaluated in laboratory and field trials. P. sinensis had a strong predatory capacity and selectivity for GAS both in laboratory and field conditions. All the sizes of P. sinensis prefer to capture smaller snails. The optimum number of P. sinensis released in Z. latifolia field was dependent on the density of over-wintered GAS, and varied between 30 and 50 turtles per 666.7 m². The number of GAS declined in the fields with turtles as compared to turtle-free field. A pattern of releasing P. sinensis in Z. latifolia fields was developed and widely adopted by farmers because of much more benefit besides biologically controlling GAS.

  17. Heavy Metal Content in Terraced Rice Fields at Sruwen Tengaran Semarang - Indonesia

    Science.gov (United States)

    Hindarwati, Yulis; Soeprobowati, Tri Retnaningsih; Sudarno

    2018-02-01

    The presence of heavy metal on agricultural soils can be caused not only natural factors but also due to human intervention. Differences in management and lack of understanding of farmers in the production input of fertilizers and pesticides ensued in land ravaged. Periodic testing of paddy fields is necessary to minimize the contaminants from being absorbed by plants that will have an impact on health decline. The purpose of the assessment was to identify the heavy metal content in the terraced rice field in Sruwen Village, Tengaran District, Semarang Regency. Survey was conducted in February 2017. Sampling on terraced rice fields of different heights consisted of upper, middle, and upper down. Taken as many as eight single points and composed at a depth of 0-20 cm and 20-40 cm. The identification results showed that heavy metal content of Pb, Cd, and Cu were present at all altitudes. Heavy Metals Pb and Cd at a depth of 0-20 cm were higher from 20-40 cm in the upper and lower rice fields but lower in the middle rice field. Cu heavy metal at a depth of 0-20 cm was higher than 20-40 cm in all altitude land. The heavy metal content of Pb, Cd, and Cu was still below the heavy metal standard set by the European Union and India.

  18. Induction of bacterial blight resistance in elite Indian rice cultivars using gamma-rays and ethyl methanesulfonate

    International Nuclear Information System (INIS)

    Agrawal, P.K.; Gosal, S.S.; Sidhu, G.S.

    2001-01-01

    Rice is the most important cereal crop in the world feeding more than 50 percent of the human population. During the last 30 years, induced mutation breeding has played a significant role in rice breeding programmes. Rice mutants with higher yield, greater tolerance to diseases and pests and other agronomic qualities have been released for commercial cultivation in many countries. Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae is the second important disease in Southeast Asia. In the Basmati field sometime the yield loss is up to 100%. Moreover, there is no resistance source available. In Basmati rice, which is known for its quality and aroma. Induction of bacterial blight resistance in Basmati will help in developing high yielding Basmati type cultivars without compromising the quality

  19. Mapping Changes in Area and the Cropping Season of Irrigated Rice in Senegal and Mauritania between 2003 and 2014 Using the PhenoRice Algorithm and MODIS Imagery

    Science.gov (United States)

    Zwart, S.; Busetto, L.; Diagne, M.; Boschetti, M.; Nelson, A.

    2017-12-01

    Government policies have resulted in rapid expansion of irrigated rice area in Mauritania and Senegal through private and public investments. Farmers switch rice cultivation from the wet to the dry season to achieve higher production while rice double cropping is increasingly practiced. As a result Senegal is close to attaining self-sufficiency in the coming years. However, tools to monitor those changes are absent and this inhibits assessments on for example its impact on wetlands located in the delta area, increased water demands and climate induced risks to farmers. In this study we aimed to map changes in irrigated rice area in the wet and dry seasons. We applied the PhenoRice algorithm on a combined time-series of MODIS Aqua and Terra images obtained between 2003 and 2016 to map pixels dominated by rice and determine the start, end and length of the growing season from sowing/transplanting to maturity. Between 2002 and 2010 researchers from the Africa Rice Center interviewed annually around 100 rice farmers located in two irrigation schemes in Senegal. We extracted the reported sowing/transplanting and harvest dates from the data base and used these to validate the estimates obtained by PhenoRice. We also compared the obtained rice areas with official statistics provided by the Senegalese Ministry of Agriculture. Analysis of PhenoRice results highlighted that starting 2008, rice farmers cultivate also during the dry season; the area is steadily increasing from 2008 onwards and in the recent years approximately almost equals that of the wet season. This was confirmed by official statistics, though the total area estimated by PhenoRice is smaller than reported, most likely due to the mismatch between pixel size and the small cultivated areas. However, the algorithm was able to detect the overall trends and inter-annual variations observed in the wet (r2=0.57) and dry season rice cultivated area (r2=0.91). The start of the season, that varied maximally 4 weeks

  20. Novel Field Data on Phytoextraction: Pre-Cultivation With Salix Reduces Cadmium in Wheat Grains.

    Science.gov (United States)

    Greger, Maria; Landberg, Tommy

    2015-01-01

    Cadmium (Cd) is a health hazard, and up to 43% of human Cd intake comes from wheat products, since Cd accumulates in wheat grains. Salix spp. are high-accumulators of Cd and is suggested for Cd phytoextraction from agricultural soils. We demonstrate, in field, that Salix viminalis can remove Cd from agricultural soils and thereby reduce Cd accumulation in grains of wheat subsequently grown in a Salix-treated field. Four years of Salix cultivation reduce Cd concentration in the soil by up to 27% and in grains of the post-cultivated wheat by up to 33%. The higher the plant density of the Salix, the greater the Cd removal from the soil and the lower the Cd concentration in the grains of post-cultivated wheat, the Cd reduction remaining stable several years after Salix cultivation. The effect occurred in both sandy and clayey soil and in winter and spring bread wheat cultivars. Already one year of Salix cultivation significantly decrease Cd in post grown wheat grains. With this field experiment we have demonstrated that phytoextraction can reduce accumulation of a pollutant in post-cultivated wheat and that phytoextraction has no other observed effect on post-cultivated crops than reduced uptake of the removed pollutant.

  1. Changes in the status of harvested rice fields in the Sacramento Valley, California: Implications for wintering waterfowl.

    Science.gov (United States)

    Miller, Michael R.; Garr, Jay D.; Coates, Peter S.

    2010-01-01

    Harvested rice fields provide critical foraging habitat for wintering waterfowl in North America, but their value depends upon post-harvest treatments. We visited harvested ricefields in the Sacramento Valley, California, during the winters of 2007 and 2008 (recent period) and recorded their observed status as harvested (standing or mechanically modified stubble), burned, plowed, or flooded. We compared these data with those from identical studies conducted during the 1980s (early period). We documented substantial changes in field status between periods. First, the area of flooded rice increased 4-5-fold, from about 15% to >40% of fields, because of a 3-4-fold increase in the percentage of fields flooded coupled with a 37-41% increase in the area of rice produced. Concurrently, the area of plowed fields increased from 35% of fields, burned fields declined from about 40% to 1%, and fields categorized as harvested declined from 22-54% to rice field status survey in the Sacramento Valley and other North American rice growing regions as appropriate to support long-term monitoring programs and wetland habitat conservation planning for wintering waterfowl.

  2. LABA1, a Domestication Gene Associated with Long, Barbed Awns in Wild Rice[OPEN

    Science.gov (United States)

    Hua, Lei; Wang, Diane R.; Tan, Lubin; Fu, Yongcai; Liu, Fengxia; Xiao, Langtao; Zhu, Zuofeng; Fu, Qiang; Sun, Xianyou; Gu, Ping; Cai, Hongwei; McCouch, Susan R.; Sun, Chuanqing

    2015-01-01

    Common wild rice (Oryza rufipogon), the wild relative of Asian cultivated rice (Oryza sativa), flaunts long, barbed awns, which are necessary for efficient propagation and dissemination of seeds. By contrast, O. sativa cultivars have been selected to be awnless or to harbor short, barbless awns, which facilitate seed processing and storage. The transition from long, barbed awns to short, barbless awns was a crucial event in rice domestication. Here, we show that the presence of long, barbed awns in wild rice is controlled by a major gene on chromosome 4, LONG AND BARBED AWN1 (LABA1), which encodes a cytokinin-activating enzyme. A frame-shift deletion in LABA1 of cultivated rice reduces the cytokinin concentration in awn primordia, disrupting barb formation and awn elongation. Sequencing analysis demonstrated low nucleotide diversity and a selective sweep encompassing an ∼800-kb region around the derived laba1 allele in cultivated rice. Haplotype analysis revealed that the laba1 allele originated in the japonica subspecies and moved into the indica gene pool via introgression, suggesting that humans selected for this locus in early rice domestication. Identification of LABA1 provides new insights into rice domestication and also sheds light on the molecular mechanism underlying awn development. PMID:26082172

  3. Science, practice and the System of Rice Intensification in Indian agriculture

    NARCIS (Netherlands)

    Glover, D.

    2011-01-01

    The System of Rice Intensification (SRI) is claimed to be a novel approach to rice cultivation that is both more productive and more sustainable than conventional methods. Such claims have been challenged or dismissed by many rice scientists, however. Despite the lack of clear and unequivocal

  4. What factors influence choice of waste management practice? Evidence from rice straw management in the Philippines.

    Science.gov (United States)

    Launio, Cheryll C; Asis, Constancio A; Manalili, Rowena G; Javier, Evelyn F; Belizario, Annabelle F

    2014-02-01

    This study applied a multinomial logit model to understand why farmers choose to burn, incorporate or remove rice straw in the field. Four hundred randomly selected farmers were interviewed in four major rice-producing provinces covering the 2009 wet and 2010 dry seasons. Results of the model with burning as the baseline category indicate farm type, location dummies, number of household members with older than 13 years, cow ownership and distance from farm to house as significant variables influencing farmers' choice of straw incorporation or removal over burning. Significant perception variables are the negative impacts of open-field burning, awareness of environmental regulations and attitude towards incentives. Other factors significantly influencing the decision to incorporate over-burn are training attendance and perceptions of effects of straw incorporation. Income from non-rice farming, total area cultivated, tenure status, presence of burning and solid waste management provincial ordinances are significant factors affecting choice to remove over burn. Continually providing farmers' training in rice production, increasing demand for rice straw for other uses, and increasing awareness of environmental laws and regulations are policy directions recommended.

  5. Rice Seedling Substrate Produced by Coal Gangue

    Directory of Open Access Journals (Sweden)

    SHAO Yu-fei

    2017-10-01

    Full Text Available Peats are the mostly used material in making rice seedling substrate. However, mining peats could cause environmental problems. In order to reduce or replace peats in rice seedling substrate industry, this paper studied suitable way to configure rice seedling. The coal gangue was used to experiment cultivating rice. Four rice seeding experiments were carried out based on physical and chemical properties of materials attributes. The results showed:(1 Coal gangue was feasible for rice seedling; (2 The maximum adding amount of coal gangue was 80%(volume ratio though the coal gangue need to be activated; (3 In the case of no activated treatment only 38%(volume ratio of coal gangue could be added to the substrate.

  6. Soil organic carbon in riparian forests, rice fields, and pastures in Piedras, Tolima, Colombia.

    Directory of Open Access Journals (Sweden)

    Hernán Jair Andrade-Castañeda

    2016-06-01

    Full Text Available The aim of the study was to estimate the soil organic carbon (SOC storage in the interface between riparian forests and a matrix of rice fields and pastures with organic management. The study took place in Piedras, Tolima, Colombia. Two plots in production (rice and pasture were selected and SOC was estimated in these areas and in the edge and the interior of adjacent riparian forests at a depth of 0 to 20 cm. Bulk density and SOC concentration were quantified between May and July, 2013. Potential change in SOC storage due to land use change among rice fields, pastures, and riparian forests was estimated. The interfaces rice field-riparian forest and pasture-riparian forest stored an average of 65.6 and 61.3 t C/ha, respectively, with no statistical differences (p>0.05. Statistical differences were not detected (p>0.05 between agricultural matrices (rice fields and pastures in any of the variables. The sampling position (matrix and the edge and interior of forests had a significant impact (p<0.05 just in bulk density: 1.7 vs 1.1 vs 1.0 g/cm3 in interior and edge of the riparian forests and the matrix, respectively. SOC was not statistically affected (p>0.05 by the position in the riparian forest-matrix interface. Conversion from riparian forests to rice fields or pastures with organic management is not emitting greenhouse gases, on the contrary, it is increasing SOC in 3.2 t C/ha. 

  7. RPAN: rice pan-genome browser for ∼3000 rice genomes.

    Science.gov (United States)

    Sun, Chen; Hu, Zhiqiang; Zheng, Tianqing; Lu, Kuangchen; Zhao, Yue; Wang, Wensheng; Shi, Jianxin; Wang, Chunchao; Lu, Jinyuan; Zhang, Dabing; Li, Zhikang; Wei, Chaochun

    2017-01-25

    A pan-genome is the union of the gene sets of all the individuals of a clade or a species and it provides a new dimension of genome complexity with the presence/absence variations (PAVs) of genes among these genomes. With the progress of sequencing technologies, pan-genome study is becoming affordable for eukaryotes with large-sized genomes. The Asian cultivated rice, Oryza sativa L., is one of the major food sources for the world and a model organism in plant biology. Recently, the 3000 Rice Genome Project (3K RGP) sequenced more than 3000 rice genomes with a mean sequencing depth of 14.3×, which provided a tremendous resource for rice research. In this paper, we present a genome browser, Rice Pan-genome Browser (RPAN), as a tool to search and visualize the rice pan-genome derived from 3K RGP. RPAN contains a database of the basic information of 3010 rice accessions, including genomic sequences, gene annotations, PAV information and gene expression data of the rice pan-genome. At least 12 000 novel genes absent in the reference genome were included. RPAN also provides multiple search and visualization functions. RPAN can be a rich resource for rice biology and rice breeding. It is available at http://cgm.sjtu.edu.cn/3kricedb/ or http://www.rmbreeding.cn/pan3k. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. Development and appraisal of economical and sustainable approach for weed management in drill seeded aerobic rice (oryza sativa l.)

    International Nuclear Information System (INIS)

    Saqib, M.; Akbar, N.; Ehsanullah, A.; Ghafoor, A.

    2012-01-01

    Conventional rice cultivation by puddling and transplanting is a labor intensive activity. Water scarcity is a threat for the sustain ability of transplanted rice. In many areas of Asia, rice transplantation of rice is being replaced by direct seeding as farmers tried to solve the problems of labor cost and water scarcity but weed control is one of the major constraints to direct seeding. So, to control weeds in direct seeded rice present studies were designed. A two years study was conducted to develop sustainable and economical methods for managing weeds in aerobic rice grown by dry direct-seeding at Student's Farm, Department of Agronomy, University of Agriculture, Faisalabad during the years 2008 and 2009. Experiment was laid out in RCBD with five weed management strategies: hand weeding, hoeing with kasula, inter-row cultivation with tine cultivator, inter-row cultivation with spike hoe and chemical control with Nominee 100 SC along with control (no weeding). Weed dry weight was 300 g m/sup -2/, 257 g m/sup -2/, 225 g m/sup -2/ and 157 g m/sup -2/ less in hand weeding, hoeing, tine cultivator and Nominee 100 SC respectively than no weeding. Paddy yield was 221%, 203%, 181% and 105% more in hand weeding, hoeing, tine cultivator and Nominee 100 SC respectively than no weeding. (author)

  9. Air pollutant emissions from rice straw open field burning in India, Thailand and the Philippines

    International Nuclear Information System (INIS)

    Gadde, Butchaiah; Bonnet, Sebastien; Menke, Christoph; Garivait, Savitri

    2009-01-01

    Rice is a widely grown crop in Asia. China (30%) and India (21%) contribute to about half of the world's total rice production. In this study, three major rice-producing countries in Asia are considered, India, Thailand and the Philippines (the later two contributing 4% and 2% of the world's rice production). Rice straw is one of the main field based residues produced along with this commodity and its applications vary widely in the region. Although rice production practises vary from one country to another, open burning of straw is a common practice in these countries. In this study, an approach was followed aiming at (a) determining the quantity of rice straw being subject to open field burning in those countries, (b) congregating pollutant specific emissions factors for rice straw burning, and (c) quantifying the resulting air pollutant emissions. Uncertainties in the results obtained as compared to a global approach are also discussed. - This research work contributes to enhance scientific knowledge for estimating air pollutant emissions from open burning of crop residues and improve emission results accuracy.

  10. Field evidence for the potential of Rhodobacter capsulatus as Biofertilizer for flooded rice.

    Science.gov (United States)

    Gamal-Eldin, Hosny; Elbanna, Khaled

    2011-02-01

    In a previous study, we evaluated the effects of inoculating rice plants with the phototrophic purple nonsulfur bacterium Rhodobacter capsulatus (Rc) on growth and yield of rice in pots and lysimeter experiments and the results obtained have been highly encouraging. In this study, we carried out two field experiments: one in the experimental farm of the Faculty of Agriculture, Fayoum University, and the second in a farmer's field in Kafr El-sheikh, to assess the effects of Rc on growth and yield of rice in comparison and in combination with chemical nitrogen fertilizer (CNF) and farmyard manure. The results indicated that both biological and grain yields in all the Rc inoculated treatments were significantly higher than those in the uninoculated corresponding treatments in both fields. With regard to grain yield, the major factor for determining the effectiveness of any agricultural treatment, inoculation with Rc in combination with 50% of the recommended CNF rate gave a grain yield that was statistically equivalent to that obtained with 100% of the recommended CNF rate. These results provide a clear evidence for the potential of Rc as biofertilizer for flooded rice under field conditions.

  11. Ammonium sulphate fertiliser increases larval populations of Anopheles arabiensis and culicine mosquitoes in rice fields

    DEFF Research Database (Denmark)

    Mutero, C M; Ng'ang'a, P N; Wekoyela, P

    2004-01-01

    Field experiments were conducted in central Kenya, to study the effect of ammonium sulphate fertiliser ((NH(4))(2)SO(4)) on mosquito larval populations in rice fields. The experiments used a complete randomised block design having four blocks with two experimental ponds per block, and the fertili......Field experiments were conducted in central Kenya, to study the effect of ammonium sulphate fertiliser ((NH(4))(2)SO(4)) on mosquito larval populations in rice fields. The experiments used a complete randomised block design having four blocks with two experimental ponds per block...... populations of An. arabiensis (Pmosquitoes (P... in rice fields, thereby making them visually more attractive for egg-laying by An. arabiensis and culicine mosquitoes....

  12. Occurrence of Aspergillus section Flavi and aflatoxins in Brazilian rice: From field to market

    DEFF Research Database (Denmark)

    Katsurayama, Aline M.; Martins, Ligia Manoel; Iamanaka, Beatriz T.

    2018-01-01

    The guarantee of the high quality of rice is of utmost importance because any toxic contaminant may affect consumer health, especially in countries such as Brazil where rice is part of the daily diet. A total of 187 rice samples, from field, processing and market from two different production sys...

  13. Global estimations of the inventory and mitigation potential of methane emissions from rice cultivation conducted using the 2006 Intergovernmental Panel on Climate Change Guidelines

    Science.gov (United States)

    Yan, Xiaoyuan; Akiyama, Hiroko; Yagi, Kazuyuki; Akimoto, Hajime

    2009-06-01

    The Intergovernmental Panel on Climate Change (IPCC) regularly publishes guidelines for national greenhouse gas inventories and methane emission (CH4) from rice paddies has been an important component of these guidelines. While there have been many estimates of global CH4 emissions from rice fields, none of them have been obtained using the IPCC guidelines. Therefore, we used the Tier 1 method described in the 2006 IPCC guidelines to estimate the global CH4 emissions from rice fields. To accomplish this, we used country-specific statistical data regarding rice harvest areas and expert estimates of relevant agricultural activities. The estimated global emission for 2000 was 25.6 Tg a-1, which is at the lower end of earlier estimates and close to the total emission summarized by individual national communications. Monte Carlo simulation revealed a 95% uncertainty range of 14.8-41.7 Tg a-1; however, the estimation uncertainty was found to depend on the reliability of the information available regarding the amount of organic amendments and the area of rice fields that were under continuous flooding. We estimated that if all of the continuously flooded rice fields were drained at least once during the growing season, the CH4 emissions would be reduced by 4.1 Tg a-1. Furthermore, we estimated that applying rice straw off season wherever and whenever possible would result in a further reduction in emissions of 4.1 Tg a-1 globally. Finally, if both of these mitigation options were adopted, the global CH4 emission from rice paddies could be reduced by 7.6 Tg a-1. Although draining continuously flooded rice fields may lead to an increase in nitrous oxide (N2O) emission, the global warming potential resulting from this increase is negligible when compared to the reduction in global warming potential that would result from the CH4 reduction associated with draining the fields.

  14. Concentration of some heavy metals in rice types available in Shiraz market and human health risk assessment.

    Science.gov (United States)

    Naseri, Mahmood; Vazirzadeh, Arya; Kazemi, Robabeh; Zaheri, Farnaz

    2015-05-15

    This investigation was conducted to survey the levels of some heavy metals such as cadmium, lead, chromium, nickel and cobalt in domestic cultivated and imported rice sold on the Shiraz - Iran markets. The potential human health risk assessment was conducted by considering estimated weekly intake (EWI) of toxic metals from eating rice and compared calculated values with provisional tolerable weekly intake (PTWI). The mean values for lead and cadmium in domestic cultivated and imported rice were considerably higher than allowable limits set by FAO/WHO. In combination of recent rice consumption data, the estimated weekly intakes of toxic element were calculated for Iranian population. EWI for cadmium, nickel, chromium through imported and domestic cultivated rice consumption was lower than the PTWI. The EWI for lead were considerably higher than other measured toxic metals. The highest mean level of EWI for lead was observed in some imported rice samples (25.76 μg/kg body weight). Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Physical, chemical, and biological properties of soil under soybean cultivation and at an adjacent rainforest in Amazonia

    Science.gov (United States)

    T.P. Beldini; R.C. Oliveira Junior; Michael Keller; P.B. de Camargo; P.M. Crill; A. Damasceno da Silva; D. Bentes dos Santos; D. Rocha de Oliveira

    2015-01-01

    Land-use change in the Amazon basin has occurred at an accelerated pace during the last decade, and it is important that the effects induced by these changes on soil properties are better understood. This study investigated the chemical, physical, and biological properties of soil in a field under cultivation of soy and rice, and at an adjacent primary rain forest....

  16. Characteristics and land suitability of newly establish rice field in Lesung Batu Muda, Rawas Ulu, Musi Rawas, South Sumatera

    Directory of Open Access Journals (Sweden)

    R Sudaryanto

    2015-04-01

    Full Text Available Rice field has a strategic function because it is the main provider of food for the population of Indonesia. The data of the land use for the rice field in Indonesia showed that around 41% in Java Island. Agricultural technology at the level of industry experienced rapid progress, but the technology implementation at the level by farmer is relatively slow. Increased production of rice in Indonesia was reported of less than 1% per year. The research aimed to study the characteristics and land suitability of newly established rice field in Lesung Batu Muda, Rawas Ulu, Musi Rawas, South Sumatera. There were two soil land units that were tested included water availability, rooting medium, level of erosion, soil chemical properties and land preparation. The results of the study showed that newly established rice fields in Lesung Batu Muda, Rawas Ulu, Musi Rawas, South Sumatera could be used to open new rice fields by planting twice a year. In opening new rice fields, the application of organic matter and creation of terracing on sloping areas were needed.

  17. Unravelling trophic subsidies of agroecosystems for biodiversity conservation: Food consumption and nutrient recycling by waterbirds in Mediterranean rice fields

    International Nuclear Information System (INIS)

    Navedo, Juan G.; Hahn, Steffen; Parejo, Manuel; Abad-Gómez, José M.; Gutiérrez, Jorge S.; Villegas, Auxiliadora; Sánchez-Guzmán, Juan M.; Masero, José A.

    2015-01-01

    Waterbirds can reallocate a considerable amount of nutrients within agricultural fields and between agriculture sites and wetlands. However their effects on biogeochemical cycles have rarely been quantified. We estimated bird numbers, diet (from stable isotope analysis), food supply, and the food consumption on rice fields by overwintering waterbirds in one of the most important areas for rice production in southwestern Europe and a key area for various migrating and resident waterbird species. Herein, we modelled the nutrient (N and P) recycling in rice fields, and their transport to reservoirs. The energy consumption by waterbirds (96,605 ± 18,311 individuals) on rice fields during winter averaged at 89.9 ± 39.0 kJ·m −2 , with its majority (89.9%) belonging to foraging on rice seeds. Thus, the birds removed about 26% of rice seeds leftover after harvest (estimated in 932.5 ± 504.7 seeds·m −2 in early winter) wherein common cranes and dabbling ducks (four species) were the most important consumers. Waterbirds foraging and roosting in the rice fields recycled more than 24.1 (1.0 kg·ha −1 ) of N and an additional 5.0 tons (0.2 kg·ha −1 ) of P in the Extremadura's rice fields during winter. Additionally, we estimated that 2.3 tons of N and 550 kg of P were removed from rice fields and transported to reservoirs. The seasonal foraging of wildlife should result in a direct benefit for rice farmers by improving nutrient recycling through defecation by waterbirds with respect to artificial fertilisation. Additionally, rice fields located in the cranes' core wintering areas can provide sufficient food supply to induce habitat shift from their traditional wintering habitat in ‘dehesas’ to rice fields, which causes indirect socioeconomic benefit through reduced acorn consumption by cranes. Our modelling approach may thus be especially helpful for management decisions regarding rice agroecosystems in areas which are also important for the

  18. Unravelling trophic subsidies of agroecosystems for biodiversity conservation: Food consumption and nutrient recycling by waterbirds in Mediterranean rice fields

    Energy Technology Data Exchange (ETDEWEB)

    Navedo, Juan G., E-mail: jgnavedo@uach.cl [Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Facultad de Ciencias, Campus Isla Teja, 5090000 Valdivia (Chile); Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Hahn, Steffen [Department Bird Migration, Swiss Ornithological Institute, Seerose 1, 6204 Sempach (Switzerland); Parejo, Manuel; Abad-Gómez, José M. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Gutiérrez, Jorge S. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain); Department of Marine Ecology, Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB Den Burg, Texel (Netherlands); Villegas, Auxiliadora; Sánchez-Guzmán, Juan M.; Masero, José A. [Conservation Biology Research Group, Universidad de Extremadura, Avda. Elvas s/n, 06002 Badajoz (Spain)

    2015-04-01

    Waterbirds can reallocate a considerable amount of nutrients within agricultural fields and between agriculture sites and wetlands. However their effects on biogeochemical cycles have rarely been quantified. We estimated bird numbers, diet (from stable isotope analysis), food supply, and the food consumption on rice fields by overwintering waterbirds in one of the most important areas for rice production in southwestern Europe and a key area for various migrating and resident waterbird species. Herein, we modelled the nutrient (N and P) recycling in rice fields, and their transport to reservoirs. The energy consumption by waterbirds (96,605 ± 18,311 individuals) on rice fields during winter averaged at 89.9 ± 39.0 kJ·m{sup −2}, with its majority (89.9%) belonging to foraging on rice seeds. Thus, the birds removed about 26% of rice seeds leftover after harvest (estimated in 932.5 ± 504.7 seeds·m{sup −2} in early winter) wherein common cranes and dabbling ducks (four species) were the most important consumers. Waterbirds foraging and roosting in the rice fields recycled more than 24.1 (1.0 kg·ha{sup −1}) of N and an additional 5.0 tons (0.2 kg·ha{sup −1}) of P in the Extremadura's rice fields during winter. Additionally, we estimated that 2.3 tons of N and 550 kg of P were removed from rice fields and transported to reservoirs. The seasonal foraging of wildlife should result in a direct benefit for rice farmers by improving nutrient recycling through defecation by waterbirds with respect to artificial fertilisation. Additionally, rice fields located in the cranes' core wintering areas can provide sufficient food supply to induce habitat shift from their traditional wintering habitat in ‘dehesas’ to rice fields, which causes indirect socioeconomic benefit through reduced acorn consumption by cranes. Our modelling approach may thus be especially helpful for management decisions regarding rice agroecosystems in areas which are also important

  19. Improving Lowland Rice (O. sativa L. cv. MR219 Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances

    Directory of Open Access Journals (Sweden)

    Perumal Palanivell

    2015-01-01

    Full Text Available High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot−1. Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot−1 significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot−1 and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials.

  20. Improving Lowland Rice (O. sativa L. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances.

    Science.gov (United States)

    Palanivell, Perumal; Ahmed, Osumanu Haruna; Ab Majid, Nik Muhamad; Jalloh, Mohamadu Boyie; Susilawati, Kasim

    2015-01-01

    High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot(-1)). Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot(-1)) significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot(-1)) and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials.

  1. The strategies of local farmers' water management and the eco-hydrological effects of irrigation-drainage engineering systems in world heritage of Honghe Hani Rice Terraces

    Science.gov (United States)

    Gao, Xuan

    2017-04-01

    Terraces are built in mountainous regions to provide larger area for cultivation,in which the hydrological and geomorphological processes are impacted by local farmers' water management strategies and are modified by manmade irrigation-drainage engineering systems.The Honghe Hani Rice Terraces is a 1300a history of traditional agricultural landscape that was inscribed in the 2013 World Heritage List.The local farmers had developed systematic water management strategies and built perfect irrigation-drainage engineering systems to adapt the local rainfall pattern and rice farming activities.Through field investigation,interviews,combined with Geographic Information Systems,Remote Sensing images and Global Positioning Systems technology,the water management strategies as well as the irrigation-drainage systems and their impacts on eco-hydrological process were studied,the results indicate:Firstly,the local people created and maintained an unique woodcarving allocating management system of irrigating water over hundreds years,which aids distributing water and natural nutrition to each terrace field evenly,and regularly according to cultivation schedule.Secondly,the management of local people play an essential role in effective irrigation-drainage engineering system.A ditch leader takes charge of managing the ditch of their village,keeping ample amount of irrigation water,repairing broken parts of ditches,dealing with unfair water using issues,and so on.Meanwhile,some traditional leaders of minority also take part in.Thus, this traditional way of irrigation-drainage engineering has bringed Hani people around 1300 years of rice harvest for its eco-hydrological effects.Lastly we discuss the future of Honghe Hani Rice Terraces,the traditional cultivation pattern has been influenced by the rapid development of modern civilization,in which some related changes such as the new equipment of county roads and plastic channels and the water overusing by tourism are not totally

  2. Comparison of Rice Direct Seeding Methods (Mechanical and Manual with Transplanting Method

    Directory of Open Access Journals (Sweden)

    A Eyvani

    2014-04-01

    Full Text Available The main method of rice planting in Iran is transplanting. Due to poor mechanization of rice production, this method is laborious and costly. The other method is direct seeding in wet lands which is performed in the one third of rice cultivation area of the world. The most important problem in this method is high labor requirement of weed control. In order to compare the different rice planting methods (direct drilling, transplanting, and seed broadcasting a manually operated rice direct seeder (drum seeder was designed and fabricated. The research was conducted using a randomized complete block design with three treatments and three replications. Required draft force, field efficiency, effective field capacity, yield, and yield components were measured and the treatments were compared economically. Results showed that there were significant differences among the treatments from the view point of rice yield at the confidence level of 95% i.e. the transplanting method had the maximum yield. A higher rice yield was obtained from the direct seeder compared to the manual broadcasting method but, the difference between these two methods for crop yield was not significant even at the confidence level of the 95%. The coefficient of variation of seed distribution with direct seeding was more than 20%. The labor and time requirements per hectare reduced to 7 and 20 times, respectively when comparing the newly designed direct seeder with the transplanting method. The direct seeding method had the highest benefit to cost ratio in spite of its lower yield. Therefore, this method could be recommended in the rice growing regions.

  3. Analysis of rice purchase decision on rice consumer in Bandung city

    Science.gov (United States)

    Kusno, K.; Imannurdin, A.; Syamsiyah, N.; Djuwendah, E.

    2018-03-01

    This study was conducted at three kinds of purchase location which were traditional market, rice kiosk, and supermarket in Bandung City, with survey data of 108 respondents which were selected by systematic random sampling. The aim of this study is to (1) identify consumer characteristics, (2) identify which atribute is considered by consumer in buying rice, and (3) analyze the relationship between purchase decision and income class. Data were analyzed by descriptive analysis and Chi Square test. The results showed most consumers in the traditional market were middle-educated and lower middle-income, at the rice kiosk, the consumer were generally middle-educated and middle-income, and in the supermarkets, the majority were high-educated and upper middle-income consumers. “Kepulenan” be the first priority of most consumers, but for the lower-middle class, the main priority was price. Thus, in case of scarcity and rice price increase, the government should immediately arrange market operations which targeting to lower-middle class consumers. There was a significant relationship between (1) the quality of rice consumed, (2) the frequency of rice purchase per month, and (3) attitudes toward rice price increase; each with the income class. Although the price of rice increase, consumers of middle and upper-middle were remain loyal to the quality of rice they consumed. This indicates rice market in Bandung city is an ideal market for premium rice so that traders and producers are expected to maintain the quality of rice, such as keep using superior seeds and applying good cultivation based on Good Agricultural Practice (GAP) rules.

  4. Heavy metal toxicity in rice and soybean plants cultivated in contaminated soil

    Directory of Open Access Journals (Sweden)

    Maria Lígia de Souza Silva

    2014-04-01

    Full Text Available Heavy metals can accumulate in soil and cause phytotoxicity in plants with some specific symptoms. The present study evaluated the specific symptoms on rice and soybeans plants caused by excess of heavy metals in soil. Rice and soybean were grown in pots containing soil with different levels of heavy metals. A completely randomized design was used, with four replications, using two crop species and seven sample soils with different contamination levels. Rice and soybean exhibited different responses to the high concentrations of heavy metals in the soil. Rice plants accumulated higher Cu, Mn, Pb and Zn concentrations and were more sensitive to high concentrations of these elements in the soil, absorbing them more easily compared to the soybean plants. However, high available Zn concentrations in the soil caused phytotoxicity symptoms in rice and soybean, mainly chlorosis and inhibited plant growth. Further, high Zn concentrations in the soil reduced the Fe concentration in the shoots of soybean and rice plants to levels considered deficient.

  5. Assessing farmers' community readiness towards the enhancement of natural enemy population in rice fields in Malacca

    Science.gov (United States)

    Fairuz, K.; Idris, A. G.; Syahrizan, S.; Hatijah, K.

    2018-04-01

    Malacca has committed to be a green technology state by the year 2020. Agriculture is one of the main industries that have been highlighted to achieve this goal especially rice farming activities. Some limitations for this issue have restricted the accomplishment of the plan including pesticide usage among rice farmers. The use of chemicals in rice field need to be reduced significantly in order to support the goal. One of the indicators to the successfulness of pesticide reduction is the increasing numbers of natural enemies' species abundance and population in the rice field. Natural enemies were important to regulate pest populations in rice field naturally. Farmers' readiness to participate in this issue is very important to ensure the successfulness. The level of readiness of farmers' community will determine whether they are ready or not to execute the plan. Unfortunately, such information in rice farmers' community was not properly measured. Thus this study was aimed to assess the readiness level of rice farmers' community to change in order to enhance natural enemies in their rice field. This study was adapting the CR model as its theoretical framework. Three rice farming area in Malacca were involved in this study namely, Jasin, Melaka Tengah and Alor Gajah. Questionnaires were used as major instrument and were randomly distributed to 224 farmers. Data collected were tested for their reliability, significance and level of readiness. Knowledge of issue, knowledge of effort and resources dimensions were found influencing the readiness dimension significantly, whilst the attitude and leadership dimensions were not. Generally, the level of readiness for farmers' community in Malacca was found in the sixth or initial stage, where some of them initially have started to practice a few related activities to enhance the natural enemies' population in their rice field. Continuous support and assistant from the leaders and local authorities are crucially needed in

  6. Distribution and Population Dynamics of Nematodes in a Rice Field and Pasture in India

    Science.gov (United States)

    Mishra, C. C.; Dash, M. C.

    1981-01-01

    Ecological studies on soil nematodes were made in a tropical rice field and pasture. Parasitic species were more diversified in the pasture than in the rice field. Eighty-six and sixty percent of total nematodes occurred in the top 10 cm in rice field and pasture, respectively. Nematodes were not randomly or uniformly dispersed but aggregated. Parasitic forms were most abundant and correlated with root biomass in the 0-15-cm soil layer, the greatest number usually occurring at the 10-15-cm depth at both sites. In summer, however, they were densest at the 15-30-cm depth. Microbivores were most frequent in the top 5 cm of both sites. Micellaneous feeders (food sources uncertain) usually occurred in highest densities at the 15-30-cm depth. Predators showed no distinct depth preference. Temperature and moisture of the soil apparently played an important role in regulating nematode population. Peak densities of 31.3 × 10⁴/m² and 21.6 × 10⁴/m² at a 30-cm depth occurred in January, while minimum densities of 5.0-5.3 × 10⁴/m² and 4.1 × 10⁴/m² occurred in July-October and April in rice field and pasture, respectively. Monthly mean biomass of nematodes was 23.8 ± 4.5 mg/m² in rice field and 11.5 ± 1.5 mg/m² in pasture. PMID:19300801

  7. Effects on wildlife of ethyl and methyl parathion applied to California rice fields

    Science.gov (United States)

    Custer, T.W.; Hill, E.F.; Ohlendorf, H.M.

    1985-01-01

    Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

  8. Radiotracer experiments on the desorption of iodine from paddy soil with and without rice plants

    International Nuclear Information System (INIS)

    Muramatsu, Yasuyuki; Uchida, Shigeo; Yoshida, Satoshi

    1991-01-01

    In order to assess the behavior of radioiodine in rice fields, we have performed laboratory experiments, using 125 I tracer, on the desorption phenomena of iodine from soil during rice cultivation. Most of the 125 I added to the soil was adsorbed by the soil solid phase at the beginning of the experiment. However, the iodine started to desorb into the soil solution with the growth of rice plants. The highest desorption rate of iodine was found around the flowering period, i.e. nearly 30% of the 125 I was desorbed from Ando soil into the soil solution. In contrast to this, no particular increase in the iodine desorption was observed from the uncultivated flooded soil. It was suggested that rice plants had some influence upon iodine desorption from soil and the desorption also depended on the soil types. (author)

  9. Chemical, Sensorial and Rheological Properties of a New Organic Rice Bran Beverage

    OpenAIRE

    Gerson Luis FACCIN; Letícia Adélia MIOTTO; Leila do Nascimento VIEIRA; Pedro Luiz Manique BARRETO; Edna Regina AMANTE

    2009-01-01

    Rice bran is a solid residue from rice polishing that is used in animal nutrition and rice oil production. Cultivation conditions with agro-toxics, lipids instability, and tendency for mycotoxin contamination restrict its application in human nutrition. Therefore, organic agriculture is an alternative to use the properties of rice bran. Rice bran beverage is a new cereal product from organic rice. This work presents the preliminary results of the chemical and rheological studies of a bath pas...

  10. Evaluation of Heavy Metals Contamination from Environment to Food Matrix by TXRF: The Case of Rice and Rice Husk

    Directory of Open Access Journals (Sweden)

    Fabjola Bilo

    2015-01-01

    Full Text Available This paper is devoted to the chemical analysis of contaminated soils of India and the rice grown in the same area. Total reflection X-ray fluorescence spectroscopy is a well-established technique for elemental chemical analysis of environmental samples, and it can be a useful tool to assess food safety. Metals uptake in rice crop grown in soils from different areas was studied. In this work soil, rice husk and rice samples were analyzed after complete solubilization of samples by microwave acid digestion. Heavy metals concentration detected in rice samples decreases in the following order: Mn > Zn > Cu > Ni > Pb > Cr. The metal content in rice husk was higher than in rice. This study suggests, for the first time, a possible role of heavy metals filter played by rice husk. The knowledge of metals sequestration capability of rice husk may promote some new management practices for rice cultivation to preserve it from pollution.

  11. Influence of Climate Factors on Rice Yields in Cambodia

    Directory of Open Access Journals (Sweden)

    Dek Vimean Pheakdey

    2017-12-01

    Full Text Available Temperature and precipitation have been known as the key determinant factors to affect rice production in climate change. In this study, the relationship between climate variables and rice yields during 1993–2012 in Cambodia was analyzed and evaluated. The Ordinary Least Squares analysis was applied to examine the relationship of three climate variables (TCV including maximum temperature, minimum temperature and rainfall against seasonal rice yields. By this period, a remarkable increasing trend of annual temperature was observed whilst rainfall was not significantly changed. The TCV explains approximately 63% and 56% of the variability of rice yields in wet and dry seasons, respectively. It is found that in Cambodia, non-climate factors such as fertilizers, water, cultivars, and soil fertility cause 40% variation to rice yields, whereas the remaining 60% can be influenced by climate variability. The levels of temperature difference (LTD between maximum and minimum temperatures of the wet season (WS and dry season (DS were 7.0 and 8.6 oC, respectively. The lower value of LTD may cause the reduction of rice in WS (2.2 tons/ha as compared to that of DS (3.0 tons/ha. Rice yield has increased 50.5% and 33.8% in DS and WS, respectively, may due to the improvement of rice cultivation practices in Cambodia such as the better use of fertilizers, pest and weed control, and irrigation, and more effective rice cultivated protocol, as the increased trend of temperature may detrimentally affect rice yield. The breeding of heat and drought tolerance rice varieties and development of irrigation system are effective to reduce the negative influence from climate change to rice production in Cambodia.

  12. Evaluation of Rice Resistance to Southern Rice Black-Streaked Dwarf Virus and Rice Ragged Stunt Virus through Combined Field Tests, Quantitative Real-Time PCR, and Proteome Analysis.

    Science.gov (United States)

    Wang, Zhenchao; Yu, Lu; Jin, Linhong; Wang, Wenli; Zhao, Qi; Ran, Longlu; Li, Xiangyang; Chen, Zhuo; Guo, Rong; Wei, Yongtian; Yang, Zhongcheng; Liu, Enlong; Hu, Deyu; Song, Baoan

    2017-02-22

    Diseases caused by southern rice black-streaked dwarf virus (SRBSDV) and rice ragged stunt virus (RRSV) considerably decrease grain yield. Therefore, determining rice cultivars with high resistance to SRBSDV and RRSV is necessary. In this study, rice cultivars with high resistance to SRBSDV and RRSV were evaluated through field trials in Shidian and Mangshi county, Yunnan province, China. SYBR Green I-based quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to quantitatively detect virus gene expression levels in different rice varieties. The following parameters were applied to evaluate rice resistance: acre yield (A.Y.), incidence of infected plants (I.I.P.), virus load (V.L.), disease index (D.I.), and insect quantity (I.Q.) per 100 clusters. Zhongzheyou1 (Z1) and Liangyou2186 (L2186) were considered the most suitable varieties with integrated higher A.Y., lower I.I.P., V.L., D.I. and I.Q. In order to investigate the mechanism of rice resistance, comparative label-free shotgun liquid chromatography tandem-mass spectrometry (LC-MS/MS) proteomic approaches were applied to comprehensively describe the proteomics of rice varieties' SRBSDV tolerance. Systemic acquired resistance (SAR)-related proteins in Z1 and L2186 may result in the superior resistance of these varieties compared with Fengyouxiangzhan (FYXZ).

  13. EFFECT OF COVER CROPS ON SOIL ATTRIBUTES, PLANT NUTRITION, AND IRRIGATED TROPICAL RICE YIELD

    Directory of Open Access Journals (Sweden)

    ANDRE FROES DE BORJA REIS

    2017-01-01

    Full Text Available In flood plains, cover crops are able to alter soil properties and significantly affect rice nutrition and yield. The aims of this study were to determine soil properties, plant nutrition, and yield of tropical rice cultivated on flood plains after cover crop cultivation with conventional tillage (CT and no-tillage system (NTS at low and high nitrogen (N fertilization levels. The experimental design was a randomized block in a split-split-plot scheme with four replications. In the main plots were cover crops sunhemp (Crotalaria juncea and C. spectabilis, velvet bean (Mucuna aterrima, jackbean (Canavalia ensiformis, pigeon pea (Cajanus cajan, Japanese radish (Raphanus sativus, cowpea (Vigna unguiculata and a fallow field. In the subplots were the tillage systems (CT or NTS. The nitrogen fertilization levels in the sub-subplots were (10 kg N ha-1 and 45 kg N ha-1. All cover crops except Japanese radish significantly increased mineral soil nitrogen and nitrate concentrations. Sunhemp, velvet bean, and cowpea significantly increased soil ammonium content. The NTS provides higher mineral nitrogen and ammonium content than that by CT. Overall, cover crops provided higher levels of nutrients to rice plants in NTS than in CT. Cover crops provide greater yield than fallow treatments. Rice yield was higher in NTS than in CT, and greater at a higher rather than lower nitrogen fertilization level.

  14. Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

    Science.gov (United States)

    Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

    2009-05-01

    The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product.

  15. Behavior of Foliares Applications of Humus Mixed with the NPK in Rice Cultivation (Oryza Sativa L..

    Directory of Open Access Journals (Sweden)

    Rolando Saborit Reyes

    2013-12-01

    Full Text Available Taking into consideration the observation of one green yellowsh clorosis in the plantations of rice, after the cold campaings and the disminishing of the agricultural efficiency of the cerial in areas of Saint Elena Land belonging to the fortified cooperatove of credits and service (FCCS Camilo Cienfuegos in Las Nuevas, La Sierpe, Province of Sancti – Spiritus, were done foliars aplications with mineral fertilizing as, N.P.K to different doses and moments of applications, in order to obtain alternative of nutrition for the cultivation, the work was done on a green yellowish ferralitic ground since 2009 to 2011, using LP-5 cultivation doing the sowing by the method of transplantation, fertilization. It was done mixing 49L. ha-¹ of liquid warm humus with 0.35 Kg. ha-¹ of nitrogen, phosphorus and potassium. The results shown that the use of the foliar fertilization with liquid worm humus mixed with the N.P.K minerals, increased the efficiency, obtaining 5.3t. ha-¹ as an average in different variants used. The economic analysis showed that the treatment with 40% of nitrogen was reduced with seven foliars applications, it was highest to the witness N.P.K in 1.5t . ha-¹ of the grain obtaining a relative benefit of 4264.55 pesos by hectarea.

  16. Restoration potential of sedge meadows in hand-cultivated soybean fields in northeastern China

    Science.gov (United States)

    Wang, Guodong; Middleton, Beth; Jiang, Ming

    2013-01-01

    Sedge meadows can be difficult to restore from farmed fields if key structural dominants are missing from propagule banks. In hand-cultivated soybean fields in northeastern China, we asked if tussock-forming Carex and other wetland species were present as seed or asexual propagules. In the Sanjiang Plain, China, we compared the seed banks, vegetative propagules (below-ground) and standing vegetation of natural and restored sedge meadows, and hand-cultivated soybean fields in drained and flooded conditions. We found that important wetland species survived cultivation as seeds for some time (e.g. Calamogrostis angustifolia and Potamogeton crispus) and as field weeds (e.g. C. angustifolia and Phragmites australis). Key structural species were missing in these fields, for example, Carex meyeriana. We also observed that sedge meadows restored without planting or seeding lacked tussock-forming sedges. The structure of the seed bank was related to experimental water regime, and field environments of tussock height, thatch depth, and presence of burning as based on Nonmetric Multidimensional Scaling analysis. To re-establish the structure imposed by tussock sedges, specific technologies might be developed to encourage the development of tussocks in restored sedge meadows.

  17. Deciphering the role of a miRNA in rice domestication

    Directory of Open Access Journals (Sweden)

    Swetha Chenna

    2017-10-01

    Full Text Available MicroRNAs (miRNAs are a class of 21 nt non-coding small RNAs (sRNAs produced from endogenously expressed MIR genes. miRNAs are mostly involved in development and disease resistance. We are interested in identifying key miRNAs that are differentially expressed among wild and cultivated rice species. Analysis of sRNA datasets from two wild species (O. nivara and O. rufipogon and one cultivated species of rice (O. sativa var. indica Pusa Basmati-1, revealed a surprisingly higher abundance of small RNAs originating from Chromosome 2 in wild rice species. This locus codes for a novel 22 nt miRNA. This novel miRNA was found to be highly abundant in flag leaf of wild species, a tissue that usually provides 70% of energy required for grain filling. This miRNA targets a group of proteins (Os03g0273200, Os01g0827300, Os01g0850700, Os11g0708100 and Os01g0842500 which are involved in secondary metabolite production, although a functional significance of this interaction has not been understood. The expression of these targets also differs across the species. Typical of 22 nt miRNAs, the identified miRNA also triggers a secondary cascade silencing by producing small interfering RNAs (siRNAs from target mRNAs in O. nivara. These secondary siRNAs are observed only among wild rice species but not in cultivated rice. Currently we are using a range of genetic, biochemical and molecular techniques to understand role of this novel miRNA in domestication of rice.

  18. Phenotype diversity analysis of red-grained rice landraces from Yuanyang Hani's terraced fields, China

    Science.gov (United States)

    Li, Lianjie; Cheng, Long

    2017-10-01

    There are many areas in the world have terraced fields, Yuanyang Rani's terraced fields are examples in the world, and their unique ecological diversity is beyond other terraced fields, rice landraces are very rich. In order to provide useful information for protection and utilization of red-grained rice landraces from Rani's terraced fields, 61 red-grained rice landraces were assessed based 20 quantitative traits. Principal component analysis (PCA) suggested that 20 quantitative characters could be simplified to seven principal components, and their accumulative contribution ration amounted to 78.699%. The first principal component (PC1) explained 18.375% of the total variance, which was contributed by filled grain number, 1000-grain weight, spikelets per panicle, secondary branch number, grain length, and grain thickness. PC2 accounted for 16.548% of the variance and featured flag leaf width, flag leaf area, panicle neck length and primary branch number. These traits were the most effective parameters to discriminate individuals. At the request of the proceedings editor and with the approval of all authors, article 040111 titled, "Phenotype diversity analysis of red-grained rice landraces from Yuanyang Hani's terraced fields, China," is being retracted from the public record due to the fact that it is a duplication of article 040110 published in the same volume.

  19. Soil erosion from shifting cultivation and other smallholder land use in Sarawak, Malaysia

    DEFF Research Database (Denmark)

    Neergaard, Andreas de; Magid, Jakob; Mertz, Ole

    2008-01-01

    to compare soil erosion from three land use types in a shifting cultivation system, namely upland rice, pepper gardens and native forest. We used two sample sites within the humid tropical lowland zone in Sarawak, Malaysia. Both areas had steep slopes between 25° and 50°, and were characterised by a mosaic...... land use of native forest, secondary re-growth, upland rice fields and pepper gardens. Soil samples were collected to 90 cm depth from all three land use types, and analysed for various chemical parameters, including texture, total organic matter and 137Cs content. 137Cs is a radioactive isotope...... in the upper soil layers, are unlikely to change the carbon inventory dramatically. 137Cs content in the soil profile indicated largest retention of original topsoil in the native forest plots, and a loss of 18 and 35% of topsoil from upland rice and pepper gardens, respectively, over the past 40 years. When...

  20. Irradiation with protons in order to obtain new rice varieties

    International Nuclear Information System (INIS)

    Gonzalez, Maria C.; Cristo, Elizabeth; Fuentes, Jorge L.

    2001-01-01

    In the Laboratory of Genetics and Improvement of the National Institute of Agricultural Sciences was developed a Program of Genetic Improvement using Biotechnical and Nuclear Techniques in order to obtain new rice varieties of high yield potential under drought stress condition. For them different explants types were used starting from seeds of the Cuban variety of rice Amistad 82 irradiated with protons in dose of 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 Gy. The explants were cultivated in vitro in order to obtaining callus and later plant regenerate. The plant selected in vitro was multiplied being carried out several selection cycles under field conditions. A remarkable stimulation was observed from the regeneration of plants when using dose of 20 Gy and it was possible to select 4 promising lines that differ of the donor as for cycle, architecture of the plant and tolerance to drought. Tjis result demonstrates the potentialities of this radiation source for obtaining of new rice varieties

  1. Genetic control of a transition from black to straw-white seed hull in rice domestication.

    Science.gov (United States)

    Zhu, Bo-Feng; Si, Lizhen; Wang, Zixuan; Zhou, Yan; Zhu, Jinjie; Shangguan, Yingying; Lu, Danfeng; Fan, Danlin; Li, Canyang; Lin, Hongxuan; Qian, Qian; Sang, Tao; Zhou, Bo; Minobe, Yuzo; Han, Bin

    2011-03-01

    The genetic mechanism involved in a transition from the black-colored seed hull of the ancestral wild rice (Oryza rufipogon and Oryza nivara) to the straw-white seed hull of cultivated rice (Oryza sativa) during grain ripening remains unknown. We report that the black hull of O. rufipogon was controlled by the Black hull4 (Bh4) gene, which was fine-mapped to an 8.8-kb region on rice chromosome 4 using a cross between O. rufipogon W1943 (black hull) and O. sativa indica cv Guangluai 4 (straw-white hull). Bh4 encodes an amino acid transporter. A 22-bp deletion within exon 3 of the bh4 variant disrupted the Bh4 function, leading to the straw-white hull in cultivated rice. Transgenic study indicated that Bh4 could restore the black pigment on hulls in cv Guangluai 4 and Kasalath. Bh4 sequence alignment of all taxa with the outgroup Oryza barthii showed that the wild rice maintained comparable levels of nucleotide diversity that were about 70 times higher than those in the cultivated rice. The results from the maximum likelihood Hudson-Kreitman-Aguade test suggested that the significant reduction in nucleotide diversity in rice cultivars could be caused by artificial selection. We propose that the straw-white hull was selected as an important visual phenotype of nonshattered grains during rice domestication.

  2. Methane Emissions and Microbial Communities as Influenced by Dual Cropping of Azolla along with Early Rice

    Science.gov (United States)

    Liu, Jingna; Xu, Heshui; Jiang, Ying; Zhang, Kai; Hu, Yuegao; Zeng, Zhaohai

    2017-01-01

    Azolla caroliniana Willd. is widely used as a green manure accompanying rice, but its ecological importance remains unclear, except for its ability to fix nitrogen in association with cyanobacteria. To investigate the impacts of Azolla cultivation on methane emissions and environmental variables in paddy fields, we performed this study on the plain of Dongting Lake, China, in 2014. The results showed that the dual cropping of Azolla significantly suppressed the methane emissions from paddies, likely due to the increase in redox potential in the root region and dissolved oxygen concentration at the soil-water interface. Furthermore, the floodwater pH decreased in association with Azolla cultivation, which is also a factor significantly correlated with the decrease in methane emissions. An increase in methanotrophic bacteria population (pmoA gene copies) and a reduction in methanogenic archaea (16S rRNA gene copies) were observed in association with Azolla growth. During rice cultivation period, dual cropping of Azolla also intensified increasing trend of 1/Simpson of methanogens and significantly decreased species richness (Chao 1) and species diversity (1/Simpson, 1/D) of methanotrophs. These results clearly demonstrate the suppression of CH4 emissions by culturing Azolla and show the environmental and microbial responses in paddy soil under Azolla cultivation.

  3. Metabolic fate of 14-C-fenitrothion in a rice field model ecosystem

    International Nuclear Information System (INIS)

    Nashriyah binti Mat; Nambu, K.; Miyashita, T.; Sakata, S.; Ohshima, M.

    1991-01-01

    Pesticide fenitrothion (Sumithion sup R)is widely used to control rice stem borer and other pests. Its metabolic fate and degradation was studied using the sup 14 C-ring labelled fenitrothion in a model ecosystem consisting of Takarazuka paddy field soil, rice plant (Oryza sativa var. nihonbare), carp fish (Cyprinus carpio L.) and dechlorinated water. Radioactive fenitrothion was applied at a normal rate as used by Japanese farmers and samples of rice plant, fish soil and water were analysed after ten days of application. Fenitrothion was readily metabolized in rice plant and fish and also readily degraded to a number of metabolites in water and flooded soil. Most of the radioactivity applied was found in the soil component of the ecosystem. A trace amount of fenitrooxon, the activated metabolite of fenitrothion was detected only in soil and water. A possible metabolic pathway of fenitrothion in the rice model ecosystem was proposed

  4. Suitability assessment and mapping of Oyo State, Nigeria, for rice cultivation using GIS

    Science.gov (United States)

    Ayoade, Modupe Alake

    2017-08-01

    Rice is one of the most preferred food crops in Nigeria. However, local rice production has declined with the oil boom of the 1970s causing demand to outstrip supply. Rice production can be increased through the integration of Geographic Information Systems (GIS) and crop-land suitability analysis and mapping. Based on the key predictor variables that determine rice yield mentioned in relevant literature, data on rainfall, temperature, relative humidity, slope, and soil of Oyo state were obtained. To develop rice suitability maps for the state, two MCE-GIS techniques, namely the Overlay approach and weighted linear combination (WLC), using fuzzy AHP were used and compared. A Boolean land use map derived from a landsat imagery was used in masking out areas currently unavailable for rice production. Both suitability maps were classified into four categories of very suitable, suitable, moderate, and fairly moderate. Although the maps differ slightly, the overlay and WLC (AHP) approach found most parts of Oyo state (51.79 and 82.9 % respectively) to be moderately suitable for rice production. However, in areas like Eruwa, Oyo, and Shaki, rainfall amount received needs to be supplemented by irrigation for increased rice yield.

  5. Geographic authentication of Asian rice (Oryza sativa L.) using multi-elemental and stable isotopic data combined with multivariate analysis.

    Science.gov (United States)

    Chung, Ill-Min; Kim, Jae-Kwang; Lee, Kyoung-Jin; Park, Sung-Kyu; Lee, Ji-Hee; Son, Na-Young; Jin, Yong-Ik; Kim, Seung-Hyun

    2018-02-01

    Rice (Oryza sativa L.) is the world's third largest food crop after wheat and corn. Geographic authentication of rice has recently emerged asan important issue for enhancing human health via food safety and quality assurance. Here, we aimed to discriminate rice of six Asian countries through geographic authentication using combinations of elemental/isotopic composition analysis and chemometric techniques. Principal components analysis could distinguish samples cultivated from most countries, except for those cultivated in the Philippines and Japan. Furthermore, orthogonal projection to latent structure-discriminant analysis provided clear discrimination between rice cultivated in Korea and other countries. The major common variables responsible for differentiation in these models were δ 34 S, Mn, and Mg. Our findings contribute to understanding the variations of elemental and isotopic compositions in rice depending on geographic origins, and offer valuable insight into the control of fraudulent labeling regarding the geographic origins of rice traded among Asian countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. [Effects of mechanical transplanting of rice with controlled release bulk blending fertilizer on rice yield and soil fertility].

    Science.gov (United States)

    Zhang, Xuan; Ding, Jun-Shan; Liu, Yan-Ling; Gu, Yan; Han, Ke-Feng; Wu, Liang-Huan

    2014-03-01

    Abstract: A 2-year field experiment with a yellow-clay paddy soil in Zhejiang Province was conducted to study the effects of different planting measures combined with different fertilization practices on rice yield, soil nutrients, microbial biomass C and N and activities of urease, phosphatase, sucrase and hydrogen peroxidase at the maturity stage. Results showed that mechanical transplanting of rice with controlled release bulk blending (BB) fertilizer (BBMT) could achieve a significantly higher mean yield than traditional manual transplanting with traditional fertilizer (TFTM) and direct seeding with controlled release BB fertilizer (BBDS) by 16.3% and 27.0%, respectively. The yield by BBMT was similar to that by traditional manual transplanting with controlled release BB fertilizer (BBTM). Compared with TFTM, BBMT increased the contents of soil total-N, available N, available P and microbial biomass C, and the activities of urease, sucrase and hydrogen peroxidase by 21.5%, 13.6%, 41.2%, 27.1%, 50.0%, 22.5% and 46.2%, respectively. Therefore, BBMT, a simple high-efficiency rice cultivation method with use of a light-weighted mechanical transplanter, should be widely promoted and adopted.

  7. Improving Former Shifted Cultivation Land Using Wetland Cultivation in Kapuas District, Central Kalimantan

    Directory of Open Access Journals (Sweden)

    Wahyudi Wahyudi

    2016-06-01

    Full Text Available Degraded forest area in Kalimantan could be caused by shifted cultivation activity that be conducted by local peoples in the surrounding forest areas. Efforts to improve the former shifted cultivation area (non productive land is developing the settled cultivation by use of irrigation system, better paddy seed, land processing, fertilizing, spraying pesticide, weeding, and better acces to the market.  Local peoples, especially in Kalimantan, has been depended their food on the shifted cultivation pattern since the long time ago.  This tradition could cause forest damage, forest fire, forest degradation, deforestation, and lose out of children education because they were following shifted cultivation activity although itsspace is very far from their home.  This research was aimed to improve former shifted cultivation lands using wetland cultivation in order to improve land productivity and to support food securityin the local community. This research was administratively located in Tanjung Rendan Village, Kapuas Hulu Sub-Ddistrict, Kapuas District, Central Kalimantan Province, Indonesia.  Data of rice yield from settled cultivation and shifted cultivation were got from 15 households that was taking by random at 2010 to 2011. Homogeneity test, analysis of variants, and least significant different (LSD test using SPSS 15.0 for Windows. Result of this research showed that     paddy yield at settled cultivation was significantly differentand better than shifted cultivation at 0.05 level. LSD test also indicated that all paddy yields from settled cultivation were significantly different compare to shifted cultivation at the 0.05 level.  The community in Tanjung Rendan Villages preferred settled cultivation than shifted cultivation, especially due to higher paddy production. Profit for settled cultivation was IDR10.95 million ha-1, meanwhile profit for shifted cultivation was just IDR 2.81 million ha-1 only.  Settled cultivation pattern could

  8. The improvement of rice varieties for major pest and diseases resistance

    International Nuclear Information System (INIS)

    Sahi, I.; Silitonga, T.S.

    1988-01-01

    Since 1971, the rice breeding program in Indonesia has developed on intensive program to improve varieties for yield potential, resistancy to major pests and diseases, early maturity good grain and eating quality. In recent years, the attacks of insects and diseases are very severe in rice cultivation in Asia. Much of the losses were due to acontinuous planting or certain varieties. Between 1966 and 1973 tungro occured in epidemic proportions on separate occasions in Indonesia, Thailand, Nort East India, Bangladesh, and Philippine. Since 1973, investation of brown planthopper and green leafhopper several damaged rice crop in most parts of Indonesia. Presently, rice improvement are directed to develop high yielding rice varieties that are resistant to brown planthopper, ragged stunt virus, blast, green leafhopper, and gallmidge. Screening for pests and diseases are conducted in the laboratory as well as in the field. The adoption of those improved varieties by farmers has contributed greatly in our efforts to attain self sufficiency in rice production in Indonesia. GH 147 -M-40 krad-Pn-89 (irradiated Barito) showed resistant to brown planthopper biotype 1 and 2 and moderately resistant to biotype 3. Napa 40 krad-St-12 has resistant reaction to blast. (authors). 4 refs, 8 tabs

  9. Rice yield in response to climate trends and drought index in the Mun River Basin, Thailand

    NARCIS (Netherlands)

    Prabnakom, S.; Maskey, S.; Suryadi, F.X.; Fraiture, de C.M.S.

    2018-01-01

    Rice yields in Thailand are among the lowest in Asia. In northeast Thailand where about 90% of rice cultivation is rain-fed, climate variability and change affect rice yields. Understanding climate characteristics and their impacts on the rice yield is important for establishing proper adaptation

  10. Identification of heterotic loci associated with yield-related traits in Chinese common wild rice (Oryza rufipogon Griff.).

    Science.gov (United States)

    Luo, Xiaojin; Wu, Shuang; Tian, Feng; Xin, Xiaoyun; Zha, Xiaojun; Dong, Xianxin; Fu, Yongcai; Wang, Xiangkun; Yang, Jinshui; Sun, Chuanqing

    2011-07-01

    Many rice breeding programs have currently reached yield plateaus as a result of limited genetic variability in parental strains. Dongxiang common wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.) and serves as an important gene pool for the genetic improvement of rice cultivars. In this study, heterotic loci (HLs) associated with six yield-related traits were identified in wild and cultivated rice and investigated using a set of 265 introgression lines (ILs) of O. rufipogon Griff. in the background of the Indica high-yielding cultivar Guichao 2 (O. sativa L.). Forty-two HLs were detected by a single point analysis of mid-parent heterosis values from test cross F(1) offspring, and 30 (71.5%) of these HLs showed significantly positive effects, consistent with the superiority shown by the F(1) test cross population in the six yield-related traits under study. Genetic mapping of hsp11, a locus responsible for the number of spikelets per panicle, confirmed the utility of these HLs. The results indicate that favorable HLs capable of improving agronomic traits are available. The identification of HLs between wild rice and cultivated rice could lead to a new strategy for the application of heterosis in rice breeding. Copyright © 2011. Published by Elsevier Ireland Ltd.

  11. Less adaption of newly approved variety Basmati 515 among aromatic basmati rice varieties in Kallar Tract of Punjab, Pakistan

    Directory of Open Access Journals (Sweden)

    Muhammad Tahir Latif

    2017-12-01

    Full Text Available A field survey was conducted after harvesting of rice crop 2016 to identify the reasons for less adaption of aromatic rice variety Basmati 515. The rice growers adopting rice-wheat cropping pattern in kallar tract were included in population of research study. Thirty male farmers from each selected district making a total of 180 respondent farmers were interviewed by convenience sampling method. The survey findings showed that the aromatic rice variety Basmati 515 was cultivated on only 2.7% rice area while maximum area (47.3% was under Super basmati variety. The comparison of Basmati 515 was made with Super basmati and PS 2 due to comparatively more cultivated area and declared yield potential of these varieties. Overall the farmers were applying under dosed phosphorus fertilizer (DAP as 0.25, 0.20 and 0.22 bag ha-1 respectively for basmati 515, super basmati and PS-2 varieties. The descriptive analysis showed that the less adaptability of basmati 515 was due to less yield and more attacks of borer (11%, BLB (10% and leaf roller (3.25% in comparison to other aromatic and fine rice varieties. Similarly maximum lodging (16% was recorded on basmati 515. Maximum yield was estimated for PS 2 variety (4.7 t ha-1 followed by super basmati (4.0 t ha-1 and basmati 515 (3.78 t ha-1. The market price of super basmati was still higher due to its natural aroma, long & thin grain and export demand. The research institutes should focus for development of new aromatic high yielding and more qualitative rice varieties to increase the rice production and export.

  12. Diseases of wild rice

    Science.gov (United States)

    Diseases are much more pronounced in cultivated wild rice than in natural stands, most likely due to the narrower genetic base of the populations, plant stress due to high planting density and floodwater removal prior to harvest, and high relative humidity in the plant canopy. Yield losses occur as ...

  13. Impact of Organic Amendments on Global Warming Potential of Diversified Tropical Rice Rotation Systems

    Science.gov (United States)

    Janz, B.; Weller, S.; Kraus, D.; Wassmann, R.; Butterbach-Bahl, K.; Ralf, K.

    2017-12-01

    Paddy rice cultivation is increasingly challenged by irrigation water scarcity, which is forcing farmers to change traditional rice cultivation from flooded double-rice systems to the introduction of well-aerated upland crops during dry season. Emissions of methane (CH4) are expected to decrease, while there is a risk of increasing emissions of nitrous oxide (N2O) and decreasing soil organic carbon (SOC) stocks through volatilization in the form of carbon dioxide (CO2). We present a unique dataset of long-term continuous greenhouse gas emission measurements (CH4 and N2O) in the Philippines to assess global warming potentials (GWP) of diversified rice crop rotations including different field management practices such as straw residue application and legume intercropping. Since 2012, more than four years of CH4 and N2O emissions in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) during dry season have been collected. Introduction of upland crops reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Although dry season N2O emissions increased twice- to threefold in the diversified systems, the strong reduction of CH4 led to a significantly lower annual GWP (CH4 + N2O) as compared to the traditional R-R system. Diversified crop management practices were first implemented during land-preparation for dry season 2015 where i) 6 t/ha rice straw was returned to the field and ii) mungbean was grown as a cover-crop between dry and wet season in addition to rice straw application. The input of organic material (straw and mungbean) led to higher substrate availability for methanogens during the following season. Therefore, GWP was 9-39% higher following straw incorporation than the control treatment. This increase was mainly driven by additional CH4 emissions. Even more, mungbean intercropping further increased GWPs, whereby the increment was highest in R-R rotation (88%) and lowest in R

  14. 有机水稻的种植技术研究%Research of Organic rice cultivation technology

    Institute of Scientific and Technical Information of China (English)

    雷燕铭

    2013-01-01

      近年来,随着我国国民经济的发展,国民对生态环境问题普遍关注,对食品安全和无公害要求进一步提高。在此基础上,安全、清洁、无污染的有机农业逐渐兴起,成为种植业的发展热点。文章以有机水稻的种植为切入点,结合笔者自身工作经验和福建省的探索实例,介绍了有机农业与有机水稻技术,从有机水稻的种植条件、土肥管理、育苗管理、秧田管理、病虫害防治等方面,浅谈了有机水稻的种植技术。%In recent years, with the development of China's national economy,people pay more attention on issues of the environment and they have higher requirements about food safety and pollution-free food. On this basis, safe, clean, non-polluting organic agriculture is gradually emerging as a growing industry . The articles analyses organic rice cultiva-tion as the starting point,according to the author's own work experience and exploring examples of Fujian Province, the ar-ticle introduces the technology of organic agriculture and organic rice and analyses organic rice planting techniques from aspects of growing conditions and soil and fertilizer management and nursery management and seedling management and pest control, etc.

  15. Endophytic Colonization and In Planta Nitrogen Fixation by a Herbaspirillum sp. Isolated from Wild Rice Species

    Science.gov (United States)

    Elbeltagy, Adel; Nishioka, Kiyo; Sato, Tadashi; Suzuki, Hisa; Ye, Bin; Hamada, Toru; Isawa, Tsuyoshi; Mitsui, Hisayuki; Minamisawa, Kiwamu

    2001-01-01

    Nitrogen-fixing bacteria were isolated from the stems of wild and cultivated rice on a modified Rennie medium. Based on 16S ribosomal DNA (rDNA) sequences, the diazotrophic isolates were phylogenetically close to four genera: Herbaspirillum, Ideonella, Enterobacter, and Azospirillum. Phenotypic properties and signature sequences of 16S rDNA indicated that three isolates (B65, B501, and B512) belong to the Herbaspirillum genus. To examine whether Herbaspirillum sp. strain B501 isolated from wild rice, Oryza officinalis, endophytically colonizes rice plants, the gfp gene encoding green fluorescent protein (GFP) was introduced into the bacteria. Observations by fluorescence stereomicroscopy showed that the GFP-tagged bacteria colonized shoots and seeds of aseptically grown seedlings of the original wild rice after inoculation of the seeds. Conversely, for cultivated rice Oryza sativa, no GFP fluorescence was observed for shoots and only weak signals were observed for seeds. Observations by fluorescence and electron microscopy revealed that Herbaspirillum sp. strain B501 colonized mainly intercellular spaces in the leaves of wild rice. Colony counts of surface-sterilized rice seedlings inoculated with the GFP-tagged bacteria indicated significantly more bacterial populations inside the original wild rice than in cultivated rice varieties. Moreover, after bacterial inoculation, in planta nitrogen fixation in young seedlings of wild rice, O. officinalis, was detected by the acetylene reduction and 15N2 gas incorporation assays. Therefore, we conclude that Herbaspirillum sp. strain B501 is a diazotrophic endophyte compatible with wild rice, particularly O. officinalis. PMID:11679357

  16. Metaproteomic identification of diazotrophic methanotrophs and their localization in root tissues of field-grown rice plants.

    Science.gov (United States)

    Bao, Zhihua; Okubo, Takashi; Kubota, Kengo; Kasahara, Yasuhiro; Tsurumaru, Hirohito; Anda, Mizue; Ikeda, Seishi; Minamisawa, Kiwamu

    2014-08-01

    In a previous study by our group, CH4 oxidation and N2 fixation were simultaneously activated in the roots of wild-type rice plants in a paddy field with no N input; both processes are likely controlled by a rice gene for microbial symbiosis. The present study examined which microorganisms in rice roots were responsible for CH4 oxidation and N2 fixation under the field conditions. Metaproteomic analysis of root-associated bacteria from field-grown rice (Oryza sativa Nipponbare) revealed that nitrogenase complex-containing nitrogenase reductase (NifH) and the alpha subunit (NifD) and beta subunit (NifK) of dinitrogenase were mainly derived from type II methanotrophic bacteria of the family Methylocystaceae, including Methylosinus spp. Minor nitrogenase proteins such as Methylocella, Bradyrhizobium, Rhodopseudomonas, and Anaeromyxobacter were also detected. Methane monooxygenase proteins (PmoCBA and MmoXYZCBG) were detected in the same bacterial group of the Methylocystaceae. Because these results indicated that Methylocystaceae members mediate both CH4 oxidation and N2 fixation, we examined their localization in rice tissues by using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The methanotrophs were localized around the epidermal cells and vascular cylinder in the root tissues of the field-grown rice plants. Our metaproteomics and CARD-FISH results suggest that CH4 oxidation and N2 fixation are performed mainly by type II methanotrophs of the Methylocystaceae, including Methylosinus spp., inhabiting the vascular bundles and epidermal cells of rice roots. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  17. A dynamic compartment model for assessing the transfer of radionuclide deposited onto flooded rice-fields

    International Nuclear Information System (INIS)

    Keum, Dong-Kwon; Lee, Han-Soo; Choi, Heui-Ju; Kang, Hee-Seok; Lim, Kwang-Muk; Choi, Young-Ho; Lee, Chang-Woo

    2004-01-01

    A dynamic compartment model has been studied to estimate the transfer of radionuclides deposited onto flooded rice-fields after an accidental release. In the model, a surface water compartment and a direct shoot-base absorption from the surface water to the rice-plant, which are major features discriminating the present model from the existing model, has been introduced to account for the flooded condition of rice-fields. The model has been applied to the deposition experiments of 137 Cs on rice-fields that were performed at three different times to simulate the deposition before transplanting (May 2) and during the growth of the rice (June 1 and August 12), respectively. In the case of the deposition of May 2, the root-uptake is the most predominant process for transferring 137 Cs to the rice-body and grain. When the radionuclide is applied just after transplanting (June 1), the activity of the body is controlled by the shoot-base absorption and the activity of the grain by the root-uptake. The deposition just before ear-emergence (August 12) shows that the shoot-base absorption contributes entirely to the increase of both the activities of the body and grain. The model prediction agrees within one or two factors with the experimental results obtained for a respective deposition experiment

  18. The yield and quality of black rice varieties in different altitude

    Science.gov (United States)

    Purwanto, E.; Hidayati, W.; Nandariyah

    2018-03-01

    This study aims to determine the optimal environmental conditions and corresponding black rice varieties in order to produce high production and optimum quality rice. The study using nested design, first was location (2 levels: the highlands and lowland), second was varieties (3 levels: Cempo Ireng, IPB, and Gagak) the study was conducted from November 2015 until May 2016 in Karanglo and Gutanon village, Karanganyar. Anthocyanin analysis conducted in laboratory of Nutrition and Food, Faculty of Agriculture, Sebelas Maret University. Data were analyzed using analysis of variance and significant difference continued with DMRT (Duncan Multiple Range Test) level of 5%. Results showed that cultivation in highlands and use of diverse varieties showed different quantity of rice that can be seen on panicle length, and weight of grain crops. Improved quality of results showed same things, anthocyanin content and iron increased on black rice which cultivated in highlands.

  19. Effects of wildlife of ethyl and methyl parathion applied to California USA rice fields

    Science.gov (United States)

    Custer, T.W.; Hill, E.F.; Ohlendorf, H.M.

    1985-01-01

    Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

  20. Toxicity evaluation of natural samples from the vicinity of rice fields using two trophic levels.

    Science.gov (United States)

    Marques, Catarina R; Pereira, Ruth; Gonçalves, Fernando

    2011-09-01

    An ecotoxicological screening of environmental samples collected in the vicinity of rice fields followed a combination of physical and chemical measurements and chronic bioassays with two freshwater trophic levels (microalgae: Pseudokirchneriella subcapitata and Chlorella vulgaris; daphnids: Daphnia longispina and Daphnia magna). As so, water and sediment/soil elutriate samples were obtained from three sites: (1) in a canal reach crossing a protected wetland upstream, (2) in a canal reach surrounded by rice fields and (3) in a rice paddy. The sampling was performed before and during the rice culture. During the rice cropping, the whole system quality decreased comparatively to the situation before that period (e.g. nutrient overload, the presence of pesticides in elutriates from sites L2 and L3). This was reinforced by a significant inhibition of both microalgae growth, especially under elutriates. Contrary, the life-history traits of daphnids were significantly stimulated with increasing concentrations of water and elutriates, for both sampling periods.

  1. SUSTAINING PADDY SELF-SUFFICIENCY AND LAND DEMANDS IN SABAH, MALAYSIA: A STRUCTURAL PADDY AND RICE ECONOMETRIC MODEL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Wong Kelly_Kai_Seng

    2017-01-01

    Full Text Available The objective of this study is to construct an econometric commodity model in order to forecast the long term rice production performance of the state of Sabah, Malaysia. The baseline projection shows that the Sabah rice self-sufficiency is estimated to achieve approximately38% in the next 10 years due to the scarcity of the suitable land bank allocate for paddy cultivation. In order to achieve 60% of targeted rice self-sufficiency level (SSL, the size of land for paddy cultivation must be increased in Sabah. Based on the scenario simulation projection result, the expansion of paddy cultivation area will contribute a positively to the industrial rice production and consequently achieving the expected 60% of SSL by the end of 2024. In a nutshell, the state government of Sabah possess state autonomy on the land management, thus the state government plays a significant key role on promoting the local rice self-sufficiency level in the long-term period

  2. Interactive effects of straw-derived biochar and N fertilization on soil C storage and rice productivity in rice paddies of Northeast China

    International Nuclear Information System (INIS)

    Sui, Yanghui; Gao, Jiping; Liu, Caihong; Zhang, Wenzhong; Lan, Yu; Li, Shuhang; Meng, Jun; Xu, Zhengjin; Tang, Liang

    2016-01-01

    Impacts of biochar on greenhouse gas emissions and C sequestration in agricultural soils have been considered as the key to mitigate climate change. There is limited knowledge regarding the effects of rice straw-derived biochar and interaction with N fertilization on soil C sequestration and rice productivity in fertile paddy fields. A 2-year (2013 and 2014) consecutive field trial was performed using straw treatment (5.05 t ha −1 ) and biochar amendment (0, 1.78, 14.8 and 29.6 t ha −1 ) with or without urea application in a rice paddy in Northeast China. A super high yielding rice variety (Oryza sativa L. subsp. Japonica cv. ‘Shennong 265’) was cultivated with permanent flooding. Results showed that biochar amendments significantly decreased CH 4 emissions relative to straw treatment irrespective of N fertilization, especially in N-fertilized soils with 1.78 t ha −1 biochar. There were no differences in CO 2 emissions with respect to biochar amendments, except for 14.8 t ha −1 biochar with N fertilization. Straw treatment had the highest global warming potential over a 100-year time frame, which was nearly 1.5 times that of 14.8 t ha −1 biochar amendment without N fertilization. Biochar addition increased total soil C by up to 5.75 mg g −1 and 11.69 mg g −1 (with 14.8 and 29.6 t ha −1 biochar, respectively), whereas straw incorporation increased this value by only 3.92 mg g −1 . The aboveground biomass of rice in biochar-amended soils increased to varying degrees compared with that in straw-treated soils. However, biochar application had no effects on rice yield, regardless of N fertilization. This study indicated that transforming straw to biochar was more stabilized and more suitable to mitigate greenhouse gas emissions and increase C storage in agriculture soils in Northeast China. - Highlights: • Rice straw-derived biochar significantly reduced CH 4 emission. • Rice straw-derived biochar interacted with the effects of N fertilizers on

  3. GENE FLOW BETWEEN RED RICE AND CULTIVATED RICE ESTIMATED BY MICROSATELLITE MARKERS FLUXO GÊNICO ENTRE ARROZ VERMELHO E ARROZ CULTIVADO ESTIMADO POR MEIO DE MARCADORES MICROSSATÉLITES

    Directory of Open Access Journals (Sweden)

    Francisco , Moura Neto

    2007-09-01

    Full Text Available

    The study aimed to evaluate the capacity of SSR markers to detect the gene flow between the red rice (RR and the cultivated rice (CR. SSR is currently used in plant genomic analysis due to the high information content, to be co-dominant, and based on the PCR reaction. The field experiment was organized in ten concentric circles, 5 m to 50 m apart from a central red rice plant, assumed as the pollen donor. One hundred twenty rice CR plants, cv. BR-Irga 409, were planted in the intersections of the concentric circles and the twelve radii. From 51 SSR markers, four were selected due to their capacity to detect the polymorphism between RR and CR, aiming to identify RR alleles in seeds produced by BR-Irga 409 plants. The maximum distance found for gene flow between RR and CR plants was 10 m from the RR plant. In theory, at 0.1% cross pollination rate, this distance can generate 4,710 hybrids between RR and CR. In the next generation, about 3,532 plants would produce exclusively rice grains with red color. The SSR markers were able to identify the gene flow between RR and CR; therefore, they can be useful to increase the precision of cross pollination rate estimates in rice, mainly if used with other methodologies (e.g., herbicide tolerant plants.

    KEY WORDS: Cross pollination; microsatellite markers; Oryza sativa.

    Este trabalho objetivou avaliar a capacidade de marcadores SSR em detectar a ocorrência de fluxo gênico entre o arroz vermelho (AV e o arroz cultivado (AC. Marcadores SSR são utilizados em análise genômica de plantas devido ao alto conteúdo informativo, serem co-dominantes e baseados na reação de PCR. O ensaio de campo foi realizado em dez círculos concêntricos de 5 m a 50 m de distância, a partir de uma planta AV central, que foi a fonte

  4. Diversity and functional traits of culturable microbiome members, including cyanobacteria in the rice phyllosphere.

    Science.gov (United States)

    Venkatachalam, S; Ranjan, K; Prasanna, R; Ramakrishnan, B; Thapa, S; Kanchan, A

    2016-07-01

    The diversity and abundance of culturable microbiome members of the rice phyllosphere was investigated using cv. Pusa Punjab Basmati 1509. Both diversity and species richness of bacteria were significantly higher in plants in pots in a semi-controlled environment than those in fields. Application of fertilisers reduced both diversity and species richness in field-grown plants under a conventional flooded system of rice intensification (SRI) and in dry-seeded rice (DSR) modes. Sequence analyses of 16S rDNA of culturable bacteria, those selected after amplified ribosomal DNA restriction analysis (ARDRA), showed the dominance of α-proteobacteria (35%) and actinobacteria (38%); Pantoea, Exiguobacterium and Bacillus were common among the culturable phyllospheric bacteria. About 34% of 83 culturable bacterial isolates had higher potential (>2 μg·ml(-1) ) for indole acetic acid production in the absence of tryptophan. Interestingly, the phyllosphere bacterial isolates from the pot experiment had significantly higher potential for nitrogen fixation than isolates from the field experiment. Enrichment for cyanobacteria showed both unicellular forms and non-heterocystous filaments under aerobic as well as anaerobic conditions. PCR-DGGE analysis of these showed that aerobic and anaerobic conditions as well as the three modes of cultivation of rice in the field strongly influenced the number and abundance of phylotypes. The adaptability and functional traits of these culturable microbiome members suggest enormous diversity in the phyllosphere, including potential for plant growth promotion, which was also significantly influenced by the different methods of growing rice. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  5. Transgenic rice plants expressing a fused protein of Cry1Ab/Vip3H has resistance to rice stem borers under laboratory and field conditions.

    Science.gov (United States)

    Chen, Yang; Tian, Jun-Ce; Shen, Zhi-Chen; Peng, Yu-Fa; Hu, Cui; Guo, Yu-Yuan; Ye, Gong-Yin

    2010-08-01

    Six transgenic rice, Oryza sativa L., lines (G6H1, G6H2, G6H3, G6H4, G6H5, and G6H6) expressing a fused Cry1Ab/Vip3H protein, were evaluated for resistance against the Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), and the stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) in the laboratory and field. The bioassay results indicated that the mortality of Asiatic rice borer and S. inferens neonate larvae on six transgenic lines from seedling to filling stage was up to 100% at 168 h after infestation. The cumulative feeding area by Asiatic rice borer neonate larvae on all transgenic lines was significantly reduced compared with the untransformed parental 'Xiushui 110' rice. A 2-yr field evaluation showed that damage during the vegetative stage (deadheart) or during the reproductive stage (whitehead) caused by Asiatic rice borer and S. inferens for transgenic lines was much lower than the control. For three lines (G6H1, G6H2, and G6H6), no damage was found during the entire growing period. Estimation of fused Cry1Ab/Vip3H protein concentrations using PathoScreen kit for Bt-Cry1Ab/1Ac protein indicated that the expression levels of Cry1Ab protein both in main stems (within the average range of 0.006-0.073% of total soluble protein) and their flag leaves (within the average range of 0.001-0.038% of total soluble protein) were significantly different among six transgenic lines at different developmental stages. Both laboratory and field researches suggested that the transgenic rice lines have considerable potential for protecting rice from attack by both stem borers.

  6. User Guide ECOREA-RICE (version 1.0). Program for assessing the transfer of radionuclides released accidentally onto flooded rice-fields

    International Nuclear Information System (INIS)

    Keum, Dong Kwon; Lee, Han Soo; Choi, Hei Hu; Kang, Hee Seok; Lee, Chang Woo

    2004-05-01

    The computer code ECOREA-RICE is a dynamic compartment model that is specially designed for estimating the transfer of radionuclides deposited onto flooded rice-fields after an accidental release. The model consists of six independent compartments including rice-body, grain, surface water, root-zone soil, fixed soil and deep soil, and takes into account the transfer processes including radioactive decay, percolation, leaching, shoot-base absorption, root-uptake, weathering, translocation, fixation in soil by adsorption and desorption, and soil-mixing by plowing. The rate of the change of radioactivity in compartments is expressed by a set of the first order ordinary differential equations, which are solved by the fourth order Runge-Kutta algorithm. Input to the program includes the deposition date, transplanting date, ear emergence date, harvest date, soil data, the biomass data of rice-plant, and rate constants associated with transfer processes. Output includes the list of input data, the activity of radionuclides in compartment, the rate constant, and the transfer factor of rice-body and grain with time

  7. Characterization of N2-fixing plant growth promoting endophytic and epiphytic bacterial community of Indian cultivated and wild rice (Oryza spp.) genotypes.

    Science.gov (United States)

    Banik, Avishek; Mukhopadhaya, Subhra Kanti; Dangar, Tushar Kanti

    2016-03-01

    The diversity of endophytic and epiphytic diazotrophs in different parts of rice plants has specificity to the niche (i.e. leaf, stem and root) of different genotypes and nutrient availability of the organ. Inoculation of the indigenous, polyvalent diazotrophs can facilitate and sustain production of non-leguminous crops like rice. Therefore, N2-fixing plant growth promoting bacteria (PGPB) were isolated from different parts of three Indian cultivated [Oryza sativa L. var. Sabita (semi deep/deep water)/Swarna (rain fed shallow lowland)/Swarna-Sub1(submergence tolerant)] and a wild (O. eichingeri) rice genotypes which respond differentially to nitrogenous fertilizers. Thirty-five isolates from four rice genotypes were categorized based on acetylene reduction assay on nitrogenase activity, biochemical tests, BIOLOG and 16S rRNA gene sequencing. The bacteria produced 9.36-155.83 nmole C2H4 mg(-1) dry bacteria h(-1) and among them nitrogenase activity of 11 potent isolates was complemented by nifH-sequence analysis. Phylogenetic analysis based on 16S rDNA sequencing divided them into five groups (shared 95-100 % sequence homology with type strains) belonging to five classes-alpha (Ancylobacter, Azorhizobium, Azospirillum, Rhizobium, Bradyrhizobium, Sinorhizobium, Novosphingobium, spp.), beta (Burkholderia sp.), gamma (Acinetobacter, Aeromonas, Azotobacter, Enterobacter, Klebsiella, Pantoea, Pseudomonas, Stenotrophomonas spp.) Proteobacteria, Bacilli (Bacillus, Paenibacillus spp.) and Actinobacteria (Microbacterium sp.). Besides, all bacterial strains possessed the intrinsic PGP traits of like indole (0.44-7.4 µg ml(-1)), ammonia (0.18-6 mmol ml(-1)), nitrite (0.01-3.4 mol ml(-1)), and siderophore (from 0.16-0.57 μmol ml(-1)) production. Inoculation of rice (cv. Swarna) seedlings with selected isolates had a positive impact on plant growth parameters like shoot and root elongation which was correlated with in vitro PGP attributes. The results indicated that the

  8. On-farm management practices against rice root weevil (Echinocnemus oryzae Marshall)

    OpenAIRE

    Rakesh Pandey; Ajit Kumar Chaturvedi; Rudal Prasad Chaudhary; Rajendra Prasad

    2017-01-01

    Rice is the staple food of over half the world's population and occupies almost one-fifth of the global cropland under cereals. The rice root weevil, Echinocnemus oryzae Marshall, (Coleoptera: Curculionidae) has posed a problem in paddy cultivation areas in India. The damage by this root weevil results in a significant decrease in root and shoot biomass and ultimately the yield of rice plants. Studies were conducted to test the effective management practices of rice root weevil using a seedli...

  9. Effect of acetic acid on rice seeds coated with rice husk ash

    Directory of Open Access Journals (Sweden)

    Lizandro Ciciliano Tavares

    2013-06-01

    Full Text Available Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência, five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed and five concentrations of acetic acid (0, 3, 6, 9 and 12 mM, with 4 replications, totaling 50 treatments. The variables first count of germination, germination, shoot and root length, dry weight of shoots and roots were recorded. The results showed that coating rice seeds with rice husk ash up to 5 g kg-1 seed does not influence the performance of rice seeds of cultivars IRGA 424 and BRS Querência when exposed to concentrations of 12 mM acetic acid. The presence of acetic acid in the substrates used for seed germination reduced the vigor and viability of seeds of cultivars IRGA 424 and BRS Querência, as well as seedling development, affecting mainly the roots of BRS Querência.

  10. RICD: A rice indica cDNA database resource for rice functional genomics

    Directory of Open Access Journals (Sweden)

    Zhang Qifa

    2008-11-01

    Full Text Available Abstract Background The Oryza sativa L. indica subspecies is the most widely cultivated rice. During the last few years, we have collected over 20,000 putative full-length cDNAs and over 40,000 ESTs isolated from various cDNA libraries of two indica varieties Guangluai 4 and Minghui 63. A database of the rice indica cDNAs was therefore built to provide a comprehensive web data source for searching and retrieving the indica cDNA clones. Results Rice Indica cDNA Database (RICD is an online MySQL-PHP driven database with a user-friendly web interface. It allows investigators to query the cDNA clones by keyword, genome position, nucleotide or protein sequence, and putative function. It also provides a series of information, including sequences, protein domain annotations, similarity search results, SNPs and InDels information, and hyperlinks to gene annotation in both The Rice Annotation Project Database (RAP-DB and The TIGR Rice Genome Annotation Resource, expression atlas in RiceGE and variation report in Gramene of each cDNA. Conclusion The online rice indica cDNA database provides cDNA resource with comprehensive information to researchers for functional analysis of indica subspecies and for comparative genomics. The RICD database is available through our website http://www.ncgr.ac.cn/ricd.

  11. Phylogeography of Asian wild rice, Oryza rufipogon: a genome-wide view.

    Science.gov (United States)

    Huang, Pu; Molina, Jeanmaire; Flowers, Jonathan M; Rubinstein, Samara; Jackson, Scott A; Purugganan, Michael D; Schaal, Barbara A

    2012-09-01

    Asian wild rice (Oryza rufipogon) that ranges widely across the eastern and southern part of Asia is recognized as the direct ancestor of cultivated Asian rice (O. sativa). Studies of the geographic structure of O. rufipogon, based on chloroplast and low-copy nuclear markers, reveal a possible phylogeographic signal of subdivision in O. rufipogon. However, this signal of geographic differentiation is not consistently observed among different markers and studies, with often conflicting results. To more precisely characterize the phylogeography of O. rufipogon populations, a genome-wide survey of unlinked markers, intensively sampled from across the entire range of O. rufipogon is critical. In this study, we surveyed sequence variation at 42 genome-wide sequence tagged sites (STS) in 108 O. rufipogon accessions from throughout the native range of the species. Using Bayesian clustering, principal component analysis and amova, we conclude that there are two genetically distinct O. rufipogon groups, Ruf-I and Ruf-II. The two groups exhibit a clinal variation pattern generally from north-east to south-west. Different from many earlier studies, Ruf-I, which is found mainly in China and the Indochinese Peninsula, shows genetic similarity with one major cultivated rice variety, O. satvia indica, whereas Ruf-II, mainly from South Asia and the Indochinese Peninsula, is not found to be closely related to cultivated rice varieties. The other major cultivated rice variety, O. sativa japonica, is not found to be similar to either O. rufipogon groups. Our results support the hypothesis of a single origin of the domesticated O. sativa in China. The possible role of palaeoclimate, introgression and migration-drift balance in creating this clinal variation pattern is also discussed. © 2012 Blackwell Publishing Ltd.

  12. Cutaneous Mycoses among Rice Farmers in Anambra State, Nigeria

    OpenAIRE

    Ekwealor, Chito Clare; Oyeka, Christie Amechi

    2013-01-01

    Rice grain is one of the world's most important food crops, and its cultivation is a major occupation in Anambra State, Nigeria. These rice farmers are exposed to various agents that predispose them to cutaneous mycoses. The aim of this work was to screen rice farmers for lesions suggestive of cutaneous mycoses and to isolate and identify fungal agents associated with the infection. This survey was carried out between November 2009 and June 2011 in Anambra State, Nigeria. Clinical samples col...

  13. Impact Of Different Time Planting In Soybeans And Neem Seed Extract Application To Insect Population On Rice Field

    Directory of Open Access Journals (Sweden)

    Tamrin Abdullah

    2015-08-01

    Full Text Available Abstract The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e neem seed extract together with rice planting neem seed extract on soybean 17 days after rice planting synthetic insecticides on 17 days after rice planting Delthametrin on soybean and Chlorpirifos on rice respectively. Research was conducted in rice fields with irrigation channels. The land area is 0.8 hectares with extensive experiments each rice terraces approximately 900 m2 with separate by rice terraces for every treatment. Each treatment consisted of three groups and using nine rice terraces. Samples of the rice plant population is 25 plants per sample unit. The results was showed treatment by neem seed extract with different time planting of soybeans able to reduce number of pest insects populations such as N. virescens 80.38 N. lugens 67.17 S. incertulas 66.5 and L. oratorius 93.46 when compared to treatment with synthetic insecticides Delthamethrin and Chlorpyrifos.

  14. Mapping Flooded Rice Paddies Using Time Series of MODIS Imagery in the Krishna River Basin, India

    Directory of Open Access Journals (Sweden)

    Pardhasaradhi Teluguntla

    2015-07-01

    Full Text Available Rice is one of the major crops cultivated predominantly in flooded paddies, thus a large amount of water is consumed during its growing season. Accurate paddy rice maps are therefore important inputs for improved estimates of actual evapotranspiration in the agricultural landscape. The main objective of this study was to obtain flooded paddy rice maps using multi-temporal images of Moderate Resolution Imaging Spectroradiometer (MODIS in the Krishna River Basin, India. First, ground-based spectral samples collected by a field spectroradiometer, CROPSCAN, were used to demonstrate unique contrasts between the Normalized Difference Vegetation Index (NDVI and the Land Surface Water Index (LSWI observed during the transplanting season of rice. The contrast between Enhanced Vegetation Index (EVI and Land Surface Water Index (LSWI from MODIS time series data was then used to generate classification decision rules to map flooded rice paddies, for the transplanting seasons of Kharif and Rabi rice crops in the Krishna River Basin. Consistent with ground spectral observations, the relationship of the MODIS EVI vs. LSWI of paddy rice fields showed distinct features from other crops during the transplanting seasons. The MODIS-derived maps were validated against extensive reference data collected from multiple land use field surveys. The accuracy of the paddy rice maps, when determined using field plot data, was approximately 78%. The MODIS-derived rice crop areas were also compared with the areas reported by Department of Agriculture (DOA, Government of India (Government Statistics. The estimated root mean square difference (RMSD of rice area estimated using MODIS and those reported by the Department of Agriculture over 10 districts varied between 3.4% and 6.6% during 10 years of our study period. Some of the major factors responsible for this difference include high noise of the MODIS images during the prolonged monsoon seasons (typically June–October and

  15. Application of Azolla and intermittent irrigation to improve the productivity and nutrient contents of local black rice variety

    Science.gov (United States)

    Sulandjari; Yunindanova, M. B.

    2018-03-01

    Black rice is a local rice variety that contains a high level of anthocyanin pigment. Anthocyanin has been reported to be very effective in reducing cholesterol levels as well as cancer cell invasion. One of the main problems in rice cultivation is lack of water. System of Rice Intensification (SRI) has shown to be able to increase rice productivity by increasing the number of tillers. This system is known as a water-efficient cultivation. Other rice cultivation barrier is related to the use of nitrogen fertilizer. One of replacement of nitrogen fertilizer is by adding azolla. The objective of this research was identifying growth and yield of organic black rice with intermittent irrigation and application of azolla. The plant material used was black rice Cempo variety from Sleman, Yogyakarta. This experiment utilized 4 dosages of azolla as the first treatment: 100 gm-2, 200 gm-2 and 400 gm-2. The second treatment was water supply consisted of continuous flooded 2 cm; flooded 2 cm every 3 days; flooded 2 cm every 6 days. The results depicted that the application of azolla was able to increase the growth of black rice. Azolla of 200 gm-2 and 400 gm-2 and intermittent 3 days to 6 days generated higher dry grain, anthocyanin and antioxidant. Azolla 200 gm-2 with intermittent irrigation 3 days could be a good combination to improve plant growth, yield and properties of local black rice.

  16. Winter flooding of California rice fields reduces immature populations of Lissorhoptrus oryzophilus (Coleoptera: Curculionidae) in the spring.

    Science.gov (United States)

    Aghaee, Mohammad-Amir; Godfrey, Larry D

    2017-07-01

    In California, rice fields are flooded over the winter months (November to March) to facilitate degradation of post-harvest rice straw and to provide temporary habitat for migratory waterfowl. Prior research showed that winter flood rice fields had fewer rice water weevil (Lissorhoptrus oryzophilus), larvae and pupae during the rice production season than fields that were left unflooded in the winter. A series of experiments were conducted to provide further support for these trends under controlled conditions and to find a mechanism for this phenomenon. Under winter flooded conditions there was a 50% reduction in populations of weevil immatures compared with the untreated control (no straw or winter flood). These same conditions corresponded to a 20% increase in the amount of silicon found in plant tissues in 2014 and a 39 to 90% decrease in methane production in the soil from 2013 to 2014, respectively. Evidence from previous field research and these controlled studies supports winter flooding as an appropriate tactic for controlling L. oryzophilus populations in the spring. However, the mechanism that would explain why winter flooding adversely affects L. oryzophilus immatures remains unclear. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Effects of Chemical Applications to Metal Polluted Soils on Cadmium Uptake by Rice Plant

    Directory of Open Access Journals (Sweden)

    Yoo J. H.

    2013-04-01

    Full Text Available Pot experiment using metal polluted soils was conducted to investigate the effects of lime, iron and sulfur on changes in Cd availability and uptake by rice plant. Drainage and irrigation of water were performed to develop redox changes like field cultivation. Iron chloride and sodium sulfate solutions were applied to the pots in the middle of growth period of rice plant. Reactive metal pool in heavily polluted soils was slightly decreased after treatments with lime, iron chloride, sodium sulfate and combination of these chemicals. However, cadmium uptake by rice plant was significantly different across the treatments and the extent of Cd pollution. For highly polluted soils, more Cd reduction was observed in iron chloride treatments. Cd content in polished rice for iron chloride and (iron chloride+organic matter treatments was only 16-23% and 25-37% compared to control and liming, respectively. Treatment of (iron chloride+sulfate rather increased Cd content in rice. For moderately polluted soils, Cd reduction rate was the order of (OM+iron chloride > iron chloride > lime. Other treatments including sulfate rather increased Cd content in rice maximum 3 times than control. It was proposed to determine the optimum application rate of iron for minimizing hazardous effect on rice plant.

  18. Dissipation of phenanthrene and pyrene at the aerobic-anaerobic soil interface: differentiation induced by the rhizosphere of PAH-tolerant and PAH-sensitive rice (Oryza sativa L.) cultivars.

    Science.gov (United States)

    He, Yan; Xia, Wen; Li, Xinfeng; Lin, Jiajiang; Wu, Jianjun; Xu, Jianming

    2015-03-01

    A pot experiment was conducted to reveal the removal of two polycyclic aromatic hydrocarbons (PAHs) (phenanthrene, PHE, and pyrene, PYR) during rice cultivation in a paddy field. The rhizosphere effect on facilitating dissipation of PAHs varied simultaneously as a function of soil properties, PAH types, cultivation time, and genotypes within rice cultivars, with differences performed for PYR but not PHE. Changes in soil PLFA profiles evidenced that the growth of rice roots modified the dominant species within rhizosphere microbial communities and induced a selective enrichment of Gram-negative aerobic bacteria capable of degrading, thereby resulting in the differentiated dissipation of PYR. While the insignificant differences in PHE dissipation might be attributed to its higher solubility and availability under flooded condition that concealed the differences in improvement of bioavailability for microorganisms between rhizosphere and non-rhizosphere, and between both soils and both rice cultivars. Our findings illustrate that the removal of PAHs in paddy soils was more complex relative to those in dryland soils. This was possibly due to the specialty of rice roots for oxygen secretion that provides development of redox heterogeneous microbial habitats at root-soil interface under flooded condition.

  19. An integrated, multisensor system for the continuous monitoring of water dynamics in rice fields under different irrigation regimes.

    Science.gov (United States)

    Chiaradia, Enrico Antonio; Facchi, Arianna; Masseroni, Daniele; Ferrari, Daniele; Bischetti, Gian Battista; Gharsallah, Olfa; Cesari de Maria, Sandra; Rienzner, Michele; Naldi, Ezio; Romani, Marco; Gandolfi, Claudio

    2015-09-01

    The cultivation of rice, one of the most important staple crops worldwide, has very high water requirements. A variety of irrigation practices are applied, whose pros and cons, both in terms of water productivity and of their effects on the environment, are not completely understood yet. The continuous monitoring of irrigation and rainfall inputs, as well as of soil water dynamics, is a very important factor in the analysis of these practices. At the same time, however, it represents a challenging and costly task because of the complexity of the processes involved, of the difference in nature and magnitude of the driving variables and of the high variety of field conditions. In this paper, we present the prototype of an integrated, multisensor system for the continuous monitoring of water dynamics in rice fields under different irrigation regimes. The system consists of the following: (1) flow measurement devices for the monitoring of irrigation supply and tailwater drainage; (2) piezometers for groundwater level monitoring; (3) level gauges for monitoring the flooding depth; (4) multilevel tensiometers and moisture sensor clusters to monitor soil water status; (5) eddy covariance station for the estimation of evapotranspiration fluxes and (6) wireless transmission devices and software interface for data transfer, storage and control from remote computer. The system is modular and it is replicable in different field conditions. It was successfully applied over a 2-year period in three experimental plots in Northern Italy, each one with a different water management strategy. In the paper, we present information concerning the different instruments selected, their interconnections and their integration in a common remote control scheme. We also provide considerations and figures on the material and labour costs of the installation and management of the system.

  20. Effects of Mulching Mode on Canopy Physiological, Ecological Characteristics and Yield of Upland Rice

    OpenAIRE

    Yu-zhu ZHANG; Yang LIU; Xiang ZENG; Kai-lin CHEN; Ze-hui HUANG; Hong-ke XIE

    2011-01-01

    The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching, straw mulching and liquid film mulching, as well as bare cultivation (control). The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice, as shown by an increase of relative humidity, a better internal micro-meteorological...

  1. Populations of Rice Grain Bug, Paraeuscosmetus pallicomis, (Hemiptera: Lygaeidae) in Weed-free Paddy Field, Weedy Paddy Field and Paddy Dykes.

    Science.gov (United States)

    Abdullah, Tamrin; Nasruddin, Andi; Agus, Nurariaty

    2017-07-01

    Research on the populations of rice grain bug Paraeuscosmetus pallicomis Dallas (Hemiptera: Lygaeidae) in paddy field ecosystems was performed with the aim to determine the populations of rice grain bug in weed-free paddy field, weedy paddy field, and paddy dykes. Experiment was carried out in the village of Paccellekang in the district of Patallasang of Gowa Regency in South Sulawesi, Indonesia. Observations were performed during the milky grain stage (85 days after planting), the mature grain stage (105 days after planting), and one day after harvest (115 days after transplanting). Results showed that 85 days after the transplanting, the populations of rice grain bug was significantly higher in the weedy paddy field compared to weed-free field and paddy dykes with total numbers of 1.75, 3.53, and 0.31 insects per 2 hills, respectively. Similarly, 105 days after the transplanting, 2.53, 5.53, and 0.11 insects per hill, respectively. However, one day after the harvest (115 days after transplanting) the number of insects in weed-free field decreased, while in the dykes increased, and the weedy plot still had the highest number of insects per 2 hills. Our results suggested that weeds played an important role in regulating the bug population by providing alternative shelter and foods for the insect.

  2. Growth, Metabolism and Yield of Rice Cultivated in Soils Amended with Fly Ash and Cyanobacteria and Metal Loads in Plant Parts

    OpenAIRE

    Rabindra N. Padhy; Nabakishore Nayak; Rajesh R. Dash-Mohini; Shakti Rath; Rajani K. Sahu

    2016-01-01

    Soil amendment with fly ash (FA) and combined supplementation with N2-fixing cyanobacteria masses as biofertilizer were done in field experiments with rice. Amendments with FA levels, 0, 0.5, 1.0, 2.0, 4.0, 8.0 and 10.0 kg/m2, caused increase in growth and yield of rice up to 8.0 kg/m2, monitored with several parameters. Pigment contents and enzyme activities of leaves were enhanced by FA, with the maximum level of FA at 10.0 kg/m2. Protein content of rice seeds was the highest in plants grow...

  3. [Exposure degree of important non-target arthropods to Cry2Aa in Bt rice fields].

    Science.gov (United States)

    Zhang, Qing-Ling; Li, Yun-He; Hua, Hong-Xia; Yang, Chang-Ju; Wu, Hong-Jin; Peng, Yu-Fa

    2013-06-01

    Based on the principle of "risk = hazard x exposure", the selected representative nontarget organisms in the assessment of the potential effects of insect-resistant genetically modified (GM) crops on non-target arthropods in laboratory are generally the arthropod species highly exposed to the insecticidal proteins expressed by the GM crops in farmland ecosystem. In order to understand the exposure degree of the important arthropod species to Cry proteins in Bt rice fields, and to select the appropriate non-target arthropods in the risk assessment of insect-resistant GM crops, the enzyme-linked immunosorbent assay (ELISA) was conducted to measure the Cry2Aa protein concentration in the arthropods collected from the cry2Aa rice fields at different rice growth stages. The results showed that there was a significant difference in the Cry2Aa content protein concentration in different arthropod species. Some species did not contain Cry2Aa protein, while some species contained larger amounts of Cry2Aa protein. Relative to the arthropods colleted after rice anthesis, the arthropods colleted in rice anthesis contained relative higher concentrations of Cry2Aa protein, especially for the predacious arthropods. No Cry proteins were detected in parasitic arthropods. This study provided references for the laboratory assessment of the effects of GM rice on nontarget arthropods.

  4. Letter to the editor: Rice: location is vital in crop management

    NARCIS (Netherlands)

    Hengsdijk, H.; Bindraban, P.S.

    2004-01-01

    Your News Feature about rice cultivation, "Feast or famine?" (Nature 428, 360–361; 2004), is a classic example of how the debate on a potentially interesting technique can be blurred by its opponents and proponents. In this case, proponents of the System of Rice Intensification (SRI) are reported to

  5. [Nitrogen cycling in rice-duck mutual ecosystem during double cropping rice growth season].

    Science.gov (United States)

    Zhang, Fan; Chen, Yuan-Quan; Sui, Peng; Gao, Wang-Sheng

    2012-01-01

    Raising duck in paddy rice field is an evolution of Chinese traditional agriculture. In May-October 2010, a field experiment was conducted in a double cropping rice region of Hunan Province, South-central China to study the nitrogen (N) cycling in rice-duck mutual ecosystem during early rice and late rice growth periods, taking a conventional paddy rice field as the control. Input-output analysis method was adopted. The N output in the early rice-duck mutual ecosystem was 239.5 kg x hm(-2), in which, 12.77 kg x hm(-2) were from ducks, and the N output in the late rice-duck mutual ecosystem was 338.7 kg x hm(-2), in which, 23.35 kg x hm(-2) were from ducks. At the present N input level, there existed soil N deficit during the growth seasons of both early rice and late rice. The N input from duck sub-system was mainly from the feed N, and the cycling rate of the duck feces N recycled within the system was 2.5% during early rice growth season and 3.5% during late rice growth season. After late rice harvested, the soil N sequestration was 178.6 kg x hm(-2).

  6. Long-term balancing selection at the Phosphorus Starvation Tolerance 1 (PSTOL1) locus in wild, domesticated and weedy rice (Oryza).

    Science.gov (United States)

    Vigueira, Cynthia C; Small, Linda L; Olsen, Kenneth M

    2016-04-22

    The ability to grow in phosphorus-depleted soils is an important trait for rice cultivation in many world regions, especially in the tropics. The Phosphorus Starvation Tolerance 1 (PSTOL1) gene has been identified as underlying the ability of some cultivated rice varieties to grow under low-phosphorus conditions; however, the gene is absent from other varieties. We assessed PSTOL1 presence/absence in a geographically diverse sample of wild, domesticated and weedy rice and sequenced the gene in samples where it is present. We find that the presence/absence polymorphism spans cultivated, weedy and wild Asian rice groups. For the subset of samples that carry PSTOL1, haplotype sequences suggest long-term selective maintenance of functional alleles, but with repeated evolution of loss-of-function alleles through premature stops and frameshift mutations. The loss-of-function alleles have evolved convergently in multiple rice species and cultivated rice varieties. Greenhouse assessments of plant growth under low- and high-phosphorus conditions did not reveal significant associations with PSTOL1 genotype variation; however, the striking signature of balancing selection at this locus suggests that further phenotypic characterizations of PSTOL1 allelic variants is warranted and may be useful for crop improvement. These findings suggest balancing selection for both functional and non-functional PSTOL1 alleles that predates and transcends Asian rice domestication, a pattern that may reflect fitness tradeoffs associated with geographical variation in soil phosphorus content.

  7. Static Vented Chamber and Eddy Covariance Methane Flux Comparisons in Mid-South US Rice

    Science.gov (United States)

    Reba, M. L.; Fong, B.; Adviento-Borbe, A.; Runkle, B.; Suvocarev, K.; Rival, I.

    2017-12-01

    Rice cultivation contributes higher amounts of GHG emissions (CO2 and CH4) due to flooded field conditions. A comparison between eddy covariance and static vented flux chamber measurement techniques is presented. Rice GHG emissions originating from plot level chambers may not accurately describe the aggregate effects of all the soil and micrometeorological variations across a production field. Eddy covariance (EC) is a direct, integrated field measurement of field scale trace gases. Flux measurements were collected in NE Arkansas production size rice fields (16 ha, 40 ac) during the 2015 and 2016 production seasons (June-August) in continuous flood (CF) irrigation. The study objectives included quantifying the difference between chamber and EC measurements, and categorizing flux behavior to growth stage and field history. EC daily average emissions correlated with chamber measurements (R2=0.27-0.54) more than average from 09:00-12:00 which encompassed chamber measurement times (R2=0.23-0.32). Maximum methane emissions occurred in the late afternoon from 14:00-18:00 which corresponded with maximum soil heat flux and air temperature. The total emissions from the study fields ranged from 27-117 kg CH4-C ha-1 season-1. The emission profile was lower in 2015, most likely due to higher rainfall and cooler temperatures during the growing season compared to 2016. These findings improve our understanding of GHG emissions at the field scale under typical production practices and validity of chamber and EC flux measurement techniques.

  8. Impact of spatial plan on the conversion of Subak rice fields and food security, in Badung and Gianyar Regencies, Bali Province

    Science.gov (United States)

    Lanya, Indayati; Netera Subadiyasa, N.; Ratna Adi, Gst. P.

    2018-05-01

    Regional Spatial Plan of Bali Province 2009-2029, allocating rice fields can be converted 10% (± 10.800 ha). Over the next 20 years, the conversion of rice field is permitted 540 ha year-1, the real condition in Bali is 800 ha year-1.Research location in Badung and Gianyar Regencies. Visual satellite image interpretation methods, digitization of on-screen, delineation of subak rice field, field survey, superimpose analysis of Spatial Plan (SP) map with rice field map, trough toolbox-analysis tools–overlay-intersect using QGIS, Harvest Index (HI) of cropping pattern in one year. SP has a negative impact on agricultural land resources and food security. Local Regulation (SP), subak rice fields outside the agricultural area licensed to be converted, and food deficits. Regency of Badung, potential land conversion of 3,324.97 ha (34.44%) from 119 subak with paddy field area of 24,184.85 ha. There are 10 subak 100% and 8 subak > 95% can be converted; projected food deficit -115.343 tons of rice by 2020 for HI 2. In Gianyar Regency, potential land conversion 13,021.41 ha (53.51%) of 66 subak with an area of 24184.85 ha; 8 subak 100% and 8 subak with area food deficit is about -194438 tons of rice in 2040 for HI 2.

  9. Microbial Species and Functional Diversity in Rice Rhizosphere of High-yield Special Ecological Areas

    Directory of Open Access Journals (Sweden)

    PAN Li-yuan

    2016-11-01

    Full Text Available Taoyuan, Yunnan Province is a special eco-site which keeps the highest yield records of rice cultivation in small planting areas. Soil microbial species and functional diversity were evaluated using cultivation method and BIOLOG ecoplates. The results showed that the microbial community of the high yield region was more abundant, and the total microbial population was 2 times of the control, furthermore, the areas belonged to the healthy "bacteria" soil, which was showed as bacteria > actinomycetes > fungi. Bacteria were the dominant populations in the rhizosphere of high yielding rice field, and the yield formation of rice was not correlated with the depth of soil layers. In order to obtain more species diversity information, Shannon diversity index H, Shannon evenness index E and Simpson index D were analyzed, and the results showed that microbial community diversity and evenness were not the main differences between the high and general yield areas. Then, the functional diversity of soil microbial community was investigated through the average well color development(AWCD and diversity index analyses. The results of AWCD analysis indicated that the metabolic activity of soil microbial community in high yield paddy soils were stronger than the control. Moreover, the difference range from large to small showed as tillering stage > harvest period > seedling period > rotation period, the stronger the rice growth, the greater the difference between the high yield region and the control. At tillering stage and harvest stage, due to the vigorous plant growth, the root exudates were rich, and the microbial communities of high yield paddy soils showed a strong metabolic activity and strong ability to use carbon sources. The results of Shannon, Simpson and McIntosh indices analysis indicated that common microbial species was not a key factor affecting the yield of rice. Tillering stage was a key period for the growth of high yield rice, and many

  10. Timing is everything: early degradation of abscission layer is associated with increased seed shattering in U.S. weedy rice

    Directory of Open Access Journals (Sweden)

    Hepler Peter K

    2011-01-01

    Full Text Available Abstract Background Seed shattering, or shedding, is an important fitness trait for wild and weedy grasses. U.S. weedy rice (Oryza sativa is a highly shattering weed, thought to have evolved from non-shattering cultivated ancestors. All U.S. weedy rice individuals examined to date contain a mutation in the sh4 locus associated with loss of shattering during rice domestication. Weedy individuals also share the shattering trait with wild rice, but not the ancestral shattering mutation at sh4; thus, how weedy rice reacquired the shattering phenotype is unknown. To establish the morphological basis of the parallel evolution of seed shattering in weedy rice and wild, we examined the abscission layer at the flower-pedicel junction in weedy individuals in comparison with wild and cultivated relatives. Results Consistent with previous work, shattering wild rice individuals possess clear, defined abscission layers at flowering, whereas non-shattering cultivated rice individuals do not. Shattering weedy rice from two separately evolved populations in the U.S. (SH and BHA show patterns of abscission layer formation and degradation distinct from wild rice. Prior to flowering, the abscission layer has formed in all weedy individuals and by flowering it is already degrading. In contrast, wild O. rufipogon abscission layers have been shown not to degrade until after flowering has occurred. Conclusions Seed shattering in weedy rice involves the formation and degradation of an abscission layer in the flower-pedicel junction, as in wild Oryza, but is a developmentally different process from shattering in wild rice. Weedy rice abscission layers appear to break down earlier than wild abscission layers. The timing of weedy abscission layer degradation suggests that unidentified regulatory genes may play a critical role in the reacquisition of shattering in weedy rice, and sheds light on the morphological basis of parallel evolution for shattering in weedy and wild

  11. Influence of Different Supplements on the Commercial Cultivation of Milky White Mushroom

    Science.gov (United States)

    Alam, Nuhu; Amin, Ruhul; Khair, Abul

    2010-01-01

    Calocybe indica, known as milky white mushroom, grows and cultivated in the sub-tropical and temperate zones of South Asia. We investigated the most suitable supplements and their levels for the commercial cultivation of milky white mushroom. Rice bran, maize powder, and wheat bran with their different levels (10, 20, 30, 40, and 50%) were used as supplements to evaluate the yield and yield contributing characteristics of C. indica. Primordia initiation was observed between 13.5 and 19.3 days. The results indicated that the 30% maize powder supplement was effective for producing viable fruiting bodies. The maximum diameters of the pileus and stalk were observed with 30% maize powder. The highest biological and economic yield and biological efficiency were also obtained with 30% maize powder as a supplement. The results indicate that increasing the supplement level resulted in less biological efficiency, and that 30% maize powder was the best supplement level for rice straw substrate to cultivate milky white mushrooms. PMID:23956652

  12. SALINITY TOLERANCE OF SEVERAL RICE GENOTYPES AT SEEDLING STAGE

    Directory of Open Access Journals (Sweden)

    Heni Safitri

    2018-01-01

    Full Text Available Salinity is one of the most serious problems in rice cultivation. Salinity drastically reduced plant growth and yield, especially at seedling stage. Several rice genotypes have been produced, but their tolerance to salinity has not yet been evaluated. The study aimed to evaluate salinity tolerance of rice genotypes at seedling stage. The glasshouse experiment was conducted at Cimanggu Experimental Station, Bogor, from April to May 2013. Thirteen rice genotypes and two check varieties, namely Pokkali (salt tolerant and IR29 (salt sensitive were tested at seedling stage. The experiment was arranged in a randomized complete block design with three replications and two factors, namely the levels of NaCl (0 and 120 mM and 13 genotypes of rice. Rice seedlings were grown in the nutrient culture (hydroponic supplemented with NaCl at different levels. The growth and salinity injury levels of the genotypes were recorded periodically. The results showed that salinity level of 120 mM NaCl reduced seedling growth of all rice genotypes, but the tolerant ones were survived after 14 days or until the sensitive check variety died. Based on the visual injury symptoms on the leaves, five genotypes, i.e. Dendang, Inpara 5, Inpari 29, IR77674-3B-8-2-2-14-4-AJY2, and IR81493-BBB-6-B- 2-1-2 were tolerant to 120 mM salinity level, while Inpara 4 was comparable to salt sensitive IR29. Hence, Inpara 4 could be used as a salinity sensitive genotype for future research of testing tolerant variety. Further evaluation is needed to confirm their salinity tolerance under field conditions. 

  13. Genetic Control of a Transition from Black to Straw-White Seed Hull in Rice Domestication1[C][W][OA

    Science.gov (United States)

    Zhu, Bo-Feng; Si, Lizhen; Wang, Zixuan; Jingjie Zhu, Yan Zhou; Shangguan, Yingying; Lu, Danfeng; Fan, Danlin; Li, Canyang; Lin, Hongxuan; Qian, Qian; Sang, Tao; Zhou, Bo; Minobe, Yuzo; Han, Bin

    2011-01-01

    The genetic mechanism involved in a transition from the black-colored seed hull of the ancestral wild rice (Oryza rufipogon and Oryza nivara) to the straw-white seed hull of cultivated rice (Oryza sativa) during grain ripening remains unknown. We report that the black hull of O. rufipogon was controlled by the Black hull4 (Bh4) gene, which was fine-mapped to an 8.8-kb region on rice chromosome 4 using a cross between O. rufipogon W1943 (black hull) and O. sativa indica cv Guangluai 4 (straw-white hull). Bh4 encodes an amino acid transporter. A 22-bp deletion within exon 3 of the bh4 variant disrupted the Bh4 function, leading to the straw-white hull in cultivated rice. Transgenic study indicated that Bh4 could restore the black pigment on hulls in cv Guangluai 4 and Kasalath. Bh4 sequence alignment of all taxa with the outgroup Oryza barthii showed that the wild rice maintained comparable levels of nucleotide diversity that were about 70 times higher than those in the cultivated rice. The results from the maximum likelihood Hudson-Kreitman-Aguade test suggested that the significant reduction in nucleotide diversity in rice cultivars could be caused by artificial selection. We propose that the straw-white hull was selected as an important visual phenotype of nonshattered grains during rice domestication. PMID:21263038

  14. Dissipation of the Herbicide Benzobicyclon Hydrolysate in a Model California Rice Field Soil.

    Science.gov (United States)

    Williams, Katryn L; Gladfelder, Joshua J; Quigley, Lindsay L; Ball, David B; Tjeerdema, Ronald S

    2017-10-25

    The herbicide benzobicyclon (BZB; 3-(2-chloro-4-(methylsulfonyl)benzoyl)-2-phenylthiobicyclo[3.2.1]oct-2-en-4-one) has recently been approved for use on California rice fields by the United States Environmental Protection Agency (U.S. EPA). Hydrolysis of BZB rapidly forms the active compound, benzobicyclon hydrolysate (BH), whose fate is currently not well understood. A model California rice soil was used to determine BH soil dissipation. The pK a and aqueous solubility were also determined, as experimental values are not currently available. Sorption data indicate BH does not bind tightly, or irreversibly, with this soil. Flooding resulted in decreased BH loss, indicating anaerobic microbes are less likely to transform BH compared to aerobic microorganisms. Temperature increased dissipation, while autoclaving decreased BH loss. Overall, dissipation was slow regardless of treatment. Further investigation is needed to elucidate the exact routes of loss in soil, though BH is expected to dissipate slowly in flooded rice field soil.

  15. Mapping cropping patterns in irrigated rice fields in West Java: Towards mapping vulnerability to flooding using time-series MODIS imageries

    Science.gov (United States)

    Sianturi, Riswan; Jetten, V. G.; Sartohadi, Junun

    2018-04-01

    Information on the vulnerability to flooding is vital to understand the potential damages from flood events. A method to determine the vulnerability to flooding in irrigated rice fields using the Enhanced Vegetation Index (EVI) was proposed in this study. In doing so, the time-series EVI derived from time-series 8 day 500 m spatial resolution MODIS imageries (MOD09A1) was used to generate cropping patterns in irrigated rice fields in West Java. Cropping patterns were derived from the spatial distribution and phenology metrics so that it is possible to show the variation of vulnerability in space and time. Vulnerability curves and cropping patterns were used to determine the vulnerability to flooding in irrigated rice fields. Cropping patterns capture the shift in the vulnerability, which may lead to either an increase or decrease of the degree of damage in rice fields of origin and other rice fields. The comparison of rice field areas between MOD09A1 and ALOS PALSAR and MOD09A1 and Agricultural Statistics showed consistent results with R2 = 0.81 and R2 = 0.93, respectively. The estimated and observed DOYs showed RMSEs = 9.21, 9.29, and 9.69 days for the Start of Season (SOS), heading stage, and End of Season (EOS), respectively. Using the method, one can estimate the relative damage provided available information on the flood depth and velocity. The results of the study may support the efforts to reduce the potential damages from flooding in irrigated rice fields.

  16. Genetic diversity associated with conservation of endangered Dongxiang wild rice (Oryza rufipogon)

    Science.gov (United States)

    The wild progenitor species (Oryza rufipogon) of Asian cultivated rice (O. sativa) is located in Dongxiang county, China where it is considered the northernmost range worldwide. Nine ex situ and three in situ populations of the Dongxiang wild rice (DXWR) and four groups of modern cultivars were geno...

  17. Interactive effects of straw-derived biochar and N fertilization on soil C storage and rice productivity in rice paddies of Northeast China

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Yanghui [Rice Research Institute, Shenyang Agricultural University, Shenyang 110866 (China); Gao, Jiping [Rice Research Institute, Shenyang Agricultural University, Shenyang 110866 (China); Liaoning Biochar Engineering & Technology Research Center, Shenyang Agricultural University, Dongling Rd, Shenyang 110866 (China); Liu, Caihong; Zhang, Wenzhong [Rice Research Institute, Shenyang Agricultural University, Shenyang 110866 (China); Lan, Yu [Liaoning Biochar Engineering & Technology Research Center, Shenyang Agricultural University, Dongling Rd, Shenyang 110866 (China); Li, Shuhang [Rice Research Institute, Shenyang Agricultural University, Shenyang 110866 (China); Meng, Jun [Liaoning Biochar Engineering & Technology Research Center, Shenyang Agricultural University, Dongling Rd, Shenyang 110866 (China); Xu, Zhengjin, E-mail: xuzhengjin@126.com [Rice Research Institute, Shenyang Agricultural University, Shenyang 110866 (China); Tang, Liang, E-mail: tl_rice@126.com [Rice Research Institute, Shenyang Agricultural University, Shenyang 110866 (China)

    2016-02-15

    Impacts of biochar on greenhouse gas emissions and C sequestration in agricultural soils have been considered as the key to mitigate climate change. There is limited knowledge regarding the effects of rice straw-derived biochar and interaction with N fertilization on soil C sequestration and rice productivity in fertile paddy fields. A 2-year (2013 and 2014) consecutive field trial was performed using straw treatment (5.05 t ha{sup −1}) and biochar amendment (0, 1.78, 14.8 and 29.6 t ha{sup −1}) with or without urea application in a rice paddy in Northeast China. A super high yielding rice variety (Oryza sativa L. subsp. Japonica cv. ‘Shennong 265’) was cultivated with permanent flooding. Results showed that biochar amendments significantly decreased CH{sub 4} emissions relative to straw treatment irrespective of N fertilization, especially in N-fertilized soils with 1.78 t ha{sup −1} biochar. There were no differences in CO{sub 2} emissions with respect to biochar amendments, except for 14.8 t ha{sup −1} biochar with N fertilization. Straw treatment had the highest global warming potential over a 100-year time frame, which was nearly 1.5 times that of 14.8 t ha{sup −1} biochar amendment without N fertilization. Biochar addition increased total soil C by up to 5.75 mg g{sup −1} and 11.69 mg g{sup −1} (with 14.8 and 29.6 t ha{sup −1} biochar, respectively), whereas straw incorporation increased this value by only 3.92 mg g{sup −1}. The aboveground biomass of rice in biochar-amended soils increased to varying degrees compared with that in straw-treated soils. However, biochar application had no effects on rice yield, regardless of N fertilization. This study indicated that transforming straw to biochar was more stabilized and more suitable to mitigate greenhouse gas emissions and increase C storage in agriculture soils in Northeast China. - Highlights: • Rice straw-derived biochar significantly reduced CH{sub 4} emission. • Rice straw

  18. Impact Of Different Time Planting In Soybeans And Neem Seed Extract Application To Insect Population On Rice Field

    OpenAIRE

    Tamrin Abdullah; Ahdin Gassa; Sri Nur Aminah Ngatimin; Nurariaty Agus And Abdul Fattah

    2015-01-01

    Abstract The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e neem seed extract together with rice planting neem seed extract on soybean 17 days after rice planting synthetic insecticides on 17 days after rice planting Delthametrin on soybean and Chlorpirifos on rice respectively. Research was conduc...

  19. Impact Of Different Time Planting In Soybeans And Neem Seed Extract Application To Insect Population On Rice Field

    OpenAIRE

    Abdullah, Tamrin; Gassa, Ahdin; Ngatimin, Sri Nur Aminah; Agus, Nurariaty; Fattah, Abdul

    2015-01-01

    The purpose of research is to study impact of different time planting of soybean and neem seed extract application to pest insect population on rice field. The research was used Random Block Design in three treatment of insecticides application i.e: neem seed extract together with rice planting, neem seed extract on soybean 17 days after rice planting, synthetic insecticides on 17 days after rice planting (Delthametrin on soybean and Chlorpirifos on rice), respectively. Research was conducted...

  20. Rice Varieties in Archaic East Asia: Reduction of Its Diversity from Past to Present Times.

    Science.gov (United States)

    Kumagai, Masahiko; Kanehara, Masaaki; Shoda, Shin'ya; Fujita, Saburo; Onuki, Shizuo; Ueda, Shintaroh; Wang, Li

    2016-10-01

    The Asian cultivated rice, Oryza sativa, is one of the most important crops feeding more than a third of global population. In spite of the studies for several decades, the origin and domestication history of rice varietal groups, japonica and indica, have not been fully unveiled. Genetic information of ancient rice remains is essential for direct and exclusive insight into the domestication history of rice. We performed ancient DNA analysis of 950- to 2,800-year-old rice remains excavated from Japan and Korea. We found the presence of both japonica- and indica-type varieties in the Yayoi period and the middle ages of Japan and the middle part of Korea Peninsula 2,000 years ago. It is popularly considered that japonica has been exclusively cultivated in northern part of East Asia including Japan and Korea. Our result disclosed unexpectedly wide diversity of rice varieties in archaic East Asia. The present results from ancient rice DNA reveal an exclusive insight for the domestication history of rice which is not provided as far as contemporary rice. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Geoscience research helps rice farmers mitigate climate change and world hunger

    Science.gov (United States)

    Runkle, B.; Suvocarev, K.; Reba, M. L.

    2017-12-01

    Rice is a globally important crop - it comprises 30% of total human caloric consumption - and will be an important crop in the face of expanding population growth. Unfortunately, it is often grown in flooded paddies whose swampy conditions allow microbes to produce the strong greenhouse gas, methane. Over 10% of anthropogenic methane emission to the atmosphere are attributed to rice cultivation. Fortunately, a water-saving irrigation method known as Alternate Wetting and Drying can reduce methane emissions by periodically drying the soil. In our experiments, the method has no effect on rice harvest yields. In our research with rice farmers in Arkansas, we work to evaluate the amount of methane reductions on different fields with this irrigation practice. This research aims to expand the scientific basis for carbon emission reductions programs that enable farmers to be paid for implementing this practice. There are still gaps in our knowledge about how much methane is produced and under what conditions. Our research involves the continuous detection of field methane emissions and correlates then to changes in environmental conditions like the height and temperature of paddy water. Understanding these relationships may help more farmers qualify for credits in the growing carbon emission reductions programs. Because many farmers are already collecting information about their irrigation practices to reduce water applications, we aim to help them re-use this data to more quickly qualify for carbon emissions reductions payments.

  2. Estimation of Net Rice Production through Improved CASA Model by Addition of Soil Suitability Constant (ħα

    Directory of Open Access Journals (Sweden)

    Syed Muhammad Hassan Raza

    2018-05-01

    Full Text Available Net primary production (NPP is an important indicator of the supply of food and wood. We used a hierarchy model and real time field observations to estimate NPP using satellite imagery. Net radiation received by rice crop canopies was estimated as 27,428 Wm−2 (215.4 Wm−2 as averaged throughout the rice cultivation period (RCP, including 23,168 Wm−2 (118.3 Wm−2 as averaged as shortwave and 4260 Wm−2 (34.63 Wm−2 as averaged as longwave radiation. Soil, sensible and latent heat fluxes were approximated as 3324 Wm−2, 16,549 Wm−2, and 7554 Wm−2, respectively. Water stress on rice crops varied between 0.5838 and 0.1218 from the start until the end of the RCP. Biomass generation declined from 6.09–1.03 g/m2 in the tillering and ripening stages, respectively. We added a soil suitability constant (ħα into the Carnegie-Ames-Stanford Approach (CASA model to achieve a more precise estimate of yield. Classification results suggest that the total area under rice cultivation was 8861 km2. The spatial distribution of rice cultivation as per suitability zone was: 1674 km2 was not suitable (NS, 592 km2 was less suitable (LS, 2210 km2 was moderately suitable (MS and 4385 km2 was highly suitable (HS soil type with ħα ranges of 0.05–0.25, 0.4–0.6, 0.7–0.75 and 0.85–0.95 of the CASA based yield, respectively. We estimated net production as 1.63 million tons, as per 0.46 ton/ha, 1.2 ton/ha 1.9 ton/ha and 2.4 ton/ha from NS, LS, MS and HS soil types, respectively. The results obtained through this improved CASA model, by addition of the constant ħα, are likely to be useful for agronomists by providing more accurate estimates of NPP.

  3. Original Paper Field-specific difficulties for transplanted rice to cope ...

    African Journals Online (AJOL)

    Field-specific difficulties for transplanted rice to cope with ammonia from a localized enriched environment. Rémi GAUDIN1*, Berthe RASOAMAMPIONONA2 and Lilia RABEHARISOA3. 1Montpellier SupAgro, UMR System, 2 Place Viala, 34060 Montpellier, France. 2Faculté des Sciences, Université d'Antananarivo, B.P. ...

  4. Electricity Generation in Microbial Fuel Cell (MFC) by Bacterium Isolated from Rice Paddy Field Soil

    Science.gov (United States)

    Fakhirruddin, Fakhriah; Amid, Azura; Salim, Wan Wardatul Amani Wan; Suhaida Azmi, Azlin

    2018-03-01

    Microbial fuel cell (MFC) is an alternative approach in generating renewable energy by utilising bacteria that will oxidize organic or inorganic substrates, producing electrons yielded as electrical energy. Different species of exoelectrogenic bacteria capable of generating significant amount of electricity in MFC has been identified, using various organic compounds for fuel. Soil sample taken from rice paddy field is proven to contain exoelectrogenic bacteria, thus electricity generation using mixed culture originally found in the soil, and pure culture isolated from the soil is studied. This research will isolate the exoelectrogenic bacterial species in the rice paddy field soil responsible for energy generation. Growth of bacteria isolated from the MFC is observed by measuring the optical density (OD), cell density weight (CDW) and viable cell count. Mixed bacterial species found in paddy field soil generates maximum power of 77.62 μW and 0.70 mA of current. In addition, the research also shows that the pure bacterium in rice paddy field soil can produce maximum power and current at 51.32 μW and 0.28 mA respectively.

  5. Low uptake affinity cultivars with biochar to tackle Cd-tainted rice — A field study over four rice seasons in Hunan, China

    International Nuclear Information System (INIS)

    Chen, De; Guo, Hu; Li, Ruiyue; Li, Lianqing; Pan, Genxing; Chang, Andrew; Joseph, Stephen

    2016-01-01

    Biochar is becoming an environmentally friendly material for remediation of heavy metal contaminated soils and improving food safety. A field trial over four rice seasons was conducted to investigate the use of biochar and low Cd accumulating cultivars on Cd uptake in a heavy metal contaminated soil. Wheat straw derived biochar was applied at 0, 20 and 40 t ha"−"1. Two rice cultivars with differing Cd accumulation abilities were selected in each season. The results showed that both biochar and low Cd affinity cultivars significantly reduced rice grain Cd accumulation. Biochar had no significant effect the first season but thereafter consistently reduced rice grain Cd by a maximum of 61, 86 and 57% over the next three seasons. Zn accumulation in the rice grains was not decreased by biochar application, although available soil Zn was sharply reduced (35–91%). Indica conventional rice cultivars had much lower Cd, but higher Zn and lower Cd/Zn ratios in the grain than indica hybrid cultivars. Biochar was more effective for mitigating grain Cd accumulation in low Cd affinity cultivars than in high affinity cultivars. Soil pH was sustainably increased (up to nearly 1 unit) while available Cd significantly decreased by a maximum of 85% after biochar addition. The translocation of Cd from rice roots to shoots was reduced from 20 to 80% by biochar. Low uptake affinity cultivars combined with biochar reduced late rice grain Cd concentration and Cd/Zn ratios by 69–80% and 72–80%, respectively. It indicated that the management of combining biochar and low Cd affinity cultivars should be an efficient way to remediate Cd contaminated rice paddies and reduce health risk associated with consuming rice from these soils. - Highlights: • Biochar sustainably reduced soil Cd availability and Cd translocation in rice plant. • Indica conventional cultivars had lower Cd but higher Zn in grains than hybrid ones. • Biochar significantly reduced grain Cd and Cd/Zn ratio, though

  6. A Multi-Year Study on Rice Morphological Parameter Estimation with X-Band Polsar Data

    Directory of Open Access Journals (Sweden)

    Onur Yuzugullu

    2017-06-01

    Full Text Available Rice fields have been monitored with spaceborne Synthetic Aperture Radar (SAR systems for decades. SAR is an essential source of data and allows for the estimation of plant properties such as canopy height, leaf area index, phenological phase, and yield. However, the information on detailed plant morphology in meter-scale resolution is necessary for the development of better management practices. This letter presents the results of the procedure that estimates the stalk height, leaf length and leaf width of rice fields from a copolar X-band TerraSAR-X time series data based on a priori phenological phase. The methodology includes a computationally efficient stochastic inversion algorithm of a metamodel that mimics a radiative transfer theory-driven electromagnetic scattering (EM model. The EM model and its metamodel are employed to simulate the backscattering intensities from flooded rice fields based on their simplified physical structures. The results of the inversion procedure are found to be accurate for cultivation seasons from 2013 to 2015 with root mean square errors less than 13.5 cm for stalk height, 7 cm for leaf length, and 4 mm for leaf width parameters. The results of this research provided new perspectives on the use of EM models and computationally efficient metamodels for agriculture management practices.

  7. Effects of shading on starch pasting characteristics of indica hybrid rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Li Wang

    Full Text Available Rice is an important staple crop throughout the world, but environmental stress like low-light conditions can negatively impact crop yield and quality. Using pot experiments and field experiments, we studied the effects of shading on starch pasting viscosity and starch content with six rice varieties for three years, using the Rapid Visco Analyser to measure starch pasting viscosity. Shading at different growth stages and in different rice varieties all affected the starch pasting characteristics of rice. The effects of shading on starch pasting viscosity at middle and later growth stages were greater than those at earlier stages. Shading enhanced breakdown but reduced hold viscosity and setback at tillering-elongation stage. Most pasting parameters changed significantly with shading after elongation stage. Furthermore, the responses of different varieties to shading differed markedly. The change scope of starch pasting viscosity in Dexiang 4103 was rather small after heading, while that in IIyou 498 and Gangyou 906 was small before heading. We observed clear tendencies in peak viscosity, breakdown, and pasting temperature of the five rice varieties with shading in 2010 and 2011. Correlation analysis indicated that the rice amylose content was negatively correlated with breakdown, but was positively correlated with setback. Based on our results, IIyou 498, Gangyou 906, and Dexiang 4103 had higher shade endurance, making these varieties most suitable for high-quality rice cultivation in low-light regions.

  8. Effects of shading on starch pasting characteristics of indica hybrid rice (Oryza sativa L.).

    Science.gov (United States)

    Wang, Li; Deng, Fei; Ren, Wan-Jun; Yang, Wen-Yu

    2013-01-01

    Rice is an important staple crop throughout the world, but environmental stress like low-light conditions can negatively impact crop yield and quality. Using pot experiments and field experiments, we studied the effects of shading on starch pasting viscosity and starch content with six rice varieties for three years, using the Rapid Visco Analyser to measure starch pasting viscosity. Shading at different growth stages and in different rice varieties all affected the starch pasting characteristics of rice. The effects of shading on starch pasting viscosity at middle and later growth stages were greater than those at earlier stages. Shading enhanced breakdown but reduced hold viscosity and setback at tillering-elongation stage. Most pasting parameters changed significantly with shading after elongation stage. Furthermore, the responses of different varieties to shading differed markedly. The change scope of starch pasting viscosity in Dexiang 4103 was rather small after heading, while that in IIyou 498 and Gangyou 906 was small before heading. We observed clear tendencies in peak viscosity, breakdown, and pasting temperature of the five rice varieties with shading in 2010 and 2011. Correlation analysis indicated that the rice amylose content was negatively correlated with breakdown, but was positively correlated with setback. Based on our results, IIyou 498, Gangyou 906, and Dexiang 4103 had higher shade endurance, making these varieties most suitable for high-quality rice cultivation in low-light regions.

  9. Soil to rice transfer factors for 210Pb: a study on rice grown in India

    International Nuclear Information System (INIS)

    Karunakara, N.; Rao, Chetan; Ujwal, P.; Yashodhara, I.; Sudeep Kumara; Somashekarappa, H.M.; Bhaskara Shenoy, K.; Ravi, P.M.

    2013-01-01

    India is the second largest producer of rice (Oryza sativa L.) in the world and rice is the essential component of the diet for the majority of the population of India. However, detailed studies aimed at evaluation of radionuclide transfer factors (F v ) for rice grown in India are almost non-existent. This paper presents soil to rice transfer factors for 210 Pb for rice grown in natural field conditions on the West Coast of India. A rice field was developed very close to the Kaiga nuclear power plant for the field studies. For a comparative study of radionuclide transfer factors, rice samples were also collected from the rice fields of nearby villages. The soil to un-hulled rice grain 210 Pb varied in the range <1.2 x10 -2 to 8.1 x 10 -1 with a mean of 1.4 x 10 -1 . The mean values of un-hulled grain to white rice processing retention factors (F r ) was 0.03 for 210 Pb. Using the processing retention factors the soil to white rice transfer factor was estimated and found to have the mean value of 4.2 x 10 -3 . The study has shown that the transfer of 210 Pb was retained in the root and its transfer to above ground organs of rice plant is significantly lower. (author)

  10. A selfish genetic element confers non-Mendelian inheritance in rice.

    Science.gov (United States)

    Yu, Xiaowen; Zhao, Zhigang; Zheng, Xiaoming; Zhou, Jiawu; Kong, Weiyi; Wang, Peiran; Bai, Wenting; Zheng, Hai; Zhang, Huan; Li, Jing; Liu, Jiafan; Wang, Qiming; Zhang, Long; Liu, Kai; Yu, Yang; Guo, Xiuping; Wang, Jiulin; Lin, Qibing; Wu, Fuqing; Ren, Yulong; Zhu, Shanshan; Zhang, Xin; Cheng, Zhijun; Lei, Cailin; Liu, Shijia; Liu, Xi; Tian, Yunlu; Jiang, Ling; Ge, Song; Wu, Chuanyin; Tao, Dayun; Wang, Haiyang; Wan, Jianmin

    2018-06-08

    Selfish genetic elements are pervasive in eukaryote genomes, but their role remains controversial. We show that qHMS7 , a major quantitative genetic locus for hybrid male sterility between wild rice ( Oryza meridionalis ) and Asian cultivated rice ( O. sativa ), contains two tightly linked genes [ Open Reading Frame 2 ( ORF2 ) and ORF3 ]. ORF2 encodes a toxic genetic element that aborts pollen in a sporophytic manner, whereas ORF3 encodes an antidote that protects pollen in a gametophytic manner. Pollens lacking ORF3 are selectively eliminated, leading to segregation distortion in the progeny. Analysis of the genetic sequence suggests that ORF3 arose first, followed by gradual functionalization of ORF2 Furthermore, this toxin-antidote system may have promoted the differentiation and/or maintained the genome stability of wild and cultivated rice. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  11. Bacterial Diversity and Community Structure in Korean Ginseng Field Soil Are Shifted by Cultivation Time.

    Science.gov (United States)

    Nguyen, Ngoc-Lan; Kim, Yeon-Ju; Hoang, Van-An; Subramaniyam, Sathiyamoorthy; Kang, Jong-Pyo; Kang, Chang Ho; Yang, Deok-Chun

    2016-01-01

    Traditional molecular methods have been used to examine bacterial communities in ginseng-cultivated soil samples in a time-dependent manner. Despite these efforts, our understanding of the bacterial community is still inadequate. Therefore, in this study, a high-throughput sequencing approach was employed to investigate bacterial diversity in various ginseng field soil samples over cultivation times of 2, 4, and 6 years in the first and second rounds of cultivation. We used non-cultivated soil samples to perform a comparative study. Moreover, this study assessed changes in the bacterial community associated with soil depth and the health state of the ginseng. Bacterial richness decreased through years of cultivation. This study detected differences in relative abundance of bacterial populations between the first and second rounds of cultivation, years of cultivation, and health states of ginseng. These bacterial populations were mainly distributed in the classes Acidobacteria, Alphaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, and Sphingobacteria. In addition, we found that pH, available phosphorus, and exchangeable Ca+ seemed to have high correlations with bacterial class in ginseng cultivated soil.

  12. Exploring the Potential of TanDEM-X Data in Rice Monitoring

    Science.gov (United States)

    Erten, E.

    2015-12-01

    In this work, phenological parameters such as growth stage, calendar estimation, crop density and yield estimation for rice fields are estimated employing TanDEM-X data. Currently, crop monitoring is country-dependent. Most countries have databases based on cadastral information and annual farmer inputs. Inaccuracies are coming from wrong or missing farmer declarations and/or coarsely updated cadastral boundary definitions. This leads to inefficient regulation of the market, frauds as well as to ecological risks. An accurate crop calendar is also missing, since farmers provide estimations in advance and there is no efficient way to know the growth status over large plantations. SAR data is of particular interest for these purposes. The proposed method includes two step approach including field detection and phenological state estimation. In the context of precise farming it is substantial to define field borders which are usually changing every cultivation period. Linking the SAR inherit properties to transplanting practice such as irrigation, the spatial database of rice-planted agricultural crops can be updated. Boundaries of agricultural fields will be defined in the database, and assignments of crops and sowing dates will be continuously updated by our monitoring system considering that sowing practice variously changes depending on the field owner decision. To define and segment rice crops, the system will make use of the fact that rice fields are characterized as flooded parcels separated by path networks composed by soil or rare grass. This natural segmentation is well detectable by inspecting low amplitude and coherence values of bistatic acquisitions. Once the field borders are defined, the phenology estimation of crops monitored at any time is the key point of monitoring. In this aspect the wavelength and the polarization option of TanDEM-X are enough to characterize the small phenological changes. The combination of bistatic interferometry and Radiative

  13. Factors Affecting the Growth and Production of Milk-Clotting Enzyme by Amylomyces rouxii in Rice Liquid Medium

    Directory of Open Access Journals (Sweden)

    Pei-Jing Yu

    2005-01-01

    Full Text Available Amylomyces rouxii is one of the main fungi usually coexisting with yeasts in Chinese yeast ball, the starter of chiu-niang, a traditional Chinese fermented product from rice. In the present study, growth and production of milk-clotting enzyme (MCE in gelatinous rice liquid culture of A. rouxii as influenced by waxy (gelatinous rice content in the medium (5–20 %, temperature (25–40 °C, cultivation time (1–6 days, shaking speeds (0–150 rpm and metal ions (Na+, K+, Zn2+, Mg2+, Mn2+, Cu2+, Ca2+, Fe3+ and Al3+ were investigated. Results revealed that rice content in the medium, shaking speed, temperature and cultivation time all affected the mycelial propagation and the production of milk-clotting enzyme by A. rouxii in the rice liquid culture. The maximum milk-clotting enzyme activity of ca. 1.22 unit/mL of medium was observed in the 3-day static culture of test organism grown at 30 °C in the medium containing 20 % of gelatinous rice, while mycelial propagation increased with the increase of cultivation time and shaking speed. Furthermore, a significant increase (p<0.05 in the milk-clotting enzyme activity of ca. 1.90 unit/mL of medium, which was about 1.55-fold of the control, was observed when Al3+ was added to the rice liquid medium.

  14. production of bioethanol from rice straw using yeast extracts ...

    African Journals Online (AJOL)

    user

    70% of production cost using less important materials, like agricultural waste ... rice cultivation and wood industries results in the ... method for pretreatment and enzymatic saccharification ... The economic problems consist exclusive of cost.

  15. Rice microstructure

    Science.gov (United States)

    An understanding of plant structure is desirable to obtain a clear idea of the overall impact of a crop. A mature rice plant consists of leafy components (left in the field post-harvest) and paddy rice (collected). The rice plant is supported by a hollow stem (culm) with leaf sheaths attached to nod...

  16. Improvement of Salinity Stress Tolerance in Rice: Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Thi My Linh Hoang

    2016-10-01

    Full Text Available Rice (Oryza sativa L. is an important staple crop that feeds more than one half of the world’s population and is the model system for monocotyledonous plants. However, rice is very sensitive to salinity and is the most salt sensitive cereal crop with a threshold of 3 dSm−1 for most cultivated varieties. Despite many attempts using different strategies to improve salinity tolerance in rice, the achievements so far are quite modest. This review aims to discuss challenges that hinder the improvement of salinity stress tolerance in rice as well as potential opportunities for enhancing salinity stress tolerance in this important crop.

  17. The Short-Term Effects of Rice Straw Biochar, Nitrogen and Phosphorus Fertilizer on Rice Yield and Soil Properties in a Cold Waterlogged Paddy Field

    Directory of Open Access Journals (Sweden)

    Linlin Si

    2018-02-01

    Full Text Available Crop productivity in cold waterlogged paddy fields can be constrained by chronic flooding stress and low temperature. Farmers typically use chemical fertilizer to improve crop production, but this conventional fertilization is not very effective in a cold waterlogged paddy field. Biochar amendment has been proposed as a promising management approach to eliminating these obstacles. However, little is known about the performance of biochar when combined with N fertilizer and P fertilizer in cold waterlogged soils. The aim of this study was, therefore, to assess the main effects and interactive effects of rice straw biochar, N and P fertilizer on rice growth and soil properties in a cold waterlogged paddy field. The field treatments consisted of a factorial combination of two biochar levels (0 and 2.25 t ha−1, two N fertilizer levels (120.0 and 180.0 kg ha−1 and two P fertilizer levels (37.5 and 67.5 kg ha−1 which were arranged in a randomized block design, with three replicates. Results confirmed that biochar application caused a significant increase in the soil pH due to its liming effect, while this application resulted in a significant decrease in soil exchangeable cations, such as exchangeable Ca, Mg, Al and base cations. The interactive effect of N fertilizer, P fertilizer and biochar was significant for soil total N. Moreover, a negative effect of biochar on the internal K use efficiency suggested that K uptake into rice may benefit from biochar application. According to the partial Eta squared values, the combined application of N fertilizer and biochar was as effective as pure P fertilization at increasing straw P uptake. The addition of biochar to farmers’ fertilization practice treatment (180.0 kg N ha−1, 67.5 kg P2O5 ha−1 and 67.5 kg K2O ha−1 significantly increased rice yield, mainly owing to improvements in grains per panicle. However, notable effects of biochar on rice yield and biomass production were not detected

  18. Ecological investigation of application of pesticides in rice fields

    International Nuclear Information System (INIS)

    Nouri, J.; Arjomandi, R.; Bayat, H.

    2000-01-01

    Among several pests of rice as one of the main agricultural products in Iran, rice borer, C hilo sarsaparilla is one of the most important pests of this crop. Use of pesticides coincided with the occurrence of this pest in the northern region of Iran in 1972. At present in order to control this pest, more than 12000 tones of pesticides granules are used annually. Ecological effects of pesticides application and the use of Trichograma sp. as a natural enemy, for assessing the impacts of pesticides in environments, especially on different living organisms on the plant, in irrigation water, and in 5 cm depth of surface soil, were investigated in two regions of Amol, named Osk. Mahalleh and Capik Field of Tashbandan. Results indicated that the two treatments were not different on crop loss. One the contrary, in the pesticide treatment, there was a considerable dec tease in the population of living organisms, particularly, no organism was observed in 5 cm depth of surface soil. It is recommended that in order to maintain the balance of environment, the use of chemicals for controlling rice borer must be with extreme care, only in the inevitable was with the use of principles of Integrated Pest Management

  19. Silicon fertilization and soil water tensions on rice development and yield

    Directory of Open Access Journals (Sweden)

    Jakeline R. de Oliveira

    2016-02-01

    Full Text Available ABSTRACT The cultivation of upland rice (Oryza sativa in Brazil occurs mainly in the Cerrado, a region with adverse weather conditions. The use of silicon in its cultivation becomes important, since this nutrient provides higher rigidity, lower transpiration and higher resistance to dry spells in rice plants. The objective of the present study was to evaluate the effect of silicon fertilization and soil water tensions on upland rice development and yield in a Cerrado Oxisol. A 5 x 5 fractionated factorial with five soil water tensions (0, 15, 30, 45 and 60 kPa and five silicon doses (0, 120, 240, 480 and 960 mg dm-3 was used, which were distributed in a randomized block design, with four replicates. Plant height, number of tillers, number of panicles, number of grains per panicle, numbers of full and empty grains and percentage of empty grains were evaluated. Silicon fertilization promotes increased tillering in rice plants at the dose of 960 mg dm-3. The numbers of tillers and panicles decreased with the application of silicon up to the doses of 460 and 490 mg dm-3, respectively. The increase in soil water tensions reduced plant height and the number of full grains, and increased the percentage of empty grains of upland rice.

  20. Dynamical roguing model for controlling the spread of tungro virus via Nephotettix Virescens in a rice field

    Science.gov (United States)

    Blas, Nikki; David, Guido

    2017-10-01

    Rice tungro disease is described as a cancer due to its major impact on the livelihood of farmers and the difficulty of controlling it. Tungro is a semi-persistent virus transmitted by green leafhoppers called Nephotettix Virescens. In this paper, we presented a compartmental plant-vector model of the Nephotettix Virescens - rice plant interaction based on a system of ordinary differential equations to simulate the effects of roguing in controlling the spread of Tungro virus in a model rice field of susceptible rice variety (Taichung Native 1).

  1. Leaf chlorophyll and nitrogen dynamics and their relationship to lowland rice yield for site-specific paddy management

    Directory of Open Access Journals (Sweden)

    Asa Gholizadeh

    2017-12-01

    Full Text Available The optimum rate and application timing of Nitrogen (N fertilizer are crucial in achieving a high yield in rice cultivation; however, conventional laboratory testing of plant nutrients is time-consuming and expensive. To develop a site-specific spatial variable rate application method to overcome the limitations of traditional techniques, especially in fields under a double-cropping system, this study focused on the relationship between Soil Plant Analysis Development (SPAD chlorophyll meter readings and N content in leaves during different growth stages to introduce the most suitable stage for assessment of crop N and prediction of rice yield. The SPAD readings and leaf N content were measured on the uppermost fully expanded leaf at panicle formation and booting stages. Grain yield was also measured at the end of the season. The analysis of variance, variogram, and kriging were calculated to determine the variability of attributes and their relationship, and finally, variability maps were created. Significant linear relationships were observed between attributes, with the same trends in different sampling dates; however, accuracy of semivariance estimation reduces with the growth stage. Results of the study also implied that there was a better relationship between rice leaf N content (R2 = 0.93, as well as yield (R2 = 0.81, with SPAD readings at the panicle formation stage. Therefore, the SPAD-based evaluation of N status and prediction of rice yield is more reliable on this stage rather than at the booting stage. This study proved that the application of SPAD chlorophyll meter paves the way for real-time paddy N management and grain yield estimation. It can be reliably exploited in precision agriculture of paddy fields under double-cropping cultivation to understand and control spatial variations. Keywords: Spatial variability, Non-invasive measurement, Precision farming, Decision support

  2. Manejo de água e de fertilizante potássico na cultura de arroz irrigado Water and potassium fertilization management for irrigated rice cultivation

    Directory of Open Access Journals (Sweden)

    Alberto Baêta dos Santos

    1999-04-01

    Full Text Available O manejo da água de irrigação e as doses e épocas de aplicação de fertilizantes tornam-se aspectos de extrema importância no êxito do aproveitamento das várzeas para o cultivo de arroz (Oryza sativa L. irrigado ou este seguido de outras espécies. Com o objetivo de comparar distintas formas de manejo de água e de fertilizante potássico no comportamento do arroz irrigado, foram conduzidos experimentos por três anos consecutivos, em um Inceptissolo. Foram estudados os efeitos de manejo de água (MA1 - inundação contínua e MA2 - inundação intermitente seguida de contínua e o modo de aplicação de fertilizante potássico (K1 - na semeadura; K2 - parcelada e K3 - meia dose parcelada. O manejo de água apresentou efeito mais expressivo sobre o comportamento do arroz que o do fertilizante potássico. A inundação contínua durante todo o ciclo da cultura proporcionou maiores rendimentos de grãos, expressando maiores valores dos parâmetros produtivos, e melhorou a qualidade industrial dos grãos. Com esta irrigação, o parcelamento da adubação potássica aumentou o aproveitamento do fertilizante. Os manejos do fertilizante potássico afetaram diferentemente o comportamento da cultura do arroz nas distintas formas de manejo de água.Irrigation water levels and timing of potassium fertilization is extremely important for the use of lowlands for irrigated rice (Oryza sativa L. cultivation in crop rotation. A field experiment was conduced for three consecutive years in Inceptisol to study the effects of water management (WM1 - continuous flooding and WM2 - intermittent flooding followed continuous flooding and mode of potassium fertilizer application (K1 - at sowing; K2 - fractional application and K3 - fractional application of half levels on grain yield and yield components of irrigated rice. Water management presented expressive effect on rice performance as compared to potassium fertilization. Continuous flooding during whole

  3. Ecological balance between supply and demand based on cultivated land ecological footprint method in Guizhou Province

    Science.gov (United States)

    Qian, Qinghuan; Zhou, Dequan; Bai, Xiaoyong; Xiao, Jianyong; Chen, Fei; Zeng, Cheng

    2018-01-01

    In order to construct the indicators of the balance between supply and demand of the cultivated land ecological carrying capacity, basing on the relation of the cultivated land ecological carrying capacity supply and demand, applying the model of Cultivated Land Ecological Footprints and the method of CIS and considering the factors of cultivated land production, taking the statistical data of 2015 as an example, and then made a systematic evaluation of the balance between supply and demand of the cultivated land ecological carrying capacity in Guizhou Province. The results show that (1) the spatial distribution of supply and demand of cultivated land ecological carrying capacity in Guizhou is unbalanced, and the northern and eastern parts are the overloading area, the middle, the south and the west parts are the balance area. (2) From the perspective of cultivated land structure, the crops with ecological carrying capacity surplus were rice, vegetables and peanuts, among which rice was the highest and the ecological balance index was 0.7354. The crops with ecological carrying capacity overload were potato, wheat, maize, rapeseeds, soybeans and cured tobacco, of which the index of potato up to 7.11, other types of indices are less than 1.5. The research can provide the ecological security early warning, the overall plan of land use and sustainable development of the area cultivated land with scientific evidence and decision support.

  4. Agronomic and environmental aspects of diazotrophic bacteria in irrigated rice fields

    Science.gov (United States)

    This article provides an overview of the free-living and plant-associated nitrogen-fixing bacterial communities in irrigated rice fields, with a focus on describing the drivers affecting community assemblages in this soil-water-plant-atmosphere system. Theoretical and technical advances in non-legu...

  5. The phenology of malaria mosquitos in irrigated rice fields in Mali

    NARCIS (Netherlands)

    Klinkenberg, E.; Takken, W.; Huibers, F.P.; Touré, Y.T.

    2003-01-01

    A field study was carried out in the large-scale rice irrigation scheme of the Office du Niger in Mali to investigate the relation between anopheline mosquito larval development and small-scale differences in irrigation practices, such as water level, irrigation application and irrigation frequency.

  6. Wolbachia infection complexity among insects in the tropical rice-field community.

    Science.gov (United States)

    Kittayapong, P; Jamnongluk, W; Thipaksorn, A; Milne, J R; Sindhusake, C

    2003-04-01

    Wolbachia are a group of intracellular bacteria that cause reproductive alterations in their arthropod hosts. Widely discordant host and Wolbachia phylogenies indicate that horizontal transmission of these bacteria among species sometimes occurs. A likely means of horizontal transfer is through the feeding relations of organisms within communities. Feeding interactions among insects within the rice-field insect community have been well documented in the past. Here, we present the results of a polymerase chain reaction-based survey and phylogenetic analysis of Wolbachia strains in the rice-field insect community of Thailand. Our field survey indicated that 49 of 209 (23.4%) rice-field insect species were infected with Wolbachia. Of the 49 infected species, 27 were members of two feeding complexes: (i) a group of 13 hoppers preyed on by 2 mirid species and parasitized by a fly species, and (ii) 2 lepidopteran pests parasitized by 9 wasp species. Wolbachia strains found in three hoppers, Recilia dorsalis, Nephotettix malayanus and Nisia nervosa, the two mirid predators, Cyrtorhinus lividipennis and Tytthus chinensis, and the fly parasitoid, Tomosvaryella subvirescens, were all in the same Wolbachia clade. In the second complex, the two lepidopteran pests, Cnaphalocrocis medinalis and Scirpophaga incertulas, were both infected with Wolbachia from the same clade, as was the parasitoid Tropobracon schoenobii. However, none of the other infected parasitoid species in this feeding complex was infected by Wolbachia from this clade. Mean (+/- SD) genetic distance of Wolbachia wsp sequences among interacting species pairs of the hopper feeding complex (0.118 +/- 0.091 nucleotide sequence differences), but not for the other two complexes, was significantly smaller than that between noninteracting species pairs (0.162 +/- 0.079 nucleotide sequence differences). Our results suggest that some feeding complexes, such as the hopper complex described here, could be an important

  7. Rice management interventions to mitigate greenhouse gas emissions: a review.

    Science.gov (United States)

    Hussain, Saddam; Peng, Shaobing; Fahad, Shah; Khaliq, Abdul; Huang, Jianliang; Cui, Kehui; Nie, Lixiao

    2015-03-01

    Global warming is one of the gravest threats to crop production and environmental sustainability. Rice, the staple food of more than half of the world's population, is the most prominent cause of greenhouse gas (GHG) emissions in agriculture and gives way to global warming. The increasing demand for rice in the future has deployed tremendous concerns to reduce GHG emissions for minimizing the negative environmental impacts of rice cultivation. In this review, we presented a contemporary synthesis of existing data on how crop management practices influence emissions of GHGs in rice fields. We realized that modifications in traditional crop management regimes possess a huge potential to overcome GHG emissions. We examined and evaluated the different possible options and found that modifying tillage permutations and irrigation patterns, managing organic and fertilizer inputs, selecting suitable cultivar, and cropping regime can mitigate GHG emissions. Previously, many authors have discussed the feasibility principle and the influence of these practices on a single gas or, in particular, in the whole agricultural sector. Nonetheless, changes in management practices may influence more than one gas at the same time by different mechanisms or sometimes their effects may be antagonistic. Therefore, in the present attempt, we estimated the overall global warming potential of each approach to consider the magnitude of its effects on all gases and provided a comprehensive assessment of suitable crop management practices for reducing GHG emissions in rice culture.

  8. Tool for Land Suitability Assessment for Rice Production in

    African Journals Online (AJOL)

    komla

    Emphasis on rice production should be to target a higher ... from 25 °C, Ghana's thermal .... mechanical cultivation, effective soil depth Climate data. TABLE 2. Statistical weightings for dominant and ... calculated from historical daily.

  9. Paddy-field contamination with 134Cs and 137Cs due to Fukushima Dai-ichi Nuclear Power Plant accident and soil-to-rice transfer coefficients

    International Nuclear Information System (INIS)

    Endo, Satoru; Kajimoto, Tsuyoshi; Shizuma, Kiyoshi

    2013-01-01

    The transfer coefficient (TF) from soil to rice plants of 134 Cs and 137 Cs in the form of radioactive deposition from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011 was investigated in three rice paddy fields in Minami-Soma City. Rice crops were planted in the following May and harvested at the end of September. Soil cores of 30-cm depth were sampled from rice-planted paddy fields to measure 134 Cs and 137 Cs radioactivity at 5-cm intervals. 134 Cs and 137 Cs radioactivity was also measured in rice ears (rice with chaff), straws and roots. The rice ears were subdivided into chaff, brown rice, polished rice and rice bran, and the 134 Cs and 137 Cs radioactivity concentration of each plant part was measured to calculate the respective TF from the soil. The TF of roots was highest at 0.48 ± 0.10 in the field where the 40 K concentration in the soil core was relatively low, in comparison with TF values of 0.31 and 0.38 in other fields. Similar trends could be found for the TF of whole rice plants, excluding roots. The TF of rice ears was relatively low at 0.019–0.026. The TF of chaff, rice bran, brown rice and polished rice was estimated to be 0.049, 0.10–0.16, 0.013–0.017 and 0.005–0.013, respectively. - Highlights: ► We investigated the transfer coefficient of 134 Cs and 137 Cs from soil to rice plants in Minami-Soma City due to the Fukushima accident in 2011. ► The rice ears, straws, roots, chaff, brown rice, polished rice, rice bran and soil samples have been measured by Ge-detector. ► Transfer coefficient of chaff, rice bran, brown rice, and polished rice is estimated as 0.049, ranging from 0.10 to 0.16, 0.013 to 0.017, and 0.005 to 0.013, respectively.

  10. Rice straw addition as sawdust substitution in oyster mushroom (Pleurotus ostreatus) planted media

    Science.gov (United States)

    Utami, Christine Pamardining; Susilawati, Puspita Ratna

    2017-08-01

    Oyster mushroom is favorite by the people because of the high nutrients. The oyster mushroom cultivation usually using sawdust. The availability of sawdust become difficult to find. It makes difficulties of mushroom cultivation. Rice straw as an agricultural waste can be used as planted media of oyster mushroom because they contain much nutrition needed to the mushroom growth. The aims of this research were to analysis the influence of rice straw addition in a baglog as planted media and to analysis the concentration of rice straw addition which can substitute sawdust in planted media of oyster mushroom. This research used 4 treatment of sawdust and rice straw ratio K = 75 % : 0 %, P1 = 60 % : 15 %, P2 = 40 % : 35 %, P3 = 15 % : 60 %. The same material composition of all baglog was bran 20%, chalk 5%, and water 70%. The parameters used in this research were wet weight, dry weight, moisture content and number of the mushroom fruit body. Data analysis was used ANOVA test with 1 factorial. The results of this research based on statistical analysis showed that there was no influence of rice straw addition in a planted media on the oyster mushroomgrowth. 15% : 60% was the concentrationof rice straw additionwhich can substitute the sawdust in planted media of oyster mushroom.

  11. Review: Biodiversity conservation strategy in a native perspective; case study of shifting cultivation at the Dayaks of Kalimantan

    Directory of Open Access Journals (Sweden)

    AHMAD DWI SETYAWAN

    2010-07-01

    Full Text Available Setyawan AD. 2010. Biodiversity conservation strategy in a native perspective; case study of shifting cultivation at the Dayaks of Kalimantan. Nusantara Bioscience 2: 97-108. Native tribes generally are original conservationists; they build genuine conservation strategy of natural resources and environment for sustainable living. Dayak is a native tribe of Kalimantan that has been living for thousands of years; they use shifting cultivation to manage the communal forest lands due to Kalimantan’s poor soil of minerals and nutrients, where the presence of phosphorus becomes a limiting factor for crops cultivation. In tropical forests, phosphorus mostly stored in the trees, so to remove it, the forest burning is carried out. Nutrients released into the soil can be used for upland rice (gogo cultivation, until depleted; after that, cultivators need to open a forest, while the old land was abandoned (fallow until it becomes forest again (for 20-25 years. The consecutive land clearing causes the formation of mosaics land with different succession ages and diverse biodiversity. This process is often combined with agroforestry systems (multicultural forest gardens, where the will-be-abandoned fields are planted with a variety of useful trees that can be integrated in forest ecosystems, especially rubber and fruits. These systems of shifting cultivation are often blamed as the main factor of forest degradation and fires, but in the last 300 years, this system has little impact on forest degradation. But, this is relatively low in productivity and subsistent, so it is not suitable for the modern agriculture which demands high productivity and measurable, mass and continuous yield, as well as related to the market. The increased population and industrial development of forestry, plantation, mining, etc. make the communal forest become narrower, so the fallow periods are shortened (5-15 years and the lands are degraded into grasslands. In the future

  12. Water Footprint Analysis of Paddy Rice and the Nexus of Water-Land-Rice in Taiwan: 2005-2014

    Science.gov (United States)

    Wu, T. C.

    2018-05-01

    This paper explores the water footprint (WF) of paddy rice and the nexus of water-land-food (rice) in Taiwan. The research results indicate that the average annual rice WF for the years 2005-2014 was about 7,580 m3/ton, of which 80% was blue, 17% was green, and 3% was grey. This average annual footprint was about 5.7 times larger than the 2000-2004 average annual WF of rice for countries around the globe of 1325 m3/ton, of which 48% was green, 44% was blue, and 8% was grey. The blue WF is the most important source of water for rice production in Taiwan. The water consumption of the second crop is higher than that of the first crop. The water use efficiency in the southern region of Taiwan is the best, while the northern part of Taiwan exhibits relatively high inefficiency. The rates of change in cultivated land and rice production in Taiwan are decreasing in a stable manner. However, the annual rate of change in the rice WF is unstable. The nexus of land, water, and food should be taken into consideration to protect water availability, maintain agricultural production, and avoid land degradation. The results could offer useful information for agriculture policy and water resource management.

  13. Influence of the nonexchangeable potassium of mica on radiocesium uptake by paddy rice

    International Nuclear Information System (INIS)

    Eguchi, Tetsuya; Ohta, Takeshi; Ishikawa, Tetsuya; Matsunami, Hisaya; Takahashi, Yoshihiko; Kubo, Katashi; Yamaguchi, Noriko; Kihou, Nobuharu; Shinano, Takuro

    2015-01-01

    A pot cultivation experiment was conducted to elucidate the influence of the nonexchangeable potassium (K) of mica on radiocesium ( 137 Cs) uptake by paddy rice (Oryza sativa L. cv. Koshihikari), and to evaluate the potential of mica application as a countermeasure to reduce radiocesium transfer from soil to paddy rice. The increase in the exchangeable K concentrations of soils, measured before planting, due to mica (muscovite, biotite, and phlogopite) application was negligible. However, in trioctahedral mica (biotite and phlogopite)-treated soil, the release of nonexchangeable K from the mica interlayer maintained the soil-solution K at a higher level during the growing season in comparison to the control, and consequently decreased the 137 Cs transfer factor for brown rice (TF). The sodium tetraphenylboron (TPB)-extractable K concentration of the soils, measured before planting, was strongly negatively correlated with the TF, whereas the exchangeable K concentration of the soils, also measured before planting, was not correlated with the TF. Therefore, we conclude that TPB-extractable K is more reliable than exchangeable K as a basis of fertilizer recommendations for radiocesium-contaminated paddy fields. Phlogopite-treated soils exhibited higher TPB-extractable K concentrations and lower TF values than biotite-treated soils. We thus conclude that phlogopite application is an effective countermeasure to reduce radiocesium uptake in paddy rice. - Highlights: • Nonexchangeable K of added trioctahedral mica decreased 137 Cs uptake by paddy rice. • TPB-extractable K would be a more reliable indicator than exchangeable K. • Phlogopite would be a good amendment for radiocesium-contaminated paddy fields

  14. Rapid Measurement of Soil Carbon in Rice Paddy Field of Lombok Island Indonesia Using Near Infrared Technology

    Science.gov (United States)

    Kusumo, B. H.; Sukartono, S.; Bustan, B.

    2018-02-01

    Measuring soil organic carbon (C) using conventional analysis is tedious procedure, time consuming and expensive. It is needed simple procedure which is cheap and saves time. Near infrared technology offers rapid procedure as it works based on the soil spectral reflectance and without any chemicals. The aim of this research is to test whether this technology able to rapidly measure soil organic C in rice paddy field. Soil samples were collected from rice paddy field of Lombok Island Indonesia, and the coordinates of the samples were recorded. Parts of the samples were analysed using conventional analysis (Walkley and Black) and some other parts were scanned using near infrared spectroscopy (NIRS) for soil spectral collection. Partial Least Square Regression (PLSR) Models were developed using data of soil C analysed using conventional analysis and data from soil spectral reflectance. The models were moderately successful to measure soil C in rice paddy field of Lombok Island. This shows that the NIR technology can be further used to monitor the C change in rice paddy soil.

  15. Field response of aboveground non-target arthropod community to transgenic Bt-Cry1Ab rice plant residues in postharvest seasons.

    Science.gov (United States)

    Bai, Yao-Yu; Yan, Rui-Hong; Ye, Gong-Yin; Huang, Fangneng; Wangila, David S; Wang, Jin-Jun; Cheng, Jia-An

    2012-10-01

    Risk assessments of ecological effects of transgenic rice expressing lepidoptera-Cry proteins from Bacillus thuringiensis (Bt) on non-target arthropods have primarily focused on rice plants during cropping season, whereas few studies have investigated the effects in postharvest periods. Harvested rice fallow fields provide a critical over-wintering habitat for arthropods in the Chinese rice ecosystems, particularly in the southern region of the country. During 2006-08, two independent field trials were conducted in Chongqing, China to investigate the effects of transgenic Cry1Ab rice residues on non-target arthropod communities. In each trial, pitfall traps were used to sample arthropods in field plots planted with one non-Bt variety and two Bt rice lines expressing the Cry1Ab protein. Aboveground arthropods in the trial plots during the postharvest season were abundant, while community densities varied significantly between the two trials. A total of 52,386 individual insects and spiders, representing 93 families, was captured in the two trials. Predominant arthropods sampled were detritivores, which accounted for 91.9% of the total captures. Other arthropods sampled included predators (4.2%), herbivores (3.2%), and parasitoids (0.7%). In general, there were no significant differences among non-Bt and Bt rice plots in all arthropod community-specific parameters for both trials, suggesting no adverse impact of the Bt rice plant residues on the aboveground non-target arthropod communities during the postharvest season. The results of this study provide additional evidence that Bt rice is safe to non-target arthropod communities in the Chinese rice ecosystems.

  16. Impact of fungicide and insecticide use on non-target aquatic organisms in rice paddy fields

    Directory of Open Access Journals (Sweden)

    Alana Cristina Dorneles Wandscheer

    Full Text Available ABSTRACT: The intensive use of plant protection products in rice paddy fields ( Oryza sativa L. has caused concern about the environmental impact on communities of non-target organisms that are natural inhabitants in these agroecosystems. The purpose of this review is to analyze the data currently available in the literature about some important fungicides and insecticides (such as trifloxystrobin, tebuconazole, tricyclazole, lambda-cyhalothrin, and thiamethoxam, which are currently used to control pests and diseases in rice paddy fields, as well as their effects on the community of non-target aquatic organisms.

  17. Field performance of selected mutants of sorghum and rice. Field evaluation review

    International Nuclear Information System (INIS)

    1996-10-01

    Agricultural research conducted in Mali by the Institute Polytechnique Rural (IPR) and the Institute d'Economie Rural (IER), from improvement of sorghum and African rice (Oryza glaberrima) with some Agency support, resulted in several advanced generations of sorghum and African rice with improved characteristics, including high yield. Project MLI/5/014 aims at further supporting both institutions to advance these promising results, particularly by supporting multi-location field trials to select high yielding plant varieties, and by adding capability in tissue culture techniques for advanced mutation breeding as well as in the use of nuclear techniques in soil studies. The project was approved in 1995, as a model project and the current budget for the Agency's input amounts to $469,300 until 1997. The disbursements up to April 1996 amount to $168,991. The present mid-term evaluation aims at assessing the progress of the project towards its intended objectives and overall goal and the evaluation methodology applied was based on the Logical Framework Approach for project design. Figs, tabs

  18. Response of rice cultivars to rates of nitrogen and potassium application in field and pot conditions.

    Science.gov (United States)

    Bahmaniar, M A; Ranjbar, G A

    2007-05-01

    Nitrogen and potassium are the yield-limiting nutrients in rice production regions of Iran. Use of N and K efficient cultivars is an important complementary strategy in improving rice yield, increasing the quality properties of rice grains and reducing cost of production. In order to consider the effects of different amounts of N and K application on rice (Oryza sativa L.) yield and yield components in pot and field conditions these experiments were undertaken in 2004 at Sari Agricultural Station, Iran. Four levels of N (0, 50, 100 and 150 Kg N ha(-1) in field and 0, 0.6, 1.2 and 1.8 g N pot(-1) in pot) corresponding with four levels of K (0, 75, 150 and 225 kg K2O ha(-1) in field and 0, 0.5, 1 and 1.5 g K2O pot(-1) in pot) were applied in a split-factorial plot design with three replications in both pot and field experiments, variously. Grain yield, number of grain per panicle, number of tiller, plant height, length of flag leaf, total and shoot dry matter, 1000 grain weight and harvest index have been increased by N application in field conditions. However, in pot conditions grain yield, number of grain per panicle, number of tiller, plant height, width of flag leaf, total and shoot dry matter, leaf nitrogen contents and harvest index have significantly been increased (p pot conditions (p < or = 0.05).

  19. Rice monitoring with multi-temporal and dual-polarimetric TerraSAR-X data

    Science.gov (United States)

    Koppe, Wolfgang; Gnyp, Martin L.; Hütt, Christoph; Yao, Yinkun; Miao, Yuxin; Chen, Xinping; Bareth, Georg

    2013-04-01

    This study assesses the use of TerraSAR-X data for monitoring rice cultivation in the Sanjiang Plain in Heilongjiang Province, Northeast China. The main objective is the understanding of the coherent co-polarized X-band backscattering signature of rice at different phenological stages in order to retrieve growth status. For this, multi-temporal dual polarimetric TerraSAR-X High Resolution SpotLight data (HH/VV) as well as single polarized StripMap (VV) data were acquired over the test site. In conjunction with the satellite data acquisition, a ground truth field campaign was carried out. The backscattering coefficients at HH and VV of the observed fields were extracted on the different dates and analysed as a function of rice phenology to provide a physical interpretation for the co-polarized backscatter response in a temporal and spatial manner. Then, a correlation analysis was carried out between TerraSAR-X backscattering signal and rice biomass of stem, leaf and head to evaluate the relationship with different vertical layers within the rice vegetation. HH and VV signatures show two phases of backscatter increase, one at the beginning up to 46 days after transplanting and a second one from 80 days after transplanting onwards. The first increase is related to increasing double bounce reflection from the surface-stem interaction. Then, a decreasing trend of both polarizations can be observed due to signal attenuation by increasing leaf density. A second slight increase is observed during senescence. Correlation analysis showed a significant relationship with different vertical layers at different phenological stages which prove the physical interpretation of X-band backscatter of rice. The seasonal backscatter coefficient showed that X-band is highly sensitive to changes in size, orientation and density of the dominant elements in the upper canopy.

  20. ECONOMIC ANALYSIS OF SMALL HOLDER RICE PRODUCTION SYSTEMS IN EBONYI STATE SOUTH EAST, NIGERIA

    Directory of Open Access Journals (Sweden)

    Nwaobiala C.U.

    2013-11-01

    Full Text Available Economic analysis of Upland and Swamp rice production in Ebonyi State, South east Nigeria was studied and analyzed in 2011 farming season. Purposive and multistage random sampling technique was used to select agricultural blocks, circles and rice farmers. The sample size was 240 rice farmers (120 Agricultural Development Programme (ADP Upland rice contact farmers and 120 Agricultural Development Programme (ADP Swamp contact rice farmers. Data for the analysis were collected from a structured questionnaire. The result indicates that mean ages of upland rice farmers was 37.3 years while swamp rice farmers had 39.2 years. The mean farming experience for both farmers were 8.5 years (upland rice farmers and 8.8 years (swamp rice farmers with farm sizes of 1.2 and 1.1 hectares for upland rice farmers and swamp rice farmers respectively. Upland rice farmers had an annual farm income of 189,410.00 NGN (1,222USD as against 201,166.00 NGN (1,297.85USD for Swamp rice farmers. The multiple regression (Cobb Douglas estimates of the determinants of output of upland rice showed that coefficients age, farming experience, farm size, variable inputs and farm income were positively signed at given levels of probability while capital inputs was negative. The Cobb Douglas regression estimates of the determinants of output of Swamp rice showed that the coefficients of education, labour cost, farm size, variable inputs and farm income were positively signed and significant at given levels of probability as well as capital inputs which was negative. The result indicates that net profit from Upland rice cultivation was 92,800.00 NGN (598.71USD with a Benefit Cost Ratio of N1.55 (1.56USD. The net profit from Swamp rice cultivation was 132,090.00 NGN (852.19USD and a Benefit Cost Ratio of 1.75 NGN (1.75USD. Access to credit to rice farmers, subsidy on farm inputs, dissemination of improved rice technologies by extension agents and formation of farmer groups were advocated

  1. Low uptake affinity cultivars with biochar to tackle Cd-tainted rice — A field study over four rice seasons in Hunan, China

    Energy Technology Data Exchange (ETDEWEB)

    Chen, De; Guo, Hu; Li, Ruiyue [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Li, Lianqing, E-mail: lqli@njau.edu.cn [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Pan, Genxing [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Chang, Andrew [Department of Environmental Sciences, University of California, Riverside, CA 92521 (United States); Joseph, Stephen [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-01-15

    Biochar is becoming an environmentally friendly material for remediation of heavy metal contaminated soils and improving food safety. A field trial over four rice seasons was conducted to investigate the use of biochar and low Cd accumulating cultivars on Cd uptake in a heavy metal contaminated soil. Wheat straw derived biochar was applied at 0, 20 and 40 t ha{sup −1}. Two rice cultivars with differing Cd accumulation abilities were selected in each season. The results showed that both biochar and low Cd affinity cultivars significantly reduced rice grain Cd accumulation. Biochar had no significant effect the first season but thereafter consistently reduced rice grain Cd by a maximum of 61, 86 and 57% over the next three seasons. Zn accumulation in the rice grains was not decreased by biochar application, although available soil Zn was sharply reduced (35–91%). Indica conventional rice cultivars had much lower Cd, but higher Zn and lower Cd/Zn ratios in the grain than indica hybrid cultivars. Biochar was more effective for mitigating grain Cd accumulation in low Cd affinity cultivars than in high affinity cultivars. Soil pH was sustainably increased (up to nearly 1 unit) while available Cd significantly decreased by a maximum of 85% after biochar addition. The translocation of Cd from rice roots to shoots was reduced from 20 to 80% by biochar. Low uptake affinity cultivars combined with biochar reduced late rice grain Cd concentration and Cd/Zn ratios by 69–80% and 72–80%, respectively. It indicated that the management of combining biochar and low Cd affinity cultivars should be an efficient way to remediate Cd contaminated rice paddies and reduce health risk associated with consuming rice from these soils. - Highlights: • Biochar sustainably reduced soil Cd availability and Cd translocation in rice plant. • Indica conventional cultivars had lower Cd but higher Zn in grains than hybrid ones. • Biochar significantly reduced grain Cd and Cd/Zn ratio

  2. Uptake and distributions of 90Sr and 137Cs in rice plants

    International Nuclear Information System (INIS)

    Tsukada, Hirofumi; Takeda, Akira; Hasegawa, Hidenao

    2008-01-01

    Polished rice is a staple food in Asian countries and ingestion of polished rice is one of the most important pathways of radionuclides into humans. Inedible parts of rice plants are returned to the soil as fertilizer and are used as an ingredient of feed for livestock. Strontium-90 and 137 Cs are important radionuclides for the assessment of radiation exposure to the public because of their high fission yield, long-half lives and transferability in the environment. The purpose of the present study is to obtain information on the distributions of 90 Sr and 137 Cs in rice plant components for better understanding of the fate of the radionuclides in an agricultural environment. Rice plants were cultivated in an experimental field and collected at harvest time. The concentrations of 90 Sr and 137 Cs in the soil were 5.6 and 4.4 Bq kg -1 , respectively. Rice plant samples were separated into polished rice, rice bran, hull, straw and root parts, and then the concentrations of 90 Sr and 137 Cs in the samples were determined. The concentrations of 90 Sr and 137 Cs in polished rice were 0.012 and 0.0048 Bq kg -1 dry weight, respectively. The concentrations of 90 Sr and 137 Cs varied by two and one orders of magnitudes in rice plant components, respectively. The edible component, polished rice, accounted for 32% of the total dry weight. In the entire rice plants, only 0.5% of the total 90 Sr and 10% of the total 137 Cs were found in polished rice. Contents of 90 Sr and 137 Cs in the above ground parts were 0.84 and 0.021 Bq m -2 , respectively. For each cropping, the percentages of 90 Sr and 137 Cs uptake from the upper soil layer to the aboveground biomass of rice plants were calculated as 0.094 and 0.0030% of their soil inventories, respectively. (author)

  3. Carbon dioxide emissions and energy balance closure before, during, and after biomass burning in mid-South rice fields

    Science.gov (United States)

    Fong, B.; Adviento-Borbe, A.; Reba, M. L.; Runkle, B.; Suvocarev, K.

    2017-12-01

    Biomass burning or field burning is a crop management practice that removes rice straw, reduces tillage, controls pests and releases nutrients for the next cropping season. Current field burning emissions are not included in agricultural field annual emissions largely because of the lack of studies, especially on the field scale. Field burning measurements are important for greenhouse gas emission inventories and quantifying the annual carbon footprint of rice. Paired eddy covariance systems were used to measure energy balance, CO2 fluxes, and H2O fluxes in mid-South US rice fields (total area of 25 ha) before, during and after biomass burning for 20 days after harvest. During the biomass burning, air temperatures increased 29°C, while ambient CO2 concentration increased from 402 to 16,567 ppm and H2O concentrations increased from 18.73 to 25.62 ppt. For the burning period, 67-86 kg CO2 ha-1 period-1 was emitted calculated by integrating fluxes over the biomass burning event. However, the estimated emission using aboveground biomass and combustion factors was calculated as 11,733 kg CO2 ha-1 period-1. Part of the difference could be attributed to sensor sensitivity decreasing 80% during burning for two minutes due to smoke. Net ecosystem exchange (NEE) increased by a factor of two, 1.14 before burning to 2.44 μmol m-2 s-1 possibly due to greater reduction of plant material and photosynthesis following burning. This study highlights the contribution of rice straw burning to total CO2 emissions from rice production.

  4. Studies on mineral nutrition and safety of wild rice (Oryza L.).

    Science.gov (United States)

    Jiang, Shuli; Shi, Chunhai; Wu, Jianguo

    2009-01-01

    Mineral element contents of five wild rice were analyzed, including mineral nutrient elements such as phosphorus (P), potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn) and selenium (Se), and the potential toxic elements arsenic (As), mercury (Hg), lead (Pb) and cadmium (Cd). The results showed that the contents of K, Mg, Fe, Zn, Cu, Mn and Se in five wild rice materials were much higher than the cultivate variety Zhou 903 in both brown and milled rice. Wild rice also had lower potential toxic element contents of Hg, Pb and Cd compared with Zhou 903 in brown rice and milled rice, respectively. Among five wild rice samples, WR-3 from Uganda had the highest level of P, K, Ca, Na, Mg, Fe, Zn, Mn and Se, and the lowest contents of Hg, Pb and Cd.

  5. Construction of a BAC library and identification of Dmrt1 gene of the rice field eel, Monopterus albus

    International Nuclear Information System (INIS)

    Jang Songhun; Zhou Fang; Xia Laixin; Zhao Wei; Cheng Hanhua; Zhou Rongjia

    2006-01-01

    A bacterial artificial chromosome (BAC) library was constructed using nuclear DNA from the rice field eel (Monopterus albus). The BAC library consists of a total of 33,000 clones with an average insert size of 115 kb. Based on the rice field eel haploid genome size of 600 Mb, the BAC library is estimated to contain approximately 6.3 genome equivalents and represents 99.8% of the genome of the rice field eel. This is first BAC library constructed from this species. To estimate the possibility of isolating a specific clone, high-density colony hybridization-based library screening was performed using Dmrt1 cDNA of the rice field eel as a probe. Both library screening and PCR identification results revealed three positive BAC clones which were overlapped, and formed a contig covering the Dmrt1 gene of 195 kb. By sequence comparisons with the Dmrt1 cDNA and sequencing of first four intron-exon junctions, Dmrt1 gene of the rice field eel was predicted to contain four introns and five exons. The sizes of first and second intron are 1.5 and 2.6 kb, respectively, and the sizes of last two introns were predicted to be about 20 kb. The Dmrt1 gene structure was conserved in evolution. These results also indicate that the BAC library is a useful resource for BAC contig construction and molecular isolation of functional genes

  6. Microbial electricity generation in rice paddy fields: recent advances and perspectives in rhizosphere microbial fuel cells.

    Science.gov (United States)

    Kouzuma, Atsushi; Kaku, Nobuo; Watanabe, Kazuya

    2014-12-01

    Microbial fuel cells (MFCs) are devices that use living microbes for the conversion of organic matter into electricity. MFC systems can be applied to the generation of electricity at water/sediment interfaces in the environment, such as bay areas, wetlands, and rice paddy fields. Using these systems, electricity generation in paddy fields as high as ∼80 mW m(-2) (based on the projected anode area) has been demonstrated, and evidence suggests that rhizosphere microbes preferentially utilize organic exudates from rice roots for generating electricity. Phylogenetic and metagenomic analyses have been conducted to identify the microbial species and catabolic pathways that are involved in the conversion of root exudates into electricity, suggesting the importance of syntrophic interactions. In parallel, pot cultures of rice and other aquatic plants have been used for rhizosphere MFC experiments under controlled laboratory conditions. The findings from these studies have demonstrated the potential of electricity generation for mitigating methane emission from the rhizosphere. Notably, however, the presence of large amounts of organics in the rhizosphere drastically reduces the effect of electricity generation on methane production. Further studies are necessary to evaluate the potential of these systems for mitigating methane emission from rice paddy fields. We suggest that paddy-field MFCs represent a promising approach for harvesting latent energy of the natural world.

  7. Delving deeper into technological innovations to understand differences in rice quality.

    Science.gov (United States)

    Calingacion, Mariafe; Fang, Lu; Quiatchon-Baeza, Lenie; Mumm, Roland; Riedel, Arthur; Hall, Robert D; Fitzgerald, Melissa

    2015-12-01

    Increasing demand for better quality rice varieties, which are also more suited to growth under sub-optimal cultivation conditions, is driving innovation in rice research. Here we have used a multi-disciplinary approach, involving SNP-based genotyping together with phenotyping based on yield analysis, metabolomic analysis of grain volatiles, and sensory panel analysis to determine differences between two contrasting rice varieties, Apo and IR64. Plants were grown under standard and drought-induced conditions. Results revealed important differences between the volatile profiles of the two rice varieties and we relate these differences to those perceived by the sensory panel. Apo, which is the more drought tolerant variety, was less affected by the drought condition concerning both sensory profile and yield; IR64, which has higher quality but is drought sensitive, showed greater differences in these characteristics in response to the two growth conditions. Metabolomics analyses using GCxGC-MS, followed by multivariate statistical analyses of the data, revealed a number of discriminatory compounds between the varieties, but also effects of the difference in cultivation conditions. Results indicate the complexity of rice volatile profile, even of non-aromatic varieties, and how metabolomics can be used to help link changes in aroma profile with the sensory phenotype. Our outcomes also suggest valuable multi-disciplinary approaches which can be used to help define the aroma profile in rice, and its underlying genetic background, in order to support breeders in the generation of improved rice varieties combining high yield with high quality, and tolerance of both these traits to climate change.

  8. Exploring a suitable nitrogen fertilizer rate to reduce greenhouse gas emissions and ensure rice yields in paddy fields

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yiming; Wang, Xiaopeng; Yang, Jingping, E-mail: jpyang@zju.edu.cn; Zhao, Xing; Ye, Xinyi

    2016-09-15

    The application rate of nitrogen fertilizer was believed to dramatically influence greenhouse gas (GHG) emissions from paddy fields. Thus, providing a suitable nitrogen fertilization rate to ensure rice yields, reducing GHG emissions and exploring emission behavior are important issues for field management. In this paper, a two year experiment with six rates (0, 75, 150, 225, 300, 375 kg N/ha) of nitrogen fertilizer application was designed to examine GHG emissions by measuring carbon dioxide (CO{sub 2}), methane (CH{sub 4}), nitrous oxide (N{sub 2}O) flux and their cumulative global warming potential (GWP) from paddy fields in Hangzhou, Zhejiang in 2013 and 2014. The results indicated that the GWP and rice yields increased with an increasing application rate of nitrogen fertilizer. Emission peaks of CH{sub 4} mainly appeared at the vegetative phase, and emission peaks of CO{sub 2}, and N{sub 2}O mainly appeared at reproductive phase of rice growth. The CO{sub 2} flux was significantly correlated with soil temperature, while the CH{sub 4} flux was influenced by logging water remaining period and N{sub 2}O flux was significantly associated with nitrogen application rates. This study showed that 225 kg N/ha was a suitable nitrogen fertilizer rate to minimize GHG emissions with low yield-scaled emissions of 3.69 (in 2013) and 2.23 (in 2014) kg CO{sub 2}-eq/kg rice yield as well as to ensure rice yields remained at a relatively high level of 8.89 t/ha in paddy fields. - Highlights: • Exploiting co-benefits of rice yield and reduction of greenhouse gas emission. • Global warming potential and rice yield increased with nitrogen fertilizer rate up. • Emission peaks of CH{sub 4,} CO{sub 2} and N{sub 2}O appeared at vegetative and reproductive phase. • 225 kg N/ha rate benefits both rice yields and GWP reduction.

  9. Hydroponic cultivation of Oncidium baueri

    Directory of Open Access Journals (Sweden)

    Daniele Brandstetter Rodrigues

    2017-08-01

    Full Text Available In Brazil, orchid cultivation has been increasing steadily over the last few years and contributing significantly to the economy. It has been reported that several vegetable crops and ornamentals have been successfully grown by soilless cultivation. The orchid Oncidium baueri Lindl. is grown on pot substrates. Nevertheless, hydroponics is an excellent alternative, especially for the production of cut flowers and bare root plants. The objective of this study was to evaluate the development of Oncidium baueri on two soilless systems: (a pots containing Amafibra® coconut fiber, carbonized rice husk, and pine bark (1:1:1 irrigated with nutrient solution every 15 d; and (b a nutrient film technique (NFT hydroponic system irrigated with nutrient solution daily. Shoot height, pseudobulb diameter, and number of sprouts were evaluated monthly. The number of flowering plants, number of flowers, dry mass of shoots, and dry mass of roots were evaluated 11 months after onset of experiment. The pot cultivation system yielded more flowers and higher values for all vegetative parameters than the NFT hydroponic system.

  10. Occurrence of Aspergillus section Flavi and aflatoxins in Brazilian rice: From field to market.

    Science.gov (United States)

    Katsurayama, Aline M; Martins, Ligia M; Iamanaka, Beatriz T; Fungaro, Maria Helena P; Silva, Josué J; Frisvad, Jens C; Pitt, John I; Taniwaki, Marta H

    2018-02-02

    The guarantee of the high quality of rice is of utmost importance because any toxic contaminant may affect consumer health, especially in countries such as Brazil where rice is part of the daily diet. A total of 187 rice samples, from field, processing and market from two different production systems, wetland from the state of Rio Grande do Sul, dryland, from the state of Maranhão and market samples from the state of São Paulo, were analyzed for fungi belonging to Aspergillus section Flavi and the presence of aflatoxins. Twenty-three soil samples from wetland and dryland were also analyzed. A total of 383 Aspergillus section Flavi strains were isolated from rice and soil samples. Using a polyphasic approach, with phenotypic (morphology and extrolite profiles) and molecular data (beta-tubulin gene sequences), five species were identified: A. flavus, A. caelatus, A. novoparasiticus, A. arachidicola and A. pseudocaelatus. This is the first report of these last three species from rice and rice plantation soil. Only seven (17%) of the A. flavus isolates produced type B aflatoxins, but 95% produced kojic acid and 69% cyclopiazonic acid. Less than 14% of the rice samples were contaminated with aflatoxins, but two of the market samples were well above the maximum tolerable limit (5μg/kg), established by the Brazilian National Health Surveillance Agency. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Prevalence of Rice Yellow Mottle Virus (RYMV) on Rice Plants ...

    African Journals Online (AJOL)

    Abstract. Incidence of Rice yellow mottle virus (RYMV) on rice plants (ofada) grown in two local government areas (LGAs) of Ogun State had been evaluated during a two year field survey. Six month old rice plants were observed for symptom expression and leaf samples collected for serological indexing. Of the 60 leaf ...

  12. Reconciling the conservation of the purple swamphen (Porphyrio porphyrio and its damage in Mediterranean rice fields through sustainable non-lethal techniques

    Directory of Open Access Journals (Sweden)

    Rubén Moreno-Opo

    2018-04-01

    Full Text Available Resolving human–wildlife conflicts requires the assessment and implementation of appropriate technical measures that minimize negative impacts on socio-economic uses, including agriculture, and ensure the adequate protection of biological diversity. Rice paddies are widely distributed in the western Mediterranean region. Because of their high productivity, they can be a good habitat for waterbirds, including the purple swamphen Porphyrio porphyrio, particularly in areas where natural wetlands have been removed or reduced. As a result of its population growth, there have been increasing levels of damage caused by this species in rice fields due to stem-cutting and opening of bald patches in rice fields. With the aim of reducing damage, we evaluated the effectiveness of passive and active measures that would limit access to rice fields and deter/scare away purple swamphens in affected areas of the Ebro Delta (NE Spain. We selected the techniques according to the growth phase of rice and the activity of birds in the rice fields (perimeter fences and clearing vegetation around the rice plots during sprouting and growing phases, and falconry at maturation. There were positive results during the sprouting and growing phases thanks to fences and clearing vegetation, reducing the affected area by 37.8% between treatment and control plots. This would mean an economic savings of 18,550 €/year in compensation payments by regional administrations including the investment in implementing and maintaining passive protection measures. Active deterrence through falconry did not reduce the level of damage. The analysis of purple swamphen home range, activity centers (centroids, and the proportion of locations in and outside of rice fields showed no differences before and after dissuasive practices. These results were influenced by multiple concurrent factors including weather, the structural configuration of the rice plots and their location. In summary, we

  13. Climate Change Implications to Irrigated Rice Production in Southern Brazil: A Modelling Approach

    Science.gov (United States)

    Dos Santos, Thiago

    Rice is one of the staple foods for more than three billion people worldwide. When cultivated under irrigated conditions (i.e. lowland rice), rice is one of the most intensive water consumer crops globally. Therefore, representation of rice growth should be integrated into the latest land surface models to allow studies on food security and to ensure that accurate simulations of the bidirectional feedbacks between the land surface and atmosphere take place. In this study, I present a new process-based model for rice fields that includes rice growth and rice irrigation as modules within the Agro-IBIS dynamic agro-ecosystem model. The model includes a series of equations, agricultural management parameters and an irrigation scheme that are specifically tailored for rice crops. The model was evaluated against leaf area index and biomass observations, obtained for one growing season in Rio Grande do Sul state (southern Brazil), and in Los Banos, Philippines. The model accurately captured the temporal dynamics of leaf area index in both the Brazilian and the Philippine sites, and predicted end-of-season biomass with an error of between -9.5% and 11.3% depending on the location and the plant organ. Rice phenology is predicted by the model based on experimentally-derived growth rates, and was evaluated by comparing simulated and observed durations of the four growth phases considered by the model. Agro-IBIS showed a tendency to overestimate the duration of the growth stages between 3% and 16%, but underestimated by 8% the duration of the panicle formation phase in one growing season. The new irrigation model is based on the water balance at the surface and applies irrigation in order to keep the water layer at the paddy field always in the optimum level. A set of climate projections from global climate models under two emission scenarios, and excluding and considering CO2 fertilizations effects, was used to drive the updated Agro-IBIS to estimate the effects of climate

  14. Dynamics, Residue and Risk Assessment of Nitenpyram in Rice and Paddy Field

    Directory of Open Access Journals (Sweden)

    YUAN Xue-xia

    2016-09-01

    Full Text Available Residues dynamics, final residual levels and dietary intake risk of nitenpyram in rice and paddy field were investigated in three dif-ferent regions of China(Shandong, Henan and Anhui. A method was illustrated to detect nitenpyram residues in paddy, plant, brown rice, paddy water and soil. The residues in paddy and rice were extracted with methanol+phosphate buffer(0.2 mol·L-1, pH=7.0(60+40, adjust pH to 2.5, then cleaned up with solid phase extraction column and 0.22 μm filter membrane, and then analyzed by HPLC with an ul-traviolet detector at 260 nm. When spiked 0.05, 0.5, 1.0 mg·kg-1, the recoveries of nitenpyram in paddy plant and brown rice were 78.4%~94.7% and 84.0%~94.2%, respectively. The residues in paddy water and soil were extracted with phosphate buffer (0.2 mol·L-1, pH=7.0, when spiked 0.01, 0.5, 1.0 mg·kg-1, the recoveries of nitenpyram in paddy water and soil were 84.6%~98.0% and 93.7%~97.1%, respective-ly, which indicated this method match the requirement of the detection. Two years results showed that nitenpyram belongs to easily degraded pesticides, because all half-lives were below 1.4 d in rice plant, as well as below 4.2 d in paddy water. Final residual levels of nitenpyram in rice were all below 0.05 mg·kg-1,which was far below the Japanese maximum residue limit(0.5 mg·kg-1. The risk quotients (RQs were low for different populations in China, which indicated its low risk in rice. Therefore, the rice with nitenpyram applied, according to the recom-mend method, 45 g·hm-2 application once, with 21 days collection interval, was safe.

  15. Sulfate-reducing bacteria in rice field soil and on rice roots.

    Science.gov (United States)

    Wind, T; Stubner, S; Conrad, R

    1999-05-01

    Rice plants that were grown in flooded rice soil microcosms were examined for their ability to exhibit sulfate reducing activity. Washed excised rice roots showed sulfate reduction potential when incubated in anaerobic medium indicating the presence of sulfate-reducing bacteria. Rice plants, that were incubated in a double-chamber (phylloshpere and rhizosphere separated), showed potential sulfate reduction rates in the anoxic rhizosphere compartment. These rates decreased when oxygen was allowed to penetrate through the aerenchyma system of the plants into the anoxic root compartment, indicating that sulfate reducers on the roots were partially inhibited by oxygen or that sulfate was regenerated by oxidation of reduced S-compounds. The potential activity of sulfate reducers on rice roots was consistent with MPN enumerations showing that H2-utilizing sulfate-reducing bacteria were present in high numbers on the rhizoplane (4.1 x 10(7) g-1 root fresh weight) and in the adjacent rhizosperic soil (2.5 x 10(7) g-1 soil dry weight). Acetate-oxidizing sulfate reducers, on the other hand, showed highest numbers in the unplanted bulk soil (1.9 x 10(6) g-1 soil dry weight). Two sulfate reducing bacteria were isolated from the highest dilutions of the MPN series and were characterized physiologically and phylogenetically. Strain F1-7b which was isolated from the rhizoplane with H2 as electron donor was related to subgroup II of the family Desulfovibrionaceae. Strain EZ-2C2, isolated from the rhizoplane on acetate, grouped together with Desulforhabdus sp. and Syntrophobacter wolinii. Other strains of sulfate-reducing bacteria originated from bulk soil of rice soil microcosms and were isolated using different electron donors. From these isolates, strains R-AcA1, R-IbutA1, R-PimA1 and R-AcetonA170 were Gram-positive bacteria which were affiliated with the genus Desulfotomaculum. The other isolates were members of subgroup II of the Desulfovibrionaceae (R-SucA1 and R-LacA1), were

  16. Genetic relatedness among indigenous rice varieties in the Eastern Himalayan region based on nucleotide sequences of the Waxy gene.

    Science.gov (United States)

    Choudhury, Baharul I; Khan, Mohammed L; Dayanandan, Selvadurai

    2014-12-29

    Indigenous rice varieties in the Eastern Himalayan region of Northeast India are traditionally classified into sali, boro and jum ecotypes based on geographical locality and the season of cultivation. In this study, we used DNA sequence data from the Waxy (Wx) gene to infer the genetic relatedness among indigenous rice varieties in Northeast India and to assess the genetic distinctiveness of ecotypes. The results of all three analyses (Bayesian, Maximum Parsimony and Neighbor Joining) were congruent and revealed two genetically distinct clusters of rice varieties in the region. The large group comprised several varieties of sali and boro ecotypes, and all agronomically improved varieties. The small group consisted of only traditionally cultivated indigenous rice varieties, which included one boro, few sali and all jum varieties. The fixation index analysis revealed a very low level of differentiation between sali and boro (F(ST) = 0.005), moderate differentiation between sali and jum (F(ST) = 0.108) and high differentiation between jum and boro (F(ST) = 0.230) ecotypes. The genetic relatedness analyses revealed that sali, boro and jum ecotypes are genetically heterogeneous, and the current classification based on cultivation type is not congruent with the genetic background of rice varieties. Indigenous rice varieties chosen from genetically distinct clusters could be used in breeding programs to improve genetic gain through heterosis, while maintaining high genetic diversity.

  17. DIFFUSION AND ADOPTION OF NEW RICE VARIETIES FOR AFRICA

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    Saharan Africa (SSA). It is ranked ... cultivated, rice is the most rapidly growing food .... population. Another parameter of interest is the average treatment effect on the treated, commonly denoted as ATE1 or ATT (Wooldridge, 2002, chapter 18).

  18. Genetically modified parthenocarpic eggplants: improved fruit productivity under both greenhouse and open field cultivation.

    Directory of Open Access Journals (Sweden)

    Pandolfini Tiziana

    2002-04-01

    Full Text Available Abstract Background Parthenocarpy, or fruit development in the absence of fertilization, has been genetically engineered in eggplant and in other horticultural species by using the DefH9-iaaM gene. The iaaM gene codes for tryptophan monoxygenase and confers auxin synthesis, while the DefH9 controlling regions drive expression of the gene specifically in the ovules and placenta. A previous greenhouse trial for winter production of genetically engineered (GM parthenocarpic eggplants demonstrated a significant increase (an average of 33% increase in fruit production concomitant with a reduction in cultivation costs. Results GM parthenocarpic eggplants have been evaluated in three field trials. Two greenhouse spring trials have shown that these plants outyielded the corresponding untransformed genotypes, while a summer trial has shown that improved fruit productivity in GM eggplants can also be achieved in open field cultivation. Since the fruits were always seedless, the quality of GM eggplant fruits was improved as well. RT-PCR analysis demonstrated that the DefH9-iaaM gene is expressed during late stages of fruit development. Conclusions The DefH9-iaaM parthenocarpic gene is a biotechnological tool that enhances the agronomic value of all eggplant genotypes tested. The main advantages of DefH9-iaaM eggplants are: i improved fruit productivity (at least 30–35% under both greenhouse and open field cultivation; ii production of good quality (marketable fruits during different types of cultivation; iii seedless fruit with improved quality. Such advantages have been achieved without the use of either male or female sterility genes.

  19. Comparison of Chemical Compositions in Pseudostellariae Radix from Different Cultivated Fields and Germplasms by NMR-Based Metabolomics

    Directory of Open Access Journals (Sweden)

    Yujiao Hua

    2016-11-01

    Full Text Available Pseudostellariae Radix (PR is an important traditional Chinese medicine (TCM, which is consumed commonly for its positive health effects. However, the chemical differences of PR from different cultivated fields and germplasms are still unknown. In order to comprehensively compare the chemical compositions of PR from different cultivated fields, in this study, 1H-NMR-based metabolomics coupled with high performance liquid chromatography (HPLC were used to investigate the different metabolites in PR from five germplasms (jr, zs1, zs2, sb, and xc cultivated in traditional fields (Jurong, Jiangsu, JSJR and cultivated fields (Zherong, Fujian, FJZR. A total of 34 metabolites were identified based on 1H-NMR data, and fourteen of them were found to be different in PR from JSJR and FJZR. The relative contents of alanine, lactate, lysine, taurine, sucrose, tyrosine, linolenic acid, γ-aminobutyrate, and hyperoside in PR from JSJR were higher than that in PR from FJZR, while PR from FJZR contained higher levels of glutamine, raffinose, xylose, unsaturated fatty acid, and formic acid. The contents of Heterophyllin A and Heterophyllin B were higher in PR from FJZR. This study will provide the basic information for exploring the influence law of ecological environment and germplasm genetic variation on metabolite biosynthesis of PR and its quality formation mechanism.

  20. Identification of Striga hermonthica-Resistant Upland Rice Varieties in Sudan and Their Resistance Phenotypes

    OpenAIRE

    Samejima, Hiroaki; Babiker, Abdel G.; Mustafa, Ahmed; Sugimoto, Yukihiro

    2016-01-01

    Rice has become a major staple cereal in sub-Saharan Africa. Currently, upland rice cultivation is expanding particularly in rainfed areas where the root parasitic weed Striga hermonthica, a major constraint to cereal production, is endemic. Laboratory, pot, and semi-controlled open air experiments were performed to evaluate resistance of selected rice varieties in Sudan to a resident S. hermonthica population. In the laboratory, 27 varieties were screened for post-attachment resistance using...

  1. Effects of Agricultural Management Policies on the Exposure of Black-Winged Stilts (Himantopus himantopus Chicks to Cholinesterase-Inhibiting Pesticides in Rice Fields.

    Directory of Open Access Journals (Sweden)

    Gregorio M Toral

    Full Text Available Levels of exposure to pesticides in rice fields can be significant depending on the environmental policies practiced. The aim of European Union integrated management policy is to reduce pesticide use and impact on environment. Rice fields provide an alternative breeding habitat for many waterbirds that are exposed to the pesticides used and therefore can be valuable indicators of their risk for wildlife. To evaluate integrated management success we examined exposure of Black-winged Stilts (Himantopus himantopus to cholinesterase-inhibiting pesticides in rice fields under different types of management by measuring plasma cholinesterase activity. Cholinesterase activity was lower in birds sampled in (a 2008 after a period of intense pesticide application, than in (b 2005-2007 and 2011 in rice fields subject to integrated management in Doñana (SW Spain and (c in control natural wetlands in Spain and Morocco. During 2009 and 2010, cholinesterase activity was lower in rice fields in Doñana than in rice fields in Larache and Sidi Allal Tazi (NW Morocco. Our results suggest that integrated management successfully reduced the exposure of Black-winged Stilts to pesticides in most of the years. Care should be taken to implement mosquito and pest crop controls on time and with environmentally friendly products in order to reduce its impact on wildlife.

  2. The dominant factors affecting agricultural land use (rice field change in Yogyakarta Special Province

    Directory of Open Access Journals (Sweden)

    Hadi Sabari Yunus

    2013-07-01

    The research shows that the period of 1980 - 2000 in Yogyakarta Special Province has indicated very significantly the increase in population, the development of road and the extension of built up area. For the time being, agricultural land mainly in Sleman Regency, Bantul Regency and Yogyakarta Municipality has decreased. Sleman regency performed the largest decrease of rice field and followed after then by Bantul regency and Yogyakarta Municipality. The regency of Kulon Progo and Gunung Kidul have experienced reverse phenomenon i.e. the increase of rice field during this period. Individually or simultaneously, three variables used in this research (number of people, road's length and built up area have significantly influenced the agricultural land use.

  3. Characterization of isolates of meloidogyne from rice-wheat production fields in Nepal.

    Science.gov (United States)

    Pokharel, Ramesh R; Abawi, George S; Zhang, Ning; Duxbury, John M; Smart, Christine D

    2007-09-01

    Thirty-three isolates of root-knot nematode were recovered from soil samples from rice-wheat fields in Nepal and maintained on rice cv. BR 11. The isolates were characterized using morphology, host range and DNA sequence analyses in order to ascertain their identity. Results indicated phenotypic similarity (juvenile measurements, perennial pattern, host range and gall shape) of the Nepalese isolates with Meloidogyne graminicola, with minor variations. The rice varieties LA 110 and Labelle were susceptible to all of the Nepalese isolates, but differences in the aggressiveness of the isolates were observed. Phylogenetic analyses based on the sequences of partial internal transcribed spacer (ITS) of the rRNA genes indicated that all Nepalese isolates formed a distinct clade with known isolates of M. graminicola with high bootstrap support. Furthermore, two groups were identified within the M. graminicola clade. No correlation between ITS haplotype and aggressiveness or host range was found among the tested isolates.

  4. Gene, protein, and network of male sterility in rice

    OpenAIRE

    Wang, Kun; Peng, Xiaojue; Ji, Yanxiao; Yang, Pingfang; Zhu, Yingguo; Li, Shaoqing

    2013-01-01

    Rice is one of the most important model crop plants whose heterosis has been well-exploited in commercial hybrid seed production via a variety of types of male-sterile lines. Hybrid rice cultivation area is steadily expanding around the world, especially in Southern Asia. Characterization of genes and proteins related to male sterility aims to understand how and why the male sterility occurs, and which proteins are the key players for microspores abortion. Recently, a series of genes and prot...

  5. Mapping Rice Cropping Systems in Vietnam Using an NDVI-Based Time-Series Similarity Measurement Based on DTW Distance

    Directory of Open Access Journals (Sweden)

    Xudong Guan

    2016-01-01

    Full Text Available Normalized Difference Vegetation Index (NDVI derived from Moderate Resolution Imaging Spectroradiometer (MODIS time-series data has been widely used in the fields of crop and rice classification. The cloudy and rainy weather characteristics of the monsoon season greatly reduce the likelihood of obtaining high-quality optical remote sensing images. In addition, the diverse crop-planting system in Vietnam also hinders the comparison of NDVI among different crop stages. To address these problems, we apply a Dynamic Time Warping (DTW distance-based similarity measure approach and use the entire yearly NDVI time series to reduce the inaccuracy of classification using a single image. We first de-noise the NDVI time series using S-G filtering based on the TIMESAT software. Then, a standard NDVI time-series base for rice growth is established based on field survey data and Google Earth sample data. NDVI time-series data for each pixel are constructed and the DTW distance with the standard rice growth NDVI time series is calculated. Then, we apply thresholds to extract rice growth areas. A qualitative assessment using statistical data and a spatial assessment using sampled data from the rice-cropping map reveal a high mapping accuracy at the national scale between the statistical data, with the corresponding R2 being as high as 0.809; however, the mapped rice accuracy decreased at the provincial scale due to the reduced number of rice planting areas per province. An analysis of the results indicates that the 500-m resolution MODIS data are limited in terms of mapping scattered rice parcels. The results demonstrate that the DTW-based similarity measure of the NDVI time series can be effectively used to map large-area rice cropping systems with diverse cultivation processes.

  6. Yield gap of rainfed rice in farmers’ fields in Central Java, Indonesia

    NARCIS (Netherlands)

    Boling, A.A.; Tuong, T.P.; Keulen, van H.; Bouman, B.A.M.; Suganda, H.; Spiertz, J.H.J.

    2010-01-01

    Yield constraint analysis for rainfed rice at a research station gives insight into the relative role of occurring yield-limiting factors. However, soil nutrient status and water conditions along toposequences in rainfed farmers’ fields may differ from those at the research station. Therefore, yield

  7. Study of soil redistribution in cultivated fields using fallout cesium-137 at Fateh Jang, Attock, Pakistan

    International Nuclear Information System (INIS)

    Ahmad, M.; Rafique, M.; Iqbal, N.; Akram, W.; Aasi, M.R.

    2009-11-01

    The study was carried out to investigate soil redistribution and net soil losses from two cultivated fields located in the dissected loess plains in the Pothwar Plateau at Mangial (33.6 N; 72.8 E), District Attock, Pakistan. For reference site, soil samples were collected by scrapper plate at 2 cm intervals and bulk cores in a grid, while the cultivated fields were sampled taking bulk cores in grid and along transect. /sup 137/Cs was measured by gamma spectroscopy using Soil 6 (IAEA) as a standard. The established reference inventory of /sup 137/Cs for this area is 3204 Bq/m/sup 2/. The technique provides very clear quantitative information on medium-term erosion and deposition rates at different locations, and net soil loss from cultivated fields, while no other methods available can be applied so simply. Gradient of the cultivated fields play an important role in the soil redistribution and net soil loss. Due to higher gradient of Field 2, the net soil losses determined by PM and MBM-1 using 20 cm plough layer (14.18 t ha/sup -1/ yr/sup -1/ and 16.37 t ha/sup -1/ yr/sup -1/ respectively) are much higher than that for Field 1 determined by the same models (0.24 t ha-1 yr-1 and 3.84 t ha/sup -1/ yr/sup -1/). Therefore, the cultivated fields should be as much leveled as possible. Major implication arises in using soil conversion models when thickness of /sup 137/Cs bearing layer becomes more than the normal plough layer due to deposition of eroded soil at low-lying areas. In case of Field 2, using 30 cm thickness of plough layer having significant /sup 137/Cs in the deposition areas the net erosion estimates using by PM and MBM-1 are 8.71 t ha/sup -1/ yr/sup -1/ and 10.05 t ha-1 yr/sup -1/, respectively, which seem more reliable because maximum /sup 137/Cs inventory is taken into accounted. The herbicide residue varies spatially in the field, but these three distributions corresponding to the three sampling dates indicate reduction in the residue with time. The

  8. Increasing Efficiency of Soil Fertility Map for Rice Cultivation Using Fuzzy Logic, AHP and GIS

    Directory of Open Access Journals (Sweden)

    javad seyedmohammadi

    2017-02-01

    fertility groups for better management of soil and plant nutrition. Weight of soil parameters was0.54, 0.29 and 0.17 for organic carbon, available phosphor and potassium, respectively. Fuzzy map of study area includes five soil fertility groups as: 22.9% very high fertility, 27.7% high fertility, 35.53% medium fertility, 10.48% low fertility and 3.39% very low fertility. Consequently, a separated map for soil fertility prepared to evaluate soil fertility of study area for rice cultivation. Toinvestigatethe efficiency of fuzzy model and AHP in increasing the accuracy of soil fertility map, soil fertility map with Boolean method prepared as well. Boolean map showed 58.88% fertile and 41.12% unfertile.15 soil samples from different soil fertility groups of study area were derived fromcontrol of maps accuracy. 13 renewed samples of 15 and 9 soil samples have matched with fuzzy and Boolean map, respectively. Comparison of parameters mean in fuzzy map fertility groups showed that parameters mean amounts of very high and high fertility groups are higher than optimum level except potassium that is a few lower than optimum level in high fertility group, therefore, addition of fertilizers in these groups could not be useful to increase rice crop production. Phosphorus parameter amount is lower than the critical level in very low, low and medium fertility groups, then in these groups phosphorus fertilizer should be added to the soil toincreaserice production. The amount of potassium parameter is higher than the critical level and lower than optimum limit in very low, low, medium and high fertility groups, then in these groups addition of potassium fertilizer will results in theincrease of production. Organic carbon amount is lower than optimum level in very low and low fertility groups. With regard to the relation between organic carbon andnitrogen and phosphorus, therefore, the addition of organic carbon fertilizer could compensate deficit of nitrogen and phosphorus in these groups

  9. Lime and Phosphate Amendment Can Significantly Reduce Uptake of Cd and Pb by Field-Grown Rice

    Directory of Open Access Journals (Sweden)

    Rongbo Xiao

    2017-03-01

    Full Text Available Agricultural soils are suffering from increasing heavy metal pollution, among which, paddy soil polluted by heavy metals is frequently reported and has elicited great public concern. In this study, we carried out field experiments on paddy soil around a Pb-Zn mine to study amelioration effects of four soil amendments on uptake of Cd and Pb by rice, and to make recommendations for paddy soil heavy metal remediation, particularly for combined pollution of Cd and Pb. The results showed that all the four treatments can significantly reduce the Cd and Pb content in the late rice grain compared with the early rice, among which, the combination amendment of lime and phosphate had the best remediation effects where rice grain Cd content was reduced by 85% and 61%, respectively, for the late rice and the early rice, and by 30% in the late rice grain for Pb. The high reduction effects under the Ca + P treatment might be attributed to increase of soil pH from 5.5 to 6.7. We also found that influence of the Ca + P treatment on rice production was insignificant, while the available Cd and Pb content in soil was reduced by 16.5% and 11.7%, respectively.

  10. Mapping and characterizing mangrove rice growing environments in West-Africa using remote sensing and secondary data

    NARCIS (Netherlands)

    Adefurin, O.; Hamdy, M; Zwart, S.J.

    2016-01-01

    Rice is one of the major staple foods consumed in Africa and its demand continues to increase as a result of population growth, urbanization and changing diets. Mangrove rice cultivation is of importance along the West-African Atlantic coast from Senegal and Gambia down to Guinea-Bissau,

  11. Malaysian weedy rice shows its true stripes: wild Oryza and elite rice cultivars shape agricultural weed evolution in Southeast Asia.

    Science.gov (United States)

    Song, Beng-Kah; Chuah, Tse-Seng; Tam, Sheh May; Olsen, Kenneth M

    2014-10-01

    Weedy rice is a close relative of domesticated rice (Oryza sativa) that competes aggressively with the crop and limits rice productivity worldwide. Most genetic studies of weedy rice have focused on populations in regions where no reproductively compatible wild Oryza species occur (North America, Europe and northern Asia). Here, we examined the population genetics of weedy rice in Malaysia, where wild rice (O. rufipogon) can be found growing in close proximity to cultivated and weedy rice. Using 375 accessions and a combined analysis of 24 neutral SSR loci and two rice domestication genes (sh4, controlling seed shattering, and Bh4, controlling hull colour), we addressed the following questions: (i) What is the relationship of Malaysian weedy rice to domesticated and wild rice, and to weedy rice strains in the USA? (ii) To what extent does the presence of O. rufipogon influence the genetic and phenotypic diversity of Malaysian weeds? (iii) What do the distributions of sh4 and Bh4 alleles and associated phenotypes reveal about the origin and contemporary evolution of Malaysian weedy rice? Our results reveal the following: independent evolutionary origins for Malaysian weeds and US strains, despite their very close phenotypic resemblance; wild-to-weed gene flow in Malaysian weed populations, including apparent adaptive introgression of seed-shattering alleles; and a prominent role for modern Malaysian cultivars in the origin and recent proliferation of Malaysian weeds. These findings suggest that the genetic complexity and adaptability of weedy crop relatives can be profoundly influenced by proximity to reproductively compatible wild and domesticated populations. © 2014 John Wiley & Sons Ltd.

  12. Engineering properties of high and low altitude rice varieties from Kashmir valley at different processing levels

    Directory of Open Access Journals (Sweden)

    Raees Haq

    2016-12-01

    Full Text Available The knowledge of engineering properties such as gravimetrical properties (1,000 grain mass, bulk density, true density, and porosity, dimensional properties (length, width, thickness, aspect ratio, surface area, geometric mean diameter, and sphericity, frictional properties (angle of repose and coefficient of friction, and aerodynamic properties (drag coefficient and terminal velocity are necessary parameters related to machine design for different agricultural process operations such as handling, harvesting, threshing, cleaning, conveying, sorting, drying, processing, and storage. India is a vast country and contributes 20% of the total world’s rice production with cultivars ranging from the scented long grain ones to the sticky short grains. The Kashmir valley cultivates mainly short–medium bold varieties as temperate conditions in the valley are not suitable for the cultivation of long grain scented basmati rice. The most steps in cultivation and postharvest processing are manual and the aim of this work is to emphasize which variety sustains the processing steps to produce high yield quality rice for strengthening the economic conditions of the people.

  13. Herbicidal activity of pre and post emergent herbicide on control of Eleusine indica in aerobic rice system

    International Nuclear Information System (INIS)

    Selvarajh, G.; Zain, N.M.; Aminudin, A.; Seng, C.T.

    2018-01-01

    Aerobic rice system can be an alternate way to cultivate rice in less water conditions. However, weeds are a major constrain in aerobic rice field which decline its success. Weeds are being controlled by herbicides in aerobic rice but not all herbicides are effective in controlling various types of weeds. In this study, two pre-emergent (pretilachor and pendimethalin) and two post-emergent (cyhalofop-butyl and bispyribac-sodium) herbicides were evaluated for effective control of the bioassay species, Eleusine indica. It was found that pendimethalin at a higher application rate of 1.0 kg ai ha-1 strongly inhibit the emergence and shoot growth of E. indica by >75% with negligible effect on the rice growth with stimulation on the leaf greenness. Conversely, pretilachor, cyhalofop-butyl and bispyribac-sodium gave moderate inhibition (55-60% inhibition) on weed emergence and shoot growth at higher application rates of 0.44, 0.1 and 0.035 kg ai ha-1, respectively. Significant inhibitory effects on rice root growth were noticed at highest application rates of pretilachor, cyhalofop-butyl and bispyribac-sodium (40-50% inhibition) across the growth stage of rice seedlings. Great reduction in shoot height, shoot fresh weight, and greenness of rice plant also was evident at 0 DAS across herbicides rates. However, with increasing growth stages, the rice plant became less susceptible to the applied treatments. The finding suggested that pendimethalin at 1.0 kg ai ha-1 was the most suitable application rate for inhibiting E. indica without injuring the rice seedlings. (author)

  14. The dynamics of arsenic in four paddy fields in the Bengal delta

    International Nuclear Information System (INIS)

    Stroud, Jacqueline L.; Norton, Gareth J.; Islam, M. Rafiqul; Dasgupta, Tapash; White, Rodger P.; Price, Adam H.; Meharg, Andrew A.; McGrath, Steve P.; Zhao Fangjie

    2011-01-01

    Irrigation with arsenic contaminated groundwater in the Bengal Delta may lead to As accumulation in the soil and rice grain. The dynamics of As concentration and speciation in paddy fields during dry season (boro) rice cultivation were investigated at 4 sites in Bangladesh and West Bengal, India. Three sites which were irrigated with high As groundwater had elevated As concentrations in the soils, showing a significant gradient from the irrigation inlet across the field. Arsenic concentration and speciation in soil pore water varied temporally and spatially; higher As concentrations were associated with an increasing percentage of arsenite, indicating a reductive mobilization. Concentrations of As in rice grain varied by 2-7 fold within individual fields and were poorly related with the soil As concentration. A field site employing alternating flooded-dry irrigation produced the lowest range of grain As concentration, suggesting a lower soil As availability caused by periodic aerobic conditions. - Research highlights: → Irrigation with As-contaminated groundwater resulted in a gradient of As concentration in the soil. → Arsenic concentration in paddy standing water decreased as arsenite was oxidised to arsenate. → Soil pore water As increased with the %arsenite, suggesting reductive mobilisation. → Alternative flooded-dry conditions led to lowest range of As concentration in rice grain. - Spatial variations of arsenic concentrations in paddy soil and waters do not correlate to within-field variations of arsenic concentrations in rice grain.

  15. Comparative study of endophytic and endophytic diazotrophic bacterial communities across rice landraces grown in the highlands of northern Thailand.

    Science.gov (United States)

    Rangjaroen, Chakrapong; Rerkasem, Benjavan; Teaumroong, Neung; Sungthong, Rungroch; Lumyong, Saisamorn

    2014-01-01

    Communities of bacterial endophytes within the rice landraces cultivated in the highlands of northern Thailand were studied using fingerprinting data of 16S rRNA and nifH genes profiling by polymerase chain reaction-denaturing gradient gel electrophoresis. The bacterial communities' richness, diversity index, evenness, and stability were varied depending on the plant tissues, stages of growth, and rice cultivars. These indices for the endophytic diazotrophic bacteria within the landrace rice Bue Wah Bo were significantly the lowest. The endophytic bacteria revealed greater diversity by cluster analysis with seven clusters compared to the endophytic diazotrophic bacteria (three clusters). Principal component analysis suggested that the endophytic bacteria showed that the community structures across the rice landraces had a higher stability than those of the endophytic diazotrophic bacteria. Uncultured bacteria were found dominantly in both bacterial communities, while higher generic varieties were observed in the endophytic diazotrophic bacterial community. These differences in bacterial communities might be influenced either by genetic variation in the rice landraces or the rice cultivation system, where the nitrogen input affects the endophytic diazotrophic bacterial community.

  16. Soil Respiration Controls Ionic Nutrient Concentration In Percolating Water In Rice Fields

    Science.gov (United States)

    Kimura, M.

    2004-12-01

    Soil water in the plow layer in rice fields contains various kinds of cations and anions, and they are lost from the plow layer by water percolation. Some portions of CO2 produced by respirations of rice roots and soil microorganisms are also leached by water percolation to the subsoil layer as HCO3-. As the electrical neutrality of inorganic substances in percolating water is maintained when they are assumed to be in the form of simple cations and anions, soil respiration accelerates the leaching of ionic nutrients from the plow layer by water percolation. The proportion of inorganic carbon (Σ CO2) originated from photosynthates in the total Σ CO2 in soil solution in the plow layer was from 28 to 36 % in the rice straw amended soil and from 16 to 31 % in the soil without rice straw amendment in a soil pot experiment with rice plant after the maximum tillering stage. Most of Σ CO2 in percolating water from the plow layer accumulates in the subsoil layer. Periodical measurement of Σ CO2 in percolating water at 13 and 40 cm soil depths indicated that 10 % of total soil organic C in the plow layer was leached down from the plow layer (13 cm), and that about 90 % of it was retained in the subsoil layer to the depth of 40 cm. Water soluble organic materials are also leached from the plow layer by water percolation, and the leaching is accelerated by soil reduction. Soil reduction decreased the content of organic materials that were bound with ferric iron in soil (extractable by 0.1M Na4P2O7 + NaBH4) and increased the content of organic materials that were extractable by the neutral chelating solution (0.1M Na4P2O7). In addition, water percolation transformed the latter organic materials to those that were extractable by water and a neutral salt. Considerable portions of organic materials in percolating water are adsorbed in the subsoil layer, and then partially decomposed and polymerized to specific soil organic materials in the subsoil. Organic materials that were

  17. Structural properties and digestibility of pulsed electric field treated waxy rice starch.

    Science.gov (United States)

    Zeng, Feng; Gao, Qun-Yu; Han, Zhong; Zeng, Xin-An; Yu, Shu-Juan

    2016-03-01

    Waxy rice starch was subjected to pulsed electric field (PEF) treatment at intensity of 30, 40 and 50kVcm(-1). The impact of PEF treatment on the granular morphology, molecular weight, semi-crystalline structure, thermal properties, and digestibility were investigated. The micrographs suggested that electric energy could act on the granule structure of starch granule, especially at high intensity of 50kVcm(-1). Gelatinization onset temperature, peak temperature, conclusion temperature and enthalpy value of PEF treated starches were lower than that of native starch. The 9nm lamellar peak of PEF treated starches decreased as revealed by small angle X-ray scattering. The relative crystallinity of treated starches decreased as the increase of electric field intensity. Increased rapidly digestible starch level and decreased slowly digestible starch level was found on PEF treated starches. These results would imply that PEF treatment induced structural changes in waxy rice starch significantly affected its digestibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Good manufacturing practices production of a purification-free oral cholera vaccine expressed in transgenic rice plants.

    Science.gov (United States)

    Kashima, Koji; Yuki, Yoshikazu; Mejima, Mio; Kurokawa, Shiho; Suzuki, Yuji; Minakawa, Satomi; Takeyama, Natsumi; Fukuyama, Yoshiko; Azegami, Tatsuhiko; Tanimoto, Takeshi; Kuroda, Masaharu; Tamura, Minoru; Gomi, Yasuyuki; Kiyono, Hiroshi

    2016-03-01

    The first Good Manufacturing Practices production of a purification-free rice-based oral cholera vaccine (MucoRice-CTB) from transgenic plants in a closed cultivation system yielded a product meeting regulatory requirements. Despite our knowledge of their advantages, plant-based vaccines remain unavailable for human use in both developing and industrialized countries. A leading, practical obstacle to their widespread use is producing plant-based vaccines that meet governmental regulatory requirements. Here, we report the first production according to current Good Manufacturing Practices of a rice-based vaccine, the cholera vaccine MucoRice-CTB, at an academic institution. To this end, we established specifications and methods for the master seed bank (MSB) of MucoRice-CTB, which was previously generated as a selection-marker-free line, evaluated its propagation, and given that the stored seeds must be renewed periodically. The production of MucoRice-CTB incorporated a closed hydroponic system for cultivating the transgenic plants, to minimize variations in expression and quality during vaccine manufacture. This type of molecular farming factory can be operated year-round, generating three harvests annually, and is cost- and production-effective. Rice was polished to a ratio of 95 % and then powdered to produce the MucoRice-CTB drug substance, and the identity, potency, and safety of the MucoRice-CTB product met pre-established release requirements. The formulation of MucoRice-CTB made by fine-powdering of drug substance and packaged in an aluminum pouch is being evaluated in a physician-initiated phase I study.

  19. Tocopherol and tocotrienol contents of different varieties of rice in Malaysia.

    Science.gov (United States)

    Shammugasamy, Balakrishnan; Ramakrishnan, Yogeshini; Ghazali, Hasanah M; Muhammad, Kharidah

    2015-03-15

    The present study examined the contents of tocopherols and tocotrienols and their distribution in 58 different varieties of whole rice cultivated in Malaysia. The analytical method used was saponification of samples followed by dispersive liquid-liquid microextraction and reverse phase high-performance liquid chromatography. The total vitamin E contents of different varieties of whole rice ranged between 19.36 and 63.29 mg kg⁻¹. Contents of vitamin E isomers varied among rice varieties both within and between grain color groups. Black-pigmented rice showed significantly higher mean contents of α-tocopherol, β-tocopherol and α-tocotrienol than non-pigmented rice and red-pigmented rice. Red-pigmented rice had significantly lower mean contents of γ-tocotrienol and total vitamin E than non-pigmented rice. The mean contents of δ-tocotrienol and total vitamin E in non-pigmented rice, however, were similar to those in black-pigmented rice. γ-Tocotrienol was the predominant form of vitamin E isomer in all analyzed varieties. The Pearson correlations among vitamin E isomers and total vitamin E content of whole rice were also studied. This study provides information on vitamin E content of different rice varieties that would be beneficial for decision making in genetic breeding of bioactive compound-rich rice varieties. © 2014 Society of Chemical Industry.

  20. A digital photography and analysis system for estimation of root and shoot development in rice weed suppression studies in the field

    Science.gov (United States)

    Rice germplasm with an inherent ability to suppress weeds can potentially improve the economics and sustainability of weed control in rice. We devised a simple, rapid, and inexpensive digital imaging system to quantify several shoot and root growth characteristics in field-grown rice plants that ha...

  1. Tolerance of different rice genotypes (oryza sativa l.) against the infestation of rice stem borers under natural field conditions

    International Nuclear Information System (INIS)

    Sarwar, M.; Ahmad, N.; Nasrullah; Tofique, M.

    2010-01-01

    The present studies report the genotypic responses of 61 rice (Oryza sativa L.) genotypes (35 aromatic and 26 non aromatic) against the infestation of rice stem borers under natural field conditions. The data obtained on these genotypes on larval infestation in combination with yield were the criteria to assess the resistance depicted by them. The studies showed that among aromatic genotypes, 'Khushboo-95' gave the best yield of grain and harboured the least pest infestation (2.81% dead hearts and 1.85% white heads); on the other hand variety 'Sonahri Sugdasi (P)' harboured the highest borers attack (10.37% and 19.30%) and yielded the lowest grain yield. Regarding non-aromatic genotypes, IR8-2.5-11 received least infestation (1.32% and 0.26% dead hearts and white heads, respectively) generating highest yield showing its tolerance to borer's attack, in contrast, genotype IR6-252 harboured the highest infestation (5.65%, 4.28%) and yielded minimum grain indicating its susceptibility. These results demonstrate the expression of resistance gene in the genome of tolerant rice genotypes that can provide season-long protection from the natural infestation of insect pests. (author)

  2. Gene interaction at seed-awning loci in the genetic background of wild rice.

    Science.gov (United States)

    Ikemoto, Mai; Otsuka, Mitsuharu; Thanh, Pham Thien; Phan, Phuong Dang Thai; Ishikawa, Ryo; Ishii, Takashige

    2017-09-12

    Seed awning is one of the important traits for successful propagation in wild rice. During the domestication of rice by ancient humans, plants with awnless seeds may have been selected because long awns hindered collection and handling activities. To investigate domestication of awnless rice, QTL analysis for seed awning was first carried out using backcross recombinant inbred lines between Oryza sativa Nipponbare (recurrent parent) and O. rufipogon W630 (donor parent). Two strong QTLs were detected in the same regions as known major seed-awning loci, An-1 and RAE2. Subsequent causal mutation surveying and fine mapping confirmed that O. rufipogon W630 has functional alleles at both loci. The gene effects and interactions at these loci were examined using two backcross populations with reciprocal genetic backgrounds of O. sativa Nipponbare and O. rufipogon W630. As awn length in wild rice varied among seeds even in the same plant, awn length was measured based on spikelet position. In the genetic background of cultivated rice, the wild alleles at An-1 and RAE2 had awning effects, and plants having both wild homozygous alleles produced awns whose length was about 70% of those of the wild parent. On the other hand, in the genetic background of wild rice, the substitution of cultivated alleles at An-1 and RAE2 contributed little to awn length reduction. These results indicate that the domestication process of awnless seeds was complicated because many genes are involved in awn formation in wild rice.

  3. Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community.

    Science.gov (United States)

    Schmidt, Anja; John, Katharina; Arida, Gertrudo; Auge, Harald; Brandl, Roland; Horgan, Finbarr G; Hotes, Stefan; Marquez, Leonardo; Radermacher, Nico; Settele, Josef; Wolters, Volkmar; Schädler, Martin

    2015-01-01

    Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil) on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices.

  4. Interactions of rice (Oryza sativa L.) and PAH-degrading bacteria (Acinetobacter sp.) on enhanced dissipation of spiked phenanthrene and pyrene in waterlogged soil.

    Science.gov (United States)

    Gao, Y; Yu, X Z; Wu, S C; Cheung, K C; Tam, N F Y; Qian, P Y; Wong, M H

    2006-12-15

    The effects of cultivation of rice (Oryza sativa L.) and PAH-degrading bacteria (Acinetobacter sp.) separately, and in combination, on the dissipation of spiked phenanthrene and pyrene (0, 50+50, 100+100, 200+200 mg kg(-1)) in waterlogged soil were studied using pot trials. The population of introduced PAH-degrading bacteria remained at 10(5) CFU g(-1) dry soil after 20 days of treatment with Acinetobacter sp. only, but increased to 10(6) when planted with rice simultaneously. Shoot and root biomass of rice when grown alone was adversely affected by spiked PAHs, but significantly increased by 2-55% and 8-409%, respectively, when inoculated with Acinetobacter sp.. Phenanthrene and pyrene concentrations in roots ranged from 1-27 and 20-98 mg kg(-1), respectively, while their concentrations in shoots were generally lower than 0.2 mg kg(-1). The dissipation of phenanthrene was mainly due to abiotic loss as 70-78% phenanthrene was lost from the control soil at the end of 80 days, while removal of 86-87% phenanthrene had been achieved after 40 days in the treatment co-cultivated with Acinetobacter sp. and rice. Compared with the control where only 6-15% of pyrene was removed from soil, a much higher dissipation of pyrene (43-62%) was attained for the treatments co-cultivated with Acinetobacter sp. and rice at the end of 80 days. The results demonstrated that co-cultivation of rice and PAH-degrading bacteria may have a great potential to accelerate the bioremediation process of PAH-contaminated soil under waterlogged conditions.

  5. A Survey of Myanmar Rice Production and Constraints

    Directory of Open Access Journals (Sweden)

    T.A.A. Naing

    2008-10-01

    Full Text Available Although modern high yielding varieties were introduced into Myanmar in the early 1980s, the national average of rice grain yield has stagnated at 3.2-3.4 t ha-1. To identify yield constraints, input intensities and the general practices of rice cultivation in Myanmar, a survey was conducted during the wet seasons of 2001 and 2002. A total of 98 farmers from five townships in Upper Myanmar and 16 in Lower Myanmar representing the most important areas of rice production were questioned on their management practices, yields, and perceived yield constraints over the previous four years. There was a recent decrease in the overall average rate of fertilizer application, an increase in the prevalence of rice-legume cropping systems, and only localized insect pest or disease problems. Additionally, rice yields were found to be higher in Upper Myanmar, likely the results of more suitable weather conditions, better irrigation, and ready market access. Furthermore, a number of critical factors affecting production are identified and possible solutions discussed.

  6. Arsenic transport in irrigation water across rice-field soils in Bangladesh

    International Nuclear Information System (INIS)

    Polizzotto, Matthew L.; Lineberger, Ethan M.; Matteson, Audrey R.; Neumann, Rebecca B.; Badruzzaman, A. Borhan M.; Ashraf Ali, M.

    2013-01-01

    Experiments were conducted to analyze processes impacting arsenic transport in irrigation water flowing over bare rice-field soils in Bangladesh. Dissolved concentrations of As, Fe, P, and Si varied over space and time, according to whether irrigation water was flowing or static. Initially, under flowing conditions, arsenic concentrations in irrigation water were below well-water levels and showed little spatial variability across fields. As flowing-water levels rose, arsenic concentrations were elevated at field inlets and decreased with distance across fields, but under subsequent static conditions, concentrations dropped and were less variable. Laboratory experiments revealed that over half of the initial well-water arsenic was removed from solution by oxidative interaction with other water-column components. Introduction of small quantities of soil further decreased arsenic concentrations in solution. At higher soil-solution ratios, however, soil contributed arsenic to solution via abiotic and biotic desorption. Collectively, these results suggest careful design is required for land-based arsenic-removal schemes. -- Highlights: •We analyzed the processes impacting arsenic transport in flowing irrigation water. •Arsenic in Bangladesh rice-field irrigation water varied over space and time. •Arsenic was correlated with Fe, P, and Si in flowing and static water. •Oxidation, adsorption and desorption reactions controlled arsenic concentrations. •Land-based arsenic removal from water will be impacted by hydraulic conditions. -- Arsenic concentrations in flowing and static irrigation water in Bangladesh varied over space and time, suggesting careful design is required for land-based pre-treatment schemes that aim to remove As from solution

  7. Consumers' Preferences for a Local Food Product: The Case of a New Carnaroli Rice Product in Lombardy.

    Science.gov (United States)

    Ferrazzi, Giovanni; Ventura, Vera; Ratti, Sabrina; Balzaretti, Claudia

    2017-04-13

    Italy, with a cultivated area of 218,000 ha, is a European leader of rice production. In particular Lombardy region accounts for 40% of total rice cultivation and the case study in object accounts for 3.2% of Lombardy total rice area (2773 ha). Starting from 2012, through a regional project titled Buono, Sano e Vicino (good, healthy and close), Riso e Rane rural district supported local rice farmers in developing innovation in rice production and promoting an alternative supply chain to increase farmers bargaining power and promote new market strategies. More specifically, the innovation introduced is a new biotech method for variety certification, named DNA controllato (DNA tested). In the first step of the project, the attention was focused on an Italian traditional variety of rice: Carnaroli rice. Thanks to a commercial agreement with one of the most important large retailers in Lombardy, the Riso e Rane rice is offered for sale both in the traditional and wholegrain version. In this context, this work aims to evaluate the determinants of consumer's quality perception of this product, through a preference study of the commercial rice package. Preliminary results reveal that consumers perceive information about origin, local food-system and tradition more easily than DNA tested certification. In conclusion, this work contributes to evaluate the role of bio economy applications to the food sector and offers new insights for the debate about the relationships between tradition and innovation.

  8. Consumers’ preferences for a local food product: the case of a new Carnaroli rice product in Lombardy

    Directory of Open Access Journals (Sweden)

    Giovanni Ferrazzi

    2017-04-01

    Full Text Available Italy, with a cultivated area of 218,000 ha, is a European leader of rice production. In particular Lombardy region accounts for 40% of total rice cultivation and the case study in object accounts for 3.2% of Lombardy total rice area (2773 ha. Starting from 2012, through a regional project titled Buono, Sano e Vicino (good, healthy and close, Riso e Rane rural district supported local rice farmers in developing innovation in rice production and promoting an alternative supply chain to increase farmers bargaining power and promote new market strategies. More specifically, the innovation introduced is a new biotech method for variety certification, named DNA controllato (DNA tested. In the first step of the project, the attention was focused on an Italian traditional variety of rice: Carnaroli rice. Thanks to a commercial agreement with one of the most important large retailers in Lombardy, the Riso e Rane rice is offered for sale both in the traditional and wholegrain version. In this context, this work aims to evaluate the determinants of consumer’s quality perception of this product, through a preference study of the commercial rice package. Preliminary results reveal that consumers perceive information about origin, local food-system and tradition more easily than DNA tested certification. In conclusion, this work contributes to evaluate the role of bio economy applications to the food sector and offers new insights for the debate about the relationships between tradition and innovation.

  9. Transgene Flow from Glufosinate-Resistant Rice to Improved and Weedy Rice in China

    Directory of Open Access Journals (Sweden)

    Yong-liang LU

    2014-09-01

    Full Text Available The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice (Chunjiang 016 and Xiushui 09, two inbred indica rice (Zhongzu 14 and Zhongzao 22, two indica hybrid rice (Zhongzheyou 1 and Guodao 1, and one weedy indica rice (Taizhou weedy rice. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows: weedy rice > Chunjiang 016 > Xiushui 09 and Zhongzu 14 > Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and

  10. Micrometeorological principles of protected cultivation

    Science.gov (United States)

    Protected cultivation is a broad term commonly used among producers of specialty crops. Techniques can range from complex fixed structures to field site selection, to straightforward cultural practices in the field. This introduction to the ASHS workshop "Protected cultivation for fruit crops" consi...

  11. Human exposure to mercury in a compact fluorescent lamp manufacturing area: By food (rice and fish) consumption and occupational exposure

    International Nuclear Information System (INIS)

    Liang, Peng; Feng, Xinbin; Zhang, Chan; Zhang, Jin; Cao, Yucheng; You, Qiongzhi; Leung, Anna Oi Wah; Wong, Ming-Hung; Wu, Sheng-Chun

    2015-01-01

    To investigate human Hg exposure by food consumption and occupation exposure in a compact fluorescent lamp (CFL) manufacturing area, human hair and rice samples were collected from Gaohong town, Zhejiang Province, China. The mean values of total mercury (THg) and methylmercury (MeHg) concentrations in local cultivated rice samples were significantly higher than in commercial rice samples which indicated that CFL manufacturing activities resulted in Hg accumulation in local rice samples. For all of the study participants, significantly higher THg concentrations in human hair were observed in CFL workers compared with other residents. In comparison, MeHg concentrations in human hair of residents whose diet consisted of local cultivated rice were significantly higher than those who consumed commercial rice. These results demonstrated that CFL manufacturing activities resulted in THg accumulation in the hair of CFL workers. However, MeHg in hair were mainly affected by the sources of rice of the residents. - Highlights: • Rice samples were contaminated by Compact fluorescent lamp (CFL) manufacturing. • CFL manufacturing lead to THg accumulation in human hair. • MeHg in human hair were mainly affected by the sources of rice. • MeHg intake from fish consumption was lower than that from rice consumption. • PDI of MeHg by food consumption was below the guidelines for public health concern. - CFL manufacturing activities result in Hg accumulation in local rice samples and hair of CFL workers. However, MeHg in hair were mainly affected by sources of rice

  12. Determination of plant species for the phytoremediation of carbofuran residue in rice field soils

    Directory of Open Access Journals (Sweden)

    Alissara Reungsang

    2005-09-01

    Full Text Available This study searched for plant species suitable for accumulating carbofuran residue in rice field soil. Three groups of plant, i.e. grass crops, upland crops, and vegetable crops, were grown in 8 inches diameter plastic pots filled with soil containing 5 mg/kg carbofuran. Parts of plants (stems and leaves, roots, fruits were harvested at day 120 and analyzed for carbofuran residue using HPLC. The results indicated that Helianthus annuus L. (sunflower was the most suitable species for phytoremediation of carbofuran residue in rice field soil because it highly accumulated carbofuran up to 93.4 μg/kg dry weight in its stems and leaves. In addition, H. annuus L. (sunflower could tolerate carbofuran since it showed similar physical appearance (circumference and height to control not receiving carbofuran.

  13. Varietal improvement of irrigated rice under minimal water conditions

    International Nuclear Information System (INIS)

    Abdul Rahim Harun; Marziah Mahmood; Sobri Hussein

    2010-01-01

    Varietal improvement of irrigated rice under minimal water condition is a research project under Program Research of Sustainable Production of High Yielding Irrigated Rice under Minimal Water Input (IRPA- 01-01-03-0000/ PR0068/ 0504). Several agencies were involved in this project such as Malaysian Nuclear Agency (MNA), Malaysian Agricultural Research and Development Institute (MARDI), Universiti Putra Malaysia (UPM) and Ministry of Agriculture (MOA). The project started in early 2004 with approved IRPA fund of RM 275,000.00 for 3 years. The main objective of the project is to generate superior genotypes for minimal water requirement through induced mutation techniques. A cultivated rice Oryza sativa cv MR219 treated with gamma radiation at 300 and 400 Gray were used in the experiment. Two hundred gm M2 seeds from each dose were screened under minimal water stress in greenhouse at Mardi Seberang Perai. Five hundred panicles with good filled grains were selected for paddy field screening with simulate precise water stress regime. Thirty eight potential lines with required adaptive traits were selected in M3. After several series of selection, 12 promising mutant line were observed tolerance to minimal water stress where two promising mutant lines designated as MR219-4 and MR219-9 were selected for further testing under several stress environments. (author)

  14. Adsorption Kinetics of Carbamate Pesticide in Rice Field Soil

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    Soontree Khuntong

    2010-07-01

    Full Text Available Ultrasonic extraction (75.55% with petroleum ether:acetone (1:1, v/v was employed for extraction of carbofuran in rice field soil. The amounts of carbofuran were determined by reverse phase HPLC. The analytical method provided high precision and accuracy with the relative error of 0.47%. The percentage of recoveries varied from 84% to 77% in the con¬centration ranges of 10–40 mg/L of spiked soil samples. The carbofuran residues in the rice field soil significantly decreased year by year because of pesticide properties, soil properties and degradation conditions. A high amount of residues was found in the plots that contained high organic contents. The adsorption of carbofuran in soil reached equilibrium within 23 h. The percentage of adsorption varied from almost 30% to 80% depending on concentrations of carbofuran. The adsorption of carbofuran agreed with Freundlich isotherms; q = 7.07 x 10-5Cf2.5092; with the correlation coefficient of 0.9281. Organic carbon coefficient, Koc, was 1.91 x 10-3 mg/L calculated from Kd, and half-life (8.9 d of adsorbed carbofuran. The GUS index (6.37 calculated from Koc presented a high lixiviation potential. The positive ΔG indicated the non-spontaneous reaction. Carbofuran rapidly desorbed from soil at the desorption rate of 0.0228 mg/kg soil d. Kinetic studies provided the first order reaction with the reaction rate of 0.0779 mg/d and half-life of 8.9 days.

  15. Long term continuous field survey to assess nutrient emission impact from irrigated paddy field into river catchment

    Science.gov (United States)

    Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

    2017-04-01

    In order to achieve good river environment, it is very important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. As we could reduce impact from urban and industrial activities by wastewater treatment, pollution from point sources are likely to be controlled. Besides them, nutrient emission from agricultural activity is dominant pollution source into the river system. In many countries in Asia and Africa, rice is widely cultivated and paddy field covers large areas. In Japan 54% of its arable land is occupied with irrigated paddy field. While paddy field can deteriorate river water quality due to fertilization, it is also suggested that paddy field can purify water. We carried out field survey in middle reach of the Tone River Basin with focus on a paddy field IM. The objectives of the research are 1) understanding of water and nutrient balance in paddy field, 2) data collection for assessing nutrient emission. Field survey was conducted from June 2015 to October 2016 covering two flooding seasons in summer. In our measurement, all input and output were measured regarding water, N and P to quantify water and nutrient balance in the paddy field. By measuring water quality and flow rate of inflow, outflow, infiltrating water, ground water and flooding water, we tried to quantitatively understand water, N and P cycle in a paddy field including seasonal trends, and changes accompanied with rainy events and agricultural activities like fertilization. Concerning water balance, infiltration rate was estimated by following equation. Infiltration=Irrigation water + Precipitation - Evapotranspiration -Outflow We estimated mean daily water balance during flooding season. Infiltration is 11.9mm/day in our estimation for summer in 2015. Daily water reduction depth (WRD) is sum of Evapotranspiration and Infiltration. WRD is 21.5mm/day in IM and agrees with average value in previous research. Regarding nutrient balance, we estimated an annual N and

  16. Evaluating Leaf and Canopy Reflectance of Stressed Rice Plants to Monitor Arsenic Contamination

    Directory of Open Access Journals (Sweden)

    Varaprasad Bandaru

    2016-06-01

    Full Text Available Arsenic contamination is a serious problem in rice cultivated soils of many developing countries. Hence, it is critical to monitor and control arsenic uptake in rice plants to avoid adverse effects on human health. This study evaluated the feasibility of using reflectance spectroscopy to monitor arsenic in rice plants. Four arsenic levels were induced in hydroponically grown rice plants with application of 0, 5, 10 and 20 µmol·L−1 sodium arsenate. Reflectance spectra of upper fully expanded leaves were acquired over visible and infrared (NIR wavelengths. Additionally, canopy reflectance for the four arsenic levels was simulated using SAIL (Scattering by Arbitrarily Inclined Leaves model for various soil moisture conditions and leaf area indices (LAI. Further, sensitivity of various vegetative indices (VIs to arsenic levels was assessed. Results suggest that plants accumulate high arsenic amounts causing plant stress and changes in reflectance characteristics. All leaf spectra based VIs related strongly with arsenic with coefficient of determination (r2 greater than 0.6 while at canopy scale, background reflectance and LAI confounded with spectral signals of arsenic affecting the VIs’ performance. Among studied VIs, combined index, transformed chlorophyll absorption reflectance index (TCARI/optimized soil adjusted vegetation index (OSAVI exhibited higher sensitivity to arsenic levels and better resistance to soil backgrounds and LAI followed by red edge based VIs (modified chlorophyll absorption reflectance index (MCARI and TCARI suggesting that these VIs could prove to be valuable aids for monitoring arsenic in rice fields.

  17. Study on the Long Term Effects of Radiation on Irradiated Manawthukha Rice Grain (Mahsuri-M)

    International Nuclear Information System (INIS)

    Aye Aye Mar; Aye Aye Mon; Hnin Hnin Than; Ba Han; Tin Tin; Myint U

    2008-03-01

    Radioactivity monitoring of first and second generations Manawthukha paddy grain before cultivations were carried out. It was found out that there were no induced activity. Therefore it can be concluded that similarly it will be the same for third generation rice. The second generation rice was obtained from cultivation and harvesting of first generation [(i) non-irradiated (control), (ii) gamma-irradiated, (iii) neutron-one hour irradiated, (iv) neutron one-day irradiated rice]. Agronomical characteristics of three different types of generation of rice were studied. Morphological characteristics studies such as plant height, leaf width and panicle length,there was no large variation between three generations of rice. Phenotypes were found to be stable. Yield improvement was calculated. Nutritional values of rice generation were studied. They were (i) element analysis by different methods (NAA, EDXRF and AAS), vitamin determination and protein percent determination. There was no distinctive difference between first, second and third generation rice. In element analysis, eleven elements such as Mg, Mn, Na, K, Cl, Al, Ca, Fe, Zn, P and Cu were observed by NAA, AAS and EDXRF methods. Vitamin content (B1, B2) and protein content were also studied. Determination of amylose content, gel consistency and gelatinization temperature were involved in grain quality study. There was no large variation in three generations. Surface texture of first, second and third generation Manawthukha rice were studied by Scanning Electron Microscope (SEM). It was observed that the change of texture from generation to generation tend to become more distinctive in third generation.

  18. KOEFISIEN TANAMAN PADI SAWAH PADA SISTEM IRIGASI HEMAT AIR Crop Coefficient for Paddy Rice Field under Water Saving Irrigation Systems

    Directory of Open Access Journals (Sweden)

    Joko Sujono

    2012-05-01

    Full Text Available Traditional irrigation for paddy rice is the leading of consumer of water, about 80 % of the water resource availabilityused for irrigation purpose. This phenomenon is related to the way how to estimate the crop water requirement where crop coefficient for paddy rice (k (Prosida is always greater than one starting from planting up to nearly harvesting. In this research, a number of water saving irrigations (WSI systems for paddy rice cultivation using pots such asalternate wetting and drying (AWD, shallow water depth with wetting and drying (SWD, semi-dry cultivation (SDC, system of rice intensification (SRI, and  AWD with mulch (AWD-Mul were applied. The amount of irrigated water and when it should be irrigated depend on evapotranspiration rate, soil moisture condition and the WSI system used. For this purpose, daily measurement of the pot weight was carried out. Crop coefficient (k  is then caluculated as a cratio between crop and reference evapotranspiration computed using Penman-Montheit  method. Results show that up to 45 days after transplanting, the k of WSI treatments were around half of the k (Prosida values currently used for computing the water requirement, whereas at the productive stage the k of WSI systems were relatively equal (AWD, SDC to or greater (SRI, SWD than the k (Prosida. Based on the the k values, the AWD and the SDC systems could save much water compared to the SRI or the SWD. Water saving could be increased by applying the AWD with mulch. ABSTRAK Irigasi padi sawah dengan sistem tradisional merupakan sistem irigasi  yang boros air, hampir 80 % sumber air yang ada untuk irigasi. Hal ini tidak terlepas dari perhitungan kebutuhan air tanaman dengan nilai koefisien tanaman (k menurut Standar Perencanaan Irigasi (Prosida selalu lebih besar dari satu mulai dari tanam hingga menjelang panen.Dalam penelitian ini beberapa metoda budidaya padi hemat air seperti alternate wetting and drying (AWD, shallow water depth

  19. The use of Chironomus riparius larvae to assess effects of pesticides from rice fields in adjacent freshwater ecosystems.

    Science.gov (United States)

    Faria, Mafalda S; Nogueira, António J A; Soares, Amadeu M V M

    2007-06-01

    A bioassay with Chironomus riparius larvae, using larval development and growth as endpoints, was carried out inside a rice field and in the adjacent wetland channel in Portugal, during pesticide treatments (molinate, endosulfan and propanil) to determine impact caused by pesticide contamination in freshwater ecosystems. The bioassay was also performed under laboratory conditions, to assess whether in situ and laboratory bioassays demonstrated comparable results. Growth was inhibited by concentrations of endosulfan (2.3 and 1.9 microgL(-1) averages) in water from rice field in both the field and laboratory, and by concentrations of endosulfan (0.55 and 0.76 microgL(-1) averages) in water from the wetland channel in the laboratory bioassay, while development was not affected. C. riparius larvae were not affected by molinate and propanil concentrations. The results indicate that endosulfan treatments in rice fields may cause an ecological impairment in adjacent freshwater ecosystems. The results also indicate that laboratory testing can be used to assess in situ toxicity caused by pesticide contamination.

  20. Bulk density of an alfisol under cultivation systems in a long-term experiment evaluated with gamma ray computed tomography

    International Nuclear Information System (INIS)

    Bamberg, Adilson Luis; Silva, Thiago Rech da; Pauletto, Eloy Antonio; Pinto, Luiz Fernando Spinelli; Lima, Ana Claudia Rodrigues de; Timm, Luis Carlos

    2009-01-01

    The sustainability of irrigated rice (Oryza sativa L.) in lowland soils is based on the use of crop rotation and succession, which are essential for the control of red and black rice. The effects on the soil properties deserve studies, particularly on soil compaction. The objective of this study was to identify compacted layers in an albaqualf under different cultivation and tillage systems, by evaluating the soil bulk density (Ds) with Gamma Ray Computed Tomography (TC). The analysis was carried out in a long-term experiment, from 1985 to 2004, at an experimental station of EMBRAPA Clima Temperado, Capao do Leao, RS, Brazil, in a random block design with seven treatments, with four replications (T1 - one year rice with conventional tillage followed by two years fallow; T2 - continuous rice under conventional tillage; T4 - rice and soybean (Glycine Max L.) rotation under conventional tillage; T5 - rice, soybean and corn (Zea maize L.) rotation under conventional tillage; T6 - rice under no-tillage in the summer in succession to rye-grass (Lolium multiflorum L.) in the winter; T7 - rice under no-tillage and soybean under conventional tillage rotation; T8 - control: uncultivated soil). The Gamma Ray Computed Tomography method did not identify compacted soil layers under no tillage rice in succession to rye-grass; two fallow years in the irrigated rice production system did not prevent the formation of a compacted layer at the soil surface; and in the rice, soybean and corn rotation under conventional tillage two compacted layers were identified (0.0 to 1.5 cm and 11 to 14 cm), indicating that they may restrict the agricultural production in this cultivation system on Albaqualf soils. (author)

  1. Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community.

    Directory of Open Access Journals (Sweden)

    Anja Schmidt

    Full Text Available Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices.

  2. Characterization and Selection of Phosphorus Deficiency Tolerant Rice Genotypes in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Y.C. Aluwihare

    2016-07-01

    Full Text Available Phosphorus (P deficiency in soil is a major constrain for rice production. An important set of rice genotypes (landraces, old improved and new improved varieties were screened for P deficiency tolerance in two major cropping seasons of Sri Lanka, in 2012. The Ultisol soil, which was collected from a plot cultivated with rice without fertilizer application for past 40 years (P0 at the Rice Research and Development Institute (RRDI, Bathalagoda, Sri Lanka, was used as the potting medium for greenhouse trials. Two field trials were conducted in the same plots at RRDI. Both P0 and P30 (30 mg/kg P2O5 conditions were used in the two greenhouse trials. At the early vegetative (three weeks after transplanting, late vegetative (six weeks after transplanting and flowering stages, plant height and number of tillers per plant were recorded. At the flowering stage, shoots were harvested and shoot dry weight, shoot P concentration, shoot P uptake and P utilization efficiency were measured. All data were statistically analyzed using analysis of variance, regression and cluster procedures. The measured parameters were significantly different between P0 and P30 conditions (P < 0.05. Higher shoot dry weight was reported by the rice genotypes H4 and Marss under P0 conditions. The regression analysis between shoot dry weight and P utilization efficiency revealed that the studied rice genotypes could be categorized to three P deficiency tolerance classes. A total of 13 genotypes could be considered as highly tolerant and 4 genotypes as sensitive for P deficiency. These results could be used to select parental genotypes for breeding and genetic studies and also to select interesting varieties or landraces for organic rice production.

  3. Elemental content of Vietnamese rice. Part 2. Multivariate data analysis.

    Science.gov (United States)

    Kokot, S; Phuong, T D

    1999-04-01

    Rice samples were obtained from the Red River region and some other parts of Vietnam as well as from Yanco, Australia. These samples were analysed for 14 elements (P, K, Mg, Ca, Mn, Zn, Fe, Cu, Al, Na, Ni, As, Mo and Cd) by ICP-AES, ICP-MS and FAAS as described in Part 1. This data matrix was then submitted to multivariate data analysis by principal component analysis to investigate the influences of environmental and crop cultivation variables on the elemental content of rice. Results revealed that geographical location, grain variety, seasons and soil conditions are the most likely significant factors causing changes in the elemental content between the rice samples. To assess rice quality according to its elemental content and physio-biological properties, a multicriteria decision making method (PROMETHEE) was applied. With the Vietnamese rice, the sticky rice appeared to contain somewhat higher levels of nutritionally significant elements such as P, K and Mg than the non-sticky rice. Also, rice samples grown during the wet season have better levels of nutritionally significant mineral elements than those of the dry season, but in general, the wet season seemed to provide better overall elemental and physio-biological rice quality.

  4. Water Use for Cultivation Management of Watermelon in Upland Field on Sand Dune

    Science.gov (United States)

    Hashimoto, Iwao; Senge, Masateru; Itou, Kengo; Maruyama, Toshisuke

    Early-maturing cultivation of watermelon in a plastic tunnel was invetigated in upland field on sand dune on the coast of the Japan Sea to find water use to control blowing sand and to transplant seedlings. This region has low precipitation, low humidity, and strong wind in March and April, when sand is readily blown in the field. Water is used to control blowing sand on days with precipitation below 5 mm, minimum humidity below the meteorological average in April, and maximum wind velocity above the meteorological average in April. For the rooting and growth of watermelon seedlings, soil temperature needs to be raised because it is low in April. Ridges are mulched with transparent, porous polyethylene films 10 or more days before transplanting the seedlings and irrigated with sprinklers on fine days for the thermal storage of solar energy. The stored heat steams the mulched ridges to raise soil temperature to 15°C or higher on the day of transplanting the seedlings. The total amount of irrigation water used for watermelon cultivation was 432.7 mm, of which 23.6 mm was for blowing sand control and 26.6 mm was for transplanting the seedlings. The combined amount, 50.2 mm, is 11.6% of the total amount of water used for cultivation management.

  5. Geographical information system based model of land suitability for good yield of rice in prachuap khiri khan province, thailand

    International Nuclear Information System (INIS)

    Hussain, W.; Sohaib, O.

    2012-01-01

    Correct assessment of land is a major issue in agricultural sector to use possible capability of any land, to raise cultivation and production of rice. Geographical Information System (GIS) provides broad techniques for suitable land classifications. This study is GIS based on land suitability analysis for rice farming in Prachuap Khiri Khan Province, Thailand, where the main livelihood of people is rice farming. This analysis was conducted considering the relationship of rice production with various data layers of elevation, slope, soil pH, rainfall, fertilizer use and land use. ArcView GIS 3.2 software is used to consider each layer according to related data to weight every coefficient, ranking techniques are used. It was based on determining correlation of rice production and these variables. This analysis showed a positive correlation with these variables in varying degrees depending on the magnitude and quality of these factors. By combining both data layers of GIS and weighted linear combination, various suitable lands have been developed for cultivation of rice. Integrated suitable assessment map and current land were compared to find suitable land in Prachuap Khiri Khan Province of Thailand. As a result of this comparison, we get a land which is suitable for optimum utilization for rice production in Prachuap Khiri Khan Province. (author)

  6. Use of the p-SINE1-r2 in inferring evolutionary relationships of Thai rice varieties with AA genome

    Directory of Open Access Journals (Sweden)

    Preecha Prathepha

    2006-01-01

    Full Text Available In a previous study we described the prevalence and distribution in Thailand of the retroposon p- SINE1-r2, in the intron 10 of the waxy gene in cultivated and wild rice with the AA genome. In this study, additional varieties of rice were collected and sequencing was used to further characterize p-SINE1-r2. It was found that the length of the p-SINE1-r2 nucleotide sequences was about 125 bp, flanked by identical direct repeats of a 14 bp sequence. These sequences were compared and found to be similar to the sequences of p- SINE1-r2 found in Nipponbare, a rice strain discussed in a separate study. However, when compared the 48 DNA sequences identified in this study, much dissimilarity was found within the nucleotide sequences of p- SINE1-r2, in the form of base substitution mutations. Phylogenetic relationships inferred from the nucleotide sequences of these elements in cultivated rice (O. sativa and wild rice (O. nivara. It was found that rice accessions collected from the same geographical distribution have been placed in the same clade. The phylogenetic tree supports the origin and distribution of these rice strains.

  7. Multisensor Capacitance Probes for Simultaneously Monitoring Rice Field Soil-Water- Crop-Ambient Conditions.

    Science.gov (United States)

    Brinkhoff, James; Hornbuckle, John; Dowling, Thomas

    2017-12-26

    Multisensor capacitance probes (MCPs) have traditionally been used for soil moisture monitoring and irrigation scheduling. This paper presents a new application of these probes, namely the simultaneous monitoring of ponded water level, soil moisture, and temperature profile, conditions which are particularly important for rice crops in temperate growing regions and for rice grown with prolonged periods of drying. WiFi-based loggers are used to concurrently collect the data from the MCPs and ultrasonic distance sensors (giving an independent reading of water depth). Models are fit to MCP water depth vs volumetric water content (VWC) characteristics from laboratory measurements, variability from probe-to-probe is assessed, and the methodology is verified using measurements from a rice field throughout a growing season. The root-mean-squared error of the water depth calculated from MCP VWC over the rice growing season was 6.6 mm. MCPs are used to simultaneously monitor ponded water depth, soil moisture content when ponded water is drained, and temperatures in root, water, crop and ambient zones. The insulation effect of ponded water against cold-temperature effects is demonstrated with low and high water levels. The developed approach offers advantages in gaining the full soil-plant-atmosphere continuum in a single robust sensor.

  8. Selenium inhibits sulfate-mediated methylmercury production in rice paddy soil.

    Science.gov (United States)

    Wang, Yong-Jie; Dang, Fei; Zhao, Jia-Ting; Zhong, Huan

    2016-06-01

    There is increasing interest in understanding factors controlling methylmercury (MeHg) production in mercury-contaminated rice paddy soil. Sulfate has been reported to affect MeHg biogeochemistry under anoxic conditions, and recent studies revealed that selenium (Se) could evidently reduce MeHg production in paddy soil. However, the controls of sulfate and Se on net MeHg production in paddy soil under fluctuating redox conditions remain largely unknown. Microcosm experiments were conducted to explore the effects of sulfate and Se on net MeHg production in rice paddy soil. Soil was added with 0-960 mg/kg sulfate, in the presence or absence of 3.0 mg/kg selenium (selenite or selenate), and incubated under anoxic (40 days) or suboxic conditions (5 days), simulating fluctuating redox conditions in rice paddy field. Sulfate addition moderately affected soil MeHg concentrations under anoxic conditions, while reoxidation resulted in evidently higher (18-40%) MeHg levels in sulfate amended soils than the control. The observed changes in net MeHg production were related to dynamics of sulfate and iron. However, Se could inhibit sulfate-mediated MeHg production in the soils: Se addition largely reduced net MeHg production in the soils (23-86%, compared to the control), despite of sulfate addition. Similarly, results of the pot experiments (i.e., rice cultivation in amended soils) indicated that soil MeHg levels were rather comparable in Se-amended soils during rice growth period, irrespective of added sulfate doses. The more important role of Se than sulfate in controlling MeHg production was explained by the formation of HgSe nanoparticles irrespective of the presence of sulfate, confirmed by TEM-EDX and XANES analysis. Our findings regarding the effects of sulfate and Se on net MeHg production in rice paddy soil together with the mechanistic explanation of the processes advance our understanding of MeHg dynamics and risk in soil-rice systems. Copyright © 2016 Elsevier

  9. Influence of the nonexchangeable potassium of mica on radiocesium uptake by paddy rice.

    Science.gov (United States)

    Eguchi, Tetsuya; Ohta, Takeshi; Ishikawa, Tetsuya; Matsunami, Hisaya; Takahashi, Yoshihiko; Kubo, Katashi; Yamaguchi, Noriko; Kihou, Nobuharu; Shinano, Takuro

    2015-09-01

    A pot cultivation experiment was conducted to elucidate the influence of the nonexchangeable potassium (K) of mica on radiocesium ((137)Cs) uptake by paddy rice (Oryza sativa L. cv. Koshihikari), and to evaluate the potential of mica application as a countermeasure to reduce radiocesium transfer from soil to paddy rice. The increase in the exchangeable K concentrations of soils, measured before planting, due to mica (muscovite, biotite, and phlogopite) application was negligible. However, in trioctahedral mica (biotite and phlogopite)-treated soil, the release of nonexchangeable K from the mica interlayer maintained the soil-solution K at a higher level during the growing season in comparison to the control, and consequently decreased the (137)Cs transfer factor for brown rice (TF). The sodium tetraphenylboron (TPB)-extractable K concentration of the soils, measured before planting, was strongly negatively correlated with the TF, whereas the exchangeable K concentration of the soils, also measured before planting, was not correlated with the TF. Therefore, we conclude that TPB-extractable K is more reliable than exchangeable K as a basis of fertilizer recommendations for radiocesium-contaminated paddy fields. Phlogopite-treated soils exhibited higher TPB-extractable K concentrations and lower TF values than biotite-treated soils. We thus conclude that phlogopite application is an effective countermeasure to reduce radiocesium uptake in paddy rice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Introduction and Utilization of INGER Rice Germplasm in China

    Institute of Scientific and Technical Information of China (English)

    TANGSheng-xiang; WEIXing-hua; ELJavier

    2004-01-01

    The International Network for Genetic Evaluation of Rice (INGER) is a global partnership between international and national agricultural research institutions. INGER focuses on worldwide exchange, evaluation and utilization of improved varieties and elite breeding lines of rice. China has actively participated in the activities of INGER since 1980.During the pasted years, 26 500 INGER entries with diversity genetic background have been introduced and evaluated by Chinese scientists. Among of them, 37 commercial varieties directly from elite INGER entries and 27 rice hybrids using INGER lines as their restorer lines/donors have been released to farmers in China. About 1 900 INGER entries were indirectly utilized as cross parents or pest resistant donors in various national and provincial rice breeding programs. Based on the incomplete statistics, there were 14.5 million cumulated hectares planting these varieties and hybrids, from which 5.44 MT of increased rough rice has been received by farmers. INGER accelerates the transfer of adapted varieties and hybrids to farmers, and increases the diversity of rice germplasm in cultivation. Therefore, INGER cooperation has made great benefit both in economy and society in China.

  11. Introduction and Utilization of INGER Rice Germplasm in China

    Institute of Scientific and Technical Information of China (English)

    TANG Sheng-xiang; WEI Xing-hua; E L Javier

    2004-01-01

    The International Network for Genetic Evaluation of Rice (INGER) is a global partnership between international and national agricultural research institutions. INGER focuses on worldwide exchange, evaluation and utilization of improved varieties and elite breeding lines of rice. China has actively participated in the activities of INGER since 1980.During the pasted years, 26 500 INGER entries with diversity genetic background have been introduced and evaluated by Chinese scientists. Among of them, 37 commercial varieties directly from elite INGER entries and 27 rice hybrids using INGER lines as their restorer lines/donors have been released to farmers in China. About 1 900 INGER entries were indirectly utilized as cross parents or pest resistant donors in various national and provincial rice breeding programs. Based on the incomplete statistics, there were 14.5million cumulated hectares planting these varieties and hybrids, from which 5.44 MT of increased rough rice has been received by farmers. INGER accelerates the transfer of adapted varieties and hybrids to farmers, and increases the diversity of rice germplasm in cultivation. Therefore, INGER cooperation has made great benefit both in economy and society in China.

  12. Promising mutant variety of rice evolved through gamma irradiation

    International Nuclear Information System (INIS)

    Prasad, S.C.; Sinha, S.K.

    1980-01-01

    Rice occupies a major share in crop production in the Chotanagpur plateau of Bihar State. Uplands are roughly 40% in area where traditional low yielding rice, known as ''gora'' is cultivated as directly sown crop. Despite introduction of high yielding rice varieties, gora group of rices continue to prevail. It is therefore desired to increase the productivity level of the gora rice by mutation breeding. One such mutant known as ''gora mutant'' was obtained through gamma irradiation (10 kR) of variety Brown gora. The maturity of both parent and mutant remaining constant (ie. 100 days), there is some improvement in other characteristics like plant height, tillering capacity and kernel character. The parent being tall, shy in tillering and red bold kernel, the mutant has dwarfish characteristics, profuse tillering habit and white kernel with fine grains. The yielding capacity of mutant derivative is 30-40% higher than the parent Brown gora. This variety is in pre-release stage, and the farmers have taken great liking for it. (author)

  13. Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.).

    Science.gov (United States)

    Zhou, Yi; Yang, Ping; Cui, Fenglei; Zhang, Fantao; Luo, Xiangdong; Xie, Jiankun

    2016-01-01

    Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated) and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated). Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice.

  14. Detection of DNA fingerprints of cultivated rice by hybridization with a human minisatellite DNA probe

    International Nuclear Information System (INIS)

    Dallas, J.F.

    1988-01-01

    A human minisatellite DNA probe detects several restriction fragment length polymorphisms in cultivars of Asian and African rice. Certain fragments appear to be inherited in a Mendelian fashion and may represent unlinked loci. The hybridization patterns appear to be cultivar-specific and largely unchanged after the regeneration of plants from tissue culture. The results suggest that these regions of the rice genome may be used to generate cultivar-specific DNA fingerprints. The demonstration of similarity between a human minisatellite sequence and polymorphic regions in the rice genome suggests that such regions also occur in the genomes of many other plant species

  15. Long-term monitoring and analysis of 90Sr and 137Cs concentrations in rice, wheat and soils in Japan from 1959 to 2000

    International Nuclear Information System (INIS)

    Komamura, M.; Tsumura, A.; Yamaguchi, N.; Fujiwara, H.; Kihou, N.; Kodaira, K.

    2006-01-01

    Atmospheric nuclear tests in the 1950s and thereafter had showered radioactive fallout throughout Japan. Therefore, radioactive contamination of crops cultivated in Japan was concerned. We continued to monitor concentrations of 90Sr and 137Cs in rice, wheat and soils collected annually from sixteen national and prefectural experimental farms for forty-two years, from 1959 to 2000. In 1963, when the largest annual precipitation of radioactive fallout was observed, 90Sr and 137Cs concentration in rice and wheat reached at their maximum; 0.27 Bq/kg for 90Sr and 4.2 Bq/kg for 137Cs in polished rice and 12 Bq/kg for 90Sr and 44 Bq/kg for 137Cs in wheat grain. The concentration of 90Sr and 137Cs in the plowed layer of paddy and upland soils reached maximum from 1963 to 1966. After 1966, concentrations of 90Sr and 137Cs in polished rice, wheat grain, and soils were gradually decreased although there were some minor fluctuations. The Chernobyl nuclear power plant accident in 1986 caused contamination of wheat grain by 137Cs up to 6.0 Bq/kg. However, the concentration of 137Cs in wheat grain decreased to its normal level in the following year. There was no evidence for the polished rice contamination in Japan that could be ascribed to the accident at Chernobyl. Based on the analyses of the data above, we made several interesting findings as follows: a) The accumulated amounts of 90Sr and 137Cs in fallout during cultivation period were highly correlated with those concentrations in husked rice, polished rice and wheat grain. The estimate equations derived from the correlations were accurate enough for quick prediction of contamination level of polished rice and wheat grain based on 90Sr and 137Cs contents in fallout in case of contingencies. b) The sensitive response of 90Sr and 137Cs in polished rice and wheat grain to concentrations of fallout suggested that direct absorption of 90Sr and 137Cs from radioactive fallout deposited on plant body played important role. In 1963

  16. Agricultural residues and expanded clay in Oncidium baueri Lindl. orchid cultivation

    Directory of Open Access Journals (Sweden)

    Matheus Marchezi Mora

    2015-02-01

    Full Text Available For orchid cultivation in containers is essential to select the right substrate, since this will influence the quality of the final product, it serve as a support for the root system of the plants. This study aimed to evaluate different agricultural residues and expanded clay in Oncidium baueri Lindl. orchid cultivation. The plants were subjected to treatments: pinus husk + carbonized rice husk, pinus husk + coffee husk, pinus husk + fibered coconut, pecan nut husk, expanded clay, fibered coconut, coffee husk, carbonized rice husk, pinus husk. After eleven months of the experiment, the following variables were evaluated: plant height; largest pseudo-bulb diameter; number of buds; shoot fresh dry matter; the longest root length; number of roots; root fresh matter; root dry matter; and electric conductivity; pH and water retention capacity of the substrates. Except the expanded clay, the other substrates showed satisfactory results in one or more traits. Standing out among these substrates pinus husk + coffee husk and pine bark + fibered coconut, which favored the most vegetative and root characteristic of the orchid. The mixture of pinus husk + coffee husk and pinus husk + fibered coconut, provided the best results in vegetative and root growth of the orchid Oncidium baueri and the expanded clay did not show favorable results in the cultivation of this species.

  17. Development of dynamic compartment models for prediction of radionuclide behaviors in rice paddy fields

    International Nuclear Information System (INIS)

    Takahashi, Tomoyuki; Tomita, Ken'ichi; Yamamoto, Kazuhide; Uchida, Shigeo

    2007-01-01

    We are developing dynamic compartment models for prediction of behaviors of some important radionuclides in rice paddy fields for safety assessment of nuclear facilities. For a verification of these models, we report calculations for several different deposition patterns of radionuclides. (author)

  18. Identification of qSOR1, a major rice QTL involved in soil-surface rooting in paddy fields.

    Science.gov (United States)

    Uga, Yusaku; Hanzawa, Eiko; Nagai, Shinsei; Sasaki, Kazuhiro; Yano, Masahiro; Sato, Tadashi

    2012-01-01

    Specific Indonesian lowland rice (Oryza sativa L.) cultivars elongate thick primary roots on the soil surface of paddy fields. To clarify the genetic factors controlling soil-surface rooting, we performed quantitative trait locus (QTL) analyses using 124 recombinant inbred lines (RILs) derived from a cross between Gemdjah Beton, an Indonesian lowland rice cultivar with soil-surface roots, and Sasanishiki, a Japanese lowland rice cultivar without soil-surface roots. These cultivars and the RILs were tested for soil-surface rooting in a paddy field. We identified four regions of chromosomes 3, 4, 6, and 7 that were associated with soil-surface rooting in the field. Among them, one major QTL was located on the long arm of chromosome 7. This QTL explained 32.5-53.6% of the total phenotypic variance across three field evaluations. To perform fine mapping of this QTL, we measured the basal root growth angle of crown roots at the seedling stage in seven BC(2)F(3) recombinant lines grown in small cups in a greenhouse. The QTL was mapped between markers RM21941 and RM21976, which delimit an 812-kb interval in the reference cultivar Nipponbare. We have designated this QTL qSOR1 (quantitative trait locus for SOIL SURFACE ROOTING 1).

  19. Antagonism of rice phylloplane fungi against Cercospora oryzae

    Science.gov (United States)

    Mardani, A.; Hadiwiyono

    2018-03-01

    Narrow brown leaf spot (NBLS) caused by Cercospora oryzae Miyake is one of the important obstacle in rice cultivation that can decrease the productivity up to 40%. It has been known well that some phylloplane fungi are antagonistic to some leaf diseases. Phylloplane fungi of rice however haven’t been studied much and poorly understood as biological control agent of rice pathogen such C. oryzae. The research aimed to study the antagonism of some phylloplane fungi of rice against C. oryzae. At least 14 isolates of phylloplane fungi were collected which consisted of six pathogenic and eight nonpathogenic variants. All of nonpathogenic isolates were antagonistic against C. oryzae both in vitro and only one isolate could not inhibit the infection of the pathogen in vivo. Some isolates were identified as Aspergillus, Mucor, Penicillium, Fusarium, and Trichoderma. The isolate of Mucor and Fusarium could inhibit the highest growth of pathogen on potato dextrose medium that were at 36.0% and 35.5% respectively. Whereas on artificial inoculation on rice, some isolates such Penicillium and Fusarium could inhibit most effectively and were significantly different to Mencozeb application with dosage 5g L-1.

  20. Agmatine Production by Aspergillus oryzae is Elevated by Low pH During Solid-State Cultivation.

    Science.gov (United States)

    Akasaka, Naoki; Kato, Saori; Kato, Saya; Hidese, Ryota; Wagu, Yutaka; Sakoda, Hisao; Fujiwara, Shinsuke

    2018-05-25

    Sake (rice wine) produced by multiple parallel fermentation (MPF) involving Aspergillus oryzae (strain RW) and Saccharomyces cerevisiae under solid-state cultivation conditions contained 3.5 mM agmatine, while that produced from enzymatically saccharified rice syrup by S. cerevisiae contained oryzae under solid-state cultivation (3.1 mM) but not under submerged cultivation, demonstrating that A. oryzae in solid-state culture produces agmatine. The effect of cultivation conditions on agmatine production was examined. Agmatine production was boosted at 30°C and reached the highest level (6.3 mM) at pH 5.3. The addition of l-lactic, succinic, and citric acids reduced the initial culture pH to 3.0, 3.5, and 3.2, respectively, resulting in further increase in agmatine accumulation (8.2, 8.7, and 8.3 mM, respectively). Homogenate from a solid-state culture exhibited a maximum l-arginine decarboxylase (ADC) activity (74 pmol min -1 μg -1 ) at pH 3.0 at 30°C; that from a submerged culture exhibited an extremely low activity (oryzae , even though A. oryzae lacks ADC orthologs and, instead, possesses four ornithine decarboxylases (ODC1-4). Recombinant ODC1 and ODC2 exhibited no ADC activity at acidic pH (pH 4.0>), suggesting that other decarboxylases or an unidentified ADC is involved in agmatine production. IMPORTANCE It has been speculated that, in general, fungi do not synthesize agmatine from l-arginine because they do not possess genes encoding for arginine decarboxylase. Numerous preclinical studies have shown that agmatine exerts pleiotropic effects on various molecular targets, leading to an improved quality of life. In the present study, we first demonstrated that l-arginine was a feasible substrate for agmatine production by the fungus Aspergillus oryzae RW. We observed that the productivity of agmatine by A. oryzae RW was elevated at low pH only during solid-state cultivation. A. oryzae is utilized in the production of various oriental fermented foods. The

  1. Nitrogen fertilizer management for tidal submergence tolerant landrace rice (Oryza sativa L. cultivars

    Directory of Open Access Journals (Sweden)

    M.A.A. Mamun

    2017-12-01

    Full Text Available In tidal submergence ecosystem, nitrogen (N is a crucial nutrient for improved and sustainable rice production. Therefore, a series of on-farm and on-station field experiments were conducted to develop a suitable N management practice for tidal submergence tolerant landrace aman rice. In on-farm, urea deep placement (UDP through urea super granule before panicle initiation (PI stage was compared with no fertilizer application. Similarly, five N fertilizer management practices viz. (i. two splits of prilled urea (PU, (ii. UDP at 10 DAT, (iii. UDP before PI, (iv. full dose PU before PI and (v. No urea (control were compared at on-station trial. Tidal submergence tolerance aman rice varieties (Rajashail, Kutiagni, Sadamota and Lalmota were used as testing materials. In on farm experiment, aman cultivars produced 2.0–2.5 t ha−1 grain without N fertilizer. But, cultivated Rajashail, Kutiagni, Sadachikon, Sadapajam, Lalmota and Sadamota gave 3.0–3.5 t ha−1 grain yield with the UDP before PI in tidal prone areas. Though UDP required fertilizer and application cost but it gave profit upto 22,000 BDT ha−1 (Bangladeshi Taka. In on-station experiment, UDP before PI stage significantly increased rice yield and economic return although it was comparable to two splits of PU and top dressing of PU before PI stage. However, UDP at 10 DAT increased straw yield but failed to increase grain yield even compared to control. It could be concluded that UDP before PI stage of rice is an effective method for increasing rice yield and farm income in tidal prone areas.

  2. Crop performance, nitrogen and water use in flooded and aerobic rice

    NARCIS (Netherlands)

    Belder, P.; Bouman, B.A.M.; Spiertz, J.H.J.; Peng, S.; Castañeda, A.R.; Visperas, R.M.

    2005-01-01

    Abstract Irrigated aerobic rice is a new system being developed for lowland areas with water shortage and for favorable upland areas with access to supplementary irrigation. It entails the cultivation of nutrient-responsive cultivars in nonsaturated soil with sufficient external inputs to reach

  3. Suppression of Rhizome Rot in Organically Cultivated Ginger Using Integrated Pest Management

    Directory of Open Access Journals (Sweden)

    Chang-Ki Shim

    2015-09-01

    Full Text Available This study was conducted to control ginger rhizome rot treated with the combined treatment, the hairy vetch, carbonized rice husk and eggshell calcium in organic ginger farm. Early symptoms of leaf yellowing and plant wilt began in the chemical fertilizer treatment on July 1. Ginger rhizome rot was more progressed on October 2, and stem browning and dead plant showed a high disease incidence with from 36.7% to 43.0%. On the other hand, the combined treatment did not occur at all until July 1 and delayed the disease incidence to October 2. It showed a low disease incidence of 1.3% to 1.7%. In the combined treatment, the content of soil Na, Fe, Cu was decreased and organic matter was increased twice with 31.6% than previous. Population density of Pythium sp. is lower in the combined treatment (0.3-2.0×103 cfu/g than the chemical fertilizer treatments (12.0-12.3×103 cfu/g. The combined treatment, hairy vetch, carbonized rice husk and the eggshell calcium is able to control the ginger rhizome rot in organically cultivated ginger field.

  4. Comparative study of endophytic and endophytic diazotrophic bacterial communities across rice landraces grown in the highlands of northern Thailand

    OpenAIRE

    Rangjaroen, C.; Rerkasem, B.; Teaumroong, N.; Sungthong, R.; Lumyong, S.

    2014-01-01

    Communities of bacterial endophytes within the rice landraces cultivated in the highlands of northern Thailand were studied using fingerprinting data of 16S rRNA and nifH genes profiling by polymerase chain reaction-denaturing gradient gel electrophoresis. The bacterial communities' richness, diversity index, evenness, and stability were varied depending on the plant tissues, stages of growth, and rice cultivars. These indices for the endophytic diazotrophic bacteria within the landrace rice ...

  5. Methane emissions and microbial communities as influenced by dual cropping of Azolla along with early Rice

    DEFF Research Database (Denmark)

    Liu, Jingna; Xu, Heshui; Jiang, Ying

    2017-01-01

    Azolla caroliniana Willd. is widely used as a green manure accompanying rice, but its ecological importance remains unclear, except for its ability to fix nitrogen in association with cyanobacteria. To investigate the impacts of Azolla cultivation on methane emissions and environmental variables...... in paddy fields, we performed this study on the plain of Dongting Lake, China, in 2014. The results showed that the dual cropping of Azolla significantly suppressed the methane emissions from paddies, likely due to the increase in redox potential in the root region and dissolved oxygen concentration...... at the soil-water interface. Furthermore, the floodwater pH decreased in association with Azolla cultivation, which is also a factor significantly correlated with the decrease in methane emissions. An increase in methanotrophic bacteria population (pmoA gene copies) and a reduction in methanogenic archaea (16...

  6. Performance of super hybrid rice cultivars grown under no-tillage and direct seeding

    Directory of Open Access Journals (Sweden)

    Min Huang

    2012-04-01

    Full Text Available Good progress has been made in the super hybrid rice (Oryza sativa L. breeding in China. However, rice yield not only depends on the genetic characteristics but also on the agronomic practices. No-tillage and direct seeding (NTDS is a simplified cultivation technology that greatly simplifies both land preparation and crop establishment. Aiming to determine the grain yield performance of super hybrid rice under NTDS and to identify critical factors that determine grain yield, field experiments were conducted in Nanxian, Hunan Province, China in 2009 and 2010. Two super hybrid cultivars, Liangyoupeijiu and Y-liangyou 1, were grown under conventional tillage and transplanting (CTTP and NTDS. Grain yield, yield components, biomass production, crop growth rate and biomass accumulation during sowing to heading (HD and HD to maturity were measured for each cultivar. There was no difference in grain yield under NTDS and CTTP. However, grain yield differed with cultivar and year. Y-liangyou 1 produced 4 % higher grain yield than Liangyoupeijiu in 2009, whereas in 2010 both cultivars yielded similarly. Grain yields of both cultivars were higher in 2009 than in 2010. Higher grain yield of Y-liangyou 1 in 2009 was associated with higher spikelet filling (spikelet filling percentage and grain weight, which resulted from higher biomass production. Crop growth rate after HD was critical for biomass production by the super hybrid rice. We suggest that increasing the crop growth rate after HD is an effective approach to increase grain yield of super hybrid rice under NTDS.

  7. Microbial, physical and chemical properties of irrigation water in rice fields of Southern Brazil

    Directory of Open Access Journals (Sweden)

    MARIA HELENA L.R. RECHE

    2016-03-01

    Full Text Available ABSTRACT This paper presents the results of the statistical analysis of microbiological, physical and chemical parameters related to the quality of the water used in rice fields in Southern Brazil. Data were collected during three consecutive crop years, within structure of a comprehensive monitoring program. The indicators used were: potential hydrogen, electrical conductivity, turbidity, nitrogen, phosphorus, potassium, calcium, total and fecal coliforms. Principal Component and Discriminant Analysis showed consistent differences between the water irrigation and drainage, as the temporal variation demonstrated a clear reduction in the concentration of most of the variables analyzed. The pattern of this reduction is not the same in the two regions - that is, the importance of each of the different variables in the observed differentiation is modified in two locations. These results suggested that the variations in the water quality utilized for rice irrigation was influenced by certain specific aspects of each rice region in South Brazilian - such as anthropic action or soil/climate conditions in each hydrographic basin.

  8. Creating rigorous pathways to monetize methane and nitrous oxide emission reductions at small scale rice farms in three states of semi-arid peninsular India

    Science.gov (United States)

    Kritee, K.; Tiwari, R.; Nair, D.; Adhya, T. K.; Rudek, J.

    2014-12-01

    As a part of a joint undertaking by Environmental Defense Fund and the Fair Climate Network, we have measured reduction in methane and nitrous oxide emissions due to alternate "low carbon" rice cultivation practices for three ago-ecological zones in India for the past two years. Sampling for nitrous oxide and methane emissions was done on approximately 60-80% of the total number of days in a growing season and was based on modified GRACEnet protocol. In recognition of farmer's economic interest and global food security demands, we also measured the effect of rice cultivation practices on farm economics and yields. Our data from three agro-ecological zones for 2012-2014 suggest that, for semi-arid peninsular India, low-carbon rice cultivation practices offer large range of emission reduction potential (0.5-5 metric tons CO2e/acre/year). The regions with sandy soils (Alfisols) had high rates of nitrous oxide emissions even under baseline "flooded" rice cultivation regimes and, thus, the Tier 1 IPCC emissions factors grossly underestimate both the amount of nitrous oxide emission from conventional rice cultivation practices, and the extent to which it can be reduced through better fertilizer management. Also, the IPCC factors overestimate the methane emission reduction possible due to water management for rice paddies. Therefore, it is crucial to customize N and water management to each region such that yields and net GHG emission reduction are maximized. These practices also have the potential to decrease water use by 10-30% and improve long term soil health by optimizing organic matter and increasing water-holding capacity. In addition, through GPS based demarcation of farmer plots, recording baseline practices through extensive surveys, documenting the parameters required to aggregate and prove implementation of low carbon rice farming practices, and to model the GHG emission reduction over large scales, we have put forward a path for better monetization of GHG

  9. Impacts of climate change on paddy rice yield in a temperate climate.

    Science.gov (United States)

    Kim, Han-Yong; Ko, Jonghan; Kang, Suchel; Tenhunen, John

    2013-02-01

    The crop simulation model is a suitable tool for evaluating the potential impacts of climate change on crop production and on the environment. This study investigates the effects of climate change on paddy rice production in the temperate climate regions under the East Asian monsoon system using the CERES-Rice 4.0 crop simulation model. This model was first calibrated and validated for crop production under elevated CO2 and various temperature conditions. Data were obtained from experiments performed using a temperature gradient field chamber (TGFC) with a CO2 enrichment system installed at Chonnam National University in Gwangju, Korea in 2009 and 2010. Based on the empirical calibration and validation, the model was applied to deliver a simulated forecast of paddy rice production for the region, as well as for the other Japonica rice growing regions in East Asia, projecting for years 2050 and 2100. In these climate change projection simulations in Gwangju, Korea, the yield increases (+12.6 and + 22.0%) due to CO2 elevation were adjusted according to temperature increases showing variation dependent upon the cultivars, which resulted in significant yield decreases (-22.1% and -35.0%). The projected yields were determined to increase as latitude increases due to reduced temperature effects, showing the highest increase for any of the study locations (+24%) in Harbin, China. It appears that the potential negative impact on crop production may be mediated by appropriate cultivar selection and cultivation changes such as alteration of the planting date. Results reported in this study using the CERES-Rice 4.0 model demonstrate the promising potential for its further application in simulating the impacts of climate change on rice production from a local to a regional scale under the monsoon climate system. © 2012 Blackwell Publishing Ltd.

  10. Effect of organic fertiliser residues from rice production on nitrogen fixation of soya (Glycine max L. Merrill, Chiang Mai 60 variety

    Directory of Open Access Journals (Sweden)

    Nattida Luangmaka

    2013-09-01

    Full Text Available A field study was undertaken on the residual effect of organic fertilisers applied to the preceding rice cropping on nitrogen fixation of soya in a rice-soya cropping system. The experiment was conducted on a farmer’s lowland paddy in Mae Rim district, Chiang Mai province, Thailand. Organic fertiliser treatments assigned were: 1 control (no fertiliser, 2 animal manure of cattle (AM, 3 compost (CP, 4 azolla (AZ, 5 AM + CP, 6 AM + AZ, 7 CP + AZ and 8 AM + CP + AZ. Soya seeds were planted without rhizobial inoculation in December 2011, four months after the application of organic fertilisers. Nodule weight, total shoot nitrogen accumulation and relative ureide index at various growth stages were recorded as the indices of nitrogen fixation. Results of the study demonstrate that the residues from the application the organic fertilisers of narrow C/N ratios during the land preparation for rice cropping four months before soya cultivation promoted nitrogen fixation by native rhizobia.

  11. Effects of fish and prawn culture on physico-chemical parameters of water and rice yield in rice fields

    OpenAIRE

    Razzak, M.A.; Nahar, A.; Mirhaj, M.; Becker, K.; Dewan, S.

    2009-01-01

    An experiment was conducted with five treatments i.e. rice combined with fish having regular urea fertilization (T1), rice combined with prawn having regular urea fertilization (T2), rice combined with fish with supplementary feeding (T3), rice combined with prawn with supplementary feeding (T4) and without fish and prawn (T5) was kept as control. The dissolved oxygen values obtained in treatments with fish both in morning and afternoon were lower than the values of prawn containing treatment...

  12. Policies, Socioeconomic, Institutional and Biophysical Factors Influencing the Change from Rice to Sugarcane in Nong Bua Lamphu Province, Thailand

    Science.gov (United States)

    Lakapunrat, Narinpat; Thapa, Gopal B.

    2017-06-01

    For the past decade, Thailand pursued a strategy of promoting biofuel crop production, including sugarcane, to meet the ever increasing energy demand and to increase the income of farmers. This study analyzed the influence of policy instruments implemented to promote the sugarcane cultivation, farm household socioeconomic levels, biophysical, and institutional factors driving the conversion of rice fields into sugarcane farms. Primary information was collected from 230 farm households through a structured questionnaire. Relevant policy documents published by the responsible government agencies were the main sources of secondary information collected for policy analysis. The analyses revealed that farmers in the study area converted 25-75% of their rice fields into sugarcane farms as a result of implementation of policy instruments that made sugarcane financially far more attractive than rice. The results of the regression analysis showed that eight variables were found significant and positively influenced the conversion of rice fields into sugarcane farms. These were access to extension services, information, sugarcane loading stations, and ground water for irrigation, and duration of experience in sugarcane farming as well as household head's age and education. Irrespective of landholding size, the majority of farmers were not concerned about food security. In view of the finding, if feasible, in the form of additional price supports and commercial cane sugar index-based pricing strategies to promote sugarcane production should benefit all concerned farmers. Likewise, attention should be paid to deliver essential extension and marketing services in an effective way, particularly to those farmers who are not receiving such services.

  13. Improving water management practices to reduce nutrient export from rice paddy fields.

    Science.gov (United States)

    Zhang, Zhi-Jian; Yao, Ju-Xiang; Wang, Zhao-De; Xu, Xin; Lin, Xian-Yong; Czapar, George F; Zhang, Jian-Ying

    2011-01-01

    Nitrogen (N) and phosphorus (P) loss from rice paddy fields represents a significant threat to water quality in China. In this project, three irrigation-drainage regimes were compared, including one conventional irrigation-drainage regime, i.e. continuous submergence regime (CSR), and two improved regimes, i.e. the alternating submergence-nonsubmergence regime (ASNR) and the zero-drainage irrigation technology (ZDIT), to seek cost-effective practices for reducing nutrient loss. The data from these comparisons showed that, excluding the nutrient input from irrigation, the net exports of total N and total P via surface field drainage ranged from -3.93 to 2.39 kg ha and 0.17 to 0.95 g ha(-1) under the CSR operation, respectively, while N loss was -2.46 to -2.23 kg ha(-1) and P export was -0.65 to 0.31 kg ha(-1) under the improved regimes. The intensity of P export was positively correlated to the rate of P application. Reducing the draining frequency or postponing the draining operation would shift the ecological role of the paddy field from a nutrient export source to an interception sink when ASNR or the zero-drainage water management was used. In addition, since the rice yields are being guaranteed at no additional cost, the improved irrigation-drainage operations would have economic as well as environmental benefits.

  14. Influence of water management and fertilizer application on "1"3"7Cs and "1"3"3Cs uptake in paddy rice fields

    International Nuclear Information System (INIS)

    Wakabayashi, Shokichi; Itoh, Sumio; Kihou, Nobuharu; Matsunami, Hisaya; Hachinohe, Mayumi; Hamamatsu, Shioka; Takahashi, Shigeru

    2016-01-01

    Cesium-137 derived from the Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident contaminated large areas of agricultural land in Eastern Japan. Previous studies before the accident have indicated that flooding enhances radiocesium uptake in rice fields. We investigated the influence of water management in combination with fertilizers on "1"3"7Cs concentrations in rice plants at two fields in southern Ibaraki Prefecture. Stable Cs ("1"3"3Cs) in the plants was also determined as an analogue for predicting "1"3"7Cs behavior after long-term aging of soil "1"3"7Cs. The experimental periods comprised 3 y starting from 2012 in one field, and 2 y from 2013 in another field. These fields were divided into three water management sections: a long-flooding section without midsummer drainage, and medial-flooding, and short-flooding sections with one- or two-week midsummer drainage and earlier end of flooding than the long-flooding section. Six or four types of fertilizer subsections (most differing only in potassium application) were nested in each water management section. Generally, the long-flooding treatment led to higher "1"3"7Cs and "1"3"3Cs concentrations in both straw and brown rice than medial- and short-flooding treatments, although there were some notable exceptions in the first experimental year at each site. Effects of differing potassium fertilizer treatments were cumulative; the effects on "1"3"7Cs and "1"3"3Cs concentrations in rice plants were not obvious in 2012 and 2013, but in 2014, these concentrations were highest where potassium fertilizer had been absent and lowest where basal dressings of K had been tripled. The relationship between "1"3"7Cs and "1"3"3Cs in rice plants was not correlative in the first experimental year at each site, but correlation became evident in the subsequent year(s). This study demonstrates a novel finding that omitting midsummer drainage and/or delaying drainage during the grain-filling period

  15. The role of Bh4 in parallel evolution of hull colour in domesticated and weedy rice.

    Science.gov (United States)

    Vigueira, C C; Li, W; Olsen, K M

    2013-08-01

    The two independent domestication events in the genus Oryza that led to African and Asian rice offer an extremely useful system for studying the genetic basis of parallel evolution. This system is also characterized by parallel de-domestication events, with two genetically distinct weedy rice biotypes in the US derived from the Asian domesticate. One important trait that has been altered by rice domestication and de-domestication is hull colour. The wild progenitors of the two cultivated rice species have predominantly black-coloured hulls, as does one of the two U.S. weed biotypes; both cultivated species and one of the US weedy biotypes are characterized by straw-coloured hulls. Using Black hull 4 (Bh4) as a hull colour candidate gene, we examined DNA sequence variation at this locus to study the parallel evolution of hull colour variation in the domesticated and weedy rice system. We find that independent Bh4-coding mutations have arisen in African and Asian rice that are correlated with the straw hull phenotype, suggesting that the same gene is responsible for parallel trait evolution. For the U.S. weeds, Bh4 haplotype sequences support current hypotheses on the phylogenetic relationship between the two biotypes and domesticated Asian rice; straw hull weeds are most similar to indica crops, and black hull weeds are most similar to aus crops. Tests for selection indicate that Asian crops and straw hull weeds deviate from neutrality at this gene, suggesting possible selection on Bh4 during both rice domestication and de-domestication. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  16. Field experiment for determining lead accumulation in rice grains of different genotypes and correlation with iron oxides deposited on rhizosphere soil.

    Science.gov (United States)

    Lai, Yu-Cheng; Syu, Chien-Hui; Wang, Pin-Jie; Lee, Dar-Yuan; Fan, Chihhao; Juang, Kai-Wei

    2018-01-01

    Paddy rice (Oryza sativa L.) is a major staple crop in Asia. However, heavy metal accumulation in paddy soil poses a health risk for rice consumption. Although plant uptake of Pb is usually low, Pb concentrations in rice plants have been increasing with Pb contamination in paddy fields. It is known that iron oxide deposits in the rhizosphere influence the absorption of soil Pb by rice plants. In this study, 14 rice cultivars bred in Taiwan, including ten japonica cultivars (HL21, KH145, TC192, TK9, TK14, TK16, TN11, TNG71, TNG84, and TY3) and four indica cultivars (TCS10, TCS17, TCSW2, and TNGS22), were used in a field experiment. We investigated the genotypic variation in rice plant Pb in relation to iron oxides deposited in the rhizosphere, as seen in a suspiciously contaminated site in central Taiwan. The results showed that the cultivars TCSW2, TN11, TNG71, and TNG84 accumulated brown rice Pb exceeding the tolerable level of 0.2mgkg -1 . In contrast, the cultivars TNGS22, TK9, TK14, and TY3 accumulated much lower brown rice Pb (iron oxides deposited on the rhizosphere soil show stronger affinity to soil-available Pb than those on the root surface to form iron plaque. The relative tendency of Pb sequestration toward rhizosphere soil was negatively correlated with the Pb concentrations in brown rice. The iron oxides deposited on the rhizosphere soil but not on the root surface to form iron plaque dominate Pb sequestration in the rhizosphere. Therefore, the enhancement of iron oxide deposits on the rhizosphere soil could serve as a barrier preventing soil Pb on the root surface and result in reduced Pb accumulation in brown rice. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Cultivation of Flammulina velutipesmushroom using various agro-residues as a fruiting substrate

    Directory of Open Access Journals (Sweden)

    Nooraishah Harith

    2014-03-01

    Full Text Available The objective of this work was to evaluate the feasibility of different agro-residues as a carbon source in the fruiting substrates of Flammulina velutipesmushroom and the effect of supplementation with the nitrogen sources spent brewer's yeast and rice bran. The following fruiting substrates were evaluated: rubber wood sawdust (SD, paddy straw (PS, palm empty fruit bunches (EFB, and palm-pressed fiber (PPF. Cultivation was done on each agro-residue, based on formulations consisting of two substrates at the ratios of 3:1, 1:1, and 1:3. Mycelial growth rate and basidiocarp yield were evaluated. The best fruiting substrates were PS+EFB (25:75, PS+PPF (50:50, and PPF (100, with biological efficiency of 185.09±36.98, 150.89±50.35, and 129.06±14.51%, respectively. No significant effects of supplementation with rice bran and spent yeast were observed on mycelial growth rate and biological efficiency. The cultivation of F. velutipes on oil palm wastes does not require additional nitrogen sources.

  18. Rhizosphere biodegradation of xenobiotics: Microbiological study of a rice field polluted by oil refinery residues

    Energy Technology Data Exchange (ETDEWEB)

    Rasolomanana, J.L.; Balandreau, J.

    1987-07-01

    A rice field had been studied in which the disposal of oil residues from a refinery plant seemed to improve rice growth and soil N content. To check the hypothesis that nitrogen fixation by oil-adapted bacteria could explain this observation we isolated and studied dominant diazotrophic bacteria from the rhizosphere of an actively N/sub 2/-fixing rice plant growing on the polluted soil; for this purpose we used an axenic plant as an enrichment step. The rhizosphere did not contain more than 10/sup 5/ N/sub 2/-fixing bacteria per g dry soil, essentially Bacillus polymyxa; one of the isolates, strain R3 could grow and reduce C/sub 2/H/sub 2/ on oil residues only in the presence of glucose or of exudates from an axenic plant (spermosphere model); the presence of R3 diminished the inhibition of rice growth due to the oil residues; R3 nitrogenase activity in the rhizosphere of rice was increased in the presence of these residues. This cometabolism of oil residues in the presence of exudates and their stimulating effect on N/sub 2/ fixation provide a likely explanation for observed positive effects of the disposal of oil residues on arable lands, and are conducive to the hypothesis that rhizosphere cometabolism could greatly enhance soil organic matter turn over and humification rates.

  19. LEACHING AND DEGRADATION OF 2,4-DICHLOROPHENOXIACETIC ACID, IN COLOMBIA RICE FLOODED SOIL.

    Science.gov (United States)

    Huertas, J; Guerrero, J A; Martinez-Cordon, M J

    2015-01-01

    Rice is mostly cultivated on soil held under flooded conditions. Under these conditions pesticides undergo reductive transformations which are characteristic to rice fields and other anaerobic systems. The present study was undertaken to evaluate the mobility and persistence of 2,4-dichlorophenoxy acetic acid (2,4-D) under laboratory conditions for the rice crop in Espinal, Colombia. A displacement study was performed on a hand packed soil column 30 cm length. After leaching experiment, the soil from column was sliced into six successive sections (5 cm). Methanol acidified (H3PO4 0.25%) extraction was used to determine the herbicide residues in each section. 2,4-D experimental breakthrough curve was analyzed using Stanmod program (inverse problem) to obtain transport parameters. The non-equilibrium physical model fitted well the experimental breakthrough curve. The recovery percent of 2,4-D in leachates was 36.44% after 3.4 pore volumes, and retardation factor was 2.1, indicating low adsorption in that conditions. 2,4-D was rapidly degraded, with DT50 = 11.4 days. The results suggest that 2,4-D under flooded conditions have a high potential for leaching through the soil profile, although the elevated rate of degradation reduced the ground water contamination risk.

  20. Transfer of technetium from soil to paddy and upland rice

    International Nuclear Information System (INIS)

    Yanagisawa, Kei; Muramatsu, Yasuyuki

    1995-01-01

    Soil-plant transfer factors (concentration ratio between the plant and soil) of technetium in paddy and upland rice plants were obtained from laboratory experiments. The transfer factor is one of the most important parameters for environmental radiation dose assessment. Technetium tracer ( 95m TcO 4 - ) was added to the soil prior to rice cultivation. The transfer factor of technetium for the hulled grains (brown rice) of paddy rice (≤0.0002) was much lower than for that of upland rice (0.021). The transfer factors for both types of hulled grains were much lower than in the leaves. The technetium decontamination rate from hulled grains by polishing was 34%, the percentage of the weight decrease being 12%. The concentration of technetium in the soil solution collected from the paddy rice soil (flooded conditions) decreased rapidly with time due to its adsorption on the soil. In the upland rice soil (non-flooded) solution, the decrease in the technetium concentration was fairly slow. The low transfer factors for the paddy rice plants could be explained by the immobilization of technetium in the flooded soil. The oxidation-reduction potentials (Eh) in the flooded soil decreased rapidly with time. We conclude that technetium tracer added as TcO 4 - to flooded soil is readily transformed to an insoluble form (e.g.TcO 2 ) under the reducing conditions provided by flooding. (author)

  1. Proteomics of Rice Seed Germination

    Directory of Open Access Journals (Sweden)

    Dongli eHe

    2013-07-01

    Full Text Available Seed is a condensed form of plant. Under suitable environmental conditions, it can resume the metabolic activity from physiological quiescent status, and mobilize the reserves, biosynthesize new proteins, regenerate organelles and cell membrane, eventually protrude the radicle and enter into seedling establishment. So far, how these activities are regulated in a coordinated and sequential manner is largely unknown. With the availability of more and more genome sequence information and the development of mass spectrometry (MS technology, proteomics has been widely applied in analyzing the mechanisms of different biological processes, and proved to be very powerful. Regulation of rice seed germination is critical for rice cultivation. In recent years, a lot of proteomic studies have been conducted in exploring the gene expression regulation, reserves mobilization and metabolisms reactivation, which brings us new insights on the mechanisms of metabolism regulation during this process. Nevertheless, it also invokes a lot of questions. In this mini-review, we summarized the progress in the proteomic studies of rice seed germination. The current challenges and future perspectives were also discussed, which might be helpful for the following studies.

  2. Chemical, Sensorial and Rheological Properties of a New Organic Rice Bran Beverage

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    Gerson Luis FACCIN

    2009-09-01

    Full Text Available Rice bran is a solid residue from rice polishing that is used in animal nutrition and rice oil production. Cultivation conditions with agro-toxics, lipids instability, and tendency for mycotoxin contamination restrict its application in human nutrition. Therefore, organic agriculture is an alternative to use the properties of rice bran. Rice bran beverage is a new cereal product from organic rice. This work presents the preliminary results of the chemical and rheological studies of a bath pasteurized rice bran beverage. Compared with integral defatted milk, soy extracts, and brown rice low-fat milk, the rice bran beverage studied in this work presents itself as an important source of minerals and unsaturated lipids. All essential amino acids were found in this product. Glutamic and aspartic acids were predominant. Bath pasteurization at boiling water temperature for 15 and 30 min was adequate for microbiological safety. Refrigeration storage for 20 days, evaluated by pH and acidity variations, was ideal for assessment of the beverage conservation time. The beverage viscosity was of the Newtonian standard behavior, and its viscosity during storage was not a good parameter to evaluate shelf life. Sensory preference tests showed positive perspectives for this new beverage.

  3. Gene, protein and network of male sterility in rice

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    Wang eKun

    2013-04-01

    Full Text Available Rice is one of the most important model crop plants whose heterosis has been well exploited in commercial hybrid seed production via a variety of types of male sterile lines. Hybrid rice cultivation area is steadily expanding around the world, especially in Southern Asia. Characterization of genes and proteins related to male sterility aims to understand how and why the male sterility occurs, and which proteins are the key players for microspores abortion. Recently, a series of genes and proteins related to cytoplasmic male sterility, photoperiod sensitive male sterility, self-incompatibility and other types of microspores deterioration have been characterized through genetics or proteomics. Especially the latter, offers us a powerful and high throughput approach to discern the novel proteins involving in male-sterile pathways which may help us to breed artificial male-sterile system. This represents an alternative tool to meet the critical challenge of further development of hybrid rice. In this paper, we reviewed the recent developments in our understanding of male sterility in rice hybrid production across gene, protein and integrated network levels, and also, present a perspective on the engineering of male sterile lines for hybrid rice production.

  4. Factors affecting the income from major crops in rice-wheat ecological zone

    International Nuclear Information System (INIS)

    Ashfaq, M.; Naseer, M.Z.; Hassan, S.

    2008-01-01

    Agriculture is an important sector of our economy. About twenty-two percent of national income and 44.8 percent of total employment is generated by this sector. About 66 percent of country's population is living in rural areas and is directly or indirectly linked with agriculture for their livelihood. It also supplies raw materials to industry. The rice-wheat zone of Punjab covers 1.1 million hectare, 72% of wheat is grown in rotation with rice. The main purpose of this paper was to determine the effect of different factors on the productivity and ultimately on income from of major crops (wheat, rice and sugar-cane) in rice-wheat ecological zone. The results show that for wheat crop, land preparation, use of fertilizer and chemicals, for Sugarcane crop, area under cultivation, fertilizer and chemical costs and for rice crop, applications of chemicals, irrigation and land holding were the main determinants of productivity and crop income. (author)

  5. Characterization of the exchange of PBDEs in a subtropical paddy field of China: A significant inputs of PBDEs via air–foliage exchange

    International Nuclear Information System (INIS)

    Wang, Yan; Wang, Shaorui; Xu, Yue; Luo, Chunling; Li, Jun; Zhang, Gan

    2015-01-01

    Rice and the distinctive cultivation practices employed in rice growth can significantly influence the environmental fate of polybrominated diphenyl ethers (PBDEs) in a paddy field. We studied variations in PBDE concentrations in multiple compartments of a paddy field in the suburban area of Guangzhou, South China, including air, soil, water, and rice tissues. The input/output fluxes of air–surface and air–foliage exchange, atmospheric deposition and water input during different rice growth stages were measured simultaneously. Air–foliage and air–water diffusion exchanges were the key processes controlling inputs and outputs of PBDEs in paddy fields, respectively, whereas atmospheric deposition dominated inputs of higher brominated PBDEs. The high input of PBDEs via air–foliage exchange suggested that vegetation can significantly increase the air-to-field transport of PBDEs in ecosystems. The annual input of PBDEs in all paddy fields in Guangdong Province was estimated to be 22.1 kg. - Highlights: • PBDE concentrations in multiple compartments of a suburban paddy field were measured. • Air–water exchange was the key process controlling PBDE output in paddy fields. • Air–foliage exchange dominated the inputs of PBDEs in paddy fields. • Annual PBDE input in paddy fields in Guangdong Province was calculated to be 22 kg. - Air–foliage exchange is the most dominant inputs of PBDEs in the subtropical paddy fields

  6. Insect remote sensing using a polarization sensitive cw lidar system in chinese rice fields

    Science.gov (United States)

    Zhu, Shiming; Malmqvist, Elin; Li, Yiyun; Jansson, Samuel; Li, Wansha; Duan, Zheng; Fu, Wei; Svanberg, Katarina; Bood, Joakim; Feng, Hongqiang; Åkesson, Susanne; Song, Ziwei; Zhang, Baoxin; Zhao, Guangyu; Li, Dunsong; Brydegaard, Mikkel; Svanberg, Sune

    2018-04-01

    A joint Chinese-Swedish field campaign of Scheimpflug continuous-wave lidar monitoring of rice-field flying pest insects was pursued in very hot July weather conditions close to Guangzhou, China. The occurrence of insects, birds and bats with almost 200 hours of round-the-clock polarization-sensitive recordings was studied. Wing-beat frequency recordings and depolarization properties were used for target classification. Influence of weather conditions on the flying fauna was also investigated.

  7. Evidence for the emergence of new rice types of interspecific hybrid origin in West African farmers' fields.

    Directory of Open Access Journals (Sweden)

    Edwin Nuijten

    2009-10-01

    Full Text Available In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L. co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess genetic diversity in West Africa (including the countries The Gambia, Senegal, Guinea Bissau, Guinea Conakry, Sierra Leone, Ghana and Togo using 315 rice samples morphologically classified prior to analysis. We show evidence for farmer interspecific hybrids of African and Asian rice, resulting in a group of novel genotypes, and identify possible mechanisms for in-field hybridization. Spontaneous back-crossing events play a crucial role, resulting in different groups of genetic diversity in different regions developed by natural and cultural selection, often under adverse conditions. These new groups of genotypes may have potential relevance for exploitation by plant breeders. Future advances in crop development could be achieved through co-operation between scientists and marginalized farmer groups in order to address challenges of rapid adaptation in a world of increasing socio-political and climatic uncertainty.

  8. Comparative analysis of the genomes of two field isolates of the rice blast fungus Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Minfeng Xue

    Full Text Available Rice blast caused by Magnaporthe oryzae is one of the most destructive diseases of rice worldwide. The fungal pathogen is notorious for its ability to overcome host resistance. To better understand its genetic variation in nature, we sequenced the genomes of two field isolates, Y34 and P131. In comparison with the previously sequenced laboratory strain 70-15, both field isolates had a similar genome size but slightly more genes. Sequences from the field isolates were used to improve genome assembly and gene prediction of 70-15. Although the overall genome structure is similar, a number of gene families that are likely involved in plant-fungal interactions are expanded in the field isolates. Genome-wide analysis on asynonymous to synonymous nucleotide substitution rates revealed that many infection-related genes underwent diversifying selection. The field isolates also have hundreds of isolate-specific genes and a number of isolate-specific gene duplication events. Functional characterization of randomly selected isolate-specific genes revealed that they play diverse roles, some of which affect virulence. Furthermore, each genome contains thousands of loci of transposon-like elements, but less than 30% of them are conserved among different isolates, suggesting active transposition events in M. oryzae. A total of approximately 200 genes were disrupted in these three strains by transposable elements. Interestingly, transposon-like elements tend to be associated with isolate-specific or duplicated sequences. Overall, our results indicate that gain or loss of unique genes, DNA duplication, gene family expansion, and frequent translocation of transposon-like elements are important factors in genome variation of the rice blast fungus.

  9. Optimizing cultivation of agricultural products using socio-economic and environmental scenarios.

    Science.gov (United States)

    RaheliNamin, Behnaz; Mortazavi, Samar; Salmanmahiny, Abdolrassoul

    2016-11-01

    The combination of degrading natural conditions and resources, climate change, growing population, urban development, and competition in a global market complicate optimization of land for agricultural products. The use of pesticides and fertilizers for crop production in the agricultural fields has become excessive in the recent years and Golestan Province of Iran is no exception in this regard. For this, effective management with an efficient and cost-effective practice should be undertaken, maintaining public service at a high level and preserving the environment. Improving the production efficiency of agriculture, efficient use of water resources, decreasing the use of pesticides and fertilizers, improving farmer revenue, and conservation of natural resources are the main objectives of the allocation, ranking, and optimization of agricultural products. The goal of this paper is to use an optimization procedure to lower the negative effects of agriculture while maintaining a high production rate, which is currently a gap in the study area. We collected information about fertilizer and pesticide consumption and other data in croplands of eastern Golestan Province through face-to-face interviews with farmers to optimize cultivation of the agricultural products. The toxicity of pesticides according to LD50 was also included in the optimization model. A decision-support software system called multiple criteria analysis tool was used to simultaneously minimize consumption of water, chemical fertilizers, and pesticides and maximize socio-economic returns. Three scenarios for optimization of agricultural products were generated that alternatively emphasized on environmental and socio-economic goals. Comparing socio-economic and environmental performance of the optimized agricultural products under the three scenarios illustrated the conflict between social, economic, and environmental objectives. Of the six crops studied (wheat, barley, rice, soybeans, oilseed rape

  10. Early mixed farming of millet and rice 7800 years ago in the Middle Yellow River region, China.

    Directory of Open Access Journals (Sweden)

    Jianping Zhang

    Full Text Available The Peiligang Culture (9000-7000 cal. yr BP in the Middle Yellow River region, North China, has long been considered representative of millet farming. It is still unclear, however, if broomcorn millet or foxtail millet was the first species domesticated during the Peiligang Culture. Furthermore, it is also unknown whether millet was cultivated singly or together with rice at the same period. In this study, phytolith analysis of samples from the Tanghu archaeological site reveals early crop information in the Middle Yellow River region, China. Our results show that broomcorn millet was the early dry farming species in the Peiligang Culture at 7800 cal. yr BP, while rice cultivation took place from 7800 to 4500 cal. yr BP. Our data provide new evidence of broomcorn millet and rice mixed farming at 7800 cal. yr BP in the Middle Yellow River region, which has implications for understanding the domestication process of the two crops, and the formation and continuance of the Ancient Yellow River Civilization.

  11. In Situ Biodiesel Production from Fast-Growing and High Oil Content Chlorella pyrenoidosa in Rice Straw Hydrolysate

    Science.gov (United States)

    Li, Penglin; Miao, Xiaoling; Li, Rongxiu; Zhong, Jianjiang

    2011-01-01

    Rice straw hydrolysate was used as lignocellulose-based carbon source for Chlorella pyrenoidosa cultivation and the feasibility of in situ biodiesel production was investigated. 13.7 g/L sugar was obtained by enzymatic hydrolyzation of rice straw. Chlorella pyrenoidosa showed a rapid growth in the rice straw hydrolysate medium, the maximum biomass concentration of 2.83 g/L was obtained in only 48 hours. The lipid content of the cells reached as high as 56.3%. In situ transesterification was performed for biodiesel production. The optimized condition was 1 g algal powder, 6 mL n-hexane, and 4 mL methanol with 0.5 M sulfuric acid at the temperature of 90°C in 2-hour reaction time, under which over 99% methyl ester content and about 95% biodiesel yield were obtained. The results suggested that the method has great potential in the production of biofuels with lignocellulose as an alternative carbon source for microalgae cultivation. PMID:21318171

  12. Optimizing the harvesting stage of rye as a green manure to maximize nutrient production and to minimize methane production in mono-rice paddies

    NARCIS (Netherlands)

    Kim, Sang Yun; Park, Chi Kyu; Gwon, Hyo Suk; Khan, Muhammed Israr; Kim, P.J.

    2015-01-01

    Rye (Secale cerealis) has been widely cultivated to improve soil quality in temperate paddies. However, its biomass incorporation can significantly increase greenhouse gas emissions, particularly the emission of methane (CH4), during rice cultivation. The chemical composition and productivity of

  13. Genetic diversity of high performance cultivars of upland and irrigated Brazilian rice.

    Science.gov (United States)

    Coelho, G R C; Brondani, C; Hoffmann, L V; Valdisser, P A M R; Borba, T C O; Mendonça, J A; Rodrigues, L A; de Menezes, I P P

    2017-09-21

    The objective of this study was to analyze the diversity and discrimination of high-performance Brazilian rice cultivars using microsatellite markers. Twenty-nine rice cultivars belonging to EMBRAPA Arroz e Feijão germplasm bank in Brazil were genotyped by 24 SSR markers to establish their structure and genetic discrimination. It was demonstrated that the analyzed germplasm of rice presents an expressive and significant genetic diversity with low heterogeneity among the cultivars. All 29 cultivars were differentiated genetically, and were organized into two groups related to their upland and irrigated cultivation systems. These groups showed a high genetic differentiation, with greater diversity within the group that includes the cultivars for irrigated system. The genotyping data of these cultivars, with the morphological e phenotypical data, are valuable information to be used by rice breeding programs to develop new improved cultivars.

  14. Effect of transgenic Bacillus thuringiensis rice lines on mortality and feeding behavior of rice stem borers (Lepidoptera: Crambidae).

    Science.gov (United States)

    Chen, Hao; Zhang, Guoan; Zhang, Qifa; Lin, Yongjun

    2008-02-01

    Ten transgenic Bacillus thuringiensis Bt rice, Oryza sativa L., lines with different Bt genes (two Cry1Ac lines, three Cry2A lines, and five Cry9C lines) derived from the same variety Minghui 63 were evaluated in both the laboratory and the field. Bioassays were conducted by using the first instars of two main rice lepidopteran insect species: yellow stem borer, Scirpophaga incertulas (Walker) and Asiatic rice borer, Chilo suppressalis (Walker). All transgenic lines exhibited high toxicity to these two rice borers. Field evaluation results also showed that all transgenic lines were highly insect resistant with both natural infestation and manual infestation of the neonate larvae of S. incertulas compared with the nontransformed Minghui63. Bt protein concentrations in leaves of 10 transgenic rice lines were estimated by the sandwich enzyme-linked immunosorbent assay. The cry9C gene had the highest expression level, next was cry2A gene, and the cry1Ac gene expressed at the lowest level. The feeding behavior of 7-d-old Asiatic rice borer to three classes of Bt transgenic rice lines also was detected by using rice culm cuttings. The results showed that 7-d-old larvae of Asiatic rice borer have the capacity to distinguish Bt and non-Bt culm cuttings and preferentially fed on non-Bt cuttings. When only Bt culm cuttings with three classes of different Bt proteins (CrylAc, Cry2A, and Cry9C) were fed, significant distribution difference of 7-d-old Asiatic rice borer in culm cuttings of different Bt proteins also was found. In the current study, we evaluate different Bt genes in the same rice variety in both the laboratory and the field, and also tested feeding behavior of rice insect to these Bt rice. These data are valuable for the further development of two-toxin Bt rice and establishment of appropriate insect resistance management in the future.

  15. [Influence of paddy rice-upland crop rotation of cold-waterlogged paddy field on crops produc- tion and soil characteristics].

    Science.gov (United States)

    Wang, Fei; Li, Qing-hua; Lin, Cheng; He, Chun-mei; Zhong, Shao-jie; Li, Yu; Lin, Xin-jian; Huang, Jian-cheng

    2015-05-01

    Two consecutive years (4-crop) experiments were conducted to study the influence of different paddy rice-upland crop rotation in cold-waterlogged paddy field on the growth of crops and soil characteristics. The result showed that compared with the rice-winter fallow (CK) pattern, the two-year average yield of paddy rice under four rotation modes, including rape-rice (R-R), spring corn-rice (C-R), Chinese milk vetch-rice (M-R) and bean-rice (B-R), were increased by 5.3%-26.7%, with significant difference observed in C-R and R-R patterns. Except for M-R pattern, the annual average total economic benefits were improved by 79.0%-392.4% in all rotation pattern compared with the CK, and the ration of output/input was enhanced by 0.06-0.72 unit, with the most significant effect found in the C-R pattern. Likewise, compared with the CK, the contents of chlorophyll and carotenoid, and net photosynthetic rate (Pn) of rice plant were all increased during the full-tillering stage of rice in all rotation patterns. The rusty lines and rusty spots of soils were more obvious compared with the CK during the rice harvest, particularly in R-R, C-R and B-R patterns. The ratio of water-stable soil macro aggregates of plough layer of soil (> 2 mm) decreased at different levels in all rotation patterns while the ratios of middle aggregate (0.25-2 mm, expect for M-R) and micro aggregate of soil (< 0.25 mm) were opposite. There was a decreasing trend for soil active reducing agents in all rotation patterns, whereas the available nutrient increased. The amounts of soil bacteria in C-R and B-R patterns, fungi in B-R rotation pattern, cellulose bacteria in R-R, C-R and B-R patterns and N-fixing bacteria in B-R pattern were improved by 285.7%-403.0%, 221.7%, 64.6-92.2% and 162.2%, respectively. Moreover, the differences in all microorganisms were significant. Thus, based on the experimental results of cold-waterlogged paddy field, it was concluded that changing from single cropping rice system

  16. Exploiting Co-Benefits of Increased Rice Production and Reduced Greenhouse Gas Emission through Optimized Crop and Soil Management.

    Directory of Open Access Journals (Sweden)

    Ning An

    Full Text Available Meeting the future food security challenge without further sacrificing environmental integrity requires transformative changes in managing the key biophysical determinants of increasing agronomic productivity and reducing the environmental footprint. Here, we focus on Chinese rice production and quantitatively address this concern by conducting 403 on-farm trials across diverse rice farming systems. Inherent soil productivity, management practices and rice farming type resulted in confounded and interactive effects on yield, yield gaps and greenhouse gas (GHG emissions (N2O, CH4 and CO2-equivalent with both trade-offs and compensating effects. Advances in nitrogen, water and crop management (Best Management Practices-BMPs helped closing existing yield gaps and resulted in a substantial reduction in CO2-equivalent emission of rice farming despite a tradeoff of increase N2O emission. However, inherent soil properties limited rice yields to a larger extent than previously known. Cultivating inherently better soil also led to lower GHG intensity (GHG emissions per unit yield. Neither adopting BMPs only nor improving soils with low or moderate productivity alone can adequately address the challenge of substantially increasing rice production while reducing the environmental footprint. A combination of both represents the most efficient strategy to harness the combined-benefits of enhanced production and mitigating climate change. Extrapolating from our farm data, this strategy could increase rice production in China by 18%, which would meet the demand for direct human consumption of rice by 2030. It would also reduce fertilizer nitrogen consumption by 22% and decrease CO2-equivalent emissions during the rice growing period by 7% compared with current farming practice continues. Benefits vary by rice-based cropping systems. Single rice systems have the largest food provision benefits due to its wider yield gap and total cultivated area, whereas double-rice

  17. A global analysis of alternative tillage and crop establishment practices for economically and environmentally efficient rice production.

    Science.gov (United States)

    Chakraborty, Debashis; Ladha, Jagdish Kumar; Rana, Dharamvir Singh; Jat, Mangi Lal; Gathala, Mahesh Kumar; Yadav, Sudhir; Rao, Adusumilli Narayana; Ramesha, Mugadoli S; Raman, Anitha

    2017-08-24

    Alternative tillage and rice establishment options should aim at less water and labor to produce similar or improved yields compared with traditional puddled-transplanted rice cultivation. The relative performance of these practices in terms of yield, water input, and economics varies across rice-growing regions. A global meta and mixed model analysis was performed, using a dataset involving 323 on-station and 9 on-farm studies (a total of 3878 paired data), to evaluate the yield, water input, greenhouse gas emissions, and cost and net return with five major tillage/crop establishment options. Shifting from transplanting to direct-seeding was advantageous but the change from conventional to zero or reduced tillage reduced yields. Direct-seeded rice under wet tillage was the best alternative with yield advantages of 1.3-4.7% (p Direct-seeding under zero tillage was another potential alternative with high savings in water input and cost of cultivation, with no yield penalty. The alternative practices reduced methane emissions but increased nitrous oxide emissions. Soil texture plays a key role in relative yield advantages, and therefore refinement of the practice to suit a specific agro-ecosystem is needed.

  18. Effects of Salt Stress on Germination and Early Seedling Growth of Some Kenyan Rice Cultivars

    International Nuclear Information System (INIS)

    Ochieng, C.A.; Onkware, A.O.

    1999-01-01

    Four rice cultivars (Basmati-217, BW-196, Sindano and Ita-310) were subjected to increasing substrate salinity (0-1.5 Sm -1 ECe), under both laboratory and soil experiments. The salt stress significantly (P -1 ECe) completely inhibited germination in potted soil, but not petri dish tests in the laboratory.It was concluded that the three rice cultivars are susceptible to even mild substrate salinity, and cannot be relied upon for cultivation in saline soils. There is a need to assess the response many of the rice cvv for resistance to salt stress, and, if possible isolate and develop high yielding, resistant cultivars

  19. Efficacy of Chlorella pyrenoidosa and Scenedesmus abundans for Nutrient Removal in Rice Mill Effluent (Paddy Soaked Water).

    Science.gov (United States)

    Abinandan, S; Bhattacharya, Ribhu; Shanthakumar, S

    2015-01-01

    Microalgae are product of sustainable development owing to its ability to treat variety of wastewater effluents and thus produced biomass can serve as value added product for various commercial applications. This paper deals with the cultivation of microalgae species namely Chlorella pyrenoidosa and Scenedesmus abundans in rice mill effluent (i.e., paddy soaked water) for nutrient removal. In order to investigate the nutrient removal capability, microalgae are subjected to cultivation in both raw and autoclaved samples. The maximum phosphate removal by Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 98.3% and 97.6%, respectively, whereas, the removal of ammoniacal nitrogen by Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 92% and 90.3%, respectively. The growth (measured in terms of chlorophyll content) of Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 3.88 mg/l and 5.55 mg/l, respectively. The results indicate the suitability of microalgae cultivation in rice mill effluent treatment for nutrient removal.

  20. Insect remote sensing using a polarization sensitive cw lidar system in chinese rice fields

    Directory of Open Access Journals (Sweden)

    Zhu Shiming

    2018-01-01

    Full Text Available A joint Chinese-Swedish field campaign of Scheimpflug continuous-wave lidar monitoring of rice-field flying pest insects was pursued in very hot July weather conditions close to Guangzhou, China. The occurrence of insects, birds and bats with almost 200 hours of round-the-clock polarization-sensitive recordings was studied. Wing-beat frequency recordings and depolarization properties were used for target classification. Influence of weather conditions on the flying fauna was also investigated.