Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation

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Haibing He

2014-01-01

Full Text Available Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM, furrow irrigation with nonmulching (FIN, and drip irrigation with plastic mulching (DI. Compared with the conventional flooding (CF treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN, lower maximum quantum yield (Fv/Fm, and lower effective quantum yield of PSII photochemistry (ΦPSII. And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC. Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.

Non-destructive neutron activation analysis studies on a withering disease of lowland rice occurring near an iodine plant

International Nuclear Information System (INIS)

Fukuzaki, N.; Moriyama, N.

1985-01-01

The withering disease of lowland rice that seems to be an injury caused by excess iodine was recognized in the paddy fields near an iodine isolation plant. To investigate the cause of this disease, a pot experiment of lowland rice was performed and iodine contents of soils and rice plants were determined by non-destructive neutron activation analysis. The soils of the disease-produced paddy fields were remarkably polluted with iodine, its content in roots of diseased rice plants was higher than the reported limiting values for the disease. (author)

Impacts of climate change on rice production in Africa and causes of simulated yield changes

NARCIS (Netherlands)

Oort, Van Pepijn A.J.; Zwart, Sander J.

2018-01-01

This study is the first of its kind to quantify possible effects of climate change on rice production in Africa. We simulated impacts on rice in irrigated systems (dry season and wet season) and rainfed systems (upland and lowland). We simulated the use of rice varieties with a higher temperature

[Effect of climate change on rice irrigation water requirement in Songnen Plain, Northeast China].

Science.gov (United States)

Huang, Zhi-gang; Wang, Xiao-li; Xiao, Ye; Yang, Fei; Wang, Chen-xi

2015-01-01

Based on meteorological data from China national weather stations and climate scenario grid data through regional climate model provided by National Climate Center, rice water requirement was calculated by using McCloud model and Penman-Monteith model combined with crop coefficient approach. Then the rice irrigation water requirement was estimated by water balance model, and the changes of rice water requirement were analyzed. The results indicated that either in historical period or in climate scenario, rice irrigation water requirement contour lines during the whole growth period and Lmid period decreased along southwest to northeast, and the same irrigation water requirement contour line moved north with decade alternation. Rice irrigation water requirement during the whole growth period increased fluctuantly with decade alternation at 44.2 mm . 10 a-1 in historical period and 19.9 mm . 10 a-1 in climate scenario. The increase in rice irrigation water requirement during the Lmid period with decade alternation was significant in historical period, but not significant in climate scenario. Contribution rate of climate change to rice irrigation water requirement would be fluctuantly increased with decade alternation in climate scenario. Compared with 1970s, contribution rates of climate change to rice irrigation water requirement were 23.6% in 2000s and 34.4% in 2040s, which increased 14.8 x 10(8) m3 irrigation water in 2000s and would increase 21.2 x 10(8) m3 irrigation water in 2040s.

The effect of irrigated rice cropping on the alkalinity of two alkaline rice soils in the Sahel

NARCIS (Netherlands)

Asten, van P.J.A.; Zelfde, van 't J.A.; Zee, van der S.E.A.T.M.; Hammecker, C.

2004-01-01

Irrigated rice cropping is practiced to reclaim alkaline-sodic soils in many parts of the world. This practice is in apparent contrast with earlier studies in the Sahel, which suggests that irrigated rice cropping may lead to the formation of alkaline-sodic soils. Soil column experiments were done

Cooking quality of upland and lowland rice characterized by different methods

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Diva Mendonça Garcia

2011-06-01

Full Text Available Rice cooking quality is usually evaluated by texture and stickiness characteristics using many different methods. Gelatinization temperature, amylose content, viscosity (Brookfield viscometer and Rapid Visco Analyzer, and sensory analysis were performed to characterize culinary quality of rice grains produced under two cropping systems and submitted to different technologies. All samples from the upland cropping system and two from the irrigated cropping system presented intermediate amylose content. Regarding stickiness, BRS Primavera, BRS Sertaneja, and BRS Tropical showed loose cooked grains. Irrigated cultivars presented less viscosity and were softer than upland cultivars. Upland grain samples had similar profile on the viscoamylografic curve, but the highest viscosity peaks were observed for BRS Alvorada, IRGA 417, and SCS BRS Piracema among the irrigated cropping system samples. In general, distinct grain characteristics were observed between upland and irrigated samples by cluster analysis. The majority of the upland cultivars showed soft and loose grains with adequate cooking quality confirmed by sensory tests. Most of the irrigated cultivars, however, presented soft and sticky grains. Different methodologies allowed to improve the construction of the culinary profile of the varieties studied.

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.

Use of azolla as a nitrogen source of lowland rice

International Nuclear Information System (INIS)

Sisworo, E.L.; Widjang, H.S.; Havid, S.; Hendratno; Soleh, S.; Goesworo, S.

1991-01-01

A four years experiment has been carried out to study possibility of using azolla as a nitrogen source for lowland rice. The work done in the first year, experiments were conducted in the wet season (WS) and the dry season (DS) of 1984/1985, was evaluate weather azolla could really increase rice yield. In the second year, experiments done in the WS and DS of 1985/1986, N-derived from azolla (N-dfA) and N-derived from urea (N-dfU) in rice plan were determined. The third year work done in the WS and DS of 1986/1987 was conducted to see what extend azolla could be applied in the terms of kg N/ha as a N-source for rice. While the last year was devoted to study the N-balance of azolla and urea, which was done in the DS of 1988/1989. Results of the experiments show that azolla has the same ability as urea to increase rice azolla interacted with urea. By increasing the azolla level N recovery in rice will decrease. The same phenomena was also found with urea. Another interesting fact is that an azolla cover in the rice field could promote N-uptake from urea. (author). 8 refs, 15 tabs

Agronomic efficiency and physiologic efficiency determination of Azolla-N and Urea-N applied to lowland rice

International Nuclear Information System (INIS)

Sisworo, Elsje L.; Rasjid, Havid; Sisworo, Widjang H.; Wemay, Johannis; Djawanas, Amrin

1994-01-01

Data from three field experiments using 15 N labelled Azolla and urea as an N source have been used to determine the agronomical and physiological efficiency of the N-Azoll and N-Urea applied tolowland rice. In general physiological efficiency of N from N-sources applied was lower than the agronomical efficiency. It seems that the increase of N-rates would enhance the agronomical and physiological efficiency of N applied to lowland rice but on the other hand the efficiency of N derived from the applied N-source decreased. Azolla+inorganic N-fertilizer when applied to lowland rice could increase rice yield expresses in dry weight of grain and straw above the control plants. Applying Azolla+inorganic N-fertilizer in the farmer's field located in West Java and West Sumatera often showed higher yields compared to when applied with inorganic N-fertilizer alone although the latter has higher total N-rates. (author). 9 refs, 8 tabs, 5 figs

Contamination of rice (Oryza sativa L) with Cadmium and Arsenic by irrigation with the Bogota River water in rice soils of the Lower Basin

International Nuclear Information System (INIS)

Montenegro, Omar; Mejia L

2001-01-01

In this study, field and greenhouse experiments were simultaneously carried out with rice (oryza sativa l., variedad oryzica-1) in soils of the Bogota River lower basin (Los Manueles Series, a member of the clayed, mixed, isohipertermic family of the Fluventic Vertic Haplustepts) to evaluate the effect of Cd and As content of the irrigation waters (of the Bogota River and greenhouse) on soils and: 1) rice growth physiological parameters; 2) Cd and As accumulated in different parts of rice plants; 3) yields and other aspects and properties of rice crop. The results lead to the following conclusions: 1) The Cd and As content of the Bogota River water, increased during the driest months and was minimum in those with the highest precipitation; Cd and As concentrations in both seasons surpassed the maximum permissible limits. 2) Rice height was highest when irrigation water does have neither Cd nor As. Effects of both elements showed an inverse lineal tendency. 3) The gradual increase of Cd in irrigation water reduced in 12.5% the number of grains per panicle; the increase of As induced a 10% reduction. 4) The highest concentration of Cd and As in irrigation waters significantly reduced yields; maximum yields l were obtained when Cd and As were absent from irrigation waters. 5) For any concentration of As in irrigation water the highest concentration of Cd was accumulated in rice leafs when concentration of Cd 2 was 2mg/l; above this value Cd accumulation in leafs el decreased with the gradual increase of As concentration. 6) Cd and As accumulated in rice grains increased with the gradual increment of both elements in the irrigation waters; Cd and As accumulated were respectively 50 and 15 times higher than the maximum critical levels proposed for rice grains. 7) Cd and As accumulated progressively on soils with gradual increase of both elements in irrigation waters 8) Cd and As concentration in irrigation waters apparently does not affect the rice mill behavior

Yield loss and economic thresholds of yellow nutsedge in irrigated rice as a function of the onset of flood irrigation

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Nixon da Rosa Westendorff

2014-03-01

Full Text Available Yellow nutsedge (Cyperus esculentus is adapted to flooding and reduces yield in irrigated rice. Information on the competitive ability of this weed with the crop and the size of the economic damage caused is lacking. Mathematical models quantify the damage to crops and support control decision-making. This study aimed to determine yield losses and economic thresholds (ET of this weed in the culture according to weed population and time of onset of irrigation of the crop. The field study was conducted in the agricultural year of 2010/2011 in Pelotas/RS to evaluate the competitive ability of BRS Querência in competition with different population levels of yellow nutsedge and two periods of onset of flood irrigation (14 and 21 days after emergence. The hyperbolic model satisfactorily estimated yield losses caused by yellow nutsedge. Population of yellow nutsedge was the variable most fitted to the model. The delay of seven days for the beginning of rice irrigation causes decrease in competitive ability of BRS Querência, and based on the ET calculated to the price paid for rice, it is necessary between two and thirteen plants m-2 weed to justify the control in the first and second period of irrigation, respectively. Increases in yield, price paid for rice and control efficiency of the herbicide, besides reduction of costs of controlling promote reduction of ET of yellow nutsedge in rice crops, justifying the adoption of control measures even at smaller weed population.

land evaluation for improved rice production in watari irrigation

African Journals Online (AJOL)

DR. AMINU

This study aimed at raising irrigated rice production in Watari Irrigation scheme, in Kano state, as to bridge the gap ... land including details about maintenance and ... Area of Kano state and cover a total of 4,574 .... which requires a depth of more than 50cm for efficient .... raise the productivity of the soils to optimum for.

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

Assessment of Genetic Variation and Population Structure of Diverse Rice Genotypes Adapted to Lowland and Upland Ecologies in Africa Using SNPs

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Marie Noelle Ndjiondjop

2018-04-01

Full Text Available Using interspecific crosses involving Oryza glaberrima Steud. as donor and O. sativa L. as recurrent parents, rice breeders at the Africa Rice Center developed several ‘New Rice for Africa (NERICA’ improved varieties. A smaller number of interspecific and intraspecific varieties have also been released as ‘Advanced Rice for Africa (ARICA’. The objective of the present study was to investigate the genetic variation, relatedness, and population structure of 330 widely used rice genotypes in Africa using DArTseq-based single nucleotide polymorphisms (SNPs. A sample of 11 ARICAs, 85 NERICAs, 62 O. sativa spp. japonica, and 172 O. sativa spp. indica genotypes were genotyped with 27,560 SNPs using diversity array technology (DArT-based sequencing (DArTseq platform. Nearly 66% of the SNPs were polymorphic, of which 15,020 SNPs were mapped to the 12 rice chromosomes. Genetic distance between pairs of genotypes that belong to indica, japonica, ARICA, and NERICA varied from 0.016 to 0.623, from 0.020 to 0.692, from 0.075 to 0.763, and from 0.014 to 0.644, respectively. The proportion of pairs of genotypes with genetic distance > 0.400 was the largest within NERICAs (35.1% of the pairs followed by ARICAs (18.2%, japonica (17.4%, and indica (5.6%. We found one pair of japonica, 11 pairs of indica, and 35 pairs of NERICA genotypes differing by <2% of the total scored alleles, which was due to 26 pairs of genotypes with identical pedigrees. Cluster analysis, principal component analysis, and the model-based population structure analysis all revealed two distinct groups corresponding to the lowland (primarily indica and lowland NERICAs and upland (japonica and upland NERICAs growing ecologies. Most of the interspecific lowland NERICAs formed a sub-group, likely caused by differences in the O. glaberrima genome as compared with the indica genotypes. Analysis of molecular variance revealed very great genetic differentiation (FST = 0.688 between the

Assessment of Genetic Variation and Population Structure of Diverse Rice Genotypes Adapted to Lowland and Upland Ecologies in Africa Using SNPs.

Science.gov (United States)

Ndjiondjop, Marie Noelle; Semagn, Kassa; Sow, Mounirou; Manneh, Baboucarr; Gouda, Arnaud C; Kpeki, Sèdjro B; Pegalepo, Esther; Wambugu, Peterson; Sié, Moussa; Warburton, Marilyn L

2018-01-01

Using interspecific crosses involving Oryza glaberrima Steud. as donor and O. sativa L. as recurrent parents, rice breeders at the Africa Rice Center developed several 'New Rice for Africa (NERICA)' improved varieties. A smaller number of interspecific and intraspecific varieties have also been released as 'Advanced Rice for Africa (ARICA)'. The objective of the present study was to investigate the genetic variation, relatedness, and population structure of 330 widely used rice genotypes in Africa using DArTseq-based single nucleotide polymorphisms (SNPs). A sample of 11 ARICAs, 85 NERICAs, 62 O. sativa spp. japonica , and 172 O. sativa spp. indica genotypes were genotyped with 27,560 SNPs using diversity array technology (DArT)-based sequencing (DArTseq) platform. Nearly 66% of the SNPs were polymorphic, of which 15,020 SNPs were mapped to the 12 rice chromosomes. Genetic distance between pairs of genotypes that belong to indica, japonica, ARICA, and NERICA varied from 0.016 to 0.623, from 0.020 to 0.692, from 0.075 to 0.763, and from 0.014 to 0.644, respectively. The proportion of pairs of genotypes with genetic distance > 0.400 was the largest within NERICAs (35.1% of the pairs) followed by ARICAs (18.2%), japonica (17.4%), and indica (5.6%). We found one pair of japonica, 11 pairs of indica, and 35 pairs of NERICA genotypes differing by <2% of the total scored alleles, which was due to 26 pairs of genotypes with identical pedigrees. Cluster analysis, principal component analysis, and the model-based population structure analysis all revealed two distinct groups corresponding to the lowland (primarily indica and lowland NERICAs) and upland (japonica and upland NERICAs) growing ecologies. Most of the interspecific lowland NERICAs formed a sub-group, likely caused by differences in the O. glaberrima genome as compared with the indica genotypes. Analysis of molecular variance revealed very great genetic differentiation ( F ST = 0.688) between the lowland and upland

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

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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.

Yield-scaled global warming potential of two irrigation management systems in a highly productive rice system

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Silvana Tarlera

2016-02-01

Full Text Available ABSTRACT Water management impacts both methane (CH4 and nitrous oxide (N2O emissions from rice paddy fields. Although controlled irrigation is one of the most important tools for reducing CH4emission in rice production systems it can also increase N2O emissions and reduce crop yields. Over three years, CH4 and N2O emissions were measured in a rice field in Uruguay under two different irrigation management systems, using static closed chambers: conventional water management (continuous flooding after 30 days of emergence, CF30; and an alternative system (controlled deficit irrigation allowing for wetting and drying, AWDI. AWDI showed mean cumulative CH4 emission values of 98.4 kg CH4 ha−1, 55 % lower compared to CF30, while no differences in nitrous oxide emissions were observed between treatments ( p > 0.05. No yield differences between irrigation systems were observed in two of the rice seasons ( p > 0.05 while AWDI promoted yield reduction in one of the seasons ( p< 0.05. When rice yield and greenhouse gases (GHG emissions were considered together, the AWDI irrigation system allowed for lower yield-scaled total global warming potential (GWP. Higher irrigation water productivity was achieved under AWDI in two of the three rice seasons. These findings suggest that AWDI could be an option for reducing GHG emissions and increasing irrigation water productivity. However, AWDI may compromise grain yield in certain years, reflecting the importance of the need for fine tuning of this irrigation strategy and an assessment of the overall tradeoff between relationships in order to promote its adoption by farmers.

Towards a smart automated surface irrigation management in rice-growing areas in Italy

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Daniele Masseroni

2017-02-01

Full Text Available Italy is the leading rice producer in Europe, accounting for more than half of the total high-quality production of this crop. Rice is traditionally grown in fields that remain flooded starting with crop establishment until close to harvest, and this traditional irrigation technique (i.e., continuous submergence is recognised as an important water resource sink (almost 40% of the irrigation water available worldwide is used for paddy areas. Meanwhile, the water management in rice areas requires a high level of labour because it is based on maintaining a predetermined water height in paddy fields and because the regulation of input and output flow is typically operated manually by the farmer. This study reveals the hardware and software characteristics of an automated and remote controlled technology tested for the first time in a rice farm near Pavia (Italy, during the 2016 growing season, aiming at a more efficient and less burdensome irrigation management system for rice fields. A water level sensor in the field provides the data required to govern the inflow regulation gate in real-time, according to the precise time to cut off the flow rate. Using a dedicated web page, the farmer can control flows, volumes and water levels in the fields by operating directly on the gate if necessary or setting the irrigation program according to his agronomic practices.

Selectivity and weed control efficacy of some herbicides applied to sprinkler irrigated rice (Oryza sativa L.)

Energy Technology Data Exchange (ETDEWEB)

Cavero, J; Zaragoza, C; Cirujeda, A; Anzalone, A; Faci, J M; Blanco, O

2011-07-01

Sprinkler irrigation can reduce the irrigation water needed to grow rice. However, most available information on weed control with herbicides is related to flood irrigated rice because this is the main growing method. Field experiments were conducted at Zaragoza (Spain) during two years to study weed control and tolerance of sprinkler irrigated rice to several herbicides. The main weeds were Atriplex prostrata Boucher ex DC., Cyperus rotundus L., Echinochloa crus-galli (L.) Beauv. and Sonchus oleraceus L. Rice cv Guadiamar was tolerant to preemergence (PRE) application of clomazone at 0.36 kg ha{sup -}1 and oxadiazon at 0.5 kg ha{sup -}1. PRE application of pendimethalin at 1.32 kg ha{sup -}1 combined with clomazone at 0.36 kg ha{sup -}1 decreased rice yield. Postemergence (POST) application of bentazon at 1.6 kg ha{sup -}1 + MCPA at 0.25 kg ha{sup -}1 did not injure rice but POST application of azimsulfuron at 0.025 kg ha{sup -}1 produced visual crop injury. Only treatments that controlled grassy weeds since rice was planted and by more than 80% at harvest time lead to acceptable rice yield (> 5,000 kg ha{sup -}1). Clomazone applied PRE at 0.36 kg ha{sup -}1 provided good control of grassy weeds (> 80%) and the highest rice yield, so it is recommended as a selective and efficacious PRE treatment for weed control of annual weeds in sprinkler irrigated rice. The perennial purple nutsedge was difficult to control at high plant densities (> 150 plants m{sup -}2) and the recommended herbicide is azimsulfuron applied at POST at 0.02 kg ha{sup -}1. (Author) 37 refs.

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.

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.

Actual and potential salt-related soil degradation in an irrigated rice scheme in the Sahelian zone of Mauritania

NARCIS (Netherlands)

Asten, van P.J.A.; Barbi'ro, L.; Wopereis, M.C.S.; Maeght, J.L.; Zee, van der S.E.A.T.M.

2003-01-01

Salt-related soil degradation due to irrigation activities is considered a major threat to the sustainability of rice cropping under semi-arid conditions in West Africa. Rice productivity problems related to soil salinity, alkalinity and topographic position were observed in an irrigated rice scheme

Leaching and residual activity of imidazolinone herbicides in lowland soils

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João Paulo Refatti

Full Text Available ABSTRACT: Herbicides used in the Clearfield® rice (Oryza sativa L. production system have a potential for leaching. This can result in contamination of underground water resources and cause injury to not tolerant crops that are sown in a succession and/or crop rotation. The objective of this study was to determine the leaching potential and the residual activity of the herbicides used in the Clearfield® rice system. The experiment was conducted over a period of two years and consisted of conducting a field test to be followed by two bioassays with a year of difference between their implementation. Initially an experiment was conducted in lowland area where it was planted the cultivar of rice ‘PUITA INTA CL’. Approximately one and two years thereafter, soil samples from each plot were collected at intervals of 5cm to a depth of 30cm (B factor for the bioassay to evaluate persistence of herbicides. Factor A was composed of mixtures formulated of imazethapyr + imazapic (75 + 25g a.i. L-1, imazapyr + imazapic (525 + 175g a.i. kg-1 in two doses, imazethapyr (100g a.i. L-1 and treatment control without application. Basing on results, it was concluded that the mixtures imazethapyr + imazapic, imazapyr + imazapic and imazethapyr leached into the soil, reaching depths of up to 25cm in lowland soil. Imidazolinone herbicides used today in the irrigated rice Clearfield® system are persistent in soil, and their phytotoxic activity can be observed up to two years after application.

Effects of Furrow Irrigation on the Growth, Production, and Water Use Efficiency of Direct Sowing Rice

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Chunlin He

2010-01-01

Full Text Available Rice farming is the major crop production in Asia and is predicted to increase significantly in the near future in order to meet the demands for the increasing human population. Traditional irrigation methods used in rice farming often result in great water loss. New water-saving methods are urgently needed to reduce water consumption. Three field and pot experiments were conducted to evaluate the furrow irrigation (FI system to improve water use efficiency (WUE and production of direct sowing rice in southern China. Compared to the conventional irrigation (CI system (continuous flooding irrigation, for every square hectometer of rice field, the FI system reduced water use by 3130 m3, or 48.1%, and increased grain production by 13.9% for an early cultivar. For a late cultivar, the FI system reduced water use by 2655 m3, or 40.6%, and an increase of grain production by 12.1%. The improved WUE in the FI system is attributed to (1 a significant reduction of irrigation rate, seepage, evaporation, and evapotranspiration; (2 a significant reduction in the reduced materials, such as ferrous ion (Fe2+, and therefore an increase in the vitality of the root system, evident by the increases in the number of white roots by 32.62%, and decreases in the number of black roots by 20.04% and yellow roots by 12.58%; the use of the FI system may also reduce humidity of the rice field and enhance gas transport in the soil and light penetration, which led to reduced rice diseases and increased leaf vitality; and (3 increases in tiller and effective spikes by 11.53% and the weight per thousand grains by 1.0 g. These findings suggest that the shallow FI system is a promising means for rice farming in areas with increasing water shortages.

Effects of furrow irrigation on the growth, production, and water use efficiency of direct sowing rice.

Science.gov (United States)

He, Chunlin

2010-08-03

Rice farming is the major crop production in Asia and is predicted to increase significantly in the near future in order to meet the demands for the increasing human population. Traditional irrigation methods used in rice farming often result in great water loss. New water-saving methods are urgently needed to reduce water consumption. Three field and pot experiments were conducted to evaluate the furrow irrigation (FI) system to improve water use efficiency (WUE) and production of direct sowing rice in southern China. Compared to the conventional irrigation (CI) system (continuous flooding irrigation), for every square hectometer of rice field, the FI system reduced water use by 3130 m3, or 48.1%, and increased grain production by 13.9% for an early cultivar. For a late cultivar, the FI system reduced water use by 2655 m3, or 40.6%, and an increase of grain production by 12.1%. The improved WUE in the FI system is attributed to (1) a significant reduction of irrigation rate, seepage, evaporation, and evapotranspiration; (2) a significant reduction in the reduced materials, such as ferrous ion (Fe2+), and therefore an increase in the vitality of the root system, evident by the increases in the number of white roots by 32.62%, and decreases in the number of black roots by 20.04% and yellow roots by 12.58%; the use of the FI system may also reduce humidity of the rice field and enhance gas transport in the soil and light penetration, which led to reduced rice diseases and increased leaf vitality; and (3) increases in tiller and effective spikes by 11.53% and the weight per thousand grains by 1.0 g. These findings suggest that the shallow FI system is a promising means for rice farming in areas with increasing water shortages.

INVENTORY OF IRRIGATED RICE ECOSYSTEM USING POLARIMETRIC SAR DATA

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P. Srikanth

2012-08-01

Full Text Available An attempt has been made in the current study to assess the potential of polarimetric SAR data for inventory of kharif rice and the major competing crop like cotton. In the process, physical process of the scattering mechanisms occurring in rice and cotton crops at different phonological stages was studied through the use of temporal Radarsat 2 Fine quadpol SAR data. The temporal dynamics of the volume, double and odd bounce, entropy, anisotropy, alpha parameters and polarimertic signatures, classification through isodata clustering and Wishart techniques were assessed. The Wishart (H-a classification showed higher overall as well as rice and cotton crop accuracies compared to the isodata clustering from Freeman 3-component decomposition. The classification of temporal SAR data sets independently showed that the rice crop forecasting can be advanced with the use of appropriate single date polarimetric SAR data rather than using temporal SAR amplitude data sets with the single polarization in irrigated rice ecosystems

Influence of pH of acid irrigation water on the transfer of elements into rice plant from soils

International Nuclear Information System (INIS)

Maeno, Tomokazu; Tanizaki, Yoshiyuki

1996-01-01

Rice plant samples were grown in 14 cultivative pots under six different pH conditions of acid irrigation water (pH: 6.5, 6.0, 4.5, 3.5, 3.0. 2.5) and ion exchange water (pH: 7.5), in order to study an influence of pH of irrigation water on the transfer of elements into rice plant from soils. The acid irrigation water was prepared by adding mixed solution of 1N H 2 SO 4 and 1N HNO 3 (1:1) to ion exchange water. The rice grain yielded was separated into three parts, i.e., polished rice, bran and chaff and they were powdered one by one. The contents of twenty five elements in the three parts of grain (14 samples each) were determined by a neutron activation analysis. It was clarified that the contents of Cu, Zn, Fe, Cr, Mg, Rb, Mo, Ni, and Cs in the polished rice increased with decreasing pH of the acid irrigation water. The contents of Se and Br, on the contrary, decreased. Significant changes of the contents were not observed for Na, Al, Sc, Mn, Cl, Ca, V and Co. The relationships between the contents of elements in the bran or chaff and pH of the acid irrigation water were not so clear as the case of polished rice. The enrichment factor of trace elements from soils was calculated for the polished rice, bran and chaff The high enrichment of Cl, Mo, Zn, Se and Cu was observed in the polished rice. Manganese and Cr were concentrated more in the bran than in the polished rice. (author)

The rice agroecosystem of the MUDA irrigation scheme: an overview

International Nuclear Information System (INIS)

Ho Nai Kin

2002-01-01

The Green Revolution technologies were introduced to the Muda area of Malaysia in the late 1960s. These technological innovations have resulted in rapid modification of the crop habitat and triggered a chain reaction in the rice agroecosystem. The impact of these technologies on the pest flora and fauna are significant. Indiscriminate use of pesticides causes disruption of natural enemy equilibrium and other undesirable effects to the farmers and the rice environment. The main emphasis of this paper is focused on the interactions between the various biological factors such as pathogenic microorganisms, arthropods, gastropods, fishes, birds, rodents, weeds, and the physical factors in the rice agroecosystem. The impact of double cropping of rice, the provision of irrigation facilities, the changes of crop establishment methods, and the adoption of pesticides on the rice agroecosystem are found to have far reaching effects on the sustainability of rice production in the Muda area. (Author)

N-Urea Efficiency In Lowland Rice Applied With Azolla

International Nuclear Information System (INIS)

Rasjid, Havid; Sisworo, E.L.; Wemay, Y.; Sisworo, W.H.

2000-01-01

Two N-fertilizer experiments have been conducted using urea tablet and prill urea combined with Azolla application. Twelve treatments have been tested using 2 rice varieties namely Atomita-4 and IR-64. To enable the determination of N-urea efficiency 15 N labelled urea was used. The experiments were conducted in the dry and wet season (DS and WS) 1994/1995 at the experimental station, pusaka negara, Subang West Java. Data obtained from the two experiments showed that the highest N-urea efficiency was found in Atomita-4 applied with urea-tablet (DS=46,1%, WS= 35,8%). Letting the Azolla grow during one lowland rice growth period could increase the N-urea prill efficiency (±5%) compared when no azolla was applied. Apparently Atomita-4 could use N-urea more efficiently compared to IR-64, showing higher grain yield (atomita-4 DS=6.2 ton ha -1 WS=5.9 ton ha -1 ) vs IR-64 (DS=5.8 ton ha -1 , WS=5.3 ton ha -1 ). Decreasing the levels of TSP not influence to the urea efficiency at the DS and WS

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

Water Use and Crop Coefficients in Sprinkler Irrigated Rice

Directory of Open Access Journals (Sweden)

Antonino Spanu

Full Text Available Field experiments were carried out during the years 2002, 2004, 2005 and 2006 to analyze water-soil-atmosphere interactions in sprinkler irrigated rice. The research was carried out in Sardinia (39º 59’ N; 8º 40’ E, at altitude 15 m. The cultivars used in the experiments, respectively in 2002 and in 2004-2005-2006, were Irat 212 and Eurosis. In each year cultivars were subjected to the same crop management. Irrigation was applied since the emergence with the sprinkler method, taking into account the loss of water from ‘Class A’ pan evaporation. Soil water content was monitored at 0.10 m intervals until 1.00-m depth using a ‘Diviner 2000’ (Sentek. In 2002 seven irrigation scheduling treatments were compared. In 2004, 2005, 2006 irrigation treatments provided for optimal soil water conditions during the growing season. In 2002 the results highlighted: 1 0-0.20 m depth was the most important layer for crop water uptake and the best correlated layer with rice rough yield; 2 the positive relationship between yield and water supply was significant until 6500 m3 ha-1 of water applied. Further seasonal irrigation volumes did not increase significantly yield. In 2004, 2005 and 2006 the analysis of the soil water balance at different crop phenological stages allowed to estimate crop coefficients (Kc using the Penman-Monteith equation and the ‘Class A’ pan evaporation (Kcev. Kc varied over the three-year period on average from 0.90 to 1.07 and 0.97, respectively for the emergence-end of tillering, end of tillering-heading and heading-maturing periods, while crop coefficients as a ratio between maximum crop evapotranspiration (ETc and Epan, Kcev ranged from 0.78 to 0.92 and 0.81 for the same time periods.

Rice agroecosystem of the Muda irrigation scheme, Malaysia

International Nuclear Information System (INIS)

Nashriyah Mat; Ho Nai Kin; Ismail Sahid; Ahyaudin Ali; Lum Keng Yeang

1998-01-01

Pesticides have become one of the major components of modern farming practice. However, their usage needs to be properly carried out and regulated. Farmers need to be aware of the potential hazards arising out of improper use of pesticides, to them as well to the environment. This book presents the results of a comprehensive study on the impact of pesticide usage in the largest rice agroecosystem in Malaysia, the Muda Irrigation Scheme. The study, carried out by a group of local scientists, covers the impact of pesticide usage on biodiversity and bioresources (forest, weed, insect, fish and bird). In addition to farmers education, it shows the potential of crop establishment, irrigation method and double cropping of rice as useful factors that can be employed in minimizing the impact. The book also provides good foundation for future work and points out areas for further studies. It is a valuable reference to policy makers, researchers, regulators, agriculture-related agencies, chemical / fertilizer companies as well as those concerned with sustainable farming. The ecologists, chemists, biochemists, entomologists, zoologists, botanists, microbiologists, agronomists and medical practitioners involved in this study are congratulated for their efforts. (Nahrul Khair Alang Md Rashid)

Rice agroecosystem of the Muda irrigation scheme, Malaysia

Energy Technology Data Exchange (ETDEWEB)

Mat, Nashriyah [Malaysian Institute for Nuclear Technology Research MINT, Bangi (Malaysia); Kin, Ho Nai [Muda Agricultural Development Authority MADA, Alor Setar (Malaysia); Sahid, Ismail [Universiti Kebangsaan Malaysia, Bangi (Malaysia); Ali, Ahyaudin [Universiti Sains Malaysia, Penang (Malaysia); Yeang, Lum Keng [Malaysian Agricultural Research and Development Institute, Serdang (Malaysia)

1998-07-01

Pesticides have become one of the major components of modern farming practice. However, their usage needs to be properly carried out and regulated. Farmers need to be aware of the potential hazards arising out of improper use of pesticides, to them as well to the environment. This book presents the results of a comprehensive study on the impact of pesticide usage in the largest rice agroecosystem in Malaysia, the Muda Irrigation Scheme. The study, carried out by a group of local scientists, covers the impact of pesticide usage on biodiversity and bioresources (forest, weed, insect, fish and bird). In addition to farmers education, it shows the potential of crop establishment, irrigation method and double cropping of rice as useful factors that can be employed in minimizing the impact. The book also provides good foundation for future work and points out areas for further studies. It is a valuable reference to policy makers, researchers, regulators, agriculture-related agencies, chemical / fertilizer companies as well as those concerned with sustainable farming. The ecologists, chemists, biochemists, entomologists, zoologists, botanists, microbiologists, agronomists and medical practitioners involved in this study are congratulated for their efforts. (Nahrul Khair Alang Md Rashid)

Adubarroz: a brazilian experience for fertilization and liming recommendation of irrigated rice via computational system

Directory of Open Access Journals (Sweden)

Felipe de Campos Carmona

Full Text Available ABSTRACT: Recommendations for fertilizing irrigated rice in southern Brazil have been constantly evolving over years. In this process, the influence of factors such as the development cycle of varieties and sowing period increased. Thus, computational tools that take these and others important aspects into account can potentiate the fertilization response of rice. This study describes the computer program "ADUBARROZ". The software provides recommendations of fertilizer rates and liming requirements of irrigated rice, based on information entered by the user. The system takes various factors that regulate the crop response to fertilization into account. A final report is established with the graphical representation of input management over time.

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

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

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)

The effect of toposequence position on soil properties, hydrology, and yield of rainfed lowland rice in Southeast Asia

NARCIS (Netherlands)

Boling, A.A.; Tuong, T.P.; Suganda, H.; Konboon, Y.; Harnpichitvitaya, D.; Bouman, B.A.M.; Franco, D.T.

2008-01-01

large proportion of rainfed lowland rice in Southeast Asia is grown in gently sloping areas along toposequences with differences in elevation of a few meters. These small differences in elevation can lead to differentiation in soil properties and hydrological conditions, which in turn may affect

Scaling up Intermittent Rice Irrigation for Malaria Control on the ...

International Development Research Centre (IDRC) Digital Library (Canada)

The water used for rice farming is a breeding ground for malarial mosquitoes that ... climate variability and change are threatening the sources of irrigation water and ... skills (farmer-to-farmer agricultural extension); - assess and document social, ... Adaptation strategies for two Colombian cities were discussed at ADAPTO's ...

The Contribution of Azolla and Urea in Lowland Rice Growth Production for Three Consecutive Seasons

International Nuclear Information System (INIS)

E-L-Sisworo; H-Rasjid; Haryanto; Idawati

2008-01-01

Three field experiments have been carried out in three consecutive seasons namely wet season (120 days), dry season (120 days), wet season (120 days) at Pusakanegara. The purpose of this experiment is to test whether urea combined with Azolla could increase lowland rice production and soil quality. The experimental plots have a size of 20 m 2 and in each experimental plot an isotope plot was placed with a size of 1 m 2 . The isotope plots were used to apply labeled 15 N urea. Treatments conducted were lowland varieties: Atomita I (V1) and IR-64 (V2); several levels of urea and Azolla : Pu1 urea-tablets + an Azolla cover (Azc), Pu2 = urea-tablets + Azolla incorporated (Azi ), Pu3 = urea-prill + Azc , Pu4 = urea-prill + Azi; seasons : Ss 1 = wet season, Ss2 = dry season, Ss3 = wet season. The experimental design used was a factorial experiment in a Randomized Block Design, where each treatment was replicated four times. Parameters used were, dry weight of straw (St), grain (G), plant (P1 = St + G) in kg/ha; N-total percentage (% N-to) of St and G, percentage N-derived from urea + Az (% N-Pu) of St and G; percentage N-derived from soil (% N-S) of St and G; uptake of N-Pu and N-S in St, G and P1. Some results of these experiment were, N-Pu play a less important role in growth of lowland crop expressed in several parameters compared to N-soil. The form of N-urea in tablets are superior to that the form of urea in prills. For the last product of lowland rice which is grain obviously V1 (Atomita-1) is better than V2 (IR-64) expressed in t/ha. The progress of seasons showed clearly that there is an N accumulation which might be the increase of soil organic matter (SOM) and that means there is an increase in soil quality in the view point of N. (author)

The Contribution of Azolla and Urea in Lowland Rice Growth Production for Three Consecutive Seasons

Directory of Open Access Journals (Sweden)

EL. Sisworo

2008-01-01

Full Text Available Three field experiments have been carried out in three consecutive seasons namely wet season (120 days, dry season (120 days, wet season (120 days at Pusakanegara. The purpose of this experiment is to test whether urea combined with Azolla could increase lowland rice production and soil quality. The experimental plots have a size of 20 m2 and in each experimental plot an isotope plot was placed with a size of 1 m2. The isotope plots were used to apply labeled 15N urea. Treatments conducted were lowland varieties: Atomita I (V1 and IR-64 (V2; several levels of urea and Azolla : Pu1 = urea-tablets + an Azolla cover (Azc, Pu2 = urea-tablets + Azolla incorporated (Azi , Pu3 = urea-prill + Azc , Pu4 = urea-prill + Azi; seasons : Ss 1 = wet season, Ss2 = dry season, Ss3 = wet season. The experimental design used was a factorial experiment in a Randomized Block Design, where each treatment was replicated four times. Parameters used were, dry weight of straw (St, grain (G, plant (P1 = St + G in kg/ha; N-total percentage (% N-to of St and G, percentage N-derived from urea + Az (% N-Pu of St and G; percentage N-derived from soil (% N-S of St and G; uptake of N-Pu and N-S in St, G and P1. Some results of these experiment were, N-Pu play a less important role in growth of lowland crop expressed in several parameters compared to N-soil. The form of N-urea in tablets are superior to that the form of urea in prills. For the last product of lowland rice which is grain obviously V1 (Atomita-1 is better than V2 (IR-64 expressed in t/ha. The progress of seasons showed clearly that there is an N accumulation which might be the increase of soil organic matter (SOM and that means there is an increase in soil quality in the view point of N

Growth and Physiological Performance of Aerobic and Lowland Rice as Affected by Water Stress at Selected Growth Stages

Directory of Open Access Journals (Sweden)

Nadzariah Kamarul Zaman

2018-03-01

Full Text Available Aerobic rice technology is still new in Malaysia, and information regarding MARDI Aerob 1 (MA1, the first local aerobic rice variety, is still lacking. Therefore, comparative studies were carried out to determine the physiological performance of aerobic rice variety MA1 and lowland rice variety MR253 under water stress given at the panicle initiation, flowering and ripening stages. This experiment was arranged in a randomized complete block design. Stomatal conductance (gs, chlorophyll a fluorescence (Fv/Fm, leaf relative water content (leaf RWC, and soil moisture content (SMC as well as yield component parameters such as panicle number, grain yield and 100-grain weight were measured. Results revealed that gs and leaf RWC for both varieties decreased with depletion of SMC. The correlation study between the physiological parameters and SMC indicated that Fv/Fm was not affected by water stress, regardless of varieties. The yield components (panicle number, grain yield and 100-grain weight for both varieties greatly decreased when water stress was imposed at the panicle initiation stage. This study showed that the panicle initiation period was the most sensitive stage to water stress that contributed to a substantial reduction in yield for both varieties. Under the aerobic condition (control, MR253 produced higher panicle number, 100-grain weight and yield than MA1. Although MR253 is bred for lowland, it is well adapted to aerobic condition.

Soil salinization processes in rice irrigation schemes in the Senegal River Delta

International Nuclear Information System (INIS)

Ceuppens, J.; Wopereis, M.C.S.; Miezan, K.M.

1997-01-01

Soil salinization constitutes a major threat to irrigated agriculture (mainly rice, Oryza sativa L.) in the Senegal River Delta. It is generally hypothesized that salinization is caused by (i) capillary rise from a saline water table and (ii) concentration of salts in the field due to lack of adequate drainage facilities. The impact of field water management and rice cropping intensity on salinization in the Delta was determined using an electromagnetic conductivity meter (Geonics EM38). More than 4000 measurements were made in 40 rice fields on a typical heavy clay soil (Vertic Xerofluvent). Thirty EM38 measurements per field (0.25 ha) estimated average field soil salinity with a relative error of 20%. A multiple linear regression model based on EM38 readings explained 60 to 75% of the variability in conductivity of 1:5 saturation extracts at 0- to 5-, 10- to 15-, and 30- to 35-cm depths. Higher cropping intensity limited upward salt transport from the water table. Average horizontal and vertical EM38 measurements increased in the following order two rice crops per year with drainage: 0.73 and 0.98 dS m -1 ; one rice crop per year with drainage: 1.26 and 1.76 dS m -1 ; one rice crop per year without drainage: 2.23 and 2.98 dS m -1 ; and abandoned fields: 4.77 and 4.29 dS m -1 . Results indicate a beneficial effect of flooded rice on salinity for this type of heavy clay soil. Irrigation development in the area needs to be accompanied by monitoring of water table depth. (author)

Temporal changes of radiocesium in irrigated paddy fields and its accumulation in rice plants in Fukushima.

Science.gov (United States)

Yang, Baolu; Onda, Yuichi; Wakiyama, Yoshifumi; Yoshimura, Kazuya; Sekimoto, Hitoshi; Ha, Yiming

2016-01-01

About half of the total paddy field area, which is the dominant agricultural land in Fukushima Prefecture, was contaminated by radiocesium released by the Fukushima Daiichi Nuclear Power Plant accident. In this study, we investigated the temporal changes of radiocesium in soil, irrigation water, and rice plant in two adjacent rice paddies, with and without surface-soil-removal, in Fukushima Prefecture for over three years (2012-2014) after the nuclear accident. Our results showed that radiocesium migrated into 24-28 cm soil layers and that the activity concentration of radiocesium in paddy soils showed a significant reduction in 2014. The newly added radiocesium to paddies through irrigation water contributed only a maximum value of 0.15% and 0.75% of the total amount present in control and decontaminated paddies, respectively, throughout the study period. The radiocesium activity concentration in suspended sediment in irrigation water exponentially decreased, and the effective half-lives (Teff) for (137)Cs and (134)Cs were 1.3 and 0.9 years, respectively. Additionally, the average suspended sediment concentration in irrigation water increased between 2012 and 2014, suggesting that enhanced soil erosion had occurred in the surrounding environment. Radiocesium accumulation in rice plant also decreased with time in both paddies. However, the concentration ratio of radiocesium for rice plant in the decontaminated paddy increased compared with control paddy, despite approximately 96% of fallout radiocesium removed in paddy soil. Further analysis is required to clarify the reasons of high concentration ratio of radiocesium for rice plant in the decontaminated paddy. Copyright © 2015 Elsevier Ltd. All rights reserved.

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...

Effect of saline irrigation water on yield and yield components of rice ...

African Journals Online (AJOL)

vaio

2013-05-29

May 29, 2013 ... levels at different growth stages of rice on yield and its components. Treatments included ... Therefore, irrigation with saline water at the early growth stages has more negative effect on ...... diversification. Land Degrad. Dev.

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

Impacts of climate change on rice production in Africa and causes of simulated yield changes.

Science.gov (United States)

van Oort, Pepijn A J; Zwart, Sander J

2018-03-01

This study is the first of its kind to quantify possible effects of climate change on rice production in Africa. We simulated impacts on rice in irrigated systems (dry season and wet season) and rainfed systems (upland and lowland). We simulated the use of rice varieties with a higher temperature sum as adaptation option. We simulated rice yields for 4 RCP climate change scenarios and identified causes of yield declines. Without adaptation, shortening of the growing period due to higher temperatures had a negative impact on yields (-24% in RCP 8.5 in 2070 compared with the baseline year 2000). With varieties that have a high temperature sum, the length of the growing period would remain the same as under the baseline conditions. With this adaptation option rainfed rice yields would increase slightly (+8%) but they remain subject to water availability constraints. Irrigated rice yields in East Africa would increase (+25%) due to more favourable temperatures and due to CO2 fertilization. Wet season irrigated rice yields in West Africa were projected to change by -21% or +7% (without/with adaptation). Without adaptation irrigated rice yields in West Africa in the dry season would decrease by -45% with adaptation they would decrease significantly less (-15%). The main cause of this decline was reduced photosynthesis at extremely high temperatures. Simulated heat sterility hardly increased and was not found a major cause for yield decline. The implications for these findings are as follows. For East Africa to benefit from climate change, improved water and nutrient management will be needed to benefit fully from the more favourable temperatures and increased CO2 concentrations. For West Africa, more research is needed on photosynthesis processes at extreme temperatures and on adaptation options such as shifting sowing dates. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

The role of phosphorus sources in the growth of lowland rice plant

International Nuclear Information System (INIS)

Sisworo, Widjang Herry

1975-01-01

The role of phosphorus sources in the growth of lowland rice plant was studied using P 32 -labelled superphosphate. The experiment was carried out in the glass house. Three high yielding rice varieties used in the experiment were PB 5, IR 22 and Pelita I/1. Results obtained from the experiment showed that, during early growth, seedlings in the nursery did not require any phosphorus from outside. The phosphorus needed was apparently supplied by the seeds themselves. After 10 days seedlings started using phosphorus from outside the plants. Phosphorus in the plants derived from fertilizer reached 5-12% at 16 days old and 25-40% at transplanting time depending on the varieties. Higher response to phosphorus application in the nursery was given by Pelita I/1, the phosphorus in the plants derived from fertilizer was 40% at transplanting time. The phosphorus requirement was mostly supplied by the application of phosphorus fertilizer till 20 days after transplanting but after 40 days soil-phosphorus became the main source for the plants. (author)

Effects of compost on soil fertility in irrigated rice growing at Kou ...

African Journals Online (AJOL)

Effects of compost on soil fertility in irrigated rice growing at Kou Valley (Burkina Faso) : Amélioration de la fertilité du sol par utilisation du compost en riziculture irriguée dans la Vallée du Kou au Burkina Faso.

Soil quality and rice productivity problems in Sahelian irrigation schemes

NARCIS (Netherlands)

Asten, van P.J.A.

2003-01-01

In irrigation schemes in theSahel, rice yields and cropping

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.

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.

Rice production with less irrigation water is possible in a Sahelian environment

NARCIS (Netherlands)

Vries, de M.E.; Rodenburg, J.; Bado, B.V.; Sow, A.; Leffelaar, P.A.; Giller, K.E.

2010-01-01

We investigated the possibility of saving irrigation water in rice production in a Sahelian environment with different nitrogen rates and weed control treatments. A series of field experiments was conducted at Ndiaye (shallow water table, dry and wet season) and at Fanaye (deep water table, wet

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.

Manejo de água e de fertilizante potássico na cultura de arroz irrigado Water and potassium fertilization management for irrigated rice cultivation

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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

IMPROVEMENT OF RICE GROWTH AND PRODUCTIVITY THROUGH BALANCE APPLICATION OF INORGANIC FERTILIZER AND BIOFERTILIZER IN INCEPTISOL SOIL OF LOWLAND SWAMP AREA

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Neni Marlina

2014-02-01

Full Text Available The objective of this study was to obtain a proper balance dose between biofertilizer and inorganic fertilizer in order to increase the growth and yield of rice in Inceptisol soil of lowland swamp origin. Biofertilizer was made by enriching straw compost with N2 interceptor bacteria, phosphate solvent bacteria and growth stimulator bacteria isolated from swamp lowland in South Sumatra. This study was conducted from November 2012 to March 2013 in a greenhouse. The design used was completely randomized design (CRD factorial, with two treatment factors consisting of inorganic fertilizer (0,25, 50, 75 and 100% recommended dosage and biofertilizer (0, 100, 200, 300, 400 and 500 kg.ha-1. The results showed that the best treatment in term of plant height at 8 weeks after planting (WAP, the maximum number of tillers, number of productive tillers, number of grains per panicle and weight of milled dry rice were obtained in combination of 75% inorganic fertilizer and 300 - 400 kg.ha-1biofertilizer.

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

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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.

Irrigation with oxygen-nanobubble water can reduce methane emission and arsenic dissolution in a flooded rice paddy

Science.gov (United States)

Minamikawa, Kazunori; Takahashi, Masayoshi; Makino, Tomoyuki; Tago, Kanako; Hayatsu, Masahito

2015-08-01

A remarkable feature of nanobubbles (pot experiment and measuring redox-related variables. The NBs were introduced into control water (with properties similar to those of river water) using a commercially available generator. Rice (Oryza sativa L.) growth did not differ between plants irrigated with NB water and those irrigated with control water, but NB water significantly (p rice-growing season by 21%. The amounts of iron, manganese, and arsenic that leached into the drainage water before full rice heading were also reduced by the NB water. Regardless of the water type, weekly-measured CH4 flux was linearly correlated with the leached iron concentration during the rice-growing season (r = 0.74, p pots without rice plants, soil reduction was not enhanced, regardless of the water type. The results indicate that NB water reduced CH4 emission and arsenic dissolution through an oxidative shift of the redox conditions in the flooded soil. We propose the use of NB water as a tool for controlling redox conditions in flooded paddy soils.

Effects of water-saving irrigation on emissions of greenhouse gases and prokaryotic communities in rice paddy soil.

Science.gov (United States)

Ahn, Jae-Hyung; Choi, Min-Young; Kim, Byung-Yong; Lee, Jong-Sik; Song, Jaekyeong; Kim, Gun-Yeob; Weon, Hang-Yeon

2014-08-01

The effects of water-saving irrigation on emissions of greenhouse gases and soil prokaryotic communities were investigated in an experimental rice field. The water layer was kept at 1-2 cm in the water-saving (WS) irrigation treatment and at 6 cm in the continuous flooding (CF) irrigation treatment. WS irrigation decreased CH(4) emissions by 78 % and increased N(2)O emissions by 533 %, resulting in 78 % reduction of global warming potential compared to the CF irrigation. WS irrigation did not affect the abundance or phylogenetic distribution of bacterial/archaeal 16S rRNA genes and the abundance of bacterial/archaeal 16S rRNAs. The transcript abundance of CH(4) emission-related genes generally followed CH(4) emission patterns, but the difference in abundance between mcrA transcripts and amoA/pmoA transcripts best described the differences in CH(4) emissions between the two irrigation practices. WS irrigation increased the relative abundance of 16S rRNAs and functional gene transcripts associated with Anaeromyxobacter and Methylocystis spp., suggesting that their activities might be important in emissions of the greenhouse gases. The N(2)O emission patterns were not reflected in the abundance of N(2)O emission-related genes and transcripts. We showed that the alternative irrigation practice was effective for mitigating greenhouse gas emissions from rice fields and that it did not affect the overall size and structure of the soil prokaryotic community but did affect the activity of some groups.

Arsenic accumulation in rice: Consequences of rice genotypes and management practices to reduce human health risk.

Science.gov (United States)

Islam, Shofiqul; Rahman, Mohammad Mahmudur; Islam, M R; Naidu, Ravi

2016-11-01

Rice is an essential staple food and feeds over half of the world's population. Consumption of rice has increased from limited intake in Western countries some 50years ago to major dietary intake now. Rice consumption represents a major route for inorganic arsenic (As) exposure in many countries, especially for people with a large proportion of rice in their daily diet as much as 60%. Rice plants are more efficient in assimilating As into its grains than other cereal crops and the accumulation may also adversely affect the quality of rice and their nutrition. Rice is generally grown as a lowland crop in flooded soils under reducing conditions. Under these conditions the bioavailability of As is greatly enhanced leading to excessive As bioaccumulation compared to that under oxidizing upland conditions. Inorganic As species are carcinogenic to humans and even at low levels in the diet pose a considerable risk to humans. There is a substantial genetic variation among the rice genotypes in grain-As accumulation as well as speciation. Identifying the extent of genetic variation in grain-As concentration and speciation of As compounds are crucial to determining the rice varieties which accumulate low inorganic As. Varietal selection, irrigation water management, use of fertilizer and soil amendments, cooking practices etc. play a vital role in reducing As exposure from rice grains. In the meantime assessing the bioavailability of As from rice is crucial to understanding human health exposure and reducing the risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

Towards Global Simulation of Irrigation in a Land Surface Model: Multiple Cropping and Rice Paddy in Southeast Asia

Science.gov (United States)

Beaudoing, Hiroko Kato; Rodell, Matthew; Ozdogan, Mutlu

2010-01-01

Agricultural land use significantly influences the surface water and energy balances. Effects of irrigation on land surface states and fluxes include repartitioning of latent and sensible heat fluxes, an increase in net radiation, and an increase in soil moisture and runoff. We are working on representing irrigation practices in continental- to global-scale land surface simulation in NASA's Global Land Data Assimilation System (GLDAS). Because agricultural practices across the nations are diverse, and complex, we are attempting to capture the first-order reality of the regional practices before achieving a global implementation. This study focuses on two issues in Southeast Asia: multiple cropping and rice paddy irrigation systems. We first characterize agricultural practices in the region (i.e., crop types, growing seasons, and irrigation) using the Global data set of monthly irrigated and rainfed crop areas around the year 2000 (MIRCA2000) dataset. Rice paddy extent is identified using remote sensing products. Whether irrigated or rainfed, flooded fields need to be represented and treated explicitly. By incorporating these properties and processes into a physically based land surface model, we are able to quantify the impacts on the simulated states and fluxes.

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)

Side-effects of pesticides used in irrigated rice areas on Telenomus podisi Ashmead (Hymenoptera: Platygastridae).

Science.gov (United States)

Pazini, Juliano de Bastos; Pasini, Rafael Antonio; Seidel, Enio Júnior; Rakes, Matheus; Martins, José Francisco da Silva; Grützmacher, Anderson Dionei

2017-08-01

Telenomus podisi Ashmead (Hymenoptera: Platygastridae) is an important agent for the biological control of stink bug eggs in irrigated rice areas and the best strategy for its preservation is the use of selective pesticides. The aim of this study was to know the side-effects of pesticides used in Brazilian irrigated rice areas on egg parasitoid T. podisi. We evaluated, under laboratory conditions, 13 insecticides, 11 fungicides, 11 herbicides, and a control (distilled water) in choice and no-choice tests. In the no-choice tests, the pesticides were sprayed at pre and post-parasitism stages (egg and larval stages of T. podisi). In the choice tests, sprays were conducted only at pre-parasitism stages. For all tests, we prepared cards with 25 eggs of the alternative host Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) non-parasitized (pre-parasitism) and parasitized (post-parasitism), which were subjected to pesticide sprays. The parasitism and emergence rates of T. podisi were determined classifying the pesticides in terms of the reduction of parasitism or emergence rates compared to the control. The neurotoxic insecticide cypermethrin, lambda-cyhalothrin, zeta-cypermethrin, etofenprox, thiamethoxam, thiamethoxam + lambda-cyhalothrin, acetamiprid + alpha-cypermethrin, and bifenthrin + alpha-cypermethrin + carbosulfan were more harmful to T. podisi and, therefore, are less suitable for the integrated management of insect pests in irrigated rice areas.

Analysis of energy consumption in lowland rice-based cropping system of Malaysia

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Chan Chee Wan

2005-07-01

Full Text Available Sufficient energy is needed in the right form and at the right time for adequate crop production. One way to optimize energy consumption in agriculture is to determine the efficiency of methods and techniques used. With the current increase in world population, energy consumption needs effective planning. That is, the input elements need to be identified in order to prescribe the most efficient methods for controlling them. This study was undertaken in order to determine the direct and indirect energy consumption of field operations in a lowland rice production system of Malaysia. Field time, fuel and other energy requirements were measured for the tillage, planting, fertilizing, spraying and harvesting operations performed. Energy analysis carried out revealed the highest average operational energy consumption was for tillage (1747.33 MJ ha-1 which accounted for about 48.6% of the total operational energy consumption (3595.87 MJ ha-1, followed by harvesting (1171.44 MJ ha-1, 32.6% and planting (562.91 MJ ha-1, 15.7%. Fertilizing and pesticide spraying did not make any significant contributions to the operational energy consumption. Based on energy sources, fuel was the main consumer of direct energy with 2717.82 MJha-1 (22.2%, and fertilizer recording the highest indirect energy consumption of 7721.03 MJha-1 (63.2%. Human labour, pesticides, seeds and indirect energy for machinery use had marginal importance, contributing only 0.2%, 0.6%, 6.8% and 6.9%, respectively to the total energy consumption (12225.97 MJha-1. Average grain yield was 6470.8 kg ha-1, representing energy output of 108321.75 MJha-1, that is, 96095.78 MJ net energy gain or 8.86 MJ output per MJ input. Energy input per kilogram grain yield was 1.89 MJkg-1. The results of the study indicate energy gain in the lowland rice production system of Malaysia.

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.

Increasing water productivity, nitrogen economy, and grain yield of rice by water saving irrigation and fertilizer-N management.

Science.gov (United States)

Aziz, Omar; Hussain, Saddam; Rizwan, Muhammad; Riaz, Muhammad; Bashir, Saqib; Lin, Lirong; Mehmood, Sajid; Imran, Muhammad; Yaseen, Rizwan; Lu, Guoan

2018-06-01

The looming water resources worldwide necessitate the development of water-saving technologies in rice production. An open greenhouse experiment was conducted on rice during the summer season of 2016 at Huazhong Agricultural University, Wuhan, China, in order to study the influence of irrigation methods and nitrogen (N) inputs on water productivity, N economy, and grain yield of rice. Two irrigation methods, viz. conventional irrigation (CI) and "thin-shallow-moist-dry" irrigation (TSMDI), and three levels of nitrogen, viz. 0 kg N ha -1 (N 0 ), 90 kg N ha -1 (N 1 ), and 180 kg N ha -1 (N 2 ), were examined with three replications. Study data indicated that no significant water by nitrogen interaction on grain yield, biomass, water productivity, N uptake, NUE, and fertilizer N balance was observed. Results revealed that TSMDI method showed significantly higher water productivity and irrigation water applications were reduced by 17.49% in TSMDI compared to CI. Thus, TSMDI enhanced root growth and offered significantly greater water saving along with getting more grain yield compared to CI. Nitrogen tracer ( 15 N) technique accurately assessed the absorption and distribution of added N in the soil crop environment and divulge higher nitrogen use efficiency (NUE) influenced by TSMDI. At the same N inputs, the TSMDI was the optimal method to minimize nitrogen leaching loss by decreasing water leakage about 18.63%, which are beneficial for the ecological environment.

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

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

Doses and application methods of Azospirillum brasilense in irrigated upland rice

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Nayara F. S. Garcia

Full Text Available ABSTRACT The study was carried out in Selvíria-MS, in the 2011/12 and 2012/13 agricultural years, aiming to evaluate the efficiency of Azospirillum brasilense in nitrogen fixation in upland rice, as a function of doses and application methods of the inoculant containing this diazotrophic bacterium. The experimental design was randomized blocks, arranged in a 4 x 4 factorial scheme, with 4 doses of inoculant (control without inoculation, 100, 200 and 300 mL of the commercial product ha-1 and 4 application methods (seed inoculation, application in the sowing furrow, soil spraying after sowing, and foliar spraying at the beginning of plant tillering, with 4 replicates. During the experiment, the agronomic characteristics, production components and yield of the rice crop were evaluated. It was concluded that the inoculant containing Azospirillum brasilense promotes increase (19% in the yield of upland rice under sprinkler irrigation when used at the dose of 200 mL ha-1, regardless of the application methods.

Expansion of urban area and wastewater irrigated rice area in Hyderabad, India

Science.gov (United States)

Gumma, K.M.; van, Rooijen D.; Nelson, A.; Thenkabail, P.S.; Aakuraju, Radha V.; Amerasinghe, P.

2011-01-01

The goal of this study was to investigate land use changes in urban and peri-urban Hyderabad and their influence on wastewater irrigated rice using Landsat ETM + data and spectral matching techniques. The main source of irrigation water is the Musi River, which collects a large volume of wastewater and stormwater while running through the city. From 1989 to 2002, the wastewater irrigated area along the Musi River increased from 5,213 to 8,939 ha with concurrent expansion of the city boundaries from 22,690 to 42,813 ha and also decreased barren lands and range lands from 86,899 to 66,616 ha. Opportunistic shifts in land use, especially related to wastewater irrigated agriculture, were seen as a response to the demand for fresh vegetables and easy access to markets, exploited mainly by migrant populations. While wastewater irrigated agriculture contributes to income security of marginal groups, it also supplements the food basket of many city dwellers. Landsat ETM + data and advanced methods such as spectral matching techniques are ideal for quantifying urban expansion and associated land use changes, and are useful for urban planners and decision makers alike. ?? 2011 Springer Science+Business Media B.V.

Effect of Two Kinds of Green Manure and Urea on Production and N Uptake by Lowland Rice

International Nuclear Information System (INIS)

Haryanto; Idawati; Havid Rasjid; Elsje L Sisworo

2004-01-01

One field experiment has been conducted to study effect of two kinds of green manure and urea on production and N uptake in lowland rice. This experiment were used 11 treatments : (U) applying urea fertilizer at dose 200 kg urea/ha or recommended dose, (1/2 U) urea at 100 kg/ha, (1/2 U + Az) urea at 100 kg/ha + Azolla inoculation, (1/2 U + S) urea at 100 kg/ha + Sesbania incorporated at 50 DAT (days after transplanting), (Az + S) Azolla inoculation + Sesbania incorporated at 50 DAT, (Az + Sph) Azolla inoculation + Sesbania crop imported into the soil as green manure applied at preparation time of the land, (1/2 U + Az + S) treatment of (Az + S) combined with 100 kg urea/ha application, (1/2 U + Az + Sph) treatment of (Az + Sph) combined with 100 kg urea/ha application, (A) inoculation of Azolla, (S) Sesbania incorporated at 50 DAT, and Control (without urea, Azolla, and Sesbania). Lowland rice variety Cilosari was used in this experiment. This experiment was designed by Randomized Complete Block Design with 4 replicates for each treatment. To study the N-derived from fertilizer and green manure the 15 N isotope technique was used with the non direct method. Labelled 15 N ammonium sulphate with 10.12% 15 N was applied at 1 m x 1 m isotope plots for each plot in this experiment. The result showed that treatment combination of 100 kg urea/ha + Azolla inoculation + Sesbania crop incorporated into the soil as green manure applied at preparation time of the land gave N availability of soil higher than that resulted by 200 kg Urea/ha application. These treatments were not significantly different for total N uptake and N-derived from fertilizer in the rice grain. (author)

The use of 32P Method to Evaluate the Growth of Lowland Rice Cultivated in a System of Rice Intensification (SRI

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A. Citraresmini

2013-08-01

Full Text Available A pot experiment has been conducted to evaluate the growth of the Dyah Suci, a lowland rice variety, in an SRI (System of Rice Intensification planting system. The phosphorus-32 (32P isotope technique was used to evaluate the growth of plants in relation with their phosphorus uptake. The uptake was assumed to vary in the same direction as the growth of the plant. The 32P uptake is assumed to vary in the opposite direction to the plant’s total phosphorus uptake. Here the 32P uptake is expressed in count per minutes (cpm which is then transformed to disintegration per minute (dpm. The results show that, in terms of promoting the plant’s uptake of phosphorus, the SRI planting system is superior to the conventional planting system, and it is manifested in the higher dry weight of straw and grain. From this experiment it is concluded that the 32P method can be used satisfactorily as a tool for explaining the relation between P-uptake and plant growth

Simulation of rice yield under different irrigation and nitrogen application managements by CropSyst model

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Narjes ZARE

2015-12-01

Full Text Available The aim of this study was the calibration and validation of CropSyst model for rice in the city of Rasht. The necessary data were extracted from a field experiment which was carried out during 2005-2007 in a split-plot design. The main plots were irrigation regimes including continuous flooding irrigation and 5-day irrigation intervals. The subplots consisted of four nitrogen levels: zero N application, 45, 60 and 75 kg N ha-1. Normalized Root Mean Squared Error (nRMSE and Residual Mass Coefficient (Crm in calibration years were 9.3 % and 0.06, respectively. In validation year, nRMSE and Crm were 9.7 % and 0.11, respectively. According to other indices to assess irrigation regimes and fertilizer levels, the most suitable treatments regarding environmental aspect were 5-day irrigation regime and 45 kg N ha-1.

Evaluation of Different Rice Genotypes Tolerance to Saline Irrigation Water

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S. Jafari Rad

2015-12-01

Full Text Available To study the responses of seven rice genotypes (Khazar, SA13, Deylam, Sange Joe, Sepidrud, 831 and T5 to different levels of irrigation water salinity, and determining grain yield based on tolerance indices, a CRD based factorial pot experiment with five levels of irrigation water salinity (1, 2, 4, 6 and 8 dSm-1 and three replications was carried out at Rice Research Institute of Iran in 2011. Indices such as SSI, TOL, MP, GMP, HM, STI, YI and YSI were calculated and their correlations with grain yield were estimated for both stress and non-stress conditions. Results indicated significant differences among genotypes and the indices within both conditions. Results also showed that STI and MP indices could be considered as the best indices to screen salt tolerant genotypes. Among the genotypes used in the experiment, T5 produced the highest yield in both non-stress (19.71 g/plant and stress (10.69 g/plant conditions, while the lowest yield in normal (11.84 g/plant and stressful (4.29 g/plant conditions was recorded for Deylam and Khazar, respectively. The highest and the lowest percentage of yield reduction were found in Khazar (69.49% and Sange Joe (31.48% in stressful conditions, respectively. Overall, genotypes T5, 831, Sepidrud and Sange Joe can probably be considered as superior high yielding genotypes in both saline and non-saline conditions for further research.

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.

Water reuse and cost-benefit of pumping at different spatial levels in a rice irrigation system in UPRIIS, Philippines

Science.gov (United States)

Hafeez, M. M.; Bouman, B. A. M.; Van de Giesen, N.; Mushtaq, S.; Vlek, P.; Khan, S.

As agricultural water resources in Asia become increasingly scarce, the irrigation efficiency of rice must be improved. However, in this region there is very limited information available about water use efficiency across spatial levels in irrigation systems. This study quantifies the volume of water reuse and its related cost-benefits at five different spatial levels, ranging from 1500 ha to 18,000 ha, under gravity-fed irrigation system in Upper Pumpanga River Integrated Irrigation System (UPRIIS), Philippines. The major sources of water reuse are considered, namely groundwater pumping, pumping from creeks, combined use and irrigation supplies from check dams. The volume of water available from all four sources of water reuse was quantified through extensive measurements. Production functions were developed to quantify water-yield relationships and to measure the economic value of water reuse. This study was conducted during the dry season of 2001, which existed from 19 November 2000 until 18 May 2001. The water reuse by pumping and check dams was 7% and 22% of the applied surface water at District 1 level. The reuse of surface water through check dams increased linearly with 4.6 Mm 3 per added 1000 ha. Similarly, the total amount of reused water from pumping is equivalent to 30% of the water lost through rice evapotranspiration during the dry season 2001. The results showed that water reuse plays a dominant role in growing a rice crop during the dry season. The result showed no difference in pumping costs between the creek (US0.011/m 3) and shallow pumps (US0.012/m 3). The marginal value of productivity (MVP) of water reuse from creek (US0.044/m 3) was slightly higher than the water reuse through the pumping ground water (US0.039/m 3). Results also indicated that the total volume pumped per ha (m 3/ha) was ranging from 0.39 to 6.93 m 3/ha during the dry season. The results clearly indicate that the quantification of amount of water reuse is very crucial for

Characterization of land surface energy fluxes in a tropical lowland rice paddy

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Chatterjee, Dibyendu; Tripathi, Rahul; Chatterjee, Sumanta; Debnath, Manish; Shahid, Mohammad; Bhattacharyya, Pratap; Swain, Chinmaya Kumar; Tripathy, Rojalin; Bhattacharya, Bimal K.; Nayak, Amaresh Kumar

2018-04-01

A field experiment was conducted in 2015 to study the land surface energy fluxes from tropical lowland rice paddy in eastern India with an objective to determine the mass, momentum, and energy exchange rates between rice paddies and the atmosphere. All the land surface energy fluxes were measured by eddy covariance (EC) system (make Campbell Scientific) in dry season (DS, 1-125 Julian days), dry fallow (DF, 126-181 Julian days), wet season (WS, 182-324 Julian days), and wet fallow (WF, 325-365 Julian days). The rice was cultivated in dry season (January-May) and wet season (July-November) in low wet lands and the ground is kept fallow during the remainder of the year. Results showed that albedo varied from 0.09 to 0.24 and showed positive value from morning 6:00 h until evening 18:00 h. Mean soil temperature (T g) was highest in DF, while the skin temperature (T s) was highest in WS. Average Bowen ratio (B) ranged from 0.21 to 0.64 and large variation in B was observed during the fallow periods as compared to the cropping seasons. The magnitude of aerodynamic, canopy, and climatological resistances increased with the progress of cropping season and their magnitudes decreased during the end of both cropping seasons and found minimum during the fallow periods. At a constant vapor pressure deficit (VPD) at 0.16, 0.18, 0.15, and 0.43 kPa, latent heat flux (LE) initially increased, but later it tended to level off with an increase in VPD. The actual evapotranspiration (ETa) during both the cropping seasons was higher than the fallow period. This study can be used as a source of default values for many land surface energy fluxes which are required in various meteorological or air-quality models for rice paddies. A larger imbalance of energy was observed during the wet season as the energy is stored and perhaps advected in the fresh water.

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

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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

Incorporation of Bacterial Blight Resistance Genes Into Lowland Rice Cultivar Through Marker-Assisted Backcross Breeding.

Science.gov (United States)

Pradhan, Sharat Kumar; Nayak, Deepak Kumar; Pandit, Elssa; Behera, Lambodar; Anandan, Annamalai; Mukherjee, Arup Kumar; Lenka, Srikanta; Barik, Durga Prasad

2016-07-01

Bacterial blight (BB) of rice caused by Xanthomonas oryzae pv. oryzae is a major disease of rice in many rice growing countries. Pyramided lines carrying two BB resistance gene combinations (Xa21+xa13 and Xa21+xa5) were developed in a lowland cultivar Jalmagna background through backcross breeding by integrating molecular markers. In each backcross generation, markers closely linked to the disease resistance genes were used to select plants possessing the target genes. Background selection was continued in those plants carrying resistant genes until BC(3) generation. Plants having the maximum contribution from the recurrent parent genome were selected in each generation and hybridized with the recipient parent. The BB-pyramided line having the maximum recipient parent genome recovery of 95% was selected among BC3F1 plants and selfed to isolate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Twenty pyramided lines with two resistance gene combinations exhibited high levels of tolerance against the BB pathogen. In order to confirm the resistance, the pyramided lines were inoculated with different X. oryzae pv. oryzae strains of Odisha for bioassay. The genotypes with combination of two BB resistance genes conferred high levels of resistance to the predominant X. oryzae pv. oryzae isolates prevalent in the region. The pyramided lines showed similarity with the recipient parent with respect to major agro-morphologic traits.

Microbial community analysis in rice paddy soils irrigated by acid mine drainage contaminated water.

Science.gov (United States)

Sun, Min; Xiao, Tangfu; Ning, Zengping; Xiao, Enzong; Sun, Weimin

2015-03-01

Five rice paddy soils located in southwest China were selected for geochemical and microbial community analysis. These rice fields were irrigated with river water which was contaminated by Fe-S-rich acid mine drainage. Microbial communities were characterized by high-throughput sequencing, which showed 39 different phyla/groups in these samples. Among these phyla/groups, Proteobacteria was the most abundant phylum in all samples. Chloroflexi, Acidobacteria, Nitrospirae, and Bacteroidetes exhibited higher relative abundances than other phyla. A number of rare and candidate phyla were also detected. Moreover, canonical correspondence analysis suggested that pH, sulfate, and nitrate were significant factors that shaped the microbial community structure. In addition, a wide diversity of Fe- and S-related bacteria, such as GOUTA19, Shewanella, Geobacter, Desulfobacca, Thiobacillus, Desulfobacterium, and Anaeromyxobacter, might be responsible for biogeochemical Fe and S cycles in the tested rice paddy soils. Among the dominant genera, GOUTA19 and Shewanella were seldom detected in rice paddy soils.

Decomposition of rice residue in tropical soils, 2

International Nuclear Information System (INIS)

Yoneyama, Tadakatsu; Yoshida, Tomio

1977-01-01

The decomposition processes of intact rice residue (leaf blades) in the Maahas soil in the Philippines were investigated. Three sets of beakers simulating both lowland and upland conditions were incubated in the dark at 30 deg. C. One set of beakers had neither rice residue nor fertilizer. Pieces of leaf blades weighing 204 mg (dry weight) were inserted in the second set. Pieces of leaf blades were inserted in the third set, and 200 ppm of fertilizer nitrogen as 15 N-labelled ammonium sulfate was added. The experiment dealt with the nitrogen immobilization by rice residue under lowland and upland conditions. The rice residue which has contained low nitrogen absorbed nitrogen from the soil and from the added fertilizer (ammonium sulfate) during its decomposition under both conditions. Under the lowland condition, the amount of nitrogen immobilized was small during the first week, but became large after 2 or 3 weeks. Under the upland condition, the immobilized nitrogen reached its maximum during the first week, but the amount was not so large as that under the lowland condition. The added fertilizer stimulated the decrease of weight of the rice residue in the early incubation period, but retarded it later under both conditions. The absorption of fertilizer by the rice residue ceased at the early stage of residue decomposition, but the nitrogen content of the residue continued to increase. (Iwakiri, K.)

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

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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

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

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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.

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.

Online decision support system for surface irrigation management

Science.gov (United States)

Wang, Wenchao; Cui, Yuanlai

2017-04-01

Irrigation has played an important role in agricultural production. Irrigation decision support system is developed for irrigation water management, which can raise irrigation efficiency with few added engineering services. An online irrigation decision support system (OIDSS), in consist of in-field sensors and central computer system, is designed for surface irrigation management in large irrigation district. Many functions have acquired in OIDSS, such as data acquisition and detection, real-time irrigation forecast, water allocation decision and irrigation information management. The OIDSS contains four parts: Data acquisition terminals, Web server, Client browser and Communication system. Data acquisition terminals are designed to measure paddy water level, soil water content in dry land, ponds water level, underground water level, and canals water level. A web server is responsible for collecting meteorological data, weather forecast data, the real-time field data, and manager's feedback data. Water allocation decisions are made in the web server. Client browser is responsible for friendly displaying, interacting with managers, and collecting managers' irrigation intention. Communication system includes internet and the GPRS network used by monitoring stations. The OIDSS's model is based on water balance approach for both lowland paddy and upland crops. Considering basic database of different crops water demands in the whole growth stages and irrigation system engineering information, the OIDSS can make efficient decision of water allocation with the help of real-time field water detection and weather forecast. This system uses technical methods to reduce requirements of user's specialized knowledge and can also take user's managerial experience into account. As the system is developed by the Browser/Server model, it is possible to make full use of the internet resources, to facilitate users at any place where internet exists. The OIDSS has been applied in

Effect of Cold-Water Irrigation on Grain Quality Traits in japonica Rice Varieties from Yunnan Province, China

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Guo-zhen ZHAO

2009-09-01

Full Text Available The response of grain quality traits to cold-water irrigation and its correlation with cold tolerance were studied in 11 japonica rice varieties from Yunnan Province, China. The results indicated that the response of grain quality traits to the cold-water stress varied with rice varieties and grain quality traits. Under the cold-water stress, grain width, chalky rice rate, whiteness, 1000-grain weight, brown rice rate, taste meter value, peak viscosity, trough viscosity, breakdown viscosity and final viscosity significantly decreased, whereas grain length-width ratio, head rice rate, alkali digestion value, protein content and setback viscosity markedly increased. However, the other traits such as grain length, amylose content, milled rice rate, peak viscosity time and pasting temperature were not significantly affected by the cold-water stress. Significant correlations were discovered between phenotypic acceptability and cold response indices of taste meter value, protein content, peak viscosity and breakdown viscosity. Therefore, it would be very important to improve the cold tolerance of Yunnan rice varieties in order to stabilize and improve their eating quality.

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.

Scale Effects of Water Saving on Irrigation Efficiency: Case Study of a Rice-Based Groundwater Irrigation System on the Sanjiang Plain, Northeast China

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Haorui Chen

2017-12-01

Full Text Available This research analyzed the scale effect of water saving in Bielahonghe (BLH Basin, a rice-cultivating district on the Sanjiang Plain, Northeast China. Water budgets with different surface irrigation water supply ratios and water-saving measures were simulated with a semi-distributed water balance model. PFnws, representing the ratio of rice evapotranspiration to net water supply (the total amount of irrigation and precipitation minus the amount of water reused, was employed to assess the water use efficiency. Seven spatial scales (noted from S1 to S7, ranging from a single field (317.87 ha to the whole basin (about 100,800 ha were determined. PFnws values were quantified across scales and several water-saving measures, including water-saving irrigation regimes, canal lining, and a reduction of the surface water supply ratio (SWSR. The results indicated that PFnws increased with scale and could be calculated by a fitted power function (PFnws = 0.736Area0.033, R2 = 0.58. Furthermore, PFnws increased most prominently when the scale increased from S1 to S2. The water-saving irrigation regime (WSIR had the most substantial water-saving effect (WSE at S1. Specifically, PFnws improved by 21.2% at S1 when high-intensity WSIR was applied. Additionally, the WSE values of S3 and S5 were slightly higher than at other scales when the branch canal water delivery coefficient increased from 0.65 to 0.80 through canal lining. Furthermore, the PFnws at each scale varied with SWSR. Specifically, PFnws from S3 to S7 improved as SWSR decreased from 0.4 to 0.3 but remained approximately constant when SWSR decreased from 0.3 to 0.

EFFECT OF ALTERNATING WETTING AND DRYING IRRIGATION METHODS ON PHOTOSYNTHESIS AND TEMPERATURE OF RICE AND WEED PLANTS.

Science.gov (United States)

Reduced input systems such as alternating wetting and drying (AWD) and furrow irrigation can potentially reduce water costs and limit the release of greenhouse gases in rice production, but also can introduce unwanted crop stresses that compromise crop yield and quality, as well as introducing compl...

Application of perennial legume green manures to improve growth and yield of organic lowland rice

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M Winarni

2016-10-01

Full Text Available A pot experiment in green house was done to study the effect of the dosage and speciesof perennial legume green manures to the physiological traits, growth and yield of organic lowland rice (Oryza sativaL., and to obtain the optimal dosage as well.  The research was arranged in a factorial randomized block design consistedof two factors with three replications.The first factor was the species of perennial legume thatconsisted of threespecies: Turi (Sesbaniagrandiflora, Glirisidia (Gliricidiasepium, and Lamtoro (Leucaenaleucocephala and cow manure as control treatment. The second factor was the dosage of green manure thatconsisted of four levels: 5, 10, 20 and 40 t/ha.  The results showed that application ofperennial legumesinto the soil significantly improved the growth and yield of rice.  The application of  20 t Glirisidia leaves/haproduced the highest grain yield, followed by 20 t Lamtoro leaves/ha and 20 t Turi leaves/ha.  The optimal dosages of S. grandiflora, G. sepium and L. leucochepala leaves that could yield 58.03 g/hill (equivalent to14.51 t/ha, 53.67 g/hill (equivalent to 13.42 t/ha, and 49.67 g/hill (equivalent to 12.42 t/ha were 28.05, 25.46 and 26.41 t/ha, respectively.

Upland and lowland rice in the Netherlands Indies

NARCIS (Netherlands)

Maat, H.

2016-01-01

The global trade in rice is historically recent and its total quantity relatively small. Colonial explorations were the main incentive for its development, but only beginning in the 19th century did rice-producing countries in Asia export rice outside the continent in bulk. In previous centuries

Using farmer knowledge to combat low productive spots in rice fields of a Sahelian irrigation scheme

NARCIS (Netherlands)

Asten, van P.J.A.; Barro, S.E.; Wopereis, M.C.S.; Defoer, T.

2004-01-01

In the oldest sections of Burkina Faso's largest irrigation scheme in the Sourou Valley (13degrees 10'N, 03degrees 30'W) rice (Oryza sativa L.) yields dropped from about 5 to 6 t ha(-1) in the early 1990s, shortly after establishment of the scheme, to 2 to 4 t ha(-1) from 1995 onwards. Farmers

Soil Suitability Classification of Tomas Irrigation Scheme for Irrigated ...

African Journals Online (AJOL)

The need for sustainable rice production in Nigeria cannot be over-emphasized. Since rice can be grown both under rain-fed and irrigated conditions, the need for soil suitability evaluation becomes very necessary in order for supply to meet up with demand. Six land qualities viz; climate, soil physical properties, drainage, ...

Examination of two lowland rice cultivars reveals that gibberellin-dependent early response to submergence is not necessarily mediated by ethylene.

Science.gov (United States)

Dubois, Vincent; Moritz, Thomas; García-Martínez, José L

2011-01-01

Using two lowland rice (Oryza sativa L.) cultivars we found that in both cases submerged-induced elongation early after germination depends on gibberellins (GAs). Submergence increases the content of the active GA 1 by enhancing the expression of GA biosynthesis genes, thus facilitating the seedlings to escape from the water and preventing asphyxiation. However, the two cultivars differ in their response to ethylene. The cultivar Senia (short), by contrast to cultivar Bomba (tall), does not elongate after ethylene application, and submerged-induced elongation is not negated by an inhibitor of ethylene perception. Also, while ethylene emanation in Senia is not altered by submergence, Bomba seedlings emanate more ethylene upon de-submergence, associated with enhanced expression of the ethylene biosynthesis gene OsACS5. The cultivar Senia thus allows the possibility of clarifying the role of ethylene and other factors as triggers of GA biosynthesis enhancement in rice seedlings under submergence.

Flora, life form characteristics, and plan for the promotion of biodiversity in South Korea's Globally Important Agricultural Heritage System, the traditional Gudeuljang irrigated rice terraces in Cheongsando

Institute of Scientific and Technical Information of China (English)

Hong Chul PARK; Choong Hyeon OH

2017-01-01

The objectives of this study were to analyze the biodiversity of the Traditional Gudeuljang Irrigated Rice Terraces in Cheongsando,South Korea's representative GIAHS (Globally Important Agricultural Heritage System) site,with reference to position and land-use features,and to develop a plan to promote agricultural biodiversity in the region.We confirmed approximately 54,000 m2 of Gudeuljang paddy fields by an on-site survey.Of the Traditional Gudeuljang Irrigated Rice Terraces confirmed by onsite inspection,our survey showed that approximately 24,000 m2 are currently being used as paddy fields,approximately 15,000 m2 are being used as dry fields,and approximately 14,000 m2 are fallow.In terms of other non-agricultural land use,there was grassland,including graveyards;artificial arboreal land,such as orchards,rivers and wetlands,and man-made facilities,such as roads and residences.We also confirmed that the Traditional Gudeuljang Irrigated Rice Terraces had higher plant species diversity than conventional terraced rice paddies,and there was a difference in life form characteristics between the two types.Although the superficial topsoil structure is the same for the Traditional Gudeuljang Irrigated Rice Terraces (TGIRTs) and conventional terraced rice paddies,it is thought that the differences in the subsurface structure of the TGIRTs contribute greatly to species and habitat diversity.However,the TGIRTs in Cheongsando are facing degeneration,due to damage and reduction in agricultural activity.The main cause is the reduction in the number of farming households due to an aging population in Cheongsando.In order to address this problem,we proposed a management plan,related to fallow paddy fields in South Korea,to initiate voluntary activities in the TGIRTs.

Comparative study of irrigation water use and groundwater recharge under various irrigation schemes in an agricultural region, central Taiwan

Science.gov (United States)

Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

2016-04-01

The risk of rice production has increased notably due to climate change in Taiwan. To respond to growing agricultural water shortage without affecting normal food production in the future, the application of water-saving irrigation will be a substantial resolution. However, the adoption of water-saving irrigation may result in the reducing of groundwater recharge because continuous flooding in the paddy fields could be regarded as an important source for groundwater recharge. The aim of this study was to evaluate the irrigation water-saving benefit and groundwater recharge deficit when adopting the System of Rice Intensification, known as SRI methodology, in the Choushui River alluvial fan (the largest groundwater pumping and the most important rice-cropping region in central Taiwan). The three-dimensional finite element groundwater model, FEMWATER, was applied to simulate the infiltration process and groundwater recharge under SRI methodology and traditional irrigation schemes including continuous irrigation, and rotational irrigation in two rice-crop periods with hydro-climatic data of 2013. The irrigation water use was then calculated by water balance. The results showed that groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reduced 3.6% and 1.6% in the first crop period, and reduced 3.2% and 1.6% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. However, the SRI methodology achieved notably water-saving benefit compared to the disadvantage of reducing the groundwater recharge amount. The field irrigation requirement amount of SRI methodology was significantly lower than those of traditional irrigation schemes, saving 37% and 20% of irrigation water in the first crop period, and saving 53% and 35% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. Therefore, the amount of groundwater pumping for

Mitigating global warming potentials of methane and nitrous oxide gases from rice paddies under different irrigation regimes.

Science.gov (United States)

Ali, Muhammad Aslam; Hoque, M Anamul; Kim, Pil Joo

2013-04-01

A field experiment was conducted in Bangladesh Agricultural University Farm to investigate the mitigating effects of soil amendments such as calcium carbide, calcium silicate, phosphogypsum, and biochar with urea fertilizer on global warming potentials (GWPs) of methane (CH4) and nitrous oxide (N2O) gases during rice cultivation under continuous and intermittent irrigations. Among the amendments phosphogypsum and silicate fertilizer, being potential source of electron acceptors, decreased maximum level of seasonal CH4 flux by 25-27 % and 32-38 % in continuous and intermittent irrigations, respectively. Biochar and calcium carbide amendments, acting as nitrification inhibitors, decreased N2O emissions by 36-40 % and 26-30 % under continuous and intermittent irrigations, respectively. The total GWP of CH4 and N2O gases were decreased by 7-27 % and 6-34 % with calcium carbide, phosphogypsum, and silicate fertilizer amendments under continuous and intermittent irrigations, respectively. However, biochar amendments increased overall GWP of CH4 and N2O gases.

EFFECT OF NITROGEN-FIXING BACTERIA ON GRAIN YIELD AND DEVELOPMENT OF FLOODED IRRIGATED RICE

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AMAURI NELSON BEUTLER

2016-01-01

Full Text Available This study aimed at evaluating the effect of Azospirillum brasilense , a nitrogen - fixing bacterium, on flooded irrigated rice yield. Evaluations were carried out in a shaded nursery, with seedlings grown on an Alfisol. Were performed two sets of experiments. In the first, were carried out four experiments using the flooded rice cultivars INIA Olimar, Puitá Inta - CL, Br Irga 409 and Irga 424; these trials were set up as completely randomized design in a 5x4 factorial scheme, with four replications. Treatments consisted of five nitrogen rates (0, 40, 80, 120 and 160 kg ha - 1 and four levels of liquid inoculant Ab - V5 and Ab - V6 - A. brasilense (0, 1, 2 and 4 times the manufacturer's recommendation without seed treatment. In second set, were performed two experiments using the cultivars Puitá Inta - CL and Br Irga 409, arranged in the same design, but using a 4x2 factorial. In this set, treatments were composed of four levels of Ab - V5 and Ab - V6 - A. brasilense liquid inoculant (0, 1, 2 and 4 times the recommendation of 100 mL ha - 1 , using rice seeds with and without insecticide and fungicide treatment. Shoot dry matter, number of panicles, and rice grain yield per pot were the assessed variables. The results showed that rice seed inoculation with A. brasilense had no effects on rice grain yield of the cultivars INIA Olimar, Puitá Inta - CL, Br Irga 409 and Irga 424.

Assessing the groundwater recharge under various irrigation schemes in Central Taiwan

Science.gov (United States)

Chen, Shih-Kai; Jang, Cheng-Shin; Lin, Zih-Ciao; Tsai, Cheng-Bin

2014-05-01

The flooded paddy fields can be considered as a major source of groundwater recharge in Central Taiwan. The risk of rice production has increased notably due to climate change in this area. To respond to agricultural water shortage caused by climate change without affecting rice yield in the future, the application of water-saving irrigation is the substantial resolution. The System of Rice Intensification (SRI) was developed as a set of insights and practices used in growing irrigated rice. Based on the water-saving irrigation practice of SRI, impacts of the new methodology on the reducing of groundwater recharge were assessed in central Taiwan. The three-dimensional finite element groundwater model (FEMWATER) with the variable boundary condition analog functions, was applied in simulating groundwater recharge under different irrigation schemes. According to local climatic and environmental characteristics associated with SRI methodology, the change of infiltration rate was evaluated and compared with the traditional irrigation schemes, including continuous irrigation and rotational irrigation scheme. The simulation results showed that the average infiltration rate in the rice growing season decreased when applying the SRI methodology, and the total groundwater recharge amount of SRI with a 5-day irrigation interval reduced 12% and 9% compared with continuous irrigation (6cm constant ponding water depth) and rotational scheme (5-day irrigation interval with 6 cm initial ponding water depth), respectively. The results could be used as basis for planning long-term adaptive water resource management strategies to climate change in Central Taiwan. Keywords: SRI, Irrigation schemes, Groundwater recharge, Infiltration

IMPACTS OF CLIMATE CHANGE ON RICE AGRICULTURE IN NIGERIA

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Joshua Olusegun Ajetomobi

2011-01-01

This study employed the Ricardian approach to test the relative importance of climate normals (average long-term temperature and precipitation in explaining net revenue from Nigerian rice agriculture under irrigation and dry land conditions.   A survey was done by interviewing 1200 rice farmers from 20 rice producing states in Nigeria. The states covered all the six geopolitical zones in the country. The results showed that increase in temperature will reduce net revenue for dry land rice farms while net revenue rises with increase in temperature for irrigated rice farms. Precipitation had similar effects on rice net revenue. Increase in precipitation will cause reduction in revenue for dry land rice farms whereas it will cause increase in revenue for irrigated farms. The results clearly demonstrate irrigation as a significant techniques used by the farmers to adapt to the climate change. Other adaptation options include Keeping of livestock, engaging in off farm works and the use of different market channels.  Â

Irrigation with oxygen-nanobubble water can reduce methane emission and arsenic dissolution in a flooded rice paddy

International Nuclear Information System (INIS)

Minamikawa, Kazunori; Makino, Tomoyuki; Tago, Kanako; Hayatsu, Masahito; Takahashi, Masayoshi

2015-01-01

A remarkable feature of nanobubbles (<10 –6 m in diameter) is their long lifetime in water. Supplying oxygen-nanobubbles (NBs) to continuously flooded paddy soil may retard the development of reductive conditions, thereby reducing the emission of methane (CH 4 ), a potent greenhouse gas, and dissolution of arsenic, an environmental load. We tested this hypothesis by performing a pot experiment and measuring redox-related variables. The NBs were introduced into control water (with properties similar to those of river water) using a commercially available generator. Rice (Oryza sativa L.) growth did not differ between plants irrigated with NB water and those irrigated with control water, but NB water significantly (p < 0.05) reduced cumulative CH 4 emission during the rice-growing season by 21%. The amounts of iron, manganese, and arsenic that leached into the drainage water before full rice heading were also reduced by the NB water. Regardless of the water type, weekly-measured CH 4 flux was linearly correlated with the leached iron concentration during the rice-growing season (r = 0.74, p < 0.001). At the end of the experiment, the NB water significantly lowered the soil pH in the 0–5 cm layer, probably because of the raised redox potential. The population of methanogenic Archaea (mcrA copy number) in the 0–5 cm layer was significantly increased by the NB water, but we found no correlation between the mcrA copy number and the cumulative CH 4 emission (r = –0.08, p = 0.85). In pots without rice plants, soil reduction was not enhanced, regardless of the water type. The results indicate that NB water reduced CH 4 emission and arsenic dissolution through an oxidative shift of the redox conditions in the flooded soil. We propose the use of NB water as a tool for controlling redox conditions in flooded paddy soils. (letter)

A comprehensive assessment of agriculture in lowlands of south Brazil: characterization and comparison of current and alternative concepts

NARCIS (Netherlands)

Theisen, Giovani

2017-01-01

Agriculture in the lowlands of south Brazil is of strategic importance at the national level, since it supplies around 80% of the rice consumed by the Brazilian population. In Rio Grande do Sul, the southernmost state in Brazil, three million hectares of lowlands are ready for grain-based

Uso de efluentes da carcinicultura de águas interiores na irrigação do arroz Use of inland shrimp farm effluent for rice irrigation

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Fábio Rodrigues de Miranda

2008-12-01

Full Text Available O trabalho objetivou avaliar a produção de arroz e as alterações químicas do solo, em resposta à irrigação com o efluente da carcinicultura de águas interiores e comparar os resultados com aqueles obtidos com a irrigação convencional, utilizando água do Rio Jaguaribe. A produção de grãos obtida com o uso do efluente da carcinicultura foi semelhante àquela obtida com o uso da água de rio, quando foi utilizada na adubação uma dose de N-P-K equivalente a 100% da dose recomendada para a cultura. O uso do efluente na irrigação proporcionou maior produção de grãos em relação à irrigação com a água de rio, quando foi utilizada uma dose de N-P-K equivalente a 75% daquela recomendada para a cultura do arroz. Após o cultivo, o solo irrigado com o efluente apresentou maiores níveis de Na+, CEes e PST em relação ao solo irrigado com a água do Rio Jaguaribe.This study aimed to evaluate rice yield and soil chemical alterations in response to inland shrimp farm effluent use for irrigation, comparing the results to conventional irrigation, using the Jaguaribe River water. Rice yield obtained with the effluent was similar to that obtained with river water irrigation, when the N-P-K dose applied was equivalent to 100% of the crop recommended dose. Effluent irrigation produced higher grain yield as compared to river water irrigation when the N-P-K dose applied was equivalent to 75% of the rice recommended dose. After the crop was harvested the soil irrigated with the effluent presented higher levels of Na+, EC and ESR, as compared to the soil irrigated with the Jaguaribe River water.

Forms of trace arsenic, cesium, cadmium, and lead transported into river water for the irrigation of Japanese paddy rice fields

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Nakaya, Shinji; Chi, Hai; Muroda, Kengo; Masuda, Harue

2018-06-01

In this study, we focus on the behavior of geogenic, toxic trace elements, particularly As, Cs, Cd, and Pb, during their transportation in two rivers for irrigation commonly used in monsoon Asia; one river originates from an active volcano, Mt. Asama, and the other originates from a currently inactive volcano, Yatsugatake Mountains in Nagano, Japan. These rivers were investigated to understand the role of river water as a pollutant of rice and other aquatic plants (via irrigation) and aquatic animals. The results indicated that the behavior of toxic trace elements in river water are likely controlled by their interactions with particulate Fe, Al, and Ti compounds. The majority of Pb and Cd is transported as particulate matter with Fe, Al, and Ti, while the majority of As is transported in the dissolved form, predominantly as arsenate, with low abundance of particulate matter. Cs is transported either as the dissolved form or as particulate matter in both rivers. The investigated elements are transported in the rivers as particulate and dissolved forms, and the ratio of these forms is controlled by the pH and presence of particulate Fe, Al, and Ti phases in the river water. With respect to Cs in both rivers, the parameter governing the concentration and transportation of Cs, in the bimodal form (i.e., particulate and dissolved forms), through the river possibly shifts from sorption to pH by particulate Fe-Al-Ti, according to the abrupt increase in the concentration of Cs in the river. The chemical attraction of particulate Fe-Al-Ti for Cs is weaker than that for Pb and Cd, indicating that the lower electronegativity of Cs weakens the chemical attraction on a colloid for the competitive sorption with the other trace elements. The different relationships between As and Fe in the river and in the irrigation water and soil water, as well as those in paddy rice, suggested that As in paddy rice is not directly derived from As in the irrigation water from the river under

Comparison of the role of gibberellins and ethylene in response to submergence of two lowland rice cultivars, Senia and Bomba.

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Dubois, Vincent; Moritz, Thomas; García-Martínez, José L

2011-02-15

We examined the gibberellin (GA) and ethylene regulation of submergence-induced elongation in seedlings of the submergence-tolerant lowland rice (Oryza sativa L.) cvs Senia and Bomba. Elongation was enhanced after germination to facilitate water escape and reach air. We found that submergence-induced elongation depends on GA because it was counteracted by paclobutrazol (an inhibitor of GA biosynthesis), an effect that was negated by GA(3). Moreover, in the cv Senia, submergence increased the content of active GA(1) and its immediate precursors (GA(53), GA(19) and GA(20)) by enhancing expression of several GA biosynthesis genes (OsGA20ox1 and -2, and OsGA3ox2), but not by decreasing expression of several OsGA2ox (GA inactivating genes). Senia seedlings, in contrast to Bomba seedlings, did not elongate in response to ethylene or 1-aminocyclopropane-1-carboxylic-acid (ACC; an ethylene precursor) application, and submergence-induced elongation was not reduced in the presence of 1-methylcyclopropene (1-MCP; an ethylene perception inhibitor). Ethylene emanation was similar in Senia seedlings grown in air and in submerged-grown seedlings following de-submergence, while it increased in Bomba. The expression of ethylene biosynthesis genes (OsACS1, -2 and -3, and OsACO1) was not affected in Senia, but expression of OsACS5 was rapidly enhanced in Bomba upon submergence. Our results support the conclusion that submergence elongation enhancement of lowland rice is due to alteration of GA metabolism leading to an increase in active GA (GA(1)) content. Interestingly, in the cv Senia, in contrast to cv Bomba, this was triggered through an ethylene-independent mechanism. Copyright © 2010 Elsevier GmbH. All rights reserved.

Diet and resource partitioning among anurans in irrigated rice fields in Pantanal, Brazil

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L. Piatti

Full Text Available Artificial ponds or irrigated systems scattered throughout farmlands can offer important habitats for anurans and can be interesting sites for research on species resources use in a changing landscape. This study describes the diet and resource partitioning among anurans inhabiting irrigated rice fields in the Pantanal region. Twenty categories of prey were found in the stomachs of Leptodactylus chaquensis, L. elenae, L. podicipinus and Rhinella bergi, the most frequent being Coleoptera, Hymenoptera, larvae of Hexapoda, Hemiptera, Diptera and Orthoptera. The great differences found in the diet of these species in rice fields compared to other locations, according to available records in the literature, was the increased importance of Hemipitera and Orthoptera and the decrease in importance of Hymenoptera in the diet of leptodactylids. These differences might be attributed to changes in the availability of resources in response to habitat modification. Although diet composition was very similar among species, niche overlap was larger than expected by chance, suggesting that the competition for food resources is not, or has not been, a significant force in determining the structure of this frog community. Two non-exclusive hypotheses could be considered as a justification for this result: 1 the high niche overlap could result from resource availability, which is sufficient to satisfy all species without any strong competition; 2 or the high values of niche overlap could be a selective force driving species to compete, but there has not been enough time to express a significant divergence in the species diet because the study area is characterised as a dynamic habitat influenced by frequent and cyclical changes.

Contribution of seedling vigour and anoxia/hypoxia-responsive genes to submergence tolerance in Vietnamese lowland rice (Oryza sativa L.

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Hien Thi Thu Vu

2016-09-01

Full Text Available A direct-seeded rice cultivation system has been widely adopted in Asian countries. Optimum germination and vigorous seedling growth under submergence are key traits for the practice of direct seeding. We studied the post-germination seedling vigour in Vietnamese lowland rice accessions based on three bio-parameters, shoot elongation growth under five-day submergence in water-filled test-tubes, seedling recovery rate five days after transferring submerged seedlings to pots with soil and seedling survival rate 21 days after sowing seeds in nursery beds and immediate incubation under submergence. A large diversity was found in seedling vigour thus estimated among the accessions. Significantly high correlations were observed among all three bio-parameters, verifying the contribution of seedling vigour to the manifestation of submergence tolerance at this critical stage of rice development. To examine the roles of anoxia/hypoxia-responsive genes, the expression of 17 candidate genes was studied by reverse transcription polymerase chain reaction (RT-PCR and compared between selected vigorous and non-vigorous groups of accessions. Transcripts of all but two genes showed marked accumulation in submerged seedlings. No differences, however, were found between the two contrasting groups. The observed common and coordinate expression of anoxia/hypoxia-induced genes suggests that they might assume roles in attaining baseline tolerance against submergence stress. It was also suggested that some unknown genetic factors are operating in determining cultivar/genotype-specific levels of submergence tolerance as assessed by post-germination seedling vigour.

An integrated, multisensor system for the continuous monitoring of water dynamics in rice fields under different irrigation regimes.

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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.

The role of biotechnology to ensure rice food security

International Nuclear Information System (INIS)

Teng, P.S.

2002-01-01

Rice as a food is key to the survival of more than 60% of the world population, most of whom live in Asia. Food security in Asia is therefore strongly dependent on an adequate, available supply of affordable rice. Experts estimate that global rice supply would need to increase at an average of 1.7% per annum for the next 20 years, and average rice yields must roughly double in the next 20 years in both the irrigated and favourable rainfed lowland environments, if a global shortage is to be avoided. At the same time that the need to increase total production, and unit area productivity is being felt, society is also demanding that agricultural practices be environment friendly and be part of a sustainable agricultural system. Rice breeders have seen increased difficulties to source and utilize new genetic resources for genetic improvement of yield potential from within the rice genome. As with other cereals, rice yield potential has not been dramatically increased in the last decade when compared to the quantum increase of the early Green Revolution years. Furthermore, pest-induced losses currently account for up to 30% of the loss in yield potential. Biotechnology, especially recombinant DNA technology, offers tools to transfer genes from outside the rice genome to address the critical issues of raising the yield potential, increasing tolerance or resistance to insects, diseases and a biotic stresses, to increase the efficiency of pest management, and also to improve the nutritive value of the rice grain. Genetically modified crops have a demonstrated record of environmental and food safety, and all such crops undergo a process of safety assessment and regulatory approval before they are put into the marketplace. Serious social issues, however, arise in matching the capacity of biotechnology to change crops, and in what changes society is willing to accept; and at this early stage of biotechnology applications, science-based approaches are important so that emotion

Can deficit irrigation techniques be used to enhance phosphorus and water use efficiency and benefit crop yields?

Science.gov (United States)

Wright, Hannah R.; Dodd, Ian C.; Blackwell, Martin S. A.; Surridge, Ben W. J.

2015-04-01

Soil drying and rewetting (DRW) affects the forms and availability of phosphorus (P). Water soluble P has been reported to increase 1.8- to 19-fold after air-drying with the majority of the increase (56-100%) attributable to organic P. Similarly, in two contrasting soil types DRW increased concentrations of total P and reactive P in leachate, likely due to enhanced P mineralisation and physiochemical processes causing detachment of soil colloids, with faster rewetting rates related to higher concentrations of P. The intensity of drying as well as the rate of rewetting influences organic and inorganic P cycling. How these dynamics are driven by soil water status, and impact crop P acquisition and growth, remains unclear. Improving P and water use efficiencies and crop yields is globally important as both P and water resources become increasingly scarce, whilst demand for food increases. Irrigation supply below the water requirement for full crop evapotranspiration is employed by agricultural practitioners where water supply is limited. Regulated deficit irrigation describes the scheduling of water supply to correspond to the times of highest crop demand. Alternate wetting and drying (AWD) is applied in lowland irrigated rice production to avoid flooding at certain times of crop development, and has benefited P nutrition and yields. This research aims to optimise the benefits of P availability and uptake achieved by DRW by guiding deficit irrigation management strategies. Further determination of underlying processes driving P cycling at fluctuating soil moisture status is required. Presented here is a summary of the literature on DRW effects on soil P availability and plant P uptake and partitioning, in a range of soil types and cropping systems, with emphasis on alternate wetting and drying irrigation (AWD) compared to continuous flooding in lowland irrigated rice production. Soil water contents and matric potentials, and effects on P dynamics, are highly variable

The absorption and distribution of Cesium-134 in rice-soil system

International Nuclear Information System (INIS)

Xu Yinliang; Chen Chuanqun; Chen Bin; Sun Zhiming

1991-01-01

Dynamics of absorption of 134 Cs by rice shows that absorption rate is the fastest at boot stage; absorption capacities of 134 Cs in soils are different with the different physical-chemical properties of soils; absorption amounts vary with the time of irrigating 134 Cs; the closer the irrigation time to mature stage is, the more the absorption amount of 134 Cs in rice will be; the more the irrigating times are, and the higher the radioactivity of 134 Cs in irrigating water is, the more the absorption amount in rice will be. After brown rice is polished, contamination of 134 Cs can be decreased by 22.6-45.6%. The order of specific activity in rice is: bran > root > straw > husk > polished rice. Percentage activity of straw, brown rice, root and husk is 51.4%, 28.4%, 11.8% and 8.4% respectively. The migration of 134 Cs is very slow in soil and 95.1% of 134 Cs is concentrated in surface soil (0-2.5 cm). The distribution ratio of 134 Cs in the rice and soil is 6.1%:93.9%. Potassium ion can inhibit the absorption of 134 Cs by rice. There is an exponential function between the concentration of potassium ion and specific activity of 134 Cs in rice

Mapping suitability of rice production systems for mitigation: Strategic approach for prioritizing improved irrigation management across scales

Science.gov (United States)

Wassmann, Reiner; Sander, Bjoern Ole

2016-04-01

After the successful conclusion of the COP21 in Paris, many developing countries are now embracing the task of reducing emissions with much vigor than previously. In many countries of South and South-East Asia, the agriculture sector constitutes a vast share of the national GHG budget which can mainly be attributed to methane emissions from flooded rice production. Thus, rice growing countries are now looking for tangible and easily accessible information as to how to reduce emissions from rice production in an efficient manner. Given present and future food demand, mitigation options will have to comply with aim of increasing productivity. At the same time, limited financial resources demand for strategic planning of potential mitigation projects based on cost-benefit ratios. At this point, the most promising approach for mitigating methane emissions from rice is an irrigation technique called Alternate Wetting and Drying (AWD). AWD was initially developed for saving water and subsequently, represents an adaptation strategy in its own right by coping with less rainfall. Moreover, AWD also reduces methane emissions in a range from 30-70%. However, AWD is not universally suitable. It is attractive to farmers who have to pump water and may save fuel under AWD, but renders limited incentives in situations where there is no real pressing water scarcity. Thus, planning for AWD adoption at larger scale, e.g. for country-wide programs, should be based on a systematic prioritization of target environments. This presentation encompasses a new methodology for mapping suitability of water-saving in rice production - as a means for planning adaptation and mitigation programs - alongside with preliminary results. The latter comprises three new GIS maps on climate-driven suitability of AWD in major rice growing countries (Philippines, Vietnam, Bangladesh). These maps have been derived from high-resolution data of the areal and temporal extent of rice production that are now

Technical efficiency in rice ecologies of north central Nigeria ...

African Journals Online (AJOL)

Two mini-ecologies were identified within the lowland rice ecology in the study area, namely, River Basin Authority Catchment area (RBAC) and Non River Basin Authority Catchment area (NRBAC). Differentials in rice output were determined with the Chow test while the stochastic frontier production approach was ...

Influence of approach velocity and mesh size on the entrainment and contact of a lowland river fish assemblage at a screened irrigation pump.

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Craig A Boys

Full Text Available Fish screens can help prevent the entrainment or injury of fish at irrigation diversions, but only when designed appropriately. Design criteria cannot simply be transferred between sites or pump systems and need to be developed using an evidence-based approach with the needs of local species in mind. Laboratory testing is typically used to quantify fish responses at intake screens, but often limits the number of species that can studied and creates artificial conditions not directly applicable to screens in the wild. In this study a field-based approach was used to assess the appropriateness of different screen design attributes for the protection of a lowland river fish assemblage at an experimental irrigation pump. Direct netting of entrained fish was used along with sonar technology to quantify the probability of screen contact for a Murray-Darling Basin (Australia fish species. Two approach velocities (0.1 and 0.5 m.sec(-1 and different sizes of woven mesh (5, 10 and 20 mm were evaluated. Smaller fish (<150 mm in the assemblage were significantly more susceptible to entrainment and screen contact, especially at higher approach velocities. Mesh size appeared to have little impact on screen contact and entrainment, suggesting that approach velocity rather than mesh size is likely to be the primary consideration when developing screens. Until the effects of screen contacts on injury and survival of these species are better understood, it is recommended that approach velocities not exceed 0.1 m.sec(-1 when the desire is to protect the largest range of species and size classes for lowland river fish assemblages in the Murray-Darling Basin. The field method tested proved to be a useful approach that could compliment laboratory studies to refine fish screen design and facilitate field validation.

KOEFISIEN TANAMAN PADI SAWAH PADA SISTEM IRIGASI HEMAT AIR Crop Coefficient for Paddy Rice Field under Water Saving Irrigation Systems

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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

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.

Genetic Loci Governing Grain Yield and Root Development under Variable Rice Cultivation Conditions

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Margaret Catolos

2017-10-01

Full Text Available Drought is the major abiotic stress to rice grain yield under unpredictable changing climatic scenarios. The widely grown, high yielding but drought susceptible rice varieties need to be improved by unraveling the genomic regions controlling traits enhancing drought tolerance. The present study was conducted with the aim to identify quantitative trait loci (QTLs for grain yield and root development traits under irrigated non-stress and reproductive-stage drought stress in both lowland and upland situations. A mapping population consisting of 480 lines derived from a cross between Dular (drought-tolerant and IR64-21 (drought susceptible was used. QTL analysis revealed three major consistent-effect QTLs for grain yield (qDTY1.1, qDTY1.3, and qDTY8.1 under non-stress and reproductive-stage drought stress conditions, and 2 QTLs for root traits (qRT9.1 for root-growth angle and qRT5.1 for multiple root traits, i.e., seedling-stage root length, root dry weight and crown root number. The genetic locus qDTY1.1 was identified as hotspot for grain yield and yield-related agronomic and root traits. The study identified significant positive correlations among numbers of crown roots and mesocotyl length at the seedling stage and root length and root dry weight at depth at later stages with grain yield and yield-related traits. Under reproductive stage drought stress, the grain yield advantage of the lines with QTLs ranged from 24.1 to 108.9% under upland and 3.0–22.7% under lowland conditions over the lines without QTLs. The lines with QTL combinations qDTY1.3+qDTY8.1 showed the highest mean grain yield advantage followed by lines having qDTY1.1+qDTY8.1 and qDTY1.1+qDTY8.1+qDTY1.3, across upland/lowland reproductive-stage drought stress. The identified QTLs for root traits, mesocotyl length, grain yield and yield-related traits can be immediately deployed in marker-assisted breeding to develop drought tolerant high yielding rice varieties.

Determination of Phytochemical and Antioxidant Properties of Some ...

African Journals Online (AJOL)

Prof. Ogunji

irrigated lowland (16 %), deep water (1 %) and mangrove swamp (5 %). ... thiamine is the beriberi preventing factor, first isolated from rice polishing (Okwu, 2004). It is a ... deficiency can lead to indigestion, constipation, cardiac failure, primary ...

PM A-37Tap.pmd

African Journals Online (AJOL)

PC1

control. In western Senegal Sine Saloum Region, lowlands salinity is due to sea contact. ... et Gestion des Ressources Naturelles au Sine-. Saloum ...... en mesure de dire que : - les sols des bas ... determinants of irrigated rice performance in.

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

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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

Effects of Residue Management on Decomposition in Irrigated Rice Fields Are Not Related to Changes in the Decomposer Community.

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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.

Impact of Water Management on Rice Varieties, Yield, and Water Productivity under the System of Rice Intensification in Southern Taiwan

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Victoriano Joseph Pascual

2016-12-01

Full Text Available The system of rice intensification (SRI uses less water and enhances rice yield through synergy among several agronomic management practices. This claim was investigated to determine the effects of crop growth, yield and irrigation water use, using two thirds of the recommended SRI practices and two rice varieties, namely Tainan11 (TN11 and Tidung30 (TD30. Irrigation regimes were (a intermittent irrigation with three-day intervals (TD303 and TN113; (b intermittent irrigation with seven-day intervals (TD307 and TN117 and (c continuous flooding (TD30F and TN11F. Results showed that intermittent irrigation of three- and seven-day intervals produced water savings of 55% and 74% compared with continuous flooding. Total water productivity was greater with intermittent irrigation at seven-day intervals producing 0.35 kg·grain/m3 (TN117 and 0.46 kg·grain/m3 (TD307. Average daily headed panicle reduced by 166% and 196% for TN113 and TN117 compared with TN11F, with similar reduction recorded for TD303 (150% and TD307 (156% compared with TD30F. Grain yield of TD30 was comparable among irrigation regimes; however, it reduced by 30.29% in TN117 compared to TN11F. Plant height and leaf area were greater in plants exposed to intermittent irrigation of three-day intervals.

Trash-polluted irrigation: characteristics and impact on agriculture

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Sulaeman, D.; Arif, SS; Sudarmadji

2018-04-01

Trash pollution has been a problem in sustainable water resources management. Trash pollutes not only rivers, lakes and seas, but also irrigation canals and rice fields. This study aimed to identify the characteristics of solid waste (type, time of occurrence and sources of trash) and its impact on agriculture. The study was conducted in four irrigation areas, namely Gamping, Merdiko, Nglaren and Karangploso in Bantul District, Yogyakarta Special Region. We applied the Irrigation Rapid Trash Assessment (IRTA) as our field survey instrument. The results showed that trash was found throughout irrigation canals and rice fields, and the occurrence was influenced by water flow, time and farmer activities. The irrigation was dominantly polluted by plastic trash (52.2%), biodegradable waste (17.91%) and miscellaneous trash (12.3%). The IRTA score showed that Gamping Irrigation Area was at marginal condition, bearing a high risk of disturbing the operation and maintenance of the irrigation canals as well as farmers’ health. Trash in irrigation also generated technical impact of the irrigation operation and maintenance, environmental quality, and social life. This research also offered environmental policy integration approach and water-garbage governance approach as an alternative solution to manage water resources and agriculture in a sustainable manner, under the pressure of increasing amount of trash.

Use of the rice husk as an alternative substrate for growing media on green walls drip irrigation

Science.gov (United States)

Andrey Rivas-Sánchez, Yair; Fátima Moreno-Pérez, María; Roldán Cañas, José

2017-04-01

In the last years, we have been looking for alternatives to traditional growing mediums for green walls. Commercially available systems for green walls are commonly made with Sphagnum, rock wool or polymers that are unsustainable materials. In the design of the green wall, local components such as agricultural by-products should be considered more often. The objective of this research is to use alternative materials available in Andalusia that are suitable for use as a growing medium in green walls, using organic residues generated by agriculture as in this case the rice husk, compared to conventional and used materials as a growing media in green walls such as coconut fiber and rock wool. The physical-chemical characteristics of the water were analyzed through the collection of excess irrigation water, after passing through the prototypes of green walls, installed in the Rabanales Campus of the University of Córdoba between April and July 2016 and thus observe the feasibility of using rice husk as an alternative material. The 16 mm diameter irrigation pipes are at the top and middle of each module, with 12 adjustable drippers of 4 l / h for each module, 72 drippers in the whole experimental green wall prototype installed at every 15 centimeters of tube. Two different species of plant material (Lampranthus spectabilis) and (Lavandula stoechas), were selected, taking into account the solar exposition of the place of establishment of the prototype of the green wall and the easy acquisition of these plants in the region. Water samples were collected every day twice a day for 10 weeks of the experiment, taking a sample of the surplus runoff water from six green wall prototypes.PH 40 - pH - conductivity - TDS - temperature, CRISON. Differences in pH, electrical conductivity, turbidity and total solids of the treatments were examined by ANOVA with the test of normality and homogeneity of variances. It was observed that the substrates used in the prototypes of the

Keanekaragaman, Dominasi, Persebaran Spesies Penggerek Batang Padi dan Serangannya pada Berbagai Tipologi Lahan di Provinsi Jambi

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. Wilyus

2014-03-01

Full Text Available Diversity, domination, and distribution of rice stem borer species and its damage in various land typologies in Jambi Province.  The research was conducted to analyze the diversity, domination, species distribution of rice stem borers (RSB and its damage on various land typologies in Jambi Province.  The research was carried out using survey method, from December 2010 until June 2011.  Samples of RSB were collected from tidal swamp in Tanjung Jabung Timur District, swampy area in Muaro Jambi District, rainfed lowland in Sarolangun District, irrigated lowland in Merangin District, and irrigated upland in Kerinci District and Sungai Penuh District.  The results showed that there were five spesies of  RSB found in Jambi Province.  Scirpophaga  incertulas Walker (yellow stem borer was the most dominant of RSB, followed by Sesamia inferens Walker (pink stem borer, Chilo suppressalis Walker (striped stem borer, Chilo polychrysus Meyrick (dark-headed stem borer, and Scirpophaga innotata Walker (white stem borer.  The distribution of S. incertulas, S. inferens, C. suppressalis and C. polychrysus were in all of rice field in Jambi Province, but that of S. innotata was limited over tidal swamp and  rainfield  lowland area. The RSB damage rate was lower than economic thereshold.

Identification of criteria and subcriteria for assessment of land suitability for irrigation

OpenAIRE

Blagojević, Boško; Srđević, Zorica; Srđević, Bojan

2014-01-01

Serbia is a country with a predominantly agriculture-based economy; however, out of the total area only 3% is irrigated. One of the strategic national development goals is to increase irrigated land especially in lowlands and alluviums of major rivers in the country. There are many criteria and subcriteria which are important for a decision on where to build new, sustainable irrigation systems. After the literature review regarding this topic, we propose a set of criteria and subcriteria for ...

Making Rice Production More Environmentally-Friendly

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Norman Uphoff

2016-05-01

Full Text Available Irrigated rice production is one of the most essential agricultural activities for sustaining our global population, and at the same time, one of the agricultural sectors considered most eco-unfriendly. This is because it consumes a larger share of available freshwater resources, competing with varied ecosystems as well as other economic sectors; its paddy fields are responsible for significant emission of greenhouse gases; and the reliance on chemical fertilizers and various agrochemicals contributes to pollution of soils and water systems. These stresses on soils, hydrology and atmosphere are actually not necessary for rice production, which can be increased by modifying agronomic practices though more agroecologically-sound management practices. These, combined under the rubric of the System of Rice Intensification (SRI, can reduce requirements of irrigation water, chemical fertilizer and agrochemicals while increasing paddy yields and farmer’s net incomes. Here we discuss how irrigated rice production can be made more eco-friendly for the benefit of farmers, consumers and the environment. This is achieved by introducing practices that improve the growth and functioning of rice plants’ root systems and enhance the abundance, diversity and activity of beneficial soil organisms that live around plant roots and within the plants themselves as symbiotic endophytes.

Long-term effects of lowland properties system on soil physicochemical properties and rice yield in Ashanti Region of Ghana

Energy Technology Data Exchange (ETDEWEB)

Obalum, S. E.; Oppong, J.; Nwite, J. C.; Watanabe, Y.; Buri, M. M.; Igwe, C. A.; Wakatsuki, T.

2012-11-01

Lowland sawah is viewed as a sustainable alternative to traditional rice culture in West Africa. Sawah (a bund-demarcated, puddled, leveled, and water-regulated rice field) has received growing research attention lately, but no data exist yet on the systems long-term agronomic impact. In a clayey inland-valley soil in southern Ghana, 10-year-old sawah plots (OSP), fresh sawah plots (FSP), and non-sawah plots (NSP) were maintained under both ponded and nonponded conditions in 2007. The OSP enhanced soil status of exchangeable nutrients compared to NSP. There were relative improvements in soil bulk density, total porosity, and field moisture content (OSP = FSP > NSP), with clear benefits of ponding over non-ponding in OSP. The NSP was so unsustainable that it showed less favourable values of these variables than an adjacent fallowed plot. These soil variables deteriorated with time, with significant differences in FSP. Soil moisture retention data for tension range of 0-300 kPa depicted the importance of puddling and ponding. During 2001-2009, OSP consistently out-yielded NSP by five times on average. During 2007-2009 when all three plots co-existed, grain yields averaged 5.80, 4.80 and 1.10 Mg ha-1 in OSP, FSP and NSP, respectively. In 2007 yields, OSP minus FSP was higher than NSP; in 2008/2009, the opposite prevailed. These results highlight the agronomic benefits of continuous sawah-based rice production. Although the positive effects of puddling on the soil hydrophysical properties were largely responsible for the wide margin in yield between sawah and traditional systems, other yield-enhancing factors, particularly bunds for water control, were also lacking in the latter. (Author) 37 refs.

Impacts of aerosol pollutant mitigation on lowland rice yields in China

Science.gov (United States)

Zhang, Tianyi; Li, Tao; Yue, Xu; Yang, Xiaoguang

2017-10-01

Aerosol pollution in China is significantly altering radiative transfer processes and is thereby potentially affecting rice photosynthesis and yields. However, the response of rice photosynthesis to aerosol-induced radiative perturbations is still not well understood. Here, we employ a process-based modelling approach to simulate changes in incoming radiation (RAD) and the diffuse radiation fraction (DF) with aerosol mitigation in China and their associated impacts on rice yields. Aerosol reduction has the positive effect of increasing RAD and the negative effect of decreasing DF on rice photosynthesis and yields. In rice production areas where the average RAD during the growing season is lower than 250 W m-2, aerosol reduction is beneficial for higher rice yields, whereas in areas with RAD>250 W m-2, aerosol mitigation causes yield declines due to the associated reduction in the DF, which decreases the light use efficiency. As a net effect, rice yields were estimated to significantly increase by 0.8%-2.6% with aerosol concentrations reductions from 20 to 100%, which is lower than the estimates obtained in earlier studies that only considered the effects of RAD. This finding suggests that both RAD and DF are important processes influencing rice yields and should be incorporated into future assessments of agricultural responses to variations in aerosol-induced radiation under climate change.

Hydrology and phosphorus transport simulation in a lowland polder by a coupled modeling system.

Science.gov (United States)

Yan, Renhua; Huang, Jiacong; Li, Lingling; Gao, Junfeng

2017-08-01

Modeling the rain-runoff processes and phosphorus transport processes in lowland polders is critical in finding reasonable measures to alleviate the eutrophication problem of downstream rivers and lakes. This study develops a lowland Polder Hydrology and Phosphorus modeling System (PHPS) by coupling the WALRUS-paddy model and an improved phosphorus module of a Phosphorus Dynamic model for lowland Polder systems (PDP). It considers some important hydrological characteristics, such as groundwater-unsaturated zone coupling, groundwater-surface water feedback, human-controlled irrigation and discharge, and detailed physical and biochemical cycles of phosphorus in surface water. The application of the model in the Jianwei polder shows that the simulated phosphorus matches well with the measured values. The high precision of this model combined with its low input data requirement and efficient computation make it practical and easy to the water resources management of Chinese polders. Parameter sensitivity analysis demonstrates that K uptake , c Q2 , c W1 , and c Q1 exert a significant effect on the modeled results, whereas K resuspensionMax , K settling , and K mineralization have little effect on the modeled total phosphorus. Among the three types of uncertainties (i.e., parameter, initial condition, and forcing uncertainties), forcing uncertainty produces the strongest effect on the simulated phosphorus. Based on the analysis result of annual phosphorus balance when considering the high import from irrigation and fertilization, lowland polder is capable of retaining phosphorus and reducing phosphorus export to surrounding aquatic ecosystems because of their special hydrological regulation regime. Copyright © 2016 Elsevier Ltd. All rights reserved.

EFFECT OF ALUMINUM ON PLANT GROWTH, PHOSPORUS AND CALCIUM UPTAKE OF TROPICAL RICE (Oryza sativa, MAIZE (Zea mays, AND SOYBEAN (Glycine max

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D. Nursyamsi

2018-01-01

Full Text Available Aluminum toxicity is the most limiting factor to plant growth on acid soils. Structural and functional damages in the root system by Al decrease nutrient uptake and lead to reduce plant growth and mineral deficiency in shoot. Greenhouse experiment was conducted to study the effect of Al on plant growth, and P and Ca uptake of rice, maize, and soybean. The plants were grown in hydroponic solution added with 0, 5, 10, and 30 ppm Al, at pH 4.0. The results showed that relative growth of shoots and roots of upland rice, lowland rice, maize, and soybean decreased with an increase of Al level. However, sometimes the low Al level (5 ppm stimulated shoot and root growth of some varieties in these species. According to total AlRG30 values, which is Al concentration in solution when relative growth decreased to 50%, Al tolerance of species was in order of barley < maize < soybean < lowland rice < upland rice. For maize, Al tolerance was in the order of Arjuna < Kalingga < P 3540 < SA 5 < SA 4 < PM 95 A < SA 3 < Antasena; for soybean was Wilis < INPS < Galunggung < Kerinci < Kitamusume; for lowland rice was RD 23 < Kapuas < Cisadane < KDML 105 < IR 66 < RD 13, and for upland rice was Dodokan < JAC165 < Cirata < Orizyca sabana 6 < Danau Tempe < Laut Tawar. Based on the rank of Al tolerance, rice was the useful crop to be planted in acid soils. Antasena (maize, Kitamusume ( soybean , RD 13 (lowland rice, and Laut Tawar (upland rice were also recommended for acid soils. P and Ca concentration in shoots and roots commonly decreased with an increase of Al level. However, the low Al level stimulated absorption of P and Ca concentrations in shoots and roots.

Assessment of arsenic in Australian grown and imported rice varieties on sale in Australia and potential links with irrigation practises and soil geochemistry.

Science.gov (United States)

Fransisca, Yunnita; Small, Darryl M; Morrison, Paul D; Spencer, Michelle J S; Ball, Andrew S; Jones, Oliver A H

2015-11-01

Chronic dietary exposure to arsenic, particularly the inorganic forms (defined as elemental arsenic, predominantly As(3+) and As(5+), and all its inorganic compounds except arsine), is a matter of concern for human health. Ingestion of arsenic usually occurs via contaminated water but recent studies show there is also a risk of exposure from food, particularly Asian rice (Oryza sativa). Australia is a rice growing country, contributing around 2% of the world rice trade, and a large proportion of the population consumes rice regularly. In the present study we investigated concentrations of arsenic in both Australian grown and imported rice on sale in Australia and examined the potential links with irrigation practises and soil geochemistry. The results indicated a wide spread of arsenic levels of 0.09-0.33 mg kg(-1), with Australian grown Arborio and sushi varieties of O. sativa containing the highest mean value of ∼0.22 mg kg(-1). Arsenic levels in all samples were below the 1 mg kg(-1) limit set by Food Standards Australia New Zealand. Copyright © 2014 Elsevier Ltd. All rights reserved.

Population dynamics and breeding patterns of multimammate mouse, Mastomys natalensis (Smith 1834), in irrigated rice fields in eastern Tanzania.

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Mulungu, Loth S; Ngowo, Victoria; Mdangi, Mashaka; Katakweba, Abdul S; Tesha, Protas; Mrosso, Furaha P; Mchomvu, Mary; Sheyo, Paul M; Kilonzo, Bukhet S

2013-03-01

Multimammate mice are the most important vertebrate pests in Sub-Saharan Africa and are also reservoirs of many zoonotic diseases, including sylvan plague. This study investigated the population dynamics and breeding patterns of this mouse in irrigated rice cropping systems in eastern Tanzania. The multimammate mouse, Mastomys natalensis, population varied with habitat and months. Fallow land had a more abundant population than rice fields. The highest population peak was observed during the dry season from July to October. Mastomys natalensis is sexually active throughout the year in the study area, although it reaches the highest level in June and December when rice is at the maturity stage. This suggests that breeding is highly influenced by the presence of a rice crop in both seasons. More juvenile individuals were recorded in August and September, indicating that they were produced in the previous breeding months. The sex ratio of M. natalensis was not skewed to either males or females, indicating that it was at parity. Rodent population dynamics during the study periods in all habitats indicated that high birth rates accounted for the rapid population growth and turnover. Regular control and sustainable operations are thus essential if rodent pest populations are to be kept within tolerable limits. Copyright © 2012 Society of Chemical Industry.

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.

A Mitigation Approach to Alleviate Arsenic Accumulation in Rice through Balanced Fertilization

International Nuclear Information System (INIS)

Huq, S.M.I.; Sultana, S.; Chakraborty, G.; Chowdhury, M.T.A.

2011-01-01

Pot experiments with boro and aman season rice on the same soils treated with arsenic contaminated irrigation water and using balanced fertilizer or not revealed that balance fertilization could be a strategy to mitigate arsenic accumulation in rice grain. The study also revealed that there is a carryover effect of As applied through irrigation in the boro season to the subsequent aman season rice. This carryover effect too, could be minimized with balanced fertilization.

Crop and varietal diversification of rainfed rice based cropping systems for higher productivity and profitability in Eastern India.

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Lal, B; Gautam, Priyanka; Panda, B B; Raja, R; Singh, Teekam; Tripathi, R; Shahid, M; Nayak, A K

2017-01-01

Rice-rice system and rice fallows are no longer productive in Southeast Asia. Crop and varietal diversification of the rice based cropping systems may improve the productivity and profitability of the systems. Diversification is also a viable option to mitigate the risk of climate change. In Eastern India, farmers cultivate rice during rainy season (June-September) and land leftovers fallow after rice harvest in the post-rainy season (November-May) due to lack of sufficient rainfall or irrigation amenities. However, in lowland areas, sufficient residual soil moistures are available in rice fallow in the post-rainy season (November-March), which can be utilized for raising second crops in the region. Implementation of suitable crop/varietal diversification is thus very much vital to achieve this objective. To assess the yield performance of rice varieties under timely and late sown conditions and to evaluate the performance of dry season crops following them, three different duration rice cultivars were transplanted in July and August. In dry season several non-rice crops were sown in rice fallow to constitute a cropping system. The results revealed that tiller occurrence, biomass accumulation, dry matter remobilization, crop growth rate, and ultimately yield were significantly decreased under late transplanting. On an average, around 30% yield reduction obtained under late sowing may be due to low temperature stress and high rainfall at reproductive stages of the crop. Dry season crops following short duration rice cultivars performed better in terms of grain yield. In the dry season, toria was profitable when sown earlier and if sowing was delayed greengram was suitable. Highest system productivity and profitability under timely sown rice may be due to higher dry matter remobilization from source to sink. A significant correlation was observed between biomass production and grain yield. We infer that late transplanting decrease the tiller occurrence and assimilate

A Mitigation Approach to Alleviate Arsenic Accumulation in Rice through Balanced Fertilization

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S. M. Imamul Huq

2011-01-01

Full Text Available Pot experiments with boro and aman season rice on the same soils treated with arsenic contaminated irrigation water and using balanced fertilizer or not revealed that balance fertilization could be a strategy to mitigate arsenic accumulation in rice grain. The study also revealed that there is a carryover effect of As applied through irrigation in the boro season to the subsequent aman season rice. This carryover effect too, could be minimized with balanced fertilization.

Assessing the changes of groundwater recharge / irrigation water use between SRI and traditional irrigation schemes in Central Taiwan

Science.gov (United States)

Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

2015-04-01

To respond to agricultural water shortage impacted by climate change without affecting rice yield in the future, the application of water-saving irrigation, such as SRI methodology, is considered to be adopted in rice-cultivation in Taiwan. However, the flooded paddy fields could be considered as an important source of groundwater recharge in Central Taiwan. The water-saving benefit of this new methodology and its impact on the reducing of groundwater recharge should be integrally assessed in this area. The objective of this study was to evaluate the changes of groundwater recharge/ irrigation water use between the SRI and traditional irrigation schemes (continuous irrigation, rotational irrigation). An experimental paddy field located in the proximal area of the Choushui River alluvial fan (the largest groundwater pumping region in Taiwan) was chosen as the study area. The 3-D finite element groundwater model (FEMWATER) with the variable boundary condition analog functions, was applied in simulating groundwater recharge process and amount under traditional irrigation schemes and SRI methodology. The use of effective rainfall was taken into account or not in different simulation scenarios for each irrigation scheme. The simulation results showed that there were no significant variations of infiltration rate in the use of effective rainfall or not, but the low soil moisture setting in deep soil layers resulted in higher infiltration rate. Taking the use of effective rainfall into account, the average infiltration rate for continuous irrigation, rotational irrigation, and SRI methodology in the first crop season of 2013 were 4.04 mm/day, 4.00 mm/day and 3.92 mm/day, respectively. The groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reducing 4% and 2% compared with continuous irrigation and rotational irrigation, respectively. The field irrigation requirement amount of SRI methodology was significantly

Irrigation et paludisme : un couple infernal?

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Mergeai, G.

2016-01-01

Full Text Available Irrigation and Malaria - a Terrible Combination?. Increasing agricultural productivity is a priority in most of the developing countries and using irrigation is one of the most efficient ways of achieving this goal. Almost half a billion people in the world contract malaria every year and approximately one million die as a result. The majority of these victims are farmers or members of their families. In infected areas, malaria continues to have major negative impacts on agricultural productivity. For example, in the Equateur province of the DRC, after access to production means, fevers are considered the second biggest obstacle to the development of agricultural activities. In the Ivory Coast, a study has shown that growers suffering from malaria were about half as productive as their healthy colleagues. The disease often strikes at the start of the rainy season when work begins again in the fields. It reduces the amount of land cultivated and affects the amount of care taken with crops. Agricultural practices influence the risk of contracting malaria. Irrigation, in particular, can encourage the proliferation of vectors of the disease and make it more likely to spread. This tendency can be observed in many locations where irrigated rice production is on the increase. Paradoxically, however, an increased number of mosquitoes does not systematically result in more malaria. In Ethiopia, malaria is more prevalent close to the micro-dams sponsored by the government, whereas, in Tanzania, there is less malaria in irrigated areas. Various theories can be put forward in order to explain this paradox. In particular, increased income due to higher rice yields enables farmers to purchase insecticide-treated mosquito nets. It also allows them to eat better, which strengthens their immune systems. It also appears that the negative impact of irrigation systems is greater in areas, in which immunity levels were low in the population prior to the creation of

Study of arsenic accumulation in rice and evaluation of protective effects of Chorchorus olitorius leaves against arsenic contaminated rice induced toxicities in Wistar albino rats.

Science.gov (United States)

Hosen, Saeed Mohammed Imran; Das, Dipesh; Kobi, Rupkanowar; Chowdhury, Dil Umme Salma; Alam, Md Jibran; Rudra, Bashudev; Bakar, Muhammad Abu; Islam, Saiful; Rahman, Zillur; Al-Forkan, Mohammad

2016-10-14

In the present study, we investigated the arsenic accumulation in different parts of rice irrigated with arsenic contaminated water. Besides, we also evaluated the protective effects of Corchorus olitorius leaves against arsenic contaminated rice induced toxicities in animal model. A pot experiment was conducted with arsenic amended irrigation water (0.0, 25.0, 50.0 and 75.0 mg/L As) to investigate the arsenic accumulation in different parts of rice. In order to evaluate the protective effects of Corchorus olitorius leaves, twenty Wistar albino rats were divided into four different groups. The control group (Group-I) was supplied with normal laboratory pellets while groups II, III, and IV received normal laboratory pellets supplemented with arsenic contaminated rice, C. olitorius leaf powder (4 %), arsenic contaminated rice plus C. olitorius leaf powder (4 %) respectively. Different haematological parameters and serum indices were analyzed to evaluate the protective effects of Corchorus olitorius leaves against arsenic intoxication. To gather more supportive evidences of Corchorus olitorius potentiality against arsenic intoxication, histopathological analysis of liver, kidney, spleen and heart tissues was also performed. From the pot experiment, we have found a significant (p ≤ 0.05) increase of arsenic accumulation in different parts of rice with the increase of arsenic concentrations in irrigation water and the trend of accumulation was found as root > straw > husk > grain. Another part of the experiment revealed that supplementation of C. olitorius leaves with arsenic contaminated rice significantly (p rice induced toxicities. Arsenic accumulation in different parts of rice increased dose-dependently. Hence, for irrigation purpose arsenic contaminated water cannot be used. Furthermore, arsenic contaminated rice induced several toxicities in animal model, most of which could be minimized with the food supplementation of Corchorus olitorius

Integrating Water Supply Constraints into Irrigated Agricultural Simulations of California

Science.gov (United States)

Winter, Jonathan M.; Young, Charles A.; Mehta, Vishal K.; Ruane, Alex C.; Azarderakhsh, Marzieh; Davitt, Aaron; McDonald, Kyle; Haden, Van R.; Rosenzweig, Cynthia E.

2017-01-01

Simulations of irrigated croplands generally lack key interactions between water demand from plants and water supply from irrigation systems. We coupled the Water Evaluation and Planning system (WEAP) and Decision Support System for Agrotechnology Transfer (DSSAT) to link regional water supplies and management with field-level water demand and crop growth. WEAP-DSSAT was deployed and evaluated over Yolo County in California for corn, rice, and wheat. WEAP-DSSAT is able to reproduce the results of DSSAT under well-watered conditions and reasonably simulate observed mean yields, but has difficulty capturing yield interannual variability. Constraining irrigation supply to surface water alone reduces yields for all three crops during the 1987-1992 drought. Corn yields are reduced proportionally with water allocation, rice yield reductions are more binary based on sufficient water for flooding, and wheat yields are least sensitive to irrigation constraints as winter wheat is grown during the wet season.

Biomphalaria species distribution and its effect on human Schistosoma mansoni infection in an irrigated area used for rice cultivation in northeast Brazil

Directory of Open Access Journals (Sweden)

Delmany Moitinho Barboza

2012-09-01

Full Text Available The role of irrigated areas for the spread of schistosomiasis is of worldwide concern. The aim of the present study was to investigate the spatial distribution of the intermediate snail host Biomphalaria in an area highly endemic for schistosomiasis due to Schistosoma mansoni, evaluating the relationship between irrigation and types of natural water sources on one hand, and the influence of place and time of water exposure on the intensity of human infection on the other. A geographical information system (GIS was used to map the distribution of the intermediate snail hosts in Ilha das Flores, Sergipe, Brazil, combined with a clinical/epidemiological survey. We observed a direct correlation between the intensity of human infection with S. mansoni and irrigation projects. Malacological studies to identify snail species and infection rates showed that B. glabrata is the main species responsible for human schistosomiasis in the municipality, but that B. straminea also plays a role. Our results provide evidence for a competitive selection between the two snail species in rice fields with a predominance of B. glabrata in irrigation systems and B. straminea in natural water sources.

The fate of cadmium in field soils of the Danubian Lowland

Czech Academy of Sciences Publication Activity Database

Lichner, Ľ.; Dlapa, P.; Šír, Miloslav; Čipáková, A.; Houšková, B.; Faško, P.; Nagy, V.

2006-01-01

Roč. 85, 1-2 (2006), s. 154-165 ISSN 0167-1987 Grant - others:Czech program of bilateral cooperation in science and technology KONTAKT(SK) 185/99; Slovak Scientific Grant Agency VEGA(SK) 1/0619/03; Slovak Scientific Grant Agency VEGA(SK) 2/3032/23 Institutional research plan: CEZ:AV0Z20600510 Keywords : Danubian Lowland * Macropore flow * Field soil * Cadmium * Adsorption Subject RIV: GD - Fertilization, Irrigation, Soil Processing Impact factor: 1.619, year: 2006

Water saving in lowland rice production: an experimental and modeling study

NARCIS (Netherlands)

Belder, P.

2005-01-01

Increasing demand for rice and decreasing water diversions to agriculture, urge for higher water productivity in rice production systems. One way to deal with this challenge is using water-saving regimes on field scale. The main objective of this study was to quantify the effects of water-saving

Puddling against dry plowing for lowland rice culture in Surinam : effect on soil and plant, and interactions with irrigation and nitrogen dressing

NARCIS (Netherlands)

Scheltema, W.

1974-01-01

The influence of tillage on rice grown on heavy Surinam clay soils was investigated in pot and field trials. Included were interactions with seed rate, nitrogen dressing and distribution, water management, and variety. Four procedures for tilled layer and seedbed preparation were studied

EFFECTIVENESS OF FERTILIZER SRF-N D AND H ON RICE GROWTH AND RESULTS

Directory of Open Access Journals (Sweden)

Nasruddin Razak

2014-02-01

Full Text Available Study aims are to know effectiveness level of SRF-N (D & H on growth and yield of lowland rice, and gets fertilizer dosage that gave highest yield of lowland rice. Twelve 12 treatments added with recommendation dosage and farmer treatment. Experiment arranged in RCBD three replications. Result: SRF-N significantly effect growth and yield of lowland rice. Applied SRF-N type H with dosage 350 kg per ha which combined SP-36 and KCl gave higher dry grind grain compared to other treatments of SRF. Proposes SRF-H 280 kg and SRF-D 500 kg per ha. Treatment of farmer way with dosage Urea 300 kg, SP-36 100 kg, and KCl 50 kg per ha, gave higher dry grind grain (8.14 t DGG per ha compared to other treatments including recommendation dosage (7.65 t DGG per ha. Effectiveness of SRF-N type H with dosage 350 kg (two times applications on produce of grain, is 0.97 times compared to recommendation. Need to study more of SRF-H 350 kg and 280 kg per ha, and SRF-H 500 kg per ha (two times application which combined with P and K recommendation on different location and planting season to obtain accurate data in order to obtain locationspecific fertilizer recommendation

Irrigation ponds: Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

Institute of Scientific and Technical Information of China (English)

DONG Bin; MAO Zhi; BROWN Larry; CHEN XiuHong; PENG LiYuan; WANG JianZhang

2009-01-01

Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and un-recycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China.With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious.Traditional ir-rigation and drainage systems only focus on issues concerning water quantity, i.e.the capacity of irri-gation in drought and drainage in waterlogging period, yet have no requirement on water quality im-provement, how to clean the water quality of farmland drainage through remodeling the existing irriga-tion and drainage systems has a very important realistic meaning.Pond is an important irrigation facil-ity in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use.Such water storage features of pond provide the possibility and potential capacity for drainage water treat-ment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system.To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site.The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water.Other issues, e.g.how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

Irrigation ponds:Possibility and potentials for the treatment of drainage water from paddy fields in Zhanghe Irrigation System

Institute of Scientific and Technical Information of China (English)

BROWN; Larry

2009-01-01

Excessive application of fertilizers and pesticides as well as discharge of undecontaminated and unrecycled waste of livestock and poultry into farmland has caused serious non-point source pollution (NSP) of farmland in China. With the traditional mode of irrigation and drainage in rice-based irrigation systems, the pollution of farmland drainage water has become more and more serious. Traditional irrigation and drainage systems only focus on issues concerning water quantity, i.e. the capacity of irrigation in drought and drainage in waterlogging period, yet have no requirement on water quality improvement. how to clean the water quality of farmland drainage through remodeling the existing irrigation and drainage systems has a very important realistic meaning. Pond is an important irrigation facility in rice-based irrigation systems in southern China, which has the functions of not only a storage of water from canals but also collections of surface runoffs and farmland drainage for recycling use. Such water storage features of pond provide the possibility and potential capacity for drainage water treatment by managing such features as treatment basins as the growth of aquatic plants as well as living of fishes, batrachia and microorganisms in pond forms a soil-plant-microorganism ecological system. To explore the potential capacity of pond for drainage water nutrient reduction, the Zhanghe Irrigation System of Hubei, a typical "melon-on-the-vine" system in southern China is selected as the research site. The results of pond survey and field experiments demonstrate that plenty of ponds are suitable for collecting and cleaning paddy field drainage, and the ponds are favorable in reducing N, P nutrients in the drainage water. Other issues, e.g. how to maximize such capacity and what strategies should be sought to make existing treatment basins hydraulically more efficient, are also discussed.

Elucidation of rice rhizosphere metagenome in relation to methane and nitrogen metabolism under elevated carbon dioxide and temperature using whole genome metagenomic approach.

Science.gov (United States)

Bhattacharyya, P; Roy, K S; Das, M; Ray, S; Balachandar, D; Karthikeyan, S; Nayak, A K; Mohapatra, T

2016-01-15

Carbon (C) and nitrogen (N) mineralization is one of the key processes of biogeochemical cycling in terrestrial ecosystem in general and rice ecology in particular. Rice rhizosphere is a rich niche of microbial diversity influenced by change in atmospheric temperature and concentration of carbon dioxide (CO2). Structural changes in microbial communities in rhizosphere influence the nutrient cycling. In the present study, the bacterial diversity and population dynamics were studied under ambient CO2 (a-CO2) and elevated CO2+temperature (e-CO2T) in lowland rice rhizosphere using whole genome metagenomic approach. The whole genome metagenomic sequence data of lowland rice exhibited the dominance of bacterial communities including Proteobacteria, Firmicutes, Acidobacteria, Actinobacteria and Planctomycetes. Interestingly, four genera related to methane production namely, Methanobacterium, Methanosphaera, Methanothermus and Methanothermococcus were absent in a-CO2 but noticed under e-CO2T. The acetoclastic pathway was found as the predominant pathway for methanogenesis, whereas, the serine pathway was found as the principal metabolic pathway for CH4 oxidation in lowland rice. The abundances of reads of enzymes in the acetoclastic methanogenesis pathway and serine pathways of methanotrophy were much higher in e-CO2T (328 and 182, respectively) as compared with a-CO2 (118 and 98, respectively). Rice rhizosphere showed higher structural diversities and functional activities in relation to N metabolism involving nitrogen fixation, assimilatory and dissimilatory nitrate reduction and denitrification under e-CO2T than that of a-CO2. Among the three pathways of N metabolism, dissimilarity pathways were predominant in lowland rice rhizosphere and more so under e-CO2T. Consequently, under e-CO2T, CH4 emission, microbial biomass nitrogen (MBN) and dehydrogenase activities were 45%, 20% and 35% higher than a-CO2, respectively. Holistically, a high bacterial diversity and

Development and performance evaluation of a guided horizontal ...

African Journals Online (AJOL)

... and tested on the rice field of National Cereals Research Institute (NCRI), Moor plantation, Ibadan, to evaluate the performance of the machine. A 22 x 3 factorial experimental design with two replicates was used to analysis the effect of engine speed (1200, 1400 and 1800rpm), ecology (irrigated and rainfed-lowland) and ...

Interaction of genotype x management on vegetative growth and weed suppression of aerobic rice

NARCIS (Netherlands)

Zhao, D.L.; Bastiaans, L.; Atlin, G.N.; Spiertz, J.H.J.

2007-01-01

Water shortage in drought-prone rice-growing areas of the world is threatening conventional irrigated rice production systems, in which rice is transplanted into fields where standing water is maintained until harvest. Aerobic rice production systems, in which rice is grown as a direct-seeded upland

Stomatal conductance, mesophyll conductance, and transpiration efficiency in relation to leaf anatomy in rice and wheat genotypes under drought.

Science.gov (United States)

Ouyang, Wenjing; Struik, Paul C; Yin, Xinyou; Yang, Jianchang

2017-11-02

Increasing leaf transpiration efficiency (TE) may provide leads for growing rice like dryland cereals such as wheat (Triticum aestivum). To explore avenues for improving TE in rice, variations in stomatal conductance (gs) and mesophyll conductance (gm) and their anatomical determinants were evaluated in two cultivars from each of lowland, aerobic, and upland groups of Oryza sativa, one cultivar of O. glaberrima, and two cultivars of T. aestivum, under three water regimes. The TE of upland rice, O. glaberrima, and wheat was more responsive to the gm/gs ratio than that of lowland and aerobic rice. Overall, the explanatory power of the particular anatomical trait varied among species. Low stomatal density mostly explained the low gs in drought-tolerant rice, whereas rice genotypes with smaller stomata generally responded more strongly to drought. Compared with rice, wheat had a higher gm, which was associated with thicker mesophyll tissue, mesophyll and chloroplasts more exposed to intercellular spaces, and thinner cell walls. Upland rice, O. glaberrima, and wheat cultivars minimized the decrease in gm under drought by maintaining high ratios of chloroplasts to exposed mesophyll cell walls. Rice TE could be improved by increasing the gm/gs ratio via modifying anatomical traits. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Significance of the tropical fire ant Solenopsis geminata (hymenoptera: formicidae) as part of the natural enemy complex responsible for successful biological control of many tropical irrigated rice pests.

Science.gov (United States)

Way, M J; Heong, K L

2009-10-01

The tropical fire ant Solenopsis geminata (Fabricius) often nests very abundantly in the earthen banks (bunds) around irrigated rice fields in the tropics. Where some farmers habitually drain fields to the mud for about 3-4 days, the ants can quickly spread up to about 20 m into the fields where they collect food, including pest prey such as the eggs and young of the apple snail Pomacea caniculata (Lamarck) and insects such as lepidopterous larvae and hoppers, notably Nilaparvata lugens (Stäl) the brown planthopper (Bph) and green leafhoppers Nephotettix spp. Even in drained fields, the activity of S. geminata is restricted by rainfall in the wet season. The relatively few ant workers that forage characteristically into drained fields and on to the transplanted clumps of rice plants (hills) kill the normally few immigrant Bph adults but are initially slower acting than other species of the natural enemy complex. However, larger populations of Bph are fiercely attacked and effectively controlled by rapidly recruited ant workers; whereas, in the absence of the ant, the other natural enemies are inadequate. In normal circumstances, there is no ant recruitment in response to initially small populations of immigrant Bph and no evidence of incompatibility between ant foragers and other natural enemies such as spiders. However, when many ants are quickly and aggressively recruited to attack large populations of Bph, they temporarily displace some spiders from infested hills. It is concluded that, in suitable weather conditions and even when insecticides kill natural enemies within the rice field, periodic drainage that enables S. geminata to join the predator complex is valuable for ant-based control of pests such as snails and Lepidoptera, and especially against relatively large populations of Bph. Drainage practices to benefit ants are fully compatible with recent research, which shows that periodic drainage combats problems of 'yield decline' in intensively irrigated

Greenhouse gas emissions and global warming potential of traditional and diversified tropical rice rotation systems.

Science.gov (United States)

Weller, Sebastian; Janz, Baldur; Jörg, Lena; Kraus, David; Racela, Heathcliff S U; Wassmann, Reiner; Butterbach-Bahl, Klaus; Kiese, Ralf

2016-01-01

Global rice agriculture will be increasingly challenged by water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices. These factors are changing traditional cropping patterns from double-rice cropping to the introduction of upland crops in the dry season. For a comprehensive assessment of greenhouse gas (GHG) balances, we measured methane (CH4 )/nitrous oxide (N2 O) emissions and agronomic parameters over 2.5 years in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) in upland cultivation. Introduction of upland crops in the dry season reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Moreover, for practices including upland crops, CH4 emissions in the subsequent wet season with paddy rice were reduced by 54-60%. Although annual N2 O emissions increased two- to threefold in the diversified systems, the strong reduction in CH4 led to a significantly lower (P < 0.05) annual GWP (CH4  + N2 O) as compared to the traditional double-rice cropping system. Measurements of soil organic carbon (SOC) contents before and 3 years after the introduction of upland crop rotations indicated a SOC loss for the R-M system, while for the other systems SOC stocks were unaffected. This trend for R-M systems needs to be followed as it has significant consequences not only for the GWP balance but also with regard to soil fertility. Economic assessment showed a similar gross profit span for R-M and R-R, while gross profits for R-A were reduced as a consequence of lower productivity. Nevertheless, regarding a future increase in 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. © 2015 John Wiley & Sons Ltd.

Combining eddy-covariance measurements and Penman-Monteith type models to estimate evapotranspiration of flooded and aerobic rice

Science.gov (United States)

Facchi, Arianna; Masseroni, Daniele; Gharsallah, Olfa; Gandolfi, Claudio

2014-05-01

Rice is of great importance both from a food supply point of view, since it represents the main food in the diet of over half the world's population, and from a water resources point of view, since it consumes almost 40% of the water amount used for irrigation. About 90% of global production takes place in Asia, while European production is quantitatively modest (about 3 million tons). However, Italy is the Europe's leading producer, with over half of total production, almost totally concentrated in a large traditional paddy rice area between the Lombardy and Piedmont regions, in the north-western part of the country. In this area, irrigation of rice is traditionally carried out by continuous flooding. The high water requirement of this irrigation regime encourages the introduction of water saving irrigation practices, as flood irrigation after sowing in dry soil and intermittent irrigation (aerobic rice). In the agricultural season 2013 an intense monitoring activity was conducted on three experimental fields located in the Padana plain (northern Italy) and characterized by different irrigation regimes (traditional flood irrigation, flood irrigation after sowing in dry soil, intermittent irrigation), with the aim of comparing the water balance terms for the three irrigation treatments. Actual evapotranspiration (ET) is one of the terms, but, unlike others water balance components, its field monitoring requires expensive instrumentation. This work explores the possibility of using only one eddy covariance system and Penman-Monteith (PM) type models for the determination of ET fluxes for the three irrigation regimes. An eddy covariance station was installed on the levee between the traditional flooded and the aerobic rice fields, to contemporaneously monitor the ET fluxes from this two treatments as a function of the wind direction. A detailed footprint analysis was conducted - through the application of three different analytical models - to determine the position

Effectiveness of Ammonium-Nitrogen and Nitrate-Nitrogen in Irrigation Water in Paddy Rice without Topdressed Nitrogen at the Panicle Formation Stage

OpenAIRE

池田, 元輝; 渡辺, 孝賢; Ikeda, Motoki; Watanabe, Takayasu

2002-01-01

A pot experiment was conducted to evaluate the efficiency of ammonium- and nitrate- nitrogen contained in irrigation water during the reproductive growth period of paddy rice （Oryza sativa L. cv. Hinohikari） that did not receive topdressed nitrogen at the panicle formation stage. lrrigation of water containing a low level of nitrogen （7mgNL^-1） did not increase yields so much compared to topdressed nitrogen. lrrigation of water containing a high level of nitrogen （14mgNL^-1） caused substantia...

Transfer of technetium in the soil-rice plant system

International Nuclear Information System (INIS)

Yanagisawa, K.; Muramatsu, Y.

1995-01-01

In order to assess the behavior of Tc in flooded soil-plant systems, laboratory experiments have been done using 95m Tc as a tracer. Two common soil types in Japan, Andosol and Gray lowland soils, were used. Soil-plant transfer factors of Tc in rice grain were very low, i.e. 5 x 10 -5 for Andosol and 6 x 10 -4 for Gray lowland soil. It was found that the Tc concentrations in rice plants were influenced by those in soil solutions. Concentrations of 95m Tc in both soil solutions decreased rapidly in the early period of cultivation. It was observed that redox-potential (Eh) also decreased markedly following flooding. A relationship was found between the decrease of the 95m Tc concentrations in soil solutions and the drop of Eh in the soils. The Tc (VII) added to soil was transformed to insoluble Tc (IV) under the reduced conditions existing in flooded soil. (author). 10 refs., 2 figs., 4 tabs

The use of induced mutation combined with crossing in high quality rice breeding

International Nuclear Information System (INIS)

Do Huu At; Bui Huy Thuy; Nguyen Van Bich; Tran Duy Quy; Nguyen Minh Cong

2001-01-01

The high quality rice varieties: Tam thom mutant rice Var., DT17 rice Var, DT21 glutinous rice Var were formed by induced mutation combined with crossing. Tam thom mutant rice Var. lost photosensitivity, could be planted 2 crops/year. DT17 rice Var with high yielding capacity, suitable for growth on lowland in summer crop, is replacing step-by-step Moctuyen rice Var. in North Vietnam. DT21 glutinous rice Var. could be planted 2 crops/year and had short growth duration, average yield was 4.0-4.5 tons/ha. These three ones had good quality, soft and scent cooked rice, suitable for customers and export requirements. Tam thom mutant rice Var. DT17 rice Var., DT21 and glutinous rice Var. were adopted for regional production by Ministry of Agriculture and Rural Development and allowed to be in trial production. (author)

The use of induced mutation combined with crossing in high quality rice breeding

Energy Technology Data Exchange (ETDEWEB)

Do Huu At; Bui Huy Thuy; Nguyen Van Bich; Tran Duy Quy [Agricultural Genetics Institute, Division of Genetics and Hybrid Rice Technology, Hanoi (Viet Nam); Nguyen Minh Cong [Hanoi No. 1 Teacher Training Univ., Department of Genetics (Viet Nam)

2001-03-01

The high quality rice varieties: Tam thom mutant rice Var., DT17 rice Var, DT21 glutinous rice Var were formed by induced mutation combined with crossing. Tam thom mutant rice Var. lost photosensitivity, could be planted 2 crops/year. DT17 rice Var with high yielding capacity, suitable for growth on lowland in summer crop, is replacing step-by-step Moctuyen rice Var. in North Vietnam. DT21 glutinous rice Var. could be planted 2 crops/year and had short growth duration, average yield was 4.0-4.5 tons/ha. These three ones had good quality, soft and scent cooked rice, suitable for customers and export requirements. Tam thom mutant rice Var. DT17 rice Var., DT21 and glutinous rice Var. were adopted for regional production by Ministry of Agriculture and Rural Development and allowed to be in trial production. (author)

Assessment of Potential Climate Change Effects on the Rice Yield and Water Footprint in the Nanliujiang Catchment, China

Directory of Open Access Journals (Sweden)

Mingzhi Yang

2018-01-01

Full Text Available The Nanliujiang catchment is one of major rice production bases of South China. Irrigation districts play an important role in rice production which requires a large quantity of water. There are potential risks on future climate change in response to rice production, agricultural irrigation water use and pollution control locally. The SWAT model was used to quantify the yield and water footprint (WF of rice in this catchment. A combined method of automatic and manual sub-basin delineation was used for the model setup in this work to reflect the differences between irrigation districts in yield and water use of rice. We validated our simulations against observed leaf area index, biomass and yield of rice, evapotranspiration and runoff. The outputs of three GCMs (GFDL-ESM2M, IPSL-CM5A-LR and HadGEM2-ES under three RCPs (RCP2.6, 4.5, 8.5 were fed to the SWAT model. The results showed that: (a the SWAT model is an ideal tool to simulate rice development as well as hydrology; (b there would be increases in rice yield ranged from +1.4 to +10.6% under climate projections of GFDL-ESM2M and IPSL-CM5A-LR but slight decreases ranged from −3.5 to −0.8% under that of HadGEM2-ES; (c the yield and WFs of rice displayed clear differences in the catchment, with a characteristic that high in the south and low in the north, mainly due to the differences in climatic conditions, soil quality and fertilization amount; (d there would be a decrease by 45.5% in blue WF with an increase by 88.1% in green WF, which could provide favorable conditions to enlarge irrigated areas and take technical measures for improving green water use efficiency of irrigation districts; (e a clear rise in future grey WF would present enormous challenges for the protection of water resources and environmental pollution control in this catchment. So it should be to improved nutrient management strategies for the agricultural non-point source pollution control in irrigation districts

UV-B effects on crops: response of the irrigated rice ecosystem

International Nuclear Information System (INIS)

Olszyk, D.; Dai, Q.; Teng, P.; Leung, H.; Luo, Y.; Peng, S.

1996-01-01

Increasing ultraviolet-B (UV-B) radiation resulting from depletion of the stratospheric ozone layer could have damaging effects on crops. This paper reviews recent findings on direct effects of UV-B on rice growth and yield as well as indirect effects via impacts on other organisms in the rice (Oryza sativa) agroecosystem. The findings are based on research by scientists at the International Rice Research Institute (IRRI) in Los Baños, the Philippines, and their collaborators in China and the United States; with comparison to research by scientists in other countries. Current results indicate that while enhanced UV-B directly impacts many aspects of rice growth, physiology, and biochemistry under controlled phytotron conditions; in general rice growth and yield are not affected under natural field conditions. The difference in response may be related both to the levels of UV-B exposure used in phytotron vs. field studies and the lower ratio of UV-A to UV-B in the phytotron compared to field. In terms of indirect effects on rice blast disease, enhanced UV-B affected both the fungus itself (Pyricularia grisea) and the susceptibility of the rice plant to the fungus. Based on these data, simulation models estimated potential impacts of higher UV-B levels on blast severity and rice yield in different countries of southeast and east Asia. Ultimately, results from rice studies can be used to identify strategies to minimize any negative effects of UV-B on rice productivity

Reduced ABA Accumulation in the Root System is Caused by ABA Exudation in Upland Rice (Oryza sativa L. var. Gaoshan1) and this Enhanced Drought Adaptation.

Science.gov (United States)

Shi, Lu; Guo, Miaomiao; Ye, Nenghui; Liu, Yinggao; Liu, Rui; Xia, Yiji; Cui, Suxia; Zhang, Jianhua

2015-05-01

Lowland rice (Nipponbare) and upland rice (Gaoshan 1) that are comparable under normal and moderate drought conditions showed dramatic differences in severe drought conditions, both naturally occurring long-term drought and simulated rapid water deficits. We focused on their root response and found that enhanced tolerance of upland rice to severe drought conditions was mainly due to the lower level of ABA in its roots than in those of the lowland rice. We first excluded the effect of ABA biosynthesis and catabolism on root-accumulated ABA levels in both types of rice by monitoring the expression of four OsNCED genes and two OsABA8ox genes. Next, we excluded the impact of the aerial parts on roots by suppressing leaf-biosynthesized ABA with fluridone and NDGA (nordihydroguaiaretic acid), and measuring the ABA level in detached roots. Instead, we proved that upland rice had the ability to export considerably more root-sourced ABA than lowland rice under severe drought, which improved ABA-dependent drought adaptation. The investigation of apoplastic pH in root cells and root anatomy showed that ABA leakage in the root system of upland rice was related to high apoplastic pH and the absence of Casparian bands in the sclerenchyma layer. Finally, taking some genes as examples, we predicted that different ABA levels in rice roots stimulated distinct ABA perception and signaling cascades, which influenced its response to water stress. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Optimization of planting pattern plan in Logung irrigation area using linear program

Science.gov (United States)

Wardoyo, Wasis; Setyono

2018-03-01

Logung irrigation area is located in Kudus Regency, Central Java Province, Indonesia. Irrigation area with 2810 Ha of extent is getting water supply from Logung dam. Yet, the utilization of water at Logung dam is not optimal and the distribution of water is still not evenly distributed. Therefore, this study will discuss about the optimization of irrigation water utilization based on the beginning of plant season. This optimization begins with the analysis of hydrology, climatology and river discharge in order to determine the irrigation water needs. After determining irrigation water needs, six alternatives of planting patterns with the different early planting periods, i.e. 1st November, 2nd November, 3rd November, 1st December, 2nd December, and 3rd December with the planting pattern of rice-secondary crop-sugarcane is introduced. It is continued by the analysis of water distribution conducted using linear program assisted by POM-Quantity method for Windows 3 with the reliable discharge limit and the available land area. Output of this calculation are to determine the land area that can be planted based on the type of plant and growing season, and to obtaine the profits of harvest yields. Based on the optimum area of each plant species with 6 alternatives, the most optimum area was obtained at the early planting periods on 3rd December with the production profit of Rp 113.397.338.854,- with the planting pattern of rice / beans / sugarcane-rice / beans / sugarcane-beans / sugarcane.

An assessment of Wx microsatellite allele, alkali degradation and differentiation of chloroplast DNA in traditional black rice (Oryza sativa L.) from Thailand and Lao PDR.

Science.gov (United States)

Prathepha, Preecha

2007-01-15

Thailand and Lao PDR are the country's rich rice diversity. To contribute a significant knowledge for development new rice varieties, a collection of 142 black rice (Oryza sativa) accessions were determined for variation of physico-chemical properties, Wx microsatellite allele, Wx allele and chloroplast DNA type. The results showed that amylose content of black rice accessions were ranged from 1.9 to 6.8%. All of the alkali disintegration types (high, intermediate and low) was observed in these rice with average of 1.75 on the 1-3 digestibility scale. The unique Wx microsatellite allele (CT)17 was found in these samples and all black rice strains carried Wx(b) allele. In addition, all black rice accessions were found the duplication of the 23 bp sequence motif in the exon 2 of the wx gene. This evidence is a common phenomenon in glutinous rice. Based on two growing condition for black rice, rainfed lowland and rainfed upland, chloroplast DNA type was distinct from each other. All rice strains from rainfed lowland was deletion plastotype, but all other rainfed upland strains were non-deletion types.

Rice yield prediction from yield components and limiting factors

NARCIS (Netherlands)

Casanova, D.; Goudriaan, J.; Catala Former, M.M.; Withagen, J.C.M.

2002-01-01

This article aims to quantify growth at field level in relation to crop status and soil properties in irrigated direct-seeded rice. Forty fields were selected in the Ebro Delta (Spain). Rice growth was monitored and soil properties measured. Yield was related to soil properties by a deductive

Risk assessment and vertical distribution of thallium in paddy soils and uptake in rice plants irrigated with acid mine drainage.

Science.gov (United States)

Huang, Xuexia; Li, Ning; Wu, Qihang; Long, Jianyou; Luo, Dinggui; Zhang, Ping; Yao, Yan; Huang, Xiaowu; Li, Dongmei; Lu, Yayin; Liang, Jianfeng

2016-12-01

The objective of this paper is to assess the influence of irritating paddy fields with acid mine drainage containing thallium (Tl) to rice plant-soil system and potential health risks for local residents. Vertical distribution of Tl, pH, organic matter (OM), and cation exchange capacity (CEC) in 24 paddy soil profiles around Yunfu pyrite mine area was investigated. Rice plant samples were collected from the corresponding soil sampling site. The results showed that Tl concentrations in paddy soils at 0-60 cm depth range from 3.07 to 9.42 mg kg -1 , with a mean of 5.74 mg kg -1 , which were significantly higher than the background value of soil in China (0.58 mg kg -1 ). On the whole, Tl contents in paddy soil profiles increased quickly with soil depth from 0 to 30 cm and decreased slowly with soil depth from 30 to 60 cm. The soil Tl content was significant negatively correlated with soil pH. The mean content of Tl in the root, stem, leaf, and rice was 4.36, 1.83, 2.74, and 1.42 mg kg -1 , respectively, which exceeded the proposed permissible limits for foods and feedstuffs in Germany. The Tl content in various tissues of the rice plants followed the order root > leaf > stem (rice), which suggested that most Tl taken up by rice plants retained in the root, and a little migrated to the leaf, stem, and rice. Correlation analysis showed that Tl content in root was significant positively correlated with Tl content in leaf and rice. The ranges of hazard quotient (HQ) values were 4.08∼24.50 and 3.84∼22.38 for males and females, respectively. Males have higher health risk than females in the same age group. In childhood age groups (2 to <21 years) and adult age groups (21 to <70 years), the highest health risk level was observed in the 11 to 16 age group and 21 to 50 age group, respectively. The findings indicated that regular irrigation with Tl-bearing acid mine drainage led to considerable contamination of Tl in paddy soil and rice plant. Local government

Parasitic weed incidence and related economic losses in rice in Africa

NARCIS (Netherlands)

Rodenburg, Jonne; Demont, Matty; Zwart, Sander J.; Bastiaans, Lammert

2016-01-01

Parasitic weeds pose increasing threats to rain-fed rice production in Africa. Most important species are Striga asiatica, S. aspera and S. hermonthica in rain-fed uplands, and Rhamphicarpa fistulosa in rain-fed lowlands. Information on the regional spread and economic importance of parasitic weeds

Management of soil physical properties of lowland puddled rice soil for sustainable food production

International Nuclear Information System (INIS)

Bhagat, R.M.

2004-01-01

About 3 billion people who rely on rice as their staple food today will have multiplied to some 4.4 billion by the middle of this century. With rice demand growing at an average rate of about 3 percent annually, 70 percent more rice has to be produced in next 30 years compared to present day production levels. More rice has to come from less favorable environments, with less water and nutrients. Agricultural population densities on Asia's rice producing lands are among the highest in the world and continue to increase at a remarkable rate. Rice has widely adapted itself: to the hot Australian and Egyptian deserts, to the cool Himalayan foothills of Nepal. Hill tribes in Southeast Asia plant it on slash-and-burned forest slopes; that's upland rice. However, low lying areas in Asia, which are subject to uncontrolled flooding, are home to more than 100 million poor farmers. Puddling or wet tillage in rice, decreases total soil porosity only slightly, but markedly changes porosity distribution with both storage and residual porosity increasing at the expanse of transmission porosity. Soil texture plays an important role in soil water retention following soil disturbance. Cracking pattern of the soils is studied after six years of different levels of regular addition of residue. Cracking pattern at a soil surface affects the hydrodynamic properties of soil. Cracking extends the soil-air interface into the soil profile and thereby may increase the moisture loss through evaporation

Influence of Climate Factors on Rice Yields in Cambodia

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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.

Economic Valuation of Sufficient and Guaranteed Irrigation Water Supply for Paddy Farms of Guilan Province

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Mohammad Kavoosi Kalashami

2014-08-01

Full Text Available Cultivation of the strategic crop of rice highly depends to the existence of sufficient and guaranteed irrigation water, and water shortage stresses have irreparable effects on yield and quality of productions. Decrease of the Sefidrud river inflow in Guilan province which is the main source of supplying irrigation water for 171 thousand hectares under rice cropping area of this province, has been challenged sufficient and guaranteed irrigation water supply in many regions of mentioned province. Hence, in present study estimating the value that paddy farmers place on sufficient and guaranteed irrigation water supply has been considered. Economic valuation of sufficient and guaranteed irrigation water supply improves water resource management policies in demand side. Requested data set were obtained on the base of a survey and are collected from 224 paddy farms in rural regions that faced with irrigation water shortages. Then, using open-ended valuation approach and estimation of Tobit model via ML and two stages Heckman approach, eliciting paddy farmers' willingness to pay for sufficient and guaranteed irrigation water supply has been accomplished. Results revealed that farmers in investigated regions willing to pay 26.49 percent more than present costs of providing irrigation water in order to have sufficient and guaranteed irrigation water.

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).

The influence of acid rain on the intake of trace elements into rice plant from soils

International Nuclear Information System (INIS)

Tanizaki, Yoshiyuki; Nakamura, Masaru; Maeno, Tomokazu

1995-01-01

Rice plant samples were grown in 14 cultivative pots by irrigation using the six conditions of artificial acid rain waters (pH: 6.5, 6.0, 4.5, 3.5, 3.0 and 2.5) and tap water (pH: 7.5). The rice grain yielded were separated into three parts, i.e., polished rice, bran and chaff, and they were reduced to powder one by one. Twenty six element contents in the three parts of grain (each 14 samples) were determined by a neutron activation analysis. The contents of Cr, Fe, Ni, Zn, Cu, Rb, Mo in the polished rice increased with decreasing of pH of the irrigation waters. The contents of Se and Br, on the contrary, decreased with decreasing of pH of the irrigation waters. Significant changes of the contents were not observed for the elements Na, Al, Cl, Sc, Mn, Co, V. The enrichment factor of trace elements to soils were calculated for the polished rice, bran and chaff. The high enrichments of Cl, Mo, Zn, Se, Cu and Ni were observed in the polished rice. The elements K, Rb, Mn, Mg and Cr were highly concentrated in the bran. (author)

affect rice in integrated rice-fish culture in Lake Victoria Basin, Kenya?

African Journals Online (AJOL)

AGHOGHO A

Rice field ecology and fish culture - an overview. Hydrobiologia 259:91-113. Fernando CH, Halwart M (2000). Fish farming in irrigation systems. Fisheries Management and Ecol. 7:45-54. Frei M, Razzak MA, Hossain MM, Ochme M, Dewan S, Becker K. (2007). Performance of common carp, Cyprinus carpio L. and Nile.

Ground-water pumpage in the Willamette lowland regional aquifer system, Oregon and Washington, 1990

Science.gov (United States)

Collins, Charles A.; Broad, Tyson M.

1996-01-01

Ground-water pumpage for 1990 was estimated for an area of about 5,700 square miles in northwestern Oregon and southwestern Washington as part of the Puget-Willamette Lowland Regional Aquifer System Analysis study. The estimated total ground-water pumpage in 1990 was about 340,000 acre-feet. Ground water in the study area is pumped mainly from Quaternary sediment; lesser amounts are withdrawn from Tertiary volcanic materials. Large parts of the area are used for agriculture, and about two and one-half times as much ground water was pumped for irrigation as for either public- supply or industrial needs. Estimates of ground- water pumpage for irrigation in the central part of the Willamette Valley were generated by using image-processing techniques and Landsat Thematic Mapper data. Field data and published reports were used to estimate pumpage for irrigation in other parts of the study area. Information on public- supply and industrial pumpage was collected from Federal, State, and private organizations and individuals.

Manutenção da área foliar e produtividade de arroz irrigado com a aplicação de fertilizantes foliares no estádio de emborrachamento Foliar area maintenance and yield with application of foliar fertilizers on booting stage of irrigated rice

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Edinalvo Rabaioli Camargo

2008-08-01

Full Text Available A utilização de fertilizantes foliares, aplicados ao final do ciclo da cultura do arroz irrigado, pode proporcionar complementação nutricional para a planta e proteção contra patógenos com reflexos na produtividade. O objetivo do estudo foi avaliar a utilização de fertilizantes foliares, aplicados no estádio de emborrachamento, sobre a produtividade do arroz irrigado. O experimento foi conduzido no ano agrícola 2005/2006, em área experimental de várzea do Departamento de Fitotecnia da Universidade Federal de Santa Maria. O delineamento experimental utilizado foi o de blocos ao acaso com quatro repetições. Os tratamentos foram compostos por 10 fertilizantes foliares, dois produtos aplicados via sementes, um fungicida e a testemunha. Os fertilizantes não influenciaram qualquer parâmetro avaliado. As condições climáticas e o manejo da adubação anterior à aplicação dos tratamentos foliares propiciaram condições favoráveis para o arroz expressar o seu potencial produtivo, em torno de 10.000kg ha-1. Neste nível de produtividade, os produtos utilizados não aumentaram a produtividade do arroz irrigado.The use of foliar fertilizers applied to the reproductive phase of rice can improve the plant nutrition and protect the field against foliar diseases with gains in yield. The objective of this experiment was to evaluate the use of the foliar fertilizers applied to the booting stage in order to verify the irrigated rice yield. The experiment was carried out in 2005/06 in a lowland area in Santa Maria-RS, Brazil. The treatments, arranged in a randomized block design with four replications, were constituted by 10 foliar fertilizers available in the market, two products applied to seeds, a fungicide, and a check treatment. The treatments presented no effects on any of the variables studied. The suitable climatic conditions and the fertilizer management carried out before the application of the foliar treatments led to the

Efficacy and economics of different herbicides in aerobic rice system ...

African Journals Online (AJOL)

Aerobic rice system, the most promising irrigation water saving rice production technology, is highly impeded by severe weed pressure. Weed control through the use of same herbicide causes development of herbicide resistant weed biotypes and serious problem in weed management. This study was aimed at finding out ...

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

Water and radiation use efficiencies of transplanted rice (Oryza sativa L.) at different plant densities and irrigation regimes under semi-arid environment

International Nuclear Information System (INIS)

Ahmad, S.; Ali, H.; Shad, S.A.; Zia-ul-Haq, M.; Ahmad, A.; Maqsood, M.; Khan, M.B.; Mehmood, S.; Hussain, A.

2008-01-01

Growth and yield of rice (Oryza sativa L.), in response to plant densities and irrigation (optimum to stress) were analyzed in terms of interception and utilization of photo-synthetically active radiation (PAR) and water use efficiency (WUE). The amount of PAR intercepted and cumulative evapotranspiration (ET) by each treatment was estimated from the measured leaf area index. The relationships between total dry matter grain yield and accumulated intercepted PAR and cumulative ET were linear. Yield differences among the treatments were attributed to the amount of PAR intercepted and water transpired their efficiencies of utilization or both. The fraction of intercepted radiation and WUE was significantly affected by the plant densities and various irrigation regimes, while, radiation utilization efficiency (RUE) and water use efficiency (WUE) for TDM varied from 1.15 g MJ-1 to 1.36 g MJ-1 and 22.6 kg per ha mm-1 to 24.3 kg per ha mm-1 during both the seasons

Effect of resource conserving techniques on crop productivity in rice-wheat cropping system

International Nuclear Information System (INIS)

Mann, R.A.; Munir, M.; Haqqani, A.M.

2004-01-01

Rice-wheat cropping system is the most important one in Pakistan. The system provides food and livelihood for more than 15 million people in the country. The productivity of the system is much lower than the potential yields of both rice and wheat crops. With the traditional methods, rice-wheat system is not a profitable one to many farmers. Hence, Cost of cultivation must be reduced and at the same time, efficiency of resources like irrigation water, fuel, and fertilizers must be improved to make the crop production system more viable and eco- friendly. Resource conserving technology (RCT) must figure highly in this equation, since they play a major role in achieving the above goals. The RCT include laser land leveling, zero-tillage, bed furrow irrigation method and crop residue management. These technologies were evaluated in irrigated areas of Punjab where rice follows wheat. The results showed that paddy yield was not affected by the new methods. Direct seeding of rice crop saved irrigation water by 13% over the conventionally planted crop. Weeds were the major problem indirect seeded crop, which could be eliminated through cultural, mechanical and chemical means. Wheat crop on beds produced the highest yield but cost of production was minimum in the zero-till wheat crop. Planting of wheat on raised beds in making headway in low- lying and poorly drained areas. Thus, resource conserving tillage technology provides a tool for making progress towards improving and sustaining wheat production system, helping with food security and poverty alleviation in Pakistan in the next few decades. (author)

Rainfall Variability, Adaptation through Irrigation, and Sustainable Management of Water Resources in India

Science.gov (United States)

Fishman, R.

2013-12-01

Most studies of the impact of climate change on agriculture account for shifts in temperature and total seasonal (or monthly) precipitation. However, climate change is also projected to increase intra-seasonal precipitation variability in many parts of the world. To provide first estimates of the potential impact, I paired daily rainfall and rice yield data during the period 1970-2004, from across India, where about a fifth of the world's rice is produced, and yields have always been highly dependent on the erratic monsoon rainfall. Multivariate regression models revealed that the number of rainless days during the wet season has a statistically robust negative impact on rice yields that exceeds that of total seasonal rainfall. Moreover, a simulation of climate change impacts found that the negative impact of the projected increase in the number of rainless days will trump the positive impact of the projected increase in total precipitation, and reverse the net precipitation effect on rice production from positive (+3%) to negative (-10%). The results also indicate that higher irrigation coverage is correlated with reduced sensitivity to rainfall variability, suggesting the expansion of irrigation can effectively adapt agriculture to these climate change impacts. However, taking into account limitations on water resource availability in India, I calculate that under current irrigation practices, sustainable use of water can mitigate less than a tenth of the impact.

Effect of selenium application on arsenic uptake in rice (Oryza sativa L.).

Science.gov (United States)

Kaur, Sumandeep; Singh, Dhanwinder; Singh, Kuldip

2017-09-01

Alluvial aquifers of the agrarian state of Punjab of southwestern arid zone used for irrigation of rice crops are rich in arsenic concentration. In the present study, rice (Oryza sativa L.) crops were raised in pots in a greenhouse with a purpose to study whether selenium (Se) application was effective in ameliorating As uptake. The rice crop was irrigated with arsenic laced water (0, 2.5, 5.0, 10.0 μM As L -1 ) throughout the growing period, without and with selenium (0.05 and 0.10 mg kg -1 ) added through mustard biomass, grown ex situ in seleniferous soil. Arsenic uptake and dry matter yield in different parts of the rice crop were assayed after application of As alone and simultaneous supplementations (As + Se). An antagonistic interaction between Se and As was observed. Addition of As through irrigation water significantly reduced yield of rice grain, straw and root. However, subsequent addition of Se helped in mitigating the harmful effect of As and countered the yield reduction caused due to As toxicity. The effect of Se on dry matter yield was more pronounced at its higher dose (0.10 mg kg -1 ) as compared to its lower dose (0.05 mg kg -1 ). The presence of Se either alone or added along with As significantly reduced the As concentration and its uptake by different parts of rice and higher reduction in As concentration was observed with addition of the highest level of applied Se (0.10 mg kg -1 ). Our observations indicated that Se supplementation might be favourable to reduce As accumulation and toxicity in rice crops.

Avaliação de linhagens de arroz irrigado com tipo de grão para a culinária japonesa para o Estado de Roraima. = Evaluation of irrigated rice strains with grain type for Japanese cuisine in the State of Roraima.

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Antonio Carlos Centeno Cordeiro

2010-12-01

and quality of irrigated rice strains with grain types for Japanese cuisine, under the cropping conditions of Roraima. From December 2003 to March 2004, ten strains of irrigated rice were evaluated in a randomized block experimentaldesign, with four replications. In addition to the agronomic traits it was also evaluated the quality of the grains. The strain CNAi9903 was the most suitable relative to the characteristic of low amylose content, presenting good productivity and adaptation tothe growing conditions in lowland of Roraima, and therefore the greatest potential for use in Japanese cuisine.

Investigation of Flooding Water Depth Management on Yield and Quality Indices of Rice Production

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Hamid Reza Salemi

2017-03-01

Full Text Available Introduction: Water crisis as a majorlimitation factor for agriculture, like other arid and semiarid regions exists in Isfahan province which is located in the central part of the Zayandehrud River Basin (ZRB. Rice appears to be the far-most profitable crop but at the same time it has a major impact on basin scale water resources, especially affecting downstream farmers. In the study area (ShahidFozveh Research Station, the water resources for agricultural production face heightened competition from other sectors like industry and domestic use. This necessitates considering different crops, altered agricultural systems and innovative methods that can reduce the water requirements for the irrigation of rice. The Alternative Wetting and Drying (AWD seems to be an effective method reducing water use for rice crops and possibly save the water for downstream users. There have been no qualitative evaluations of rice production under deficit irrigation practices in Isfahan area. This study sought to determine, under study area conditions, the quantities of water irrigation used with AWD practices, the resulting water productivity (WP and the effects of alternative irrigation management on yield, quality indices and rice production performance. Materials and Methods: The ZRB (41,500 km2 is a closed basin with no outlet to the sea. The research was conducted in the Qahderijan region of Isfahan province, which is located in the central part of the ZRB. The ShahidFozveh Agricultural Research Station (32°, 36’ N, 51°, 36’ E is located at the altitude of 1612 m above the sea level. In order to improve WP and illustration of the impact of various levels of flooding depth on grain yield and quality indices at rice production, a field experiment (3000 m2 was conducted at ShahidFozveh Research Station for 2 years arranged in a split plot design with three replications. It will be necessary to use different scenario of water flooding depth management to

Influence of gypsum amendment on methane emission from paddy rice soil affected by saline irrigation water

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Ei Ei eTheint

2016-01-01

Full Text Available To investigate the influence of gypsum application on methane (CH4 emission from paddy rice soil affected by saline irrigation water, two pot experiments with the rice cultivation were conducted. In pot experiment (I, salinity levels 30 mMNaCl (S30 and 90 mMNaCl (S90, that showed maximum and minimum CH4 production in an incubation experiment, respectively, were selected and studied without and with application of 1 Mg gypsum ha-1(G1. In pot experiment (II, CH4 emission was investigated under different rates of gypsum application: 1 (G1, 2.5 (G2.5 and 5 (G5 Mg gypsum ha-1 under a non-saline and saline condition of 25 mMNaCl (S25. In experiment (I, the smallest CH4 emission was observed in S90. Methane emission in S30 was not significantly different with the non-saline control. The addition of gypsum showed significant lower CH4 emission in saline and non-saline treatments compared with non-saline control. In experiment (II, the CH4 emissions in the saline treatments were not significantly different to the non-saline treatments except S25-G5. However, our work has shown that gypsum can lower CH4 emissions under saline and non-saline conditions. Thus, gypsum can be used as a CH4 mitigation option in non-saline as well as in saline conditions.

Effects of Mineral N and P Fertilizers on Yield and Yield Components of Flooded Lowland Rice on Vertisols of Fogera Plain, Ethiopia

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Heluf Gebrekidan

2006-10-01

significantly (P ≤ 0.01. Besides, grain yield was positively and significantly associated with number of panicles per m2 (r = 0.61∗∗, number of spikelets per panicle (r = 0.49∗∗, panicle length (r = 0.54∗∗, dry matter accumulation (r = 0.46∗, thousand grain weight (r = 0.41∗ and harvest index (r = 0.39∗. These indicate that N and P application increased grain yield of rice by positively affecting the important yield components of the crop. Therefore, taking the findings of the present study into consideration, it may be tentatively concluded that the farmers at the Fogera plain may apply a combination of 60 kg N and 13.2 kg P ha−1 to improve the grain yield of flooded lowland rice cultivated on heavy black clay soils (Vertisols under rain fed conditions.

Economics of weed suppressive rice cultivars in flood- and furrow-irrigated systems

Science.gov (United States)

Weeds are a major constraint to rice production. In the U.S, weeds in rice are controlled primarily with synthetic herbicides. Intensive herbicide application in rice also has many potential drawbacks, resulting in environmental pollution, human health concerns, and development of weed resistance. B...

Effect of straw application on nitrogen uptake and growth of rice

International Nuclear Information System (INIS)

Haryanto; Idawati.

1990-01-01

A pot experiment has been conducted to know the effect of straw application on the efficiency of nitrogen uptake and growth rice plant. The rice straw was applied at different time i.e. 0, 1, 2, 3 and 4 weeks before tranplanting. Soil without rice straw was used as control. Thirty gram of rice straw having 3.61 percent of N-15 atom excess was incorporated into 6 kg of latosol soil originated from Pasar jumat, in which Atomoita I, a lowland rice variety, was planted. Urea was given once at the tranplanting time. The result showed that the longer the time of the rice straw application prior to the transplanting time, the higher the N-straw uptake efficiency in the rice plant at any different stages. The highest efficiency was 6.14 percent, reached with straw applicaions at 4 weeks before tranplanting. Compared to the control, straw applications 2 weeks or more before tranplanting resulted in higher grain production, while application at or before 2 weeks of tranplanting produced lower production. (authors). 9 refs.; 5 tabs

COMPETITIVENESS OF NIGERIAN RICE AND MAIZE PRODUCTION ECOLOGIES: A POLICY ANALYSIS APPROACH

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Victor Olusegun Okoruwa

2011-05-01

Full Text Available The Nigerian rice and maize sectors are faced with decreasing supply and increasing demand as rice and maize have taken a strategic place of other staples leading to excessive importation and increasing government intervention. This study therefore assesses the competitiveness of Nigerian rice and maize production ecologies using the policy analysis matrix (PAM on a sample of 122 farmers. Results of the PAM revealed that outputs from the production ecologies are taxed. This is further confirmed by the Effective protection coefficient (EPC and Subsidy ratio to producers (SRP values, however, the production ecologies are subsidized on the use of tradable inputs. The production ecologies show a strong competitiveness at the farm level (under irrigated rice, upland rice and upland maize and a strong comparative advantage. Sensitivity analysis indicated that a 50 percent increase in output and a 13.3 percent depreciation of the domestic currency will increase competitiveness and comparative advantage of rice and maize production in all ecologies. The study recommends that government should ensure a level of policy stability in the rice and maize sectors, assist farmers with irrigated water scheme to ensure constant water supply, and increase the level of output through provision of improved seed varieties.

Closing the irrigation deficit in Cambodia: Implications for transboundary impacts on groundwater and Mekong River flow

Science.gov (United States)

Erban, Laura E.; Gorelick, Steven M.

2016-04-01

Rice production in Cambodia, essential to food security and exports, is largely limited to the wet season. The vast majority (96%) of land planted with rice during the wet season remains fallow during the dry season. This is in large part due to lack of irrigation capacity, increases in which would entail significant consequences for Cambodia and Vietnam, located downstream on the Mekong River. Here we quantify the extent of the dry season ;deficit; area in the Cambodian Mekong River catchment, using a recent agricultural survey and our analysis of MODIS satellite data. Irrigation of this land for rice production would require a volume of water up to 31% of dry season Mekong River flow to Vietnam. However, the two countries share an aquifer system in the Mekong Delta, where irrigation demand is increasingly met by groundwater. We estimate expansion rates of groundwater-irrigated land to be >10% per year in the Cambodian Delta using LANDSAT satellite data and simulate the effects of future expansion on groundwater levels over a 25-year period. If groundwater irrigation continues to expand at current rates, the water table will drop below the lift limit of suction pump wells, used for domestic supply by >1.5 million people, throughout much of the area within 15 years. Extensive groundwater irrigation jeopardizes access for shallow domestic water supply wells, raises the costs of pumping for all groundwater users, and may exacerbate arsenic contamination and land subsidence that are already widespread hazards in the region.

Utilization of wastewater on seed germination and physioogical parameters of rice (Oryza sativa L.)

Science.gov (United States)

Huy, V.; Iwai, C. B.

2018-03-01

Due to increasing world population and demand, fresh water availability is becoming a limited resource. Reusing wastewater for agriculture has received attention since it contains nutrients, which are beneficial for growing crops. Even though wastewater can be used as the nutrient source for the plant, the toxicity of wastewater can still be a cause for concern and investigation. The main objective of this paper was to assess the effect of different sources of wastewater on the germination of Jasmine rice (KDML105), White rice (Phatum Thani 1), and Sticky rice (RD6) under laboratory conditions. Petri dish cultures were used with various concentrations (0, 50, and 100%) of wastewater collected from swine farm, aquaculture activity, and domestic. Seed germination, root length, shoot length, seed vigor index, fresh weight and dry weight were measured after each experiment. The results have shown that domestic wastewater and aquaculture activity wastewater did not decrease performance of Jasmine rice (KDML105), White rice (Phatum thani 1), and Sticky rice (RD6) while the germination of Jasmine rice (KDML105), White rice (Phatum thani 1), and Sticky rice (RD6) decreased when irrigated with swine farm wastewater. Therefore, using domestic and aquaculture activity wastewater for irrigation are suitable for growth of these crop.

Desempenho da cultura do arroz irrigado com esgotos sanitários previamente tratados Performance of upland rice irrigated with previously treated domestic sewage

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José T. de Sousa

2001-04-01

Full Text Available Com o presente trabalho, objetiva-se avaliar o desempenho da cultura do arroz, irrigada com efluentes de esgoto sanitário provenientes de tanque séptico e de lagoa de estabilização, tomando-se como referencial comparativo a mesma cultura irrigada com água de abastecimento em solos fertilizados com adubos minerais e sem adubo mineral. No experimento foi utilizada a cultivar Diamante, originada da EMBRAPA Meio Norte, e o sistema experimental era constituído por 4 tabuleiros com 10 m² de área unitária, irrigados por inundação intermitente, procurando-se manter sempre uma média de 5 cm de lâmina líquida a cada dois dias, durante o período de 4 meses. A análise dos dados demonstra que a produtividade da cultivar Diamante, irrigada com efluente de tanque séptico, foi superior à produtividade da mesma cultivar irrigada com água de abastecimento em solo com adubação mineral. Salienta-se, ainda, que os grãos da cultivar irrigada com efluente do tanque séptico não apresentaram, em nenhum exame, indicadores de contaminação fecal.This paper evaluates the rice crop performance irrigated by domestic wastewater effluents from septic tanks and ponds in comparison to that irrigated by muncipal water supplies in soils with and without mineral fertilizers. The "Diamante" rice cultivar originated from EMBRAPA Meio Norte was used in the experiment. The experimental system consisted of 4 plots of 10 m². The plots were intermitlenttly flooded every two days during the period of four months to maintain on an average 5 cm of water depth. The analytical data show that the productivity of the cultivar "Diamante" in this system was higher than that of the same cultivar irrigated by muncipal water supplies in soils with mineral fertilizers. Also when examined, its grains did not present any traces of fecal contamination.

Seed Priming Improves Agronomic Trait Performance under Flooding and Non-flooding Conditions in Rice with QTL SUB1

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Ramni Kumar SARKAR

2012-12-01

Full Text Available Farmers in South East Asia are adopting rice crop establishment methods from transplanting to direct wet or dry seeding as it requires less labour and time and comparatively less energy than transplanting. In contrast to irrigated condition, in rainfed lowland, direct seeding is a common practice. Early flooding controls weeds but decreases seedling establishment in direct seeded rice. Anaerobic germination is an important trait to counteract damages caused by early flooding. Management options which can help in crop establishment and improve crop growth under flooding might remove the constraints related to direct seeding. The investigation was carried out with two near isogenic lines Swarna and Swarna-Sub1. Swarna-Sub1 is tolerant to submergence whereas Swarna is susceptible. Seed priming was done with water and 2% Jamun (Syzygium cumini leaf extract, and it improved seedling establishment under flooding. Acceleration of growth occurred due to seed pretreatment, which resulted longer seedling and greater accumulation of biomass. Seed priming greatly hastened the activities of total amylase and alcohol dehydrogenase in Swarna-Sub1 than in Swarna. Swarna-Sub1 outperformed Swarna when the plants were cultivated under flooding. Weed biomass decreased significantly under flooding compared to non-flooding conditions. Seed priming had positive effects on yield and yield attributing parameters both under non-flooding and early flooding conditions.

Atributos químicos do solo afetado pelo manejo da água e do fertilizante potássico na cultura de arroz irrigado Chemical properties of soil affected by water and potassium fertilization management in irrigated rice

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Alberto B. dos Santos

2002-04-01

Full Text Available O desenvolvimento das culturas nas várzeas é extremamente influenciado pelo manejo destas, devido aos atributos químicos e físico-hídricos que elas possuem. O decréscimo na produtividade, verificado no monocultivo contínuo de arroz (Oryza sativa L. irrigado, pode estar relacionado à redução na fertilidade do solo, em decorrência da lixiviação de nutrientes. Com o objetivo de se avaliar os efeitos de manejo da água (MA1 - inundação contínua e MA2 - inundação intermitente seguida de contínua e do fertilizante potássico (K1 - na semeadura; K2 - adubação parcelada e K3 - meia dosagem parcelada na cultura de arroz irrigado sobre alguns atributos químicos de um solo Gley Pouco Húmico, foram conduzidos experimentos durante três anos consecutivos. Na inundação contínua ocorre maior lixiviação de cálcio e de potássio, teor de fósforo no solo e saturação por alumínio e menor pH na camada superficial do solo em relação à inundação intermitente, além de aumento do teor de potássio e do pH e diminuição de saturação por alumínio em profundidade. A inundação intermitente e o parcelamento do potássio podem contribuir na redução das perdas de nutrientes em solos de várzea que apresentam percolação excessiva. Alguns atributos químicos do solo podem ser melhorados através do manejo adequado da cultura do arroz irrigado, envolvendo manejo da água e do fertilizante potássico.Crop performance in lowland soils is influenced by management practices due to change in physico-chemical properties. Grain yield decrease in continuous monoculture of irrigated rice (Oryza sativa L. may be associated with decrease in soil fertility due to leaching of nutrients. The objective of this study was to evaluate effect of water management (WM1 - continuous flooding, and WM2 - intermittent flooding followed by continuous flooding and potassium fertilization (K1 - at sowing; K2 - fractional application, and K3 - fractional

Future Irrigation Requirement of Rice Under Irrigated Area - Uncertainty through GCMs and Crop Models : A Case Study of Indo-Gangetic Plains of India

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Pillai, S. N.; Singh, H.; Ruane, A. C.; Boote, K. G.; Porter, C.; Rosenzweig, C.; Panwar, A. S.

2017-12-01

Indo-Gangetic Plains (IGP), the food basket of South Asia, characterised by predominantly cereal-based farming systems where livestock is an integral part of farm economy. Climate change is projected to have significant effects on agriculture production and hence on food and livelihood security because more than 90 per cent farmers fall under small and marginal category. The rising temperatures and uncertainties in rainfall associated with global warming may have serious direct and indirect impacts on crop production. A loss of 10-40% crop production is predicted in different crops in India by the end of this century by different researchers. Cereal crops (mainly rice and wheat) are crucial to ensuring the food security in the region, but sustaining their productivity has become a major challenge due to climate variability and uncertainty. Under AgMIP Project, we have analysed the climate change impact on farm level productivity of rice at Meerut District, Uttar Pradesh using 29 GCMs under RCP4.5 and RCP8.5 during mid-century period 2041-2070. Two crop simulation models DSSAT4.6 and APSIM7.7 were used for impact study. There is lot of uncertainty in yield level by different GCMs and crop models. Under RCP4.5, APSIM showed a declining yield up to 14.5 % while DSSAT showed a declining yield level of 6.5 % only compared to the baseline (1980-2010). However, out of 29 GCMs, 15 GCMs showed negative impact and 14 showed positive impact under APSIM while it showed 21 and 8 GCMs, respectively in the case of DSSAT. DSSAT and APSIM simulated irrigation water requirement in future of the order of 645±75 mm and 730±107 mm, respectively under RCP4.5. However, the same will be of the order of 626 ± 99 mm and 749 ± 147 mm, respectively under RCP8.5. Projected irrigation water productivity showed a range of 4.87-12.15 kg ha-1 mm-1 and 6.77-12.63 kg ha-1 mm-1 through APSIM and DSSAT, respectively under RCP4.5, which stands an average of 7.81 and 8.53 kg ha-1 mm-1 during the

A study of technetium 99 uptake by irrigated rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Vandecasteele, C.M.; De Becker, R.; Tang Van Hai; Myttenaere, C.

1983-01-01

The absorption of technetium 99 (an important fission product which can be released in the environment at different steps of the nuclear fuel cycle) by rice (Oryza sativa L.) was studied in nutrient solutions and in flooded soils with contaminated water. The absorption kinetics established in water culture (continuous flowing system) for 99 Tc concentrations ranging from 0.017 to 17 μCi.I - 1 revealed two phases: the former corresponds to the diffusion in the apparent free spaces and the second, which is linear, represents the transfer of 99 Tc from the external medium into the root cells as well as its translocation to the leaves. The study of the desorption mechanism confirmed the existence of these compartments, the second one containing more than 95% of the total activity of the plant. The biological half-life of 99 Tc of the second compartment is so high that decontamination of the plant may not be expected. In soils, toxicity symptoms were observed for a 99 Tc water concentration of 17 μCi.I - 1 . The transfer factors calculated in irrigated soils are very high (>10 3 for the leafy shoots) and the distribution of 99 Tc between the different organs waries with the concentration used. More than 90% of 99 Tc is found in the leafy shoots meanwhile 1% of the plant total activity is only found in the caryopses [fr

The dynamics of rice production in Indonesia 1961–2009

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Dyah R. Panuju

2013-01-01

Full Text Available Rice is one of the important agricultural products in Indonesia. The production has been fully supported by infrastructure including research and development as well as government regulations in pricing. Its vulnerability to climate change requires adaptation strategies on irrigation, biotechnology and selection of alternative crops. The primary goal of this paper was to evaluate the historical perspective of the dynamics of rice production, technologies particularly in seed inventions, labour in farming and consumption of rice from 1961 to 2009 in conjunction with land capability. The study of historical rice production could be a benefit for future agricultural planning in Indonesia.

Effect of inoculating blue-green algae and Azolla on rice yield

International Nuclear Information System (INIS)

Kulasooriya, S.A.

1985-01-01

Nitrogen fixing blue-green algae (BGA) and the Azolla-Anaebaena symbiosis are potential alternative sources of nitrogen for lowland rice production. A survey of the literature shows that on the average, when BGA inoculation is effective, a rice yield increase of 14% (450 kg grain ha -1 ) has been observed. However, in Sri Lanka no significant increases in grain yield have been observed due to BGA inoculation. Azolla inoculation in broadcast, transplanted, and avenue transplanted rice gave yield increases of 12, 22 and 48%, and was equivalent to 55 to 80 kg N ha -1 as urea. Azolla was observed to reduce weed growth by 53%. Azolla is easier to establish in rice fields since it can be easily recognized with the naked eye, however, BGA are better able to withstand periods of desiccation which occur in rain-fed rice production. Most algalization experiments have been performed on a ''black box'' basis where only the final grain yield has been measured. Isotope experiments can play a vital role in understanding the processes by which BGA and Azolla increase rice yields. (author)

Stakeholder analysis in the management of irrigation in Kampili area

Science.gov (United States)

Jumiati; Ali, M. S. S.; Fahmid, I. M.; Mahyuddin

2018-05-01

Irrigation has appreciable contribution in building food security, particularly rice crops. This study aims to analyze the role of stakeholders involved in distributing of irrigation water. The study was conducted in the Kampili Irrigation Area in South Sulawesi Province Indonesia, the data were obtained through observation and interviews with stakeholders involved, and analysed by stakeholder analysis, based on the interests and power held by the actors. This analysis is intended to provide an optimal picture of the expected role of each stakeholder in the management of irrigation resources. The results show that there were many stakeholders involved in irrigation management. In the arrangement of irrigation distribution there was overlapping authority of the stakeholders to its management, every stakeholder had different interests and power between each other. The existence have given positive and negative values in distributing irrigation water management, then in the stakeholder collaboration there was contestation between them. This contestation took place between the agriculture department, PSDA province, the Jeneberang River Region Hall, the Farmers Group and the P3A.

Early Middle Formative Occupation in the Central Maya Lowlands: Recent Evidence from Cahal Pech, Belize

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Jaime Awe

1990-11-01

Full Text Available After more than half a century of intensive archaeological research the early Middle Formative (or Middle Preclassic period (1000-600 B.C. continues to be one of the most enigmatic eras in the study of Lowland Maya prehistory. While several factors contribte to this situation, the primary cause for this obscurity lies in the fact that few sites have produced either contextual or stratigraphic evidence of occupation during this phase (Rice 1976; Andrews 1988. Concsequently, any new site with evidence of Middle Formative occupation can contribute substantially to our limited knowledge of this pioneering stage of the lowland Maya. This paper introduces one such site, Cahal Pech, where recent investigations have uncovered a stratigraphic sequence that tentatively spans the early Middle Formative to the Late Classic period. It provides a preliminary description, of the site's early Middle Formative configuration and briefly discusses its possible regional affiliation.

Mitigating arsenic contamination in rice plants with an aquatic fern, Marsilea minuta.

Science.gov (United States)

Hassi, Ummehani; Hossain, Md Tawhid; Huq, S M Imamul

2017-10-10

Dangers of arsenic contamination are well known in human civilization. The threat increases when arsenic is accumulated in food and livestock through irrigated crops or animal food. Hence, it is important to mitigate the effects of arsenic as much as possible. This paper discusses a process for reducing the level of arsenic in different parts of rice plants with an aquatic fern, Marsilea minuta L. A pot experiment was done to study the possibility of using Marsilea minuta as a phytoremediator of arsenic. Rice and Marsilea minuta were allowed to grow together in soils. As a control, Marsilea minuta was also cultured alone in the presence and absence of arsenic (applied at 1 mg/L as irrigation water). We did not find any significant change in the growth of rice due to the association of Marsilea minuta, though it showed a reduction of approximately 58.64% arsenic accumulation in the roots of rice grown with the association of fern compared to that grown without fern. We measured a bioaccumulation factor (BF) of > 5.34, indicating that Marsilea minuta could be a good phytoremediator of arsenic in rice fields.

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.

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.

Linkage Mapping of Stem Saccharification Digestibility in Rice.

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Bohan Liu

Full Text Available Rice is the staple food of almost half of the world population, and in excess 90% of it is grown and consumed in Asia, but the disposal of rice straw poses a problem for farmers, who often burn it in the fields, causing health and environmental problems. However, with increased focus on the development of sustainable biofuel production, rice straw has been recognized as a potential feedstock for non-food derived biofuel production. Currently, the commercial realization of rice as a biofuel feedstock is constrained by the high cost of industrial saccharification processes needed to release sugar for fermentation. This study is focused on the alteration of lignin content, and cell wall chemotypes and structures, and their effects on the saccharification potential of rice lignocellulosic biomass. A recombinant inbred lines (RILs population derived from a cross between the lowland rice variety IR1552 and the upland rice variety Azucena with 271 molecular markers for quantitative trait SNP (QTS analyses was used. After association analysis of 271 markers for saccharification potential, 1 locus and 4 pairs of epistatic loci were found to contribute to the enzymatic digestibility phenotype, and an inverse relationship between reducing sugar and lignin content in these recombinant inbred lines was identified. As a result of QTS analyses, several cell-wall associated candidate genes are proposed that may be useful for marker-assisted breeding and may aid breeders to produce potential high saccharification rice varieties.

Irrigation Capability Evaluation of Illushi Floodplain, Edo State, Nigeria

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A.S. Umweni

2014-06-01

Full Text Available Many irrigation projects, especially in the developing tropical regions, are embarked upon without any land capability assessment, resulting in avoidable and undesirable ecological consequences. The aim of this study is to assess the irrigation capability potentials of the soils of a rice growing Illushi/Ega community in Edo State of Nigeria. Soils of Illushi/Ega (200 ha were studied to establish their irrigation capabilities. Water samples were collected from the rivers within and near the sites at the proposed points of intake structures and analyzed for salinity (ECw, permeability (SAR and ion toxicity [Chlorine (Cl and Boron (B]. Gravity irrigation suitability assessment was carried out following the guidelines of the United States Bureau for Land Reclamation (USBR, 1953 and FAO (1979. Results showed that about 5.5 % of the land was non-irrigable, 11.5 % was marginally irrigable, 30.5% was moderately irrigable and 52.5 % highly irrigable.Thus about 83 % of the total land area was found to be irrigable. The results of analyses of irrigation water [ECw, SAR and Cl and B (ion toxicity problems in water sources were 0.1 – 0.7 dS m-1, 1.2 – 1.7, 0.6 – 1.8 cmol kg-1 and 0.5 – 0.7 mg kg-1] also show that there is no indication of salinity or ion toxicity problem.

Dynamics of Phenol Degrading—Iron Reducing Bacteria in Intensive Rice Croopping System

Institute of Scientific and Technical Information of China (English)

LUWENJING; W.REICHARDT; 等

2001-01-01

Field and greenhouse experiments were conducted to investigate the effects of cropping season,nitrogen fertilizer input and aerated fallow o the dynamics of phenol degrading-iron reducing bacteria(PD-IRB)in tropical irrigated rice(Oryza sativa L.)systems,The PD-IRB population density was monitored at different stages of rice growth in two cropping seasons (dry and early wet) in a continuous annual triple rice cropping system under irrigated condition,In this system,the high nitrogen input (195 and 135 kg N ha-1 in dry and ewt seasons ,respectively)plots and control plots receiving no N fertilizer were compared to investigate the effect of nitrogen rate on population size.The phenol degrading-iron reducing bacteria (PD-IRB)were abundant in soils under croppin systems of tropical irrigated rice.However,density of the bacterial populations varied with rice growth stages.Cropping seasons,rhizosphere,and aerated fallow could affect the dynamics of PD-IRB,In the field trial,viable counts of PD-IRB in the topsoil layer(15 cm)ranged between 102 and 108 cells per gram of dry soil.A steep increase in viable counts during the second half of the cropping season suggested that the population density of PD-IRB increased ant advanced crop-growth stages.Population growth of PD-IRB was accelerated during the dry season compared to the wet season,In the greenhouse experiment,the adjacent aerated fallow revealed 1-2 orders of magnitude higher in most probable number(MPN)of PD-IRB than the wet fallow treated plots.As a prominent group of Fe reducing bacteria,PD-IRB predominated in the rhizosphere of rice,since maximum MPN of PD-IRB (2.62×108 g-1 soil) was found in rhizosphere soil.Mineral N fertilizer rates showed no significant effect on PD-IRB population density.

Mosquitoes of the rice agroecosystem of Malaysia: species composition and their abundance in relation to rice farming

International Nuclear Information System (INIS)

Abu Hassan Ahmad; Che Salmah Md Rawi

2002-01-01

Mosquito abundance in relation to rice farming was studied in the Muda and the Kerian Irrigation Schemes. Mosquito larvae were collected using dippers for several growing seasons. Adult mosquitoes were collected by using human bait and cow bait and net trap at nights. Culex, Mansonia and Anopheles were the three genera of mosquito found in the rice agroecosystem. Four species of Mansonia were found biting on human bait. Culex mosquitoes were caught biting on human and cow baits. Culex tritaeniorhynchus, C pseudovishnui, C vishnui, C gelidus and C bitaeniorhynchus were the most common Culex mosquitoes found. Anoheles sinensis and A. peditaeniatus were the most dominant panopheline mosquitoes. High abundance of larvae and adult mosquitoes were observed during ploughing, planting, and tillering stages of rice farming. (Author)

A multi-stakeholder partnership for the dissemination of alternate wetting and drying water-saving technology for rice farmers in the Philippines

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Florencia G. Palis

2017-09-01

Full Text Available To address issues of water scarcity and food security for sustainable rice farming and increasing production, a water-saving technology called alternate wetting and drying (AWD was disseminated in the Philippines. This study assessed the impact of facilitating a network of stakeholders on disseminating AWD in irrigated rice systems in the Philippines. It used both qualitative and quantitative data collected from 2002 to 2012 in study sites in the country. Engaging multi-stakeholders in adaptive research, training, and dissemination facilitated the process of more interaction by partners. All partners joined a knowledge and dissemination alliance for scaling out AWD activities. This in turn effected a policy outcome, and the synergetic interactions of each partner within and outside the current network fast-tracked the dissemination process and adoption of AWD by farmers. The AWD practice resulted in an increase in irrigated rice area but not necessarily in rice production and farmers’ income. It also reduced labor and fuel consumption, especially in deep-well irrigation systems.

Phytoremediation of lowland soil contaminated with a formulated mixture of Imazethapyr and Imazapic1

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Kelen Müller Souto

Full Text Available The use of plants to decontaminate water and soil contaminated with both organic and inorganic pollutants is a promising technology for sustainable agriculture. The aim of this work was to evaluate the efficiency of plant species in the remediation of formulated mixtures of imazethapyr and imazapic, using the irrigated rice cultivar IRGA 417 as bioindicator. The treatments consisted of the combination of 13 plant species with seven rates of a formulated mixture of imazethapyr and Imazapic (75+25 g e.a. L-1 respectively: 0, 200, 300, 400, 500, 1000 and 4000 mL ha-1. To evaluate the potential for phytoremediation in these species, symptoms of injury and plant height were measured in rice plants at 7, 14, 21 and 28 days after emergence and shoot dry weight at 28 days after emergence. Glycine max, Lolium multiflorum and Lotus corniculatus are potentially promising species in the phytoremediation of soils contaminated with the herbicide imazethapyr and imazapic (up to 4000 mL ha-1, due to being more adapted to hydromorphic environments, which is a feature found in soils cultivated with irrigated rice. Crotalaria juncea, Canavalia ensiformis, Stizolobium aterrimum, Vicia sativa, Raphanus sativus and Triticum aestivum are species capable of the phytoremediation of soils contaminated with imazethapyr + imazapic, however the occurrence of anoxia in hydromorphic soils reduce the establishment and development of these plants.

Transcriptomic Analysis of Gibberellin- and Paclobutrazol-Treated Rice Seedlings under Submergence

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Jing Xiang

2017-10-01

Full Text Available Submergence stress is a limiting factor for rice growing in rainfed lowland areas of the world. It is known that the phytohormone gibberellin (GA has negative effects on submergence tolerance in rice, while its inhibitor paclobutrazol (PB does the opposite. However, the physiological and molecular basis underlying the GA- and PB-regulated submergence response remains largely unknown. In this study, we reveal that PB could significantly enhance rice seedling survival by retaining a higher level of chlorophyll content and alcohol dehydrogenase activity, and decelerating the consumption of non-structure carbohydrate when compared with the control and GA-treated samples. Further transcriptomic analysis identified 3936 differentially expressed genes (DEGs among the GA- and PB-treated samples and control, which are extensively involved in the submergence and other abiotic stress responses, phytohormone biosynthesis and signaling, photosynthesis, and nutrient metabolism. The results suggested that PB enhances rice survival under submergence through maintaining the photosynthesis capacity and reducing nutrient metabolism. Taken together, the current study provided new insight into the mechanism of phytohormone-regulated submergence response in rice.

Assessing the impacts of climate change on rice yields in the main rice areas of China

International Nuclear Information System (INIS)

Yao, Fengmei; Xu, Yinglong; Lin, Erda; Yokozawa, Masayuki; Zhang, Jiahua

2007-01-01

This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071--2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within ± 10% of observed flowering duration and ± 15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances of rice yield could pose a threat to rice yield at most selected stations in the main rice areas of China. With the CO2 direct effect on rice yield, rice yield increase in all selected stations

Assessing the impacts of climate change on rice yields in the main rice areas of China

Energy Technology Data Exchange (ETDEWEB)

Yao, Fengmei [College of Earth Sciences, The Graduate University of the Chinese Academy of Sciences, 19A, Yuquan Road, Beijing, 100049 (China); Xu, Yinglong; Lin, Erda [Agricultural Environment and Sustainable Development Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081 (China); Yokozawa, Masayuki [National Institute for Agro-environmental Sciences, Tsukuba 305-8604 (Japan); Zhang, Jiahua [Chinese Academy of Meteorological Sciences, Beijing, 100081 (China)

2007-02-15

This paper assesses the impact of climate change on irrigated rice yield using B2 climate change scenario from the Regional Climate Model (RCM) and CERES-rice model during 2071--2090. Eight typical rice stations ranging in latitude, longitude, and elevation that are located in the main rice ecological zones of China are selected for impact assessment. First, Crop Estimation through Resource and Environment Synthesis (CERES)-rice model is validated using farm experiment data in selected stations. The simulated results represent satisfactorily the trend of flowering duration and yields. The deviation of simulation within {+-} 10% of observed flowering duration and {+-} 15% of observed yield. Second, the errors of the outputs of RCM due to the difference of topography between station point and grid point is corrected. The corrected output of the RCM used for simulating rice flowering duration and yield is more reliable than the not corrected. Without CO2 direct effect on crop, the results from the assessment explore that B2 climate change scenario would have a negative impact on rice yield at most rice stations and have little impacts at Fuzhou and Kunming. To find the change of inter-annual rice yield, a preliminary assessment is made based on comparative cumulative probability at low and high yield and the coefficient variable of yield between the B2 scenario and baseline. Without the CO2 direct effect on rice yield, the result indicates that frequency for low yield would increase and it reverses for high yield, and the variance for rice yield would increase. It is concluded that high frequency at low yield and high variances of rice yield could pose a threat to rice yield at most selected stations in the main rice areas of China. With the CO2 direct effect on rice yield, rice yield increase in all selected stations.

Impact of Rice Paddy Areas Decrease on Local Climate over Taiwan

Science.gov (United States)

Lo, M. H.; Wen, W. H.; Chen, C. C.

2014-12-01

Agricultural irrigation practice is one of the important anthropogenic processes in the land surface modeling. Irrigation can decrease local surface temperature with alternating surface energy partitioning. Rice paddy is the major food crop in Asian monsoon region and rice is grown under flooded conditions during the growing season; hence, the rice paddy can be considered as an open water body, which has more impacts on the surface energy budget than other cropland does. In this study, we explore how the rice paddy area changes affect Taiwan's regional climate from both observational data and numerical modeling exercise. The Weather Research and Forecasting (WRF) model is utilized to explore impacts of rice paddy area changes on the regional climate, and energy and water budget changes. In addition, temperature datasets from six automatic weather stations in the northern Taiwan and two stations in the southern Taiwan are analyzed in this study to explore how the Daily Temperature Range (DTR) changes with the decreased rice paddy areas. Previous studies show that due to the urban heat island effect, aerosol direct and indirect effects, and global warming, the DTR has decreased in the past 4 decades observed from most of the weather stations around Taiwan. However, the declined rice paddy area may increase the DTR with higher Bowen ratio during the daytime. Preliminary results show that DTR is decreased in weather stations near the urban area, but increased in weather stations near fallow areas in the past 20 years. It shows that different land use changes may have opposite impacts on local and regional climate.

Combined effects of climate and land-use change on the provision of ecosystem services in rice agro-ecosystems

Science.gov (United States)

Langerwisch, Fanny; Václavík, Tomáš; von Bloh, Werner; Vetter, Tobias; Thonicke, Kirsten

2018-01-01

Irrigated rice croplands are among the world’s most important agro-ecosystems. They provide food for more than 3.5 billion people and a range of other ecosystem services (ESS). However, the sustainability of rice agro-ecosystems is threatened by continuing climate and land-use changes. To estimate their combined effects on a bundle of ESS, we applied the vegetation and hydrology model LPJmL to seven study areas in the Philippines and Vietnam. We quantified future changes in the provision of four essential ESS (carbon storage, carbon sequestration, provision of irrigation water and rice production) under two climate scenarios (until 2100) and three site-specific land-use scenarios (until 2030), and examined the synergies and trade-offs in ESS responses to these drivers. Our results show that not all services can be provided in the same amounts in the future. In the Philippines and Vietnam the projections estimated a decrease in rice yields (by approximately 30%) and in carbon storage (by 15%) and sequestration (by 12%) towards the end of the century under the current land-use pattern. In contrast, the amount of available irrigation water was projected to increase in all scenarios by 10%-20%. However, the results also indicate that land-use change may partially offset the negative climate impacts in regions where cropland expansion is possible, although only at the expense of natural vegetation. When analysing the interactions between ESS, we found consistent synergies between rice production and carbon storage and trade-offs between carbon storage and provision of irrigation water under most scenarios. Our results show that not only the effects of climate and land-use change alone but also the interaction between ESS have to be considered to allow sustainable management of rice agro-ecosystems under global change.

Determination of trace concentrations of aluminium in rice samples by INAA and PIGE methods

International Nuclear Information System (INIS)

Nanda, B.B.; Biswal, R.R.; Acharya, R.; Pujari, P.K.

2015-01-01

Aluminium is one of the toxic elements entering human body mainly through food and food products. Though its bioavailability is very less, it is necessary to evaluate its total concentrations in food and food products entering to the body through. In order to evaluate total aluminium contents in various food items for daily dietary intake of aluminum, authors have systematically planned to carry out experiments in various food items including rice. Rice is the main food in many parts of India as well as in Odisha. Rice samples under study belong to three categories; (i) various rice samples from local market, (ii) various rice samples grown in similar irrigation (soil and water) conditions and (iii) same variety of rice with different irrigation conditions. Solid samples (pre-cleaned) were powdered, homogenized and taken for analysis by two nuclear analytical techniques (NATs) namely instrumental neutron activation analysis (INAA) using reactor neutrons at BARC and particle induced gamma ray emission (PIGE) using 4 MeV proton beam (20 nA current) from 3 MV Tandetron at IOP, Bhubaneswar in conjunction with high resolution gamma-ray spectrometry. Samples of 10-50 mg for INAA and 250 mg (pelletized in cellulose) for PIGE were used for experiments. For INAA, samples were irradiated at PCF, Dhruva reactor for 1 minute

Effect of rice hull mulch on nutrient concentration of fertilized irrigation water

Science.gov (United States)

Parboiled rice hulls are an effective mulch for controlling weeds in nursery containers. A layer of rice hulls between 1.25 and 2.5 cm deep has been shown to provide effective control of liverwort (Marchantia polymorpha), bittercress (Cardamine flexuosa), and creeping woodsorrel (Oxalis corniculata...

Micronutrient problems of crops in Pakistan with special reference to zinc and copper deficiency in rice production

International Nuclear Information System (INIS)

Chaudhry, F.M.; Sharif, M.

1975-01-01

Studies on the mechanisms of zinc-65 adsorption by various types of soil are being conducted. The soils of the Hyderabad region of the Sind province appear to de deficient in Zn for maize and in B for cotton, sweet clover, wheat and millets. Zinc, Cu and B deficiency seems to be widespread for wheat on many non-rice growing soils of the Punjab. In the North Frontier Province, sugarbeet and citrus orchards respond markedly to the application of Zn, Cu and Fe. Lowland rice responds to the addition of Zn in all the provinces of Pakistan. In rice tracts of the Punjab, Zn and Cu deficiency is quite prevalent for rice. The scope of necessary future research is discussed

Lowland Rice Yield And Fertilizer Nitrogen Contribution Affected By Zeolite And Sesbania Green Manure Application

International Nuclear Information System (INIS)

Haryanto; Idawati and Las, Tamsil

2000-01-01

A pot experiment has been conducted in P3TIR greenhouse, pasar jumat, south jakarta to study nitrogen uptake and contribution of fertilizer for lowland rice affected by zeolite and sesbania green manure application. To study the N contribution of fertilizer, 15N isotope was used. The zeorea fertilizer was made from the mixture of zeolite and 15N labelled urea having 4.0% atom. Ten treatments of N fertilization were tried : zeorea I was applied once at transplanting (ZI IX), zeorea I was applied twice I.e at transplanting and at 30 days after transplanting - DAT (ZI 2X), zeorea I was applied at transplanting and at 30 DAT (ZI + ZII), zeorea II was applied once at transplanting (ZII IX), zeorea II was applied twice I.e at transplanting and at 30 DAT (ZII 2X), zeolit was applied twice I.e at transplanting and at 30 DAT (ZO 2X), half rate of urea was applied at transplanting and another half rate at 30 DAT ( U 1/2+1/2), sesbania green manure was applied at 30 DAT and zeorea II applied at transplanting (sesbania + ZII), one tate of urea was applied at transplanting (U IX), and half rate of urea was applied at transplanting and sesbania was applied at 30 DAT (sesbania + U 1/2). Result obtained from this experiment showed that the application of zeorea I at tran planting followed by zeorea II at 30 DAT resulted the highest yield of dry grain even though it contained nitrogen only 60% of the nitrogen content of the recommended rate. The highest nitrogen contribution of zeorea I.e 75.22 mg/pot was obtained by applying zeorea II at transplanting and at 30 DAT. Urea half dose (U 1/2) combined with sesbania green manure could be effectuated if given in zeorea from even more effective than urea full dose given at transplanting time (U IX). Impact of sesbania green manure seemed to be more positive if combined with zeolite

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

Paddy rice cultivation is increasingly challenged by irrigation water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices. These factors are changing traditional cropping patterns from flooded double-rice systems to the introduction of well-aerated upland crop systems in the dry season. Emissions of methane (CH4) are expected to decrease, while emissions of nitrous oxide (N2O) will increase and soil organic carbon (SOC) stocks will most likely be volatilized in the form of carbon dioxide (CO2). We measured greenhouse gas (GHG) emissions at the International Rice Research Institute (IRRI) in the Philippines to provide a comparative assessment of the global warming potentials (GWP) as well as yield scaled GWPs of different crop rotations and to evaluate mitigation potentials or risks of new management practices i.e. mulching and inter-crop cultivation. New management practices of mulching and intercrop cultivation will also have the potential to change SOC dynamics, thus can play the key role in contributing to the GWP of upland cropping systems. To present, more than three years of continuous measurement data 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) in upland cultivation have been collected. Introduction of upland crops in the dry season reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Moreover, for practices including upland crops, CH4 emissions in the subsequent wet season with paddy rice were reduced by 54-60%. Although annual N2O emissions increased twice- to threefold in the diversified systems, the strong reduction of CH4 led to a significantly lower (pbalance but also with regard to soil fertility. New upland crop management practices where first implemented during land-preparation for dry season (July) 2015 where i) 6t/ha rice straw

REGULATED DEFICIT IRRIGATION AND DIFFERENT MULCH TYPES ON FRUIT QUALITY AND YIELD OF WATERMELON

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KLEITON ROCHA SARAIVA

2017-01-01

Full Text Available The objective of this work was to assess the pulp resistance, soluble solids and yield of watermelon fruits grown under different irrigation managements (determined by the ISAREG model and mulches, and their interactions. After a survey carried out on local producers, two experiments were conducted, using a completely randomized block design in split - plot arrangement with four replications, in the Teaching, Research and Extension Unit (UEPE of the Federal Institute of Ceara (IFCE, Jaguaribe - Apodi Irrigation District (DIJA, State of Ceara, Brazil. The treatments consisted of four irrigation managements in the plots, M1 (100% of the available - water capacity (AWC of the soil, M2 (80%, M3 (60% and M4 (average water depth used by local producers and four mulch types in the sub - plots, without mulching (C0 with rice husk (C1, white plastic (C2 and black plastic (C3 as mulches. The results were subjected to analysis of variance, and significant results were subjected to regression (irrigation managements, average test (mulches and trend graphs (interaction between the factors. The irrigation management practiced during the watermelon crop cycle by the local producers of the Irrigation District of Jaguaribe - Apodi (DIJA in the State of Ceara, Brazil, is not appropriated, since they usually apply more water than the highest water depth determined by the ISAREG model (100% of the AWC. The plants grown under irrigation water depth of 365.20 mm (M1 and soils with mulches of rice husk or white plastic had the highest yields and fruits with better quality of soluble solids and pulp resistance.

Content Of 2,4-D-14C Herbicide Residue In Water And Soil Of Irrigated Rice Field System

International Nuclear Information System (INIS)

Chairul, Sofnie M.; Djabir, Elida; Magdalena, Nelly

2000-01-01

The investigation of 2,4-D exp.-14C herbicide residue in water and soil of irrigated rice field system was carried out. Rice plant and weeds (Monochoria vaginalis Burn. F. Presl) were planted in 101 buckets using two kinds of soil condition, I.e. normal soil and 30 % above normal compact soil. After one week planting, the plants were sprayed with 1 u Ci of 2,4-D exp.-14C and 0,4 mg non labeled 2,4-D. The herbicide residue content was determined 0, 2, 4, 8 and 10 weeks after spraying with 2,4-D herbicide. The analysis was done using Combustion Biological Oxidizer merk Harvey ox-400, and counted with Liquid Scintillation Counter merk Beckman model LS-1801. The results indicates that the herbicide contents in water and soil decrease from the first spraying with herbicide until harvest herbicide Residue content in water after harvest was 0.87 x 10 exp.-6 ppm for soil normal condition, and 0.59 x 10 exp.-6 pm for the soil 30 % up normal condition, while herbicide content in soil was 1.54 x 10 exp.-6 ppm for soil normal condition and 1.48 x 10 exp.-6 ppm for soil 30 % up normal. 2,4-D herbicide residue content in rice after harvest was 0.27 x 10 exp.-6 ppm for normal soil condition and 0.25 x 10 exp.-6 ppm for the soil 30 % up normal. 2,4-D herbicide residue content in roots and leaves of weeds after harvest were respectively 0.29 x 10 exp.-6 ppm and 0.18 x 10 exp.-6 for normal soil condition, while for 30 % up normal soil were 0.25 x 10 exp.-5 ppm and 0.63 x 10 exp.-7 ppm. This result indicates that there is no effect pollution to surrounding area, because the herbicide content is still bellow the allowed detection limit, 0.05 ppm

Modeling Soil Sodicity Problems under Dryland and Irrigated Conditions: Case Studies in Argentina and Colombia

Science.gov (United States)

Pla-Sentís, Ildefonso

2014-05-01

Salt-affected soils, both saline and sodic, my develop both under dryland and irrigated conditions, affecting negatively the physical and chemical soil properties, the crop production and the animal and human health.Among the development processes of salt-affected soils, the processes of sodification have been generally received less attention and is less understood than the development of saline soils. Although in both of them, hydrological processes are involved in their development, in the case of sodic soils we have to consider some additional chemical and physicochemical reactions, making more difficult their modeling and prediction. In this contribution we present two case studies: one related to the development of sodic soils in the lowlands of the Argentina Pampas, under dryland conditions and sub-humid temperate climate, with pastures for cattle production; the other deals with the development of sodic soils in the Colombia Cauca Valley, under irrigated conditions and tropical sub-humid climate, in lands used for sugarcane cropping dedicated to sugar and ethanol production. In both cases the development of sodicity in the surface soil is mainly related to the effects of the composition and level of groundwater, affected in the case of Argentina Pampas by the off-site changes in dryland use and management in the upper zones and by the drainage conditions in the lowlands, and in the case of the Cauca Valley, by the on-site irrigation and drainage management in lands with sugarcane. There is shown how the model SALSODIMAR, developed by the main author, based on the balance of water and soluble componentes of both the irrigation water and groundwater under different water and land management conditions, may be adapted for the diagnosis and prediction of both problems, and for the selection of alternatives for their management and amelioration.

Effect of water management, tillage options and phosphorus status on arsenic uptake in rice.

Science.gov (United States)

Talukder, A S M H M; Meisner, C A; Sarkar, M A R; Islam, M S

2011-05-01

High arsenic (As) concentrations in soil may lead to elevated concentrations of arsenic in agricultural products. Field experiments were conducted to examine the effects of water management (WM) and Phosphorus (P) rates on As uptake, rice growth, yield and yield attributes of winter (boro) and monsoon (aman) rice in an As contaminated soil-water at Gobindagonj, Gaibandha, Bangladesh in 2004 and 2005. Significantly, the highest average grain yields (6.88±0.07 t ha(-1) in boro 6.38±0.06 t ha(-1) in aman) were recorded in permanent raised bed (PRB; aerobic WM: Eh=+360 mV) plus 100% P amendment. There was a 12% yield increase over conventional till on flat (CTF; anaerobic WM: Eh=-56 mV) at the same P level. In boro, the As content in grain and As content in straw were about 3 and 6 times higher in CTF compared to PRB, respectively. The highest total As content (0.646±0.01 ppm in grain and 10.93±0.19 ppm in straw) was recorded under CTF, and the lowest total As content (0.247±0.01 and 1.554±0.09 ppm in grain and straw, respectively) was recorded under PRB (aerobic WM). The results suggest that grain and straw As are closely associated in boro rice. The furrow irrigation approach of the PRB treatments consistently reduced irrigation input by 29-31% for boro and 27-30% for aman rice relative to CTF treatments in 2004 and 2005, respectively, thus reducing the amount of As added to the soil from the As-contaminated irrigation water. Yearly, 30% less As was deposited to the soil compared to CTF system through irrigation water during boro season. High As concentrations in grain and straw in rice grown using CTF in the farmers' field, and the fact that using PRB reduced grain As concentrations to value less than half of the proposed food hygiene standard. Copyright © 2010 Elsevier Inc. All rights reserved.

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.

Effects of water management on arsenic and cadmium speciation and accumulation in an upland rice cultivar.

Science.gov (United States)

Hu, Pengjie; Ouyang, Younan; Wu, Longhua; Shen, Libo; Luo, Yongming; Christie, Peter

2015-01-01

Pot and field experiments were conducted to investigate the effects of water regimes on the speciation and accumulation of arsenic (As) and cadmium (Cd) in Brazilian upland rice growing in soils polluted with both As and Cd. In the pot experiment constant and intermittent flooding treatments gave 3-16 times higher As concentrations in soil solution than did aerobic conditions but Cd showed the opposite trend. Compared to arsenate, there were more marked changes in the arsenite concentrations in the soil solution as water management shifted, and therefore arsenite concentrations dominated the As speciation and bioavailability in the soil. In the field experiment As concentrations in the rice grains increased from 0.14 to 0.21 mg/kg while Cd concentrations decreased from 0.21 to 0.02 mg/kg with increasing irrigation ranging from aerobic to constantly flooding conditions. Among the various water regimes the conventional irrigation treatment produced the highest rice grain yield of 6.29 tons/ha. The As speciation analysis reveals that the accumulation of dimethylarsinic acid (from 11.3% to 61.7%) made a greater contribution to the increase in total As in brown rice in the intermittent and constant flooding treatments compared to the intermittent-aerobic treatment. Thus, water management exerted opposite effects on Cd and As speciation and bioavailability in the soil and consequently on their accumulation in the upland rice. Special care is required when irrigation regime methods are employed to mitigate the accumulation of metal(loid)s in the grain of rice grown in soils polluted with both As and Cd. Copyright © 2014. Published by Elsevier B.V.

Induction of drought tolerant mutants of rice

International Nuclear Information System (INIS)

El-Hissewy, A.A.; Abd Allah, A.

2001-01-01

The ultimate goal of crop breeding is to develop varieties with a high yield potential and desirable agronomic characteristics. In Egypt, the most important qualities sought by breeders have been high yield potential, resistance to major diseases and insects, and improved grain and eating quality. However, breeding efforts should concentrate on varieties with the potential to minimize yield losses under unfavorable conditions such as drought, and to maximize yields when conditions are favorable. Rice (Oryza sativa L.) in Egypt is completely irrigated and a significant portion of the rice cultivated area is subject to water deficit resulting from an inadequate or insufficient irrigation supply. Drought tolerance is a complex trait in that it results from the interaction of histological and physiological characters of plant with environmental factors, both above-ground and under-ground. Accordingly, root characters are closely related to drought tolerance. Little attention has been paid in Egyptian breeding programs to root characters and their relation to shoot characters. Furthermore, induced mutations are considered as one of the most important methods to induce useful mutants, especially with improved root characters, to overcome the drought problem. The present investigation aimed to study the effect of different doses of gamma rays on several characters of three Egyptian rice varieties, i.e. 'Giza 171', 'Giza 175' and 'Giza 176' and to induce one or more mutants possessing drought tolerance

Emergy Evaluation of a Production and Utilization Process of Irrigation Water in China

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Dan Chen

2013-01-01

Full Text Available Sustainability evaluation of the process of water abstraction, distribution, and use for irrigation can contribute to the policy of decision making in irrigation development. Emergy theory and method are used to evaluate a pumping irrigation district in China. A corresponding framework for its emergy evaluation is proposed. Its emergy evaluation shows that water is the major component of inputs into the irrigation water production and utilization systems (24.7% and 47.9% of the total inputs, resp. and that the transformities of irrigation water and rice as the systems’ products (1.72E+05 sej/J and 1.42E+05 sej/J, resp.; sej/J = solar emjoules per joule represent their different emergy efficiencies. The irrigated agriculture production subsystem has a higher sustainability than the irrigation water production subsystem and the integrated production system, according to several emergy indices: renewability ratio (%R, emergy yield ratio (EYR, emergy investment ratio (EIR, environmental load ratio (ELR, and environmental sustainability index (ESI. The results show that the performance of this irrigation district could be further improved by increasing the utilization efficiencies of the main inputs in both the production and utilization process of irrigation water.

Emergy evaluation of a production and utilization process of irrigation water in China.

Science.gov (United States)

Chen, Dan; Luo, Zhao-Hui; Chen, Jing; Kong, Jun; She, Dong-Li

2013-01-01

Sustainability evaluation of the process of water abstraction, distribution, and use for irrigation can contribute to the policy of decision making in irrigation development. Emergy theory and method are used to evaluate a pumping irrigation district in China. A corresponding framework for its emergy evaluation is proposed. Its emergy evaluation shows that water is the major component of inputs into the irrigation water production and utilization systems (24.7% and 47.9% of the total inputs, resp.) and that the transformities of irrigation water and rice as the systems' products (1.72E + 05 sej/J and 1.42E + 05 sej/J, resp.; sej/J = solar emjoules per joule) represent their different emergy efficiencies. The irrigated agriculture production subsystem has a higher sustainability than the irrigation water production subsystem and the integrated production system, according to several emergy indices: renewability ratio (%R), emergy yield ratio (EYR), emergy investment ratio (EIR), environmental load ratio (ELR), and environmental sustainability index (ESI). The results show that the performance of this irrigation district could be further improved by increasing the utilization efficiencies of the main inputs in both the production and utilization process of irrigation water.

Production of pulse in mono-cropped rice system in the coastal region of Eastern India

International Nuclear Information System (INIS)

Khan, A.R.; Nanda, P.; Chandra, Dinesh; Ghorai, A.K.; Behera, M.S.

2001-04-01

This experiment was undertaken with an objective to increase the yield of black-gram leguminous pulse crop through optimal doses of phosphatic fertilizer with supplemental irrigation in mono-cropped rice-fallow regions of India. Irrigation and phosphorus fertilizer application were introduced for enhancing productivity of black-gram to provide better returns to available water resources

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

Does morphological and anatomical plasticity during the vegetative stage make wheat more tolerant of water deficit stress than rice?

NARCIS (Netherlands)

Kadam, N.N.; Yin, X.; Bindraban, P.S.; Struik, P.C.; Jagadish, K.S.V.

2015-01-01

Water scarcity and the increasing severity of water deficit stress are major challenges to sustaining irrigated rice (Oryza sativa) production. Despite the technologies developed to reduce the water requirement, rice growth is seriously constrained under water deficit stress compared with other

Iron exclusion in rice genotypes as affected by different vapor pressure deficit conditions

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Ram Kumar Shrestha

2015-08-01

Full Text Available Root iron (Fe exclusion capacity of four lowland rice genotypes were evaluated in increasing rate of Fe2+ stresses (0, 500, 1000 and 1500 mg/L in growing medium under the conditions of low and high vapor pressure deficit. Rice root excluded significantly higher amount of iron under dry atmospheric condition (655 mg Fe/g root dry matter than moist atmospheric condition (118 mg Fe/g root dry matter. But their iron exclusion capacity reduced when they were gradually exposed to the higher levels of Fe stress. Tolerant genotype such as TOX3107 excluded more iron when they were exposed to dry atmospheric condition.

Elemental composition of Malawian rice.

OpenAIRE

Joy, EJM; Louise Ander, E; Broadley, MR; Young, SD; Chilimba, AD; Hamilton, EM; Watts, MJ

2016-01-01

Widespread potential dietary deficiencies of calcium (Ca), iron (Fe), iodine (I), selenium (Se) and zinc (Zn) have been identified in Malawi. Several deficiencies are likely to be compounded by high phytic acid (PA) consumption. Rice (Oryza sativa) is commonly consumed in some Malawian populations, and its mineral micronutrient content is important for food security. The considerable irrigation requirements and flooded conditions of paddy soils can also introduce or mobilise potentially toxic...

Internasional Symposium On Lowland Technology (ISLT 2012) SUbstainability of Lowlands to Climated Change and Natural Disasters

OpenAIRE

Lawalenna

2011-01-01

???Lowland??? denotes regions of low elevation, which are particularly vulnerable to climatic and environmental changes. For example, global warming, which appears to be causing a rise in sea level, must ultimately affect the safety of coastal dikes and other coastal infrastructures, as well as threaten the water and ecological systems in lowland areas. Lowland regions are also particularly susceptible to natural disasters. Action is now required for the development of new tech...

Land Evaluation for improved Rice Production in Watari Irrigation ...

African Journals Online (AJOL)

... suggested to overcome these limitation and upgrade the suitability of the mapping units for increased rice production are; application of inorganic fertilizer, improve the low levels of nutrients and organic matter contents of the soil in the area and other recommendations include land leveling and conservation measures to ...

LANDSCAPE CHANGES IN A LOWLAND IN BENIN: ECOLOGICAL IMPACT ON PESTS AND NATURAL ENEMIES.

Science.gov (United States)

Boucher, A; Silvie, P; Menozzi, P; Adda, C; Auzoux, S; Jean, J; Huat, J

2015-01-01

Habitat management involving conservative biological control could be a good crop pest management option in poor African countries. A survey was conducted from August 2013 to July 2014 in a rainfed lowland region near Pélébina, northern Benin, in order to characterize spatiotemporal landscape changes and investigate their influence on the main crop pests and their associated natural enemies. The area was mapped mainly regarding crop fields and fallows. Visual observations were recorded and a database was compiled. Major landscape composition changes were noted between rainy and dry seasons, which affected the presence of both pests and natural enemies. Cereals (rice, maize and sorghum) and cotton were grown in the humid season, and then okra (Abelmoschus esculentus) was the dominant vegetable crop in dry season. These modifications impacted fallow abundance throughout the lowland. Different cotton (e.g. Helicoverpa armigera, Dysdercus sp., Zonocerus variegatus) or rice (e.g. Diopsis longicornis, D. apicalis) pests were observed during dry season in okra crops. Dry season surveys of Poaceae in two types of fallows ('humid', 'dry') revealed the presence of very few stem borers: only 0.04% of stems sampled were infested by stem borers, with a mean of 1.13 larvae per stem. Known cereal stem borer species such as Busseola fusco, Coniesta ignefusalis, Sesamia calamistis were not clearly identified among these larvae because of their diapausing stage and white color. Unexpected pollinators (Hymenoptera Apidae, genus Braunsapis, Ceratina and Xylocopa) and predators (Crabronidae, genus Dasyproctus) were found in the stems. Sweep-net collection of insects in humid fallows allowed us to describe for the first time in Benin seven Diopsidae species (23% of adults bearing Laboulbeniomycetes ectoparasitic fungi). Some of these species were captured in rice fields during rainy season. Parasitoids (adult Chalcidoidae and Ichneumonoidae) were observed during both seasons but their

Impact of Irrigation Method on Water Use Efficiency and Productivity of Fodder Crops in Nepal

Directory of Open Access Journals (Sweden)

Ajay K Jha

2016-01-01

Full Text Available Improved irrigation use efficiency is an important tool for intensifying and diversifying agriculture in Nepal, resulting in higher economic yield from irrigated farmlands with a minimum input of water. Research was conducted to evaluate the effect of irrigation method (furrow vs. drip on the productivity of nutritious fodder species during off-monsoon dry periods in different elevation zones of central Nepal. A split-block factorial design was used. The factors considered were treatment location, fodder crop, and irrigation method. Commonly used local agronomical practices were followed in all respects except irrigation method. Results revealed that location effect was significant (p < 0.01 with highest fodder productivity seen for the middle elevation site, Syangja. Species effects were also significant, with teosinte (Euchlaena mexicana having higher yield than cowpea (Vigna unguiculata. Irrigation method impacted green biomass yield (higher with furrow irrigation but both methods yielded similar dry biomass, while water use was 73% less under drip irrigation. Our findings indicated that the controlled application of water through drip irrigation is able to produce acceptable yields of nutritionally dense fodder species during dry seasons, leading to more effective utilization and resource conservation of available land, fertilizer and water. Higher productivity of these nutritional fodders resulted in higher milk productivity for livestock smallholders. The ability to grow fodder crops year-round in lowland and hill regions of Nepal with limited water storages using low-cost, water-efficient drip irrigation may greatly increase livestock productivity and, hence, the economic security of smallholder farmers.

Living with less water: development of viable adaptation options for Riverina irrigators

NARCIS (Netherlands)

Gaydon, D.S.

2012-01-01

In Australia, the best use of limited national water resources continues to be a major political and scientific issue. Average water allocations for rice-cereal irrigation farmers in the Riverina region have been drastically reduced since 1998 as a consequence of high rainfall variability and

Modeling water scarcity over south Asia: Incorporating crop growth and irrigation models into the Variable Infiltration Capacity (VIC) model

Science.gov (United States)

Troy, Tara J.; Ines, Amor V. M.; Lall, Upmanu; Robertson, Andrew W.

2013-04-01

Large-scale hydrologic models, such as the Variable Infiltration Capacity (VIC) model, are used for a variety of studies, from drought monitoring to projecting the potential impact of climate change on the hydrologic cycle decades in advance. The majority of these models simulates the natural hydrological cycle and neglects the effects of human activities such as irrigation, which can result in streamflow withdrawals and increased evapotranspiration. In some parts of the world, these activities do not significantly affect the hydrologic cycle, but this is not the case in south Asia where irrigated agriculture has a large water footprint. To address this gap, we incorporate a crop growth model and irrigation model into the VIC model in order to simulate the impacts of irrigated and rainfed agriculture on the hydrologic cycle over south Asia (Indus, Ganges, and Brahmaputra basin and peninsular India). The crop growth model responds to climate signals, including temperature and water stress, to simulate the growth of maize, wheat, rice, and millet. For the primarily rainfed maize crop, the crop growth model shows good correlation with observed All-India yields (0.7) with lower correlations for the irrigated wheat and rice crops (0.4). The difference in correlation is because irrigation provides a buffer against climate conditions, so that rainfed crop growth is more tied to climate than irrigated crop growth. The irrigation water demands induce hydrologic water stress in significant parts of the region, particularly in the Indus, with the streamflow unable to meet the irrigation demands. Although rainfall can vary significantly in south Asia, we find that water scarcity is largely chronic due to the irrigation demands rather than being intermittent due to climate variability.

Arsenic Accumulation in Rice and Probable Mitigation Approaches: A Review

Directory of Open Access Journals (Sweden)

Anindita Mitra

2017-10-01

Full Text Available According to recent reports, millions of people across the globe are suffering from arsenic (As toxicity. Arsenic is present in different oxidative states in the environment and enters in the food chain through soil and water. In the agricultural field, irrigation with arsenic contaminated water, that is, having a higher level of arsenic contamination on the top soil, which may affects the quality of crop production. The major crop like rice (Oryza sativa L. requires a considerable amount of water to complete its lifecycle. Rice plants potentially accumulate arsenic, particularly inorganic arsenic (iAs from the field, in different body parts including grains. Different transporters have been reported in assisting the accumulation of arsenic in plant cells; for example, arsenate (AsV is absorbed with the help of phosphate transporters, and arsenite (AsIII through nodulin 26-like intrinsic protein (NIP by the silicon transport pathway and plasma membrane intrinsic protein aquaporins. Researchers and practitioners are trying their level best to mitigate the problem of As contamination in rice. However, the solution strategies vary considerably with various factors, such as cultural practices, soil, water, and environmental/economic conditions, etc. The contemporary work on rice to explain arsenic uptake, transport, and metabolism processes at rhizosphere, may help to formulate better plans. Common agronomical practices like rain water harvesting for crop irrigation, use of natural components that help in arsenic methylation, and biotechnological approaches may explore how to reduce arsenic uptake by food crops. This review will encompass the research advances and practical agronomic strategies on arsenic contamination in rice crop.

Natural resource management issues of pakistan's agriculture: the cases of land, labour and irrigation

International Nuclear Information System (INIS)

Arifullah, S.A.; Farid, N.

2009-01-01

With the objective to understand the optimization behavior of farmers in allocating land, labor and irrigation water, Linear Programming (LP) analytic technique was applied to 13 Kharif and 7 Rabi crops, using national level data from 1990-2005. The crops included in the analysis have been occupying 80 - 85 percent of Pakistan's cropped area for the last three to four decades. The optimization analysis resulted in bringing up three major natural resource management issues of the Pakistan's crop sector to the forefront. First, Basmati rice, mung, fodders of millet and sorghum, onion and IRRI rice were found optimal Kharif crops relative to sugarcane, maize, maize fodder, millet, sorghum, cotton and tomato. For Rabi wheat, potato, gram, rapeseed and berseem proved to be optimal relative to barley and sugarcane, for this period. The results imply that to have an efficient agriculture base Pakistan should either replace the sub-optimal crops with the optimal ones, or the resource management side of such crops should be improved with the help sensitivity analysis. Second, cotton and tomato appeared to be relatively sensitive to labor availability than other crops; they seemed to establish a direct correlation between the optimality status and labor availability. And third, irrigation emerged as a critical input for IRRI rice in Kharif and for potato and gram in Rabi season; for these crops the crop optimality was directly correlated to the number of irrigations applied. In contrast, its opportunity cost is higher than the per unit return in cotton, tomato, wheat and berseem. This signified that irrigation needs to be managed efficiently in the latter four crops; whereas in the former three crops use of extra water would help in optimizing. (author)

Microbial-driven arsenic cycling in rice paddies amended with monosodium methanearsonate

Science.gov (United States)

Maguffin, S. C.; McClung, A.; Rohila, J. S.; Derry, L. A.; Huang, R.; Reid, M. C.

2017-12-01

Rice consumption is the second largest contributor to human arsenic exposure worldwide and is linked to many serious diseases. Because rice is uniquely adapted for agricultural production under flooded soils, arsenic species solubilized in such environments can be effectively transported into plant tissue via root transporters. Through this process, both inorganic and organic (methylated) arsenic species can accumulate to problematic concentrations and may affect grain yield as well as crop value. The distribution of these species in plant tissue is determined by arsenic sources, as well as enzymatic redox and methylation-demethylation reactions in soils and pore water. Historic use of organoarsenic-based pesticides in US agriculture may provide an enduring source of arsenic in rice paddies. However, it is unclear how persistent these organic species are in the adsorbed phase or how available they remain to rice cultivars throughout the growing season. We conducted a field experiment in a 2x2 factorial design examining the effects of irrigation methods (continuous flooding and alternate wetting and drying) and monosodium methanearsonate (MSMA) application on the abundance and speciation of arsenic in pore water, soil, and rice plant tissues. We monitored arsenic speciation and partitioning between these reservoirs at semi-weekly to semi-monthly frequencies. Pore water arsenic speciation was determined using LC-ICP-MS, and X-ray absorption near-edge structure (XANES) analysis was employed to speciate the arsenic within solid-phase soil and plant tissue throughout the growing season. These data help clarify the role of two irrigation methods and MSMA amendments for arsenic bioavailability and speciation in rice. Furthermore, the study illuminates the significance of microbial metabolism in the reapportionment of arsenic within the soil-plant-water system and its impact on arsenic levels in rice grains.

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.

Soil Degradation-Induced Decline in Productivity of Sub-Saharan African Soils: The Prospects of Looking Downwards the Lowlands with the Sawah Ecotechnology

Directory of Open Access Journals (Sweden)

Sunday E. Obalum

2012-01-01

Full Text Available The paper provides an insight into the problem of land degradation in Sub-Saharan Africa, with emphasis on soil erosion and its effect on soil quality and productivity, and proposes a lowland-based rice-production technology for coping with the situation. Crop yields are, in addition to the degree of past and current erosion, determined by a number of interacting variables. This, coupled with the generally weak database on erosion-induced losses in crop yield in spite of the region’s high vulnerability to erosion, makes it difficult to attain a reliable inference on the cause-effect relationship between soil loss and productivity. Available data suggest, however, that the region is at risk of not meeting up with the challenges of agriculture in this 21st century. Based on the few studies reviewed, methodology appears to have an overwhelming influence on the erosion-productivity response, whereas issues bordering on physical environment and soil affect the shape of the response curve. We argue that the sawah ecotechnology has the potential of countering the negative agronomic and environmental impacts of land degradation in Sub-Saharan Africa. This is a farmer-oriented, low-cost system of managing soil, water, and nutrient resources for enhancing lowland rice productivity and realizing Green Revolution in the region.

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.

Water management for controlling the breeding of Anopheles mosquitoes in rice irrigation schemes in Kenya

DEFF Research Database (Denmark)

Mutero, C M; Blank, H; Konradsen, F

2000-01-01

abundance fluctuated throughout the 12-week sampling period. The highest larval densities were recorded in the 3 weeks after transplanting the rice seedlings. Afterwards, larval numbers dropped dramatically as the height of rice plants increased. Rice yields at harvest did not show statistically significant...

Futile Na+ cycling at the root plasma membrane in rice (Oryza sativa L.): kinetics, energetics, and relationship to salinity tolerance.

Science.gov (United States)

Malagoli, Philippe; Britto, Dev T; Schulze, Lasse M; Kronzucker, Herbert J

2008-01-01

Globally, over one-third of irrigated land is affected by salinity, including much of the land under lowland rice cultivation in the tropics, seriously compromising yields of this most important of crop species. However, there remains an insufficient understanding of the cellular basis of salt tolerance in rice. Here, three methods of 24Na+ tracer analysis were used to investigate primary Na+ transport at the root plasma membrane in a salt-tolerant rice cultivar (Pokkali) and a salt-sensitive cultivar (IR29). Futile cycling of Na+ at the plasma membrane of intact roots occurred at both low and elevated levels of steady-state Na+ supply ([Na+]ext=1 mM and 25 mM) in both cultivars. At 25 mM [Na+]ext, a toxic condition for IR29, unidirectional influx and efflux of Na+ in this cultivar, but not in Pokkali, became very high [>100 micromol g (root FW)(-1) h(-1)], demonstrating an inability to restrict sodium fluxes. Current models of sodium transport energetics across the plasma membrane in root cells predict that, if the sodium efflux were mediated by Na+/H+ antiport, this toxic scenario would impose a substantial respiratory cost in IR29. This cost is calculated here, and compared with root respiration, which, however, comprised only approximately 50% of what would be required to sustain efflux by the antiporter. This suggests that either the conventional 'leak-pump' model of Na+ transport or the energetic model of proton-linked Na+ transport may require some revision. In addition, the lack of suppression of Na+ influx by both K+ and Ca2+, and by the application of the channel inhibitors Cs+, TEA+, and Ba2+, questions the participation of potassium channels and non-selective cation channels in the observed Na+ fluxes.

Consumptive use of upland rice as estimated by different methods

International Nuclear Information System (INIS)

Chhabda, P.R.; Varade, S.B.

1985-01-01

The consumptive use of upland rice (Oryza sativa Linn.) grown during the wet season (kharif) as estimated by modified Penman, radiation, pan-evaporation and Hargreaves methods showed a variation from computed consumptive use estimated by the gravimetric method. The variability increased with an increase in the irrigation interval, and decreased with an increase in the level of N applied. The average variability was less in pan-evaporation method, which could reliably be used for estimating water requirement of upland rice if percolation losses are considered

Understanding the nature of methane emission from rice ecosystems as basis of mitigation strategies

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

Methane is considered as an important Greenhouse gas and rice fields are one of the major atmospheric methane sources. The paper aims to develop sampling strategies and formulate mitigation options based on diel (day and night) and seasonal pattern of methane emission. The study was conducted in 4 countries to measure methane flux using an automatic closed chamber system. A 24-hour bihourly methane emissions were continuously obtained during the whole growing season. Daily and seasonal pattern of methane fluxes from different rice ecosystems were evaluated. Diel pattern of methane emission from irrigated rice fields, in all sites, displayed similar pattern from planting to flowering. Fluxes at 0600, 1200, and 1800 h were important components of the total diel flux. A proposed sampling frequency to accurately estimate methane emission within the growing season was designed based on the magnitude of daily flux variation. Total methane emission from different ecosystems follow the order: deepwater rice > irrigated rice > rainfed rice. Application of pig manure increased total emission by 10 times of that without manure. Green manure application increased emission by 49% of that applied only with inorganic fertilizer. Removal of floodwater at 10 DAP and 35 DAP, within a period of 4 days, inhibited production and emission of methane. The level of variation in daily methane emission and seasonal emission pattern provides useful information for accurate determination of methane fluxes. Characterization of seasonal emission pattern as to ecologies, fertilizer amendments, and water management gives an idea of where to focus mitigation strategies for sustainable rice production.

Selectivity of pesticides used in rice crop on Telenomus podisi and Trichogramma pretiosum

OpenAIRE

Pazini,Juliano de Bastos; Grützmacher,Anderson Dionei; Martins,José Francisco da Silva; Pasini,Rafael Antônio; Rakes,Matheus

2016-01-01

ABSTRACT Telenomus and Trichogramma species stand out as agents for the biological control in rice crops, and the main strategy for preserving them is the use of selective pesticides. This study aimed at evaluating the toxicity of pesticides used in irrigated rice crop on Telenomus podisi Ashmead (Hymenoptera: Platygastridae) and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae). Adults of these parasitoids were exposed to dry residues of pesticides, in a completely randomized exp...

The Assessment of Irrigated Land Salinization in the Aral Sea Region

Science.gov (United States)

Karlykhanov, Orazkhan K.; Toktaganova, Gulzhaz B.

2016-01-01

Agriculture is one of the main industries of Kazakhstan, especially in the Kyzylorda Region. Before the reforms, agriculture in this region was better developed than the manufacturing industry; this is no longer the case. The main crop grown on the irrigated land of the region is rice. Inefficient distribution of cultivated areas, their excessive…

Productivity, Profitability and Resource Use Efficiency: A Comparative Analysis between Conventional and High Yielding Rice in Rajbari District, Bangladesh

Directory of Open Access Journals (Sweden)

Md. Yahia Bapari

2016-10-01

Full Text Available The study was analyzed the determinants, costs and benefits and resources allocation of both conventional and high yielding rice cultivation over the Rajbari district of Bangladesh. Data were accumulated from 300 regular rice growers of conventional and high yielding varieties and random sampling technique was applied for selecting the respondents from the study area from which information was collected through pre-tested questionnaire. Cobb – Douglas production function and gross margin were mainly used to determine the productivities and profits of both rice and the marginal value of the product was highly recommended to derive the optimal use of the resources. Results obtained by applying ordinary least square method showed that the most important factors of production in the study area were irrigation, labor, fertilizer and insecticide costs whose elasticities were 0.904, 0.048, 0.045 and 0.044 respectively and insignificant factors were seed and ploughing costs whose elasticities were – 0.009 and 0.030 respectively for high yielding rice. On the other hand, irrigation, insecticide, seed and ploughing costs of elasticities 0.880, 0.589, 0.116 and – 0.127 respectively were the important factors and minor role playing factors were labor and fertilizer costs whose elasticities were 0.098 and 0.077 respectively for conventional yielding rice. The core message from productivity analysis was that the irrigation was key variable which played a positive and vital role in producing rice of both varieties. All variables (resources were economically misallocated in the production activities of both varieties along the study area but high yielding rice was more profitable than conventional one. Results also showed that the farmers of the study area produced rice of both varieties in the inefficient range of production. Continuous supply of electricity, flexible credit and improving the existing resources were the prime policy recommendations of

Development of a real-time hydrological cycle - rice growth coupled simulation system as a tool for farmers' decision making in an ungauged basin in Cambodia for the better agricultural water resources management

Science.gov (United States)

Tsujimoto, K.; Ohta, T.; Yasukawa, M.; Koike, T.; Kitsuregawa, M.; Homma, K.

2013-12-01

The entire country of Cambodia depends on agriculture for its economy. Rice is the staple food, making it the major agricultural product (roughly 80% of total national production). The target area of this study is western Cambodia, where rice production is the greatest in the country and most land is rainfed. Since most farmers rely only on their (non-science-based) experience, they would not adjust to changing rainfall and degraded water resources under climate change, so food security in the region would be seriously threatened (Monichoth et al., 2013). Under this condition, irrigation master plans are being considered by several ODA projects. This study aims to contribute to the design of such irrigation plans through the development of a real-time hydrological cycle - rice growth coupled simulation system. The purpose of the development of this system is to support decision making 1) for determining the necessary agricultural water resources and 2) for allocating limited water resources to various sectors. Rice growing condition as affected by water stress due to the water shortage is supposed to be shown for both of the cases with and without irrigation for several rainfall patterns. A dynamically coupled model of a distributed hydrological model (WEB-DHM., Wang et al., 2009) and a rice growth model (SIMRIW-rainfed, Homma et al., 2009) has been developed with a simple irrigation model. The target basin, a small basin in western Cambodia, is basically an ungauged basin and the model was validated by soil moisture, LAI, dry matter production of the rice crop, and rice yield, using both intensive field observation and satellite observations. Calibrating hourly satellite precipitation dataset (GSMaP/NRT) using ground rain gauges, hydrological cycle (soil moisture at three layers, river discharge, irrigatable water amount, water level of each paddy field, water demand of each paddy field, etc.) and rice growth (LAI, developmental index of the rice crop, dry matter

mathematical model for scheduling irrigation for swamp rice in port

African Journals Online (AJOL)

2017-03-24

Mar 24, 2017 ... The thirst for increased food production and management of our natural resources (water) .... 16th, 2009. .... formula, Karl Pearson, (1980), was adopted in ..... Hawksworth, D. L., 1985. Foreword. In S.H. Ou, ed. Rice diseases.

Scaling up Intermittent Rice Irrigation for Malaria Control on the ...

International Development Research Centre (IDRC) Digital Library (Canada)

The research aims to foster uptake of intermittent irrigation at the watershed level (Valle de Jequetepeque in La Libertad) by exploring ways to: - disseminate knowledge and skills (farmer-to-farmer agricultural extension); - assess and document social, health, environmental, and economic trade-offs as farmers adopt new ...

Spider assemblages associated with different crop stages of irrigated rice agroecosystems from eastern Uruguay.

Science.gov (United States)

Bao, Leticia; Ginella, Juaquín; Cadenazzi, Mónica; Castiglioni, Enrique A; Martínez, Sebastián; Casales, Luis; Caraballo, María P; Laborda, Álvaro; Simo, Miguel

2018-01-01

The rice crop and associated ecosystems constitute a rich mosaic of habitats that preserve a rich biological diversity. Spiders are an abundant and successful group of natural predators that are considered efficient in the biocontrol of the major insect pests in agroecosystems. Spider diversity in different stages of the rice crop growth from eastern Uruguay was analysed. Field study was developed on six rice farms with rotation system with pasture, installed during intercropping stage as cover crop. Six rice crops distributed in three locations were sampled with pitfall and entomological vaccum suction machine. Sixteen families, representing six guilds, were collected. Lycosidae, Linyphiidae, Anyphaenidae and Tetragnathidae were the most abundant families (26%, 25%, 20% and 12%, respectively) and comprised more than 80% of total abundance. Other hunters (29%), sheet web weavers (25%) and ground hunters (24%) were the most abundant guilds. Species composition along different crop stages was significantly different according to the ANOSIM test. The results showed higher spider abundance and diversity along the crop and intercrop stages. This study represents the first contribution to the knowledge of spider diversity associated with rice agroecosystem in the country.

Effect of salt stress on germination and early seedling growth of rice ...

African Journals Online (AJOL)

USER

2010-03-29

Mar 29, 2010 ... planting in saline soil or in areas inundated by sea water or irrigated with brackish ... Nutritional imbalance caused by such ions leads to reduction in ... rice varieties showed a great variation in germination due to salinity effect.

Optimizing Greenhouse Rice Production: Summary of Recommendations

OpenAIRE

Eddy, Robert; Acosta, Kevin; Liu, Yisi; Russell, Michael

2016-01-01

This publication provides a single-page chart summarizing our protocols for growing Rice (japonica). Split into three production goals, recommendations are given for photoperiod, temperature, lighting, container, root medium, planting density, irrigation, fertilization, algae control and fungus gnat control. This version updates our fertilization frequency, pot size, root medium and algae control recommendations. This document summarizes a series of questions and answers originally posted ...

Regulating N application for rice yield and sustainable eco-agro development in the upper reaches of Yellow River basin, China.

Science.gov (United States)

Zhang, Aiping; Liu, Ruliang; Gao, Ji; Yang, Shiqi; Chen, Zhe

2014-01-01

High N fertilizer and flooding irrigation applied to rice on anthropogenic-alluvial soil often result in N leaching and low recovery of applied fertilizer N from the rice fields in Ningxia irrigation region in the upper reaches of the Yellow River, which threatens ecological environment, food security, and sustainable agricultural development. This paper reported the regulating N application for rice yield and sustainable Eco-Agro development in the upper reaches of Yellow River basin. The results showed that reducing and postponing N application could maintain crop yields while substantially reducing N leaching losses to the environment and improving the nitrogen use efficiency. Considering the high food production, the minimum environmental threat, and the low labor input, we suggested that regulating N application is an important measure to help sustainable agricultural development in this region.

Eficiência produtiva de cultivares de arroz com divergência fenotípica Production efficiency of rice cultivars with phenotypic diversity

Directory of Open Access Journals (Sweden)

Cleber M. Guimarães

2008-10-01

supplementary irrigation, the upland rice cultivars CIRAD L(-141, Guarani, Caiapó, and Maravilha presented higher grain harvest indexes and lower spikelet sterility than the lowland cultivars BR IRGA 409 and Metica 1. It was concluded that the highest biomass yield of the lowland rice cultivars did not have an effect upon the grain yield. The upland cultivar CIRAD L(-141, with high leaf area, panicles with high grain number and average performance of the agronomic components evaluated, such as harvest index, grain weight, tiller fertility, tillering, spikelet sterility and growth index, yielded 12.5% higher than Guarani, the second best cultivar. The increase in grain harvest index and weight of grain and the reduction in spikelet sterility, due to their high correlation with grain yield, are considered high priority in the upland rice breeding programs for higher yields.

SOIL N, P AND K CONCENTRATIONS AND RICE YIELD INCREASED DUE TO THE APPLICATION OF Azolla pinnata

Directory of Open Access Journals (Sweden)

A. Arivin Rivaie*

2014-01-01

Full Text Available Many studies showed that application of Azolla pinnata as biofertilizer improved soil fertility some agricultural crops, including rice, whereas farmers in Lampung consider that A. pinnata suppresses growth of rice seedlings, so they throw it field by raising irrigation water surface. Information on effects A. pinnata application on changes in nutrient availability and rice yield obtained from paddy fields of regions still rare. A study was carried out to investigate effects of different rates of A. pinnata on changes in N, P, K concentrations in paddy soils, N uptake, and rice yield. A well-irrigated paddy field was incorporated with A. pinnata, and then rice seedlings of Ciherang variety had been grown from June up to December 2009. Results: application of A. pinnata at dose of five t per ha increased concentration of N, P and K as well as rice yield. A. pinnata had a relatively high N content, ie 2.43 percent. Application of A. pinnata of 7.5 t per ha increased significantly available soil P, indicated that A. pinnata requires a fairly high P to grow optimally. Application of A. pinnata of 7.5 t per ha gave highest dry grain yield, suggests that application A. pinnata did not suppress rice yield, even use of A. pinnata as organic matter source will help to conserve fossil fuels and foreign exchange as well as will allow more paddy fields that can be fertilized by N.

Neotropical lowland forests along environmental gradients

NARCIS (Netherlands)

Toledo, M.

2010-01-01

Neotropical lowlands feature an extraordinary display of vegetation types. This is especially the case for Bolivia where three biogeographical regions, Amazonian, Brazilian-Paranaense and Gran Chaco meet in the lowland areas, providing thus an ideal setting to study vegetation-environment

Petroleum possibilities of the James Bay Lowland area: Drilling in the James Bay Lowland

Energy Technology Data Exchange (ETDEWEB)

Martison, N W

1954-12-31

Interest in the possible occurrence of petroleum and natural gas in the James Bay lowland arises from the presence there of Palaeozoic sedimentary formations resembling those in south-western Ontario. The first part of this report reviews earlier geologic surveys conducted in the lowland and reports results of field work and drill core studies 1946-51. It describes the area`s topography, climate, stratigraphy and palaeontology (Ordovician to Lower Cretaceous, plus Pleistocene and recent glacial deposits), structural geology, and evidence of petroleum. Lists of fossils and correlations are included. The appendices include a list of fossil locations and drill logs. The second part details the drilling programs carried out in the lowland by the Ontario Dept. of Mines, including detailed logs, as well as drilling carried out by some other organisations.

Influence of composted organic waste and urea fertilization on rice ...

African Journals Online (AJOL)

The field experiment was conducted at the University of Ghana's Soil and Irrigation Research Centre - Kpong during 2014 and 2015 cropping seasons to evaluate the influence of composted organic waste and urea fertilization on rice yield, Nitrogen-use efficiency and soil chemical characteristics. The study was laid out in a ...

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.

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)

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)

[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.

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)

A Stochastic Water Balance Framework for Lowland Watersheds

Science.gov (United States)

Thompson, Sally; MacVean, Lissa; Sivapalan, Murugesu

2017-11-01

The water balance dynamics in lowland watersheds are influenced not only by local hydroclimatic controls on energy and water availability, but also by imports of water from the upstream watershed. These imports result in a stochastic extent of inundation in lowland watersheds that is determined by the local flood regime, watershed topography, and the rate of loss processes such as drainage and evaporation. Thus, lowland watershed water balances depend on two stochastic processes—rainfall and local inundation dynamics. Lowlands are high productivity environments that are disproportionately associated with urbanization, high productivity agriculture, biodiversity, and flood risk. Consequently, they are being rapidly altered by human development—generally with clear economic and social motivation—but also with significant trade-offs in ecosystem services provision, directly related to changes in the components and variability of the lowland water balance. We present a stochastic framework to assess the lowland water balance and its sensitivity to two common human interventions—replacement of native vegetation with alternative land uses, and construction of local flood protection levees. By providing analytical solutions for the mean and PDF of the water balance components, the proposed framework provides a mechanism to connect human interventions to hydrologic outcomes, and, in conjunction with ecosystem service production estimates, to evaluate trade-offs associated with lowland watershed development.

Sources, distribution and export coefficient of phosphorus in lowland polders of Lake Taihu Basin, China.

Science.gov (United States)

Huang, Jiacong; Gao, Junfeng; Jiang, Yong; Yin, Hongbin; Amiri, Bahman Jabbarian

2017-12-01

Identifying phosphorus (P) sources, distribution and export from lowland polders is important for P pollution management, however, is challenging due to the high complexity of hydrological and P transport processes in lowland areas. In this study, the spatial pattern and temporal dynamics of P export coefficient (PEC) from all the 2539 polders in Lake Taihu Basin, China were estimated using a coupled P model for describing P dynamics in a polder system. The estimated amount of P export from polders in Lake Taihu Basin during 2013 was 1916.2 t/yr, with a spatially-averaged PEC of 1.8 kg/ha/yr. PEC had peak values (more than 4.0 kg/ha/yr) in the polders near/within the large cities, and was high during the rice-cropping season. Sensitivity analysis based on the coupled P model revealed that the sensitive factors controlling the PEC varied spatially and changed through time. Precipitation and air temperature were the most sensitive factors controlling PEC. Culvert controlling and fertilization were sensitive factors controlling PEC during some periods. This study demonstrated an estimation of PEC from 2539 polders in Lake Taihu Basin, and an identification of sensitive environmental factors affecting PEC. The investigation of polder P export in a watershed scale is helpful for water managers to learn the distribution of P sources, to identify key P sources, and thus to achieve best management practice in controlling P export from lowland areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of mercury species in brown and white rice (Oryza sativa L.) grown in water-saving paddies

Energy Technology Data Exchange (ETDEWEB)

Rothenberg, Sarah E., E-mail: rothenberg.sarah@gmail.com [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Feng Xinbin, E-mail: fengxinbin@vip.skleg.cn [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Dong Bin, E-mail: dongbin@whu.edu.cn [State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072 (China); Shang Lihai, E-mail: shanglihai@vip.gyig.ac.cn [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Yin Runsheng, E-mail: yinrunsheng2002@163.com [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Yuan Xiaobo, E-mail: xiantao_131@163.com [College of Resources and the Environment, Southwest University, Chongqing 400716 (China)

2011-05-15

In China, total Hg (Hg{sub T}) and methylmercury (MeHg) were quantified in rice grain grown in three sites using water-saving rice cultivation methods, and in one Hg-contaminated site, where rice was grown under flooded conditions. Polished white rice concentrations of Hg{sub T} (water-saving: 3.3 {+-} 1.6 ng/g; flooded: 110 {+-} 9.2 ng/g) and MeHg (water-saving 1.3 {+-} 0.56 ng/g; flooded: 12 {+-} 2.4 ng/g) were positively correlated with root-soil Hg{sub T} and MeHg contents (Hg{sub T}: r{sup 2} = 0.97, MeHg: r{sup 2} = 0.87, p < 0.05 for both), which suggested a portion of Hg species in rice grain was derived from the soil, and translocation of Hg species from soil to rice grain was independent of irrigation practices and Hg levels, although other factors may be important. Concentrations of Hg{sub T} and other trace elements were significantly higher in unmilled brown rice (p < 0.05), while MeHg content was similar (p > 0.20), indicating MeHg infiltrated the endosperm (i.e., white rice) more efficiently than inorganic Hg(II). - Highlights: > First time that Hg{sub T} and MeHg were characterized in both brown and white rice. > MeHg translocation into the endosperm was more efficient than inorganic Hg(II). > In this respect, MeHg behaved like dimethylarsinic acid and organic Se species. > In white rice, Hg{sub T} and MeHg were positively correlated with soil Hg{sub T} and MeHg. > Uptake rates of Hg{sub T} and MeHg were independent of irrigation methods and Hg content. - Methylmercury was more efficiently translocated to the endosperm than inorganic mercury.

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.

Assessment of water sources to plant growth in rice based cropping systems by stable water isotopes

Science.gov (United States)

Mahindawansha, Amani; Kraft, Philipp; Racela, Heathcliff; Breuer, Lutz

2016-04-01

Rice is one of the most water-consuming crops in the world. Understanding water source utilization of rice will help us to improve water use efficiency (WUE) in paddy management. The objectives of our study are to evaluate the isotopic compositions of surface ponded water, soil water, irrigation water, groundwater, rain water and plant water and based on stable water isotope signatures to evaluate the contributions of various water sources to plant growth (wet rice, aerobic rice and maize) together with investigating the contribution of water from different soil horizons for plant growth in different maturity periods during wet and dry seasons. Finally we will compare the water balances and crop yields in both crops during both seasons and calculate the water use efficiencies. This will help to identify the most efficient water management systems in rice based cropping ecosystems using stable water isotopes. Soil samples are collected from 9 different depths at up to 60 cm in vegetative, reproductive and matured periods of plant growth together with stem samples. Soil and plant samples are extracted by cryogenic vacuum extraction. Root samples are collected up to 60 cm depth from 10 cm intercepts leading calculation of root length density and dry weight. Groundwater, surface water, rain water and irrigation water are sampled weekly. All water samples are analyzed for hydrogen and oxygen isotope ratios (d18O and dD) using Los Gatos Research DLT100. Rainfall records, ground water level, surface water level fluctuations and the amount of water irrigated in each field will be measured during the sampling period. The direct inference approach which is based on comparing isotopic compositions (dD and d18O) between plant stem water and soil water will be used to determine water sources taken up by plant. Multiple-source mass balance assessment can provide the estimated range of potential contributions of water from each soil depth to root water uptake of a crop. These

Soil Degradation-Induced Decline in Productivity of Sub-Saharan African Soils: The Prospects of Looking Downwards the Lowlands with the Sawah Ecotechnology

OpenAIRE

Obalum, Sunday E.; Buri, Mohammed M.; Nwite, John C.; Hermansah; Watanabe, Yoshinori; Igwe, Charles A.; Wakatsuki, Toshiyuki

2012-01-01

The paper provides an insight into the problem of land degradation in Sub-Saharan Africa, with emphasis on soil erosion and its effect on soil quality and productivity, and proposes a lowland-based rice-production technology for coping with the situation. Crop yields are, in addition to the degree of past and current erosion, determined by a number of interacting variables. This, coupled with the generally weak database on erosion-induced losses in crop yield in spite of the region’s high vul...

Sustainability Assessment of Large Irrigation Dams in Senegal: A Cost-Benefit Analysis for the Senegal River Valley

Directory of Open Access Journals (Sweden)

Stanislaw eManikowski

2016-03-01

Full Text Available Starting in the 1970s, the Senegalese Government invested in the development of irrigated schemes in the Senegalese part of the Senegal River Valley (S-SRV. From that time to 2012, the irrigated schemes increased from 10,000 ha to more than 110,000 ha. In the meantime, the economic viability of these schemes started to be questioned. It also appeared that the environmental health and social costs might outweigh the benefits of irrigation. Using a life cycle assessment approach and project cost-benefits modelling, this study (i quantified the costs and benefits of the S-SRV irrigated rice production, (ii evaluated the costs and benefits of its externalities and (iii discussed the irrigated rice support policy. The net financial revenues from the irrigated schemes were positive, but their economic equivalences. The economic return rate (EER was below the expected 12% and the net present value (NPV over 20 years of the project represented a loss of about US$-19.6 million. However, if we also include the project’s negative externalities, such as the reduced productivity of the valley ecosystems, protection cost of human health, environmental degradation and social impacts, then the NPV would be much worse, approximately US$-572.1 million. Therefore, the results show that to stop the economic loss and alleviate the human suffering, the S-SRV development policy should be revised using an integrated approach and the exploitation technology should aim at environmental sustainability. This paper may offer useful insights for reviewing the current Senegalese policies for the valley, as well as for assessing other similar cases or future projects worldwide, particularly in critical zones of developing countries.

Soil-based screening for iron toxicity tolerance in rice using pots

Directory of Open Access Journals (Sweden)

Mouritala Sikirou

2016-10-01

Full Text Available The objective of this study was to assess the reliability of pot-based screening method for iron (Fe toxicity tolerance in rice using soils from hot spots. Five lowland rice varieties with known reaction to Fe toxicity were grown in pots in a screen house for three seasons. Fe-toxic soils from two hot spot fields – Edozighi, Nigeria and Niaouli, Benin were used and soil from Africa Rice Center (AfricaRice experimental farm, Cotonou, Benin was included as control. Leaf bronzing score (LBS was determined at different stages, and grain yield was determined at maturity. Heritability was estimated using data across the three seasons. High heritability was recorded for LBS and grain yield. Grain yield reduction in stress treatment relative to control varied from 15 to 56% depending on the variety and soil. Bao Thai, Suakoko 8, and WITA 4 had better performance under Fe toxicity in terms of LBS, yield and relative yield reduction, whereas Bouake 189 and IR64 had poorer performance. Grain yield and LBS were significantly correlated but negatively at 60 days after sowing (DAS. Overall, the results found in this experiment were consistent with previous field studies. Therefore, pot screening using soils from hot spots can be used by rice breeding programs to reliably assess Fe toxicity tolerance ex situ.

Rice yellow mottle virus is transmitted by cows, donkeys, and grass rats in irrigated rice crops

NARCIS (Netherlands)

Sarra, S.; Peters, D.

2003-01-01

Rice yellow mottle virus (RYMV), endemic in Africa, is believed to be spread by chrysomelid beetles, although the infections in a field often cannot be explained by the prevailing number of beetles. We show that the grass rat Arvicanthis niloticus, domestic cows (Bos spp.), and donkeys (Asinus spp.)

Arsenic contamination of soils and agricultural plants through irrigation water in Nepal

International Nuclear Information System (INIS)

Dahal, B.M.; Fuerhacker, M.; Mentler, A.; Karki, K.B.; Shrestha, R.R.; Blum, W.E.H.

2008-01-01

This study monitored the influence of arsenic-contaminated irrigation water on alkaline soils and arsenic uptake in agricultural plants at field level. The arsenic concentrations in irrigation water ranges from -1 where the arsenic concentrations in the soils were measured from 6.1 to 16.7 mg As kg -1 . The arsenic content in different parts of plants are found in the order of roots > shoots > leaves > edible parts. The mean arsenic content of edible plant material (dry weight) were found in the order of onion leaves (0.55 mg As kg -1 ) > onion bulb (0.45 mg As kg -1 ) > cauliflower (0.33 mg As kg -1 ) > rice (0.18 mg As kg -1 ) > brinjal (0.09 mg As kg -1 ) > potato ( -1 ). - The arsenic content in soil and plants is influenced by the degree of arsenic amount in irrigated water

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)

Influence of technical maintenance measures on ecological status of agricultural lowland rivers - Systematic review and implications for river management.

Science.gov (United States)

Bączyk, Anna; Wagner, Maciej; Okruszko, Tomasz; Grygoruk, Mateusz

2018-06-15

Intensification of agriculture and ongoing urban sprawl exacerbate pressures on rivers. Small rivers in agricultural landscapes are especially exposed to excessive technical actions implemented in order to allow for harvesting river water for irrigation, draining agricultural water and receiving sewage. Regular dredging and macrophyte removal strongly interfere with the global need for preserving river biodiversity that allows agricultural lowland rivers to remain refuges for a variety of species, and-accordingly-to keep water bodies resilient for the benefit of society. In order to provide a comprehensive look at the influence of agricultural lowland river management on the ecological status of these water bodies, we conducted a literature review and a meta-analysis. For the structured literature review we selected 203 papers reflecting on the response of aquatic ecosystems to dredging and macrophyte management actions. The database of scientific contributions developed for our study consists of papers written by the authors from 33 countries (first authorship) addressing dredging, macrophyte removal, status of fish and macroinvertebrates as well as the general ecological status of lowland agricultural rivers. We revealed that 96% of the analyzed papers indicated unilateral, negative responses of aquatic ecosystems, particularly macroinvertebrates, ichthyofauna and macrophyte composition, to maintenance measures. We revealed that studies conducted in the European Union on the ecological status of rivers appeared to significantly increase in quantity after the implementation of the Water Framework Directive. Finally, we concluded that day-to-day management of lowland agricultural rivers requires revision in terms of compliance with environmental conservation requirements and the recurrent implementation of technical measures for river maintenance. Copyright © 2018 Elsevier B.V. All rights reserved.

Can simulation models help design rice cultivars that are more competitive against weeds?

NARCIS (Netherlands)

Bastiaans, L.; Kropff, M.J.; Kempuchetty, N.; Rajan, A.; Migo, T.R.

1997-01-01

Differences in competitive ability between rice cultivars IR8 and Mahsuri, grown in well-fertilised irrigated conditions, were analysed by means of a mechanistic simulation model (INTERCOM) for crop-weed interaction. The analysis revealed that the greater competitive ability of Mahsuri was due

Elemental composition of Malawian rice.

Science.gov (United States)

Joy, Edward J M; Louise Ander, E; Broadley, Martin R; Young, Scott D; Chilimba, Allan D C; Hamilton, Elliott M; Watts, Michael J

2017-08-01

Widespread potential dietary deficiencies of calcium (Ca), iron (Fe), iodine (I), selenium (Se) and zinc (Zn) have been identified in Malawi. Several deficiencies are likely to be compounded by high phytic acid (PA) consumption. Rice (Oryza sativa) is commonly consumed in some Malawian populations, and its mineral micronutrient content is important for food security. The considerable irrigation requirements and flooded conditions of paddy soils can also introduce or mobilise potentially toxic elements including arsenic (As), cadmium (Cd) and lead (Pb). The aim of this study was to determine the mineral composition of rice sampled from farmers' fields and markets in Malawi. Rice was sampled from 18 extension planning areas across Malawi with 21 white (i.e. polished) and 33 brown samples collected. Elemental composition was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Arsenic speciation was performed using high-performance liquid chromatography (HPLC)-ICP-MS. Concentration of PA was determined using a PA-total phosphorus assay. Median total concentrations (mg kg -1 , dry weight) of elements important for human nutrition in brown and white rice, respectively, were: Ca = 66.5 and 37.8; Cu = 3.65 and 2.49; Fe = 22.1 and 7.2; I = 0.006 and rice samples, respectively, median PA concentrations were 5438 and 1906 mg kg -1 , and median PA:Zn molar ratios were 29 and 13. Concentrations of potentially toxic elements (mg kg -1 , dry weight) in brown and white rice samples, respectively, were: As = 0.030 and 0.006; Cd  ≤ 0.002 and 0.006; Pb = 0.008 and 0.008. Approximately 95 % of As was found to be inorganic As, where this could be quantified. Malawian rice, like the more widely consumed staple grain maize, contains inadequate Ca, I, Se or Zn to meet dietary requirements. Biofortification strategies could significantly increase Se and Zn concentrations and require further investigation. Concentrations of Fe in rice grain varied

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)

Selection Of Drought Resistant Mutants In Rice Using DNA Markers

International Nuclear Information System (INIS)

Nguyen Duc Thanh; Le Thi Bich Thuy; Dang Thi Minh Lua

2008-01-01

In recent years, the marker - assisted selection (MAS) strategy have been used for selection of traits that are difficult and costly performed measurement and score. Selection for a well-developed root system could improve the drought resistance of rice as the plant would avoid water stress by absorbing water from the soil. There were several reports on map construction and identification of the markers tightly linked to morphological and physiological traits related to drought resistance in rice, in particular, root traits in upland and lowland rice (Champoux et al., 1995; Ray et al., 1996; Price et al., 1997, 2000; Yadav et al., 1997). In this report, we present the results on selection of drought resistance mutants in rice using the DNA markers tightly linked to root traits favorable for drought resistance. The mutant rice lines were obtained from irradiated seeds and calluses by gamma ray. The selection was performed at M2 mutants using the DNA markers linked to maximum root length (MRL), root weight to shoot weight ratio (RW/SR), and weight of deep root to shoot weight ratio (DRW/SR). The obtained results showed that there were many lines possessed drought resistant markers. In addition, there is a number of lines have altered genome. Several lines having drought markers proved to be more resistant to drought in green-house test. These lines could be useful for further test and development of drought resistant varieties. (author)

ANALYZING THE TECHNICAL EFFICIENCY OF RICE FARMS IN THE RIO GRANDE DO SUL

Directory of Open Access Journals (Sweden)

Augusto Mussi Alvim

2015-03-01

Full Text Available This paper evaluates the technical efficiency in rice farms in Rio Grande do Sul (RS. For this, we use the Data Envelopment Analysis (DEA and the Tobit regression model. The study use the variables available in the Census of the Institute of Irrigated Rice of RS (IRGA, 2006. The study shows that most of the rice farmers are technically inefficient on local terms, and only 5.7% are efficient. In addition, it is possible to observe that the main variables, which increase the level of efficiency in different regions of the state, are technical assistance, education level and growing system. The results show that there are important differences between the rice farms, which depends of the region of RS and of the producer condition (owner or tenant.

Organic fertilizer application increases the soil respiration and net ecosystem carbon dioxide absorption of paddy fields under water-saving irrigation.

Science.gov (United States)

Yang, Shihong; Xiao, Ya Nan; Xu, Junzeng

2018-04-01

Quantifying carbon sequestration in paddy soil is necessary to understand the effect of agricultural practices on carbon cycles. The objective of this study was to assess the effect of organic fertilizer addition (MF) on the soil respiration and net ecosystem carbon dioxide (CO 2 ) absorption of paddy fields under water-saving irrigation (CI) in the Taihu Lake Region of China during the 2014 and 2015 rice-growing seasons. Compared with the traditional fertilizer and water management (FC), the joint regulation of CI and MF (CM) significantly increased the rice yields and irrigation water use efficiencies of paddy fields by 4.02~5.08 and 83.54~109.97% (p < 0.05). The effects of organic fertilizer addition on soil respiration and net ecosystem CO 2 absorption rates showed inter-annual differences. CM paddy fields showed a higher soil respiration and net CO 2 absorption rates during some periods of the rice growth stage in the first year and during most periods of the rice growth stage in the second year. These fields also had significantly higher total CO 2 emission through soil respiration (total R soil ) and total net CO 2 absorption compared with FC paddy fields (p < 0.05). The total R soil and net ecosystem CO 2 absorption of CM paddy fields were 67.39~91.55 and 129.41~113.75 mol m -2 , which were 27.66~135.52 and 12.96~31.66% higher than those of FC paddy fields. The interaction between water and fertilizer management had significant effects on total net ecosystem CO 2 absorption. The frequent alternate wet-dry cycles of CI paddy fields increased the soil respiration and reduced the net CO 2 absorption. Organic fertilizer promoted the soil respiration of paddy soil but also increased its net CO 2 absorption and organic carbon content. Therefore, the joint regulation of water-saving irrigation and organic fertilizer is an effective measure for maintaining yield, increasing irrigation water use efficiency, mitigating CO 2 emission, and promoting paddy

Sustainable crop intensification through surface water irrigation in Bangladesh? A geospatial assessment of landscape-scale production potential.

Science.gov (United States)

Krupnik, Timothy J; Schulthess, Urs; Ahmed, Zia Uddin; McDonald, Andrew J

2017-01-01

Changing dietary preferences and population growth in South Asia have resulted in increasing demand for wheat and maize, along side high and sustained demand for rice. In the highly productive northwestern Indo-Gangetic Plains of South Asia, farmers utilize groundwater irrigation to assure that at least two of these crops are sequenced on the same field within the same year. Such double cropping has had a significant and positive influence on regional agricultural productivity. But in the risk-prone and food insecure lower Eastern Indo-Gangetic Plains (EIGP), cropping is less intensive. During the dryer winter months, arable land is frequently fallowed or devoted to lower yielding rainfed legumes. Seeing opportunity to boost cereals production, particularly for rice, donors and land use policy makers have consequently reprioritized agricultural development investments in this impoverished region. Tapping groundwater for irrigation and intensified double cropping, however, is unlikely to be economically viable or environmentally sound in the EIGP. Constraints include saline shallow water tables and the prohibitively high installation and energetic extraction costs from deeper freshwater aquifers. The network of largely underutilized rivers and natural canals in the EIGP could conversely be tapped to provide less energetically and economically costly surface water irrigation (SWI). This approach is now championed by the Government of Bangladesh, which has requested USD 500 million from donors to implement land and water use policies to facilitate SWI and double cropping. Precise geospatial assessment of where freshwater flows are most prominent, or where viable fallow or low production intensity cropland is most common, however remains lacking. In response, we used remotely sensed data to identify agricultural land, detect the temporal availability of freshwater in rivers and canals, and assess crop production intensity over a three-year study period in a 33,750�

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.

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)

Estimation of rice yield affected by drought and relation between rice yield and TVDI

Science.gov (United States)

Hongo, C.; Tamura, E.; Sigit, G.

2016-12-01

Impact of climate change is not only seen on food production but also on food security and sustainable development of society. Adaptation to climate change is a pressing issue throughout the world to reduce the risks along with the plans and strategies for food security and sustainable development. As a key adaptation to the climate change, agricultural insurance is expected to play an important role in stabilizing agricultural production through compensating the losses caused by the climate change. As the adaptation, the Government of Indonesia has launched agricultural insurance program for damage of rice by drought, flood and pest and disease. The Government started a pilot project in 2013 and this year the pilot project has been extended to 22 provinces. Having the above as background, we conducted research on development of new damage assessment method for rice using remote sensing data which could be used for evaluation of damage ratio caused by drought in West Java, Indonesia. For assessment of the damage ratio, estimation of rice yield is a key. As the result of our study, rice yield affected by drought in dry season could be estimated at level of 1 % significance using SPOT 7 data taken in 2015, and the validation result was 0.8t/ha. Then, the decrease ratio in rice yield about each individual paddy field was calculated using data of the estimated result and the average yield of the past 10 years. In addition, TVDI (Temperature Vegetation Dryness Index) which was calculated from Landsat8 data in heading season indicated the dryness in low yield area. The result suggests that rice yield was affected by irrigation water shortage around heading season as a result of the decreased precipitation by El Nino. Through our study, it becomes clear that the utilization of remote sensing data can be promising for assessment of the damage ratio of rice production precisely, quickly and quantitatively, and also it can be incorporated into the insurance procedures.

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

Localized flux maxima of arsenic, lead, and iron around root apices in flooded lowland rice.

Science.gov (United States)

Williams, Paul N; Santner, Jakob; Larsen, Morten; Lehto, Niklas J; Oburger, Eva; Wenzel, Walter; Glud, Ronnie N; Davison, William; Zhang, Hao

2014-01-01

In wetland-adapted plants, such as rice, it is typically root apexes, sites of rapid entry for water/nutrients, where radial oxygen losses (ROLs) are highest. Nutrient/toxic metal uptake therefore largely occurs through oxidized zones and pH microgradients. However, the processes controlling the acquisition of trace elements in rice have been difficult to explore experimentally because of a lack of techniques for simultaneously measuring labile trace elements and O2/pH. Here, we use new diffusive gradients in thin films (DGT)/planar optode sandwich sensors deployed in situ on rice roots to demonstrate a new geochemical niche of greatly enhanced As, Pb, and Fe(II) mobilization into solution immediately adjacent to the root tips characterized by O2 enrichment and low pH. Fe(II) mobilization was congruent to that of the peripheral edge of the aerobic root zone, demonstrating that the Fe(II) mobilization maximum only developed in a narrow O2 range as the oxidation front penetrates the reducing soil. The Fe flux to the DGT resin at the root apexes was 3-fold higher than the anaerobic bulk soil and 27 times greater than the aerobic rooting zone. These results provide new evidence for the importance of coupled diffusion and oxidation of Fe in modulating trace metal solubilization, dispersion, and plant uptake.

Understanding the physiological and molecular mechanisms of rice-microbial interactions that produce methane

Science.gov (United States)

The second most abundant greenhouse gas, methane, is ~25 times more potent in global warming potential than carbon dioxide, and 7-17% of atmospheric methane comes from flooded rice fields. Methane emissions can be greatly reduced by using alternate wetting and drying irrigation management and/or cul...

REMOTE-SENSING-BASED BIOPHYSICAL MODELS FOR ESTIMATING LAI OF IRRIGATED CROPS IN MURRY DARLING BASIN

Directory of Open Access Journals (Sweden)

I. Wittamperuma

2012-07-01

Full Text Available Remote sensing is a rapid and reliable method for estimating crop growth data from individual plant to crops in irrigated agriculture ecosystem. The LAI is one of the important biophysical parameter for determining vegetation health, biomass, photosynthesis and evapotranspiration (ET for the modelling of crop yield and water productivity. Ground measurement of this parameter is tedious and time-consuming due to heterogeneity across the landscape over time and space. This study deals with the development of remote-sensing based empirical relationships for the estimation of ground-based LAI (LAIG using NDVI, modelled with and without atmospheric correction models for three irrigated crops (corn, wheat and rice grown in irrigated farms within Coleambally Irrigation Area (CIA which is located in southern Murray Darling basin, NSW in Australia. Extensive ground truthing campaigns were carried out to measure crop growth and to collect field samples of LAI using LAI- 2000 Plant Canopy Analyser and reflectance using CROPSCAN Multi Spectral Radiometer at several farms within the CIA. A Set of 12 cloud free Landsat 5 TM satellite images for the period of 2010-11 were downloaded and regression analysis was carried out to analyse the co-relationships between satellite and ground measured reflectance and to check the reliability of data sets for the crops. Among all the developed regression relationships between LAI and NDVI, the atmospheric correction process has significantly improved the relationship between LAI and NDVI for Landsat 5 TM images. The regression analysis also shows strong correlations for corn and wheat but weak correlations for rice which is currently being investigated.

Response of high yielding rice varieties to NaCl salinity in ...

African Journals Online (AJOL)

In order to find resistant varieties and study the reaction of some newly released high yielding varieties to different levels of salinity of irrigation water an experiment was conducted at the Rice Research Institute of Iran-Amol station in a greenhouse. Eight varieties, cultivated in pots, were tested with three levels of salinity (2, ...

Sustainable and Low Greenhouse Gas Emitting Rice Production in Latin America and the Caribbean: A Review on the Transition from Ideality to Reality

Directory of Open Access Journals (Sweden)

Ngonidzashe Chirinda

2018-03-01

Full Text Available The burgeoning demand for rice in Latin America and Caribbean (LAC exceeds supply, resulting in a rice deficit. To overcome this challenge, rice production should be increased, albeit sustainably. However, since rice production is associated with increases in the atmospheric concentration of two greenhouse gases (GHGs, namely methane (CH4 and nitrous oxide (N2O, the challenge is on ensuring that production increases are not associated with an increase in GHG emissions and thus do not cause an increase in GHG emission intensities. Based on current understanding of drivers of CH4 and N2O production, we provide here insights on the potential climate change mitigation benefits of management and technological options (i.e., seeding, tillage, irrigation, residue management pursued in the LAC region. Studies conducted in the LAC region show intermittent irrigation or alternate wetting and drying of rice fields to reduce CH4 emissions by 25–70% without increasing N2O emissions. Results on yield changes associated with intermittent irrigation remain inconclusive. Compared to conventional tillage, no-tillage and anticipated tillage (i.e., fall tillage cause a 21% and 25% reduction in CH4 emissions, respectively. From existing literature, it was unambiguous that the mitigation potential of most management strategies pursued in the LAC region need to be quantified while acknowledging country-specific conditions. While breeding high yielding and low emitting rice varieties may represent the most promising and possibly sustainable approach for achieving GHG emission reductions without demanding major changes in on-farm management practices, this is rather idealistic. We contend that a more realistic approach for realizing low GHG emitting rice production systems is to focus on increasing rice yields, for obvious food security reasons, which, while not reducing absolute emissions, should translate to a reduction in GHG emission intensities. Moreover, there

Phosphate dynamics on the application of rice straw compost-biochar and phosphate fertilization in rice fields

International Nuclear Information System (INIS)

Ania Citraresmini; Taufiq Bachtiar

2016-01-01

Soil productivity is determined by soil characteristics itself, which consist of physical, chemical and biological character. The linkage between these three properties can be represented by a single indicator, namely the carbon content in the soil. One of the effects of soil organic matter fulfillment is the availability of soil nutrients, especially to the nutrient that limits the lowland rice production. In this case, P (phosphorus) nutrient become a limiting factor because their numbers are often in abundance but in a form that can not be used by plants. Experiments were carried out with the aim of studying the impact of straw compost application that integrates with Biochar, to the availability of P in lowland soil. The interaction of straw compost + Biochar with PSB inoculation and P sources, become the treatment that being tested in the experiment. Randomized Block Design with factorial pattern is applied as design experiment. As the first factor is the application dose of straw compost + Biochar, consists of 5 levels of treatment : 0; 1; 2; 3; 4 t ha -1 . Second factor is several sources of P, consist of 5 levels of treatment : without P sources (p 0 ); 100 kg ha -1 SP-36 fertilizer (p1); rock phosphate at the dose of 163 kg ha -1 (p 2 ); PSB inoculation at the inoculation dose of 2 kg ha -1 (p 3 ); and rock phosphate inoculated with PSB (p 4 ). The experiment done in the green house of PAIR-BATAN experimental station, Jakarta, on March-July 2014. Phosphorus dynamic as a result of the tested treatments, determined by using radioisotope 32 P technology at the activity of 30 mCi and described clearly on the plant P uptake data of Sidenuk rice plant variety. The experiment result showed that the treatments applied is causing significantly different response on the soil C-organic, the number of PSB populations, 32 P plant counting and plant P uptake derived from several P sources in the plant. (author)

Effects of rice straw, biochar and mineral fertiliser on methane (CH4) and nitrous oxide (N2O) emissions from rice (Oryza sativa L.) grown in a rain-fed lowland rice soil of Cambodia

DEFF Research Database (Denmark)

Ly, Proyuth; Duong, Quynh Vu; Jensen, Lars Stoumann

2015-01-01

-control, rice straw (RS) and biochar (BC). Compound fertiliser was applied to all treatments. Rice was grown in columns packed with a paddy soil from Cambodia. Results revealed faster mineralisation of organic carbon (RS and BC) when applied in water-saturated conditions lasting for 2 weeks instead of flooding...

Agro-ecological variations of sheath rot disease of rice caused by Sarocladium oryzae and DNA fingerprinting of the pathogen's population structure.

Science.gov (United States)

Tajul Islam Chowdhury, M; Salim Mian, M; Taher Mia, M A; Rafii, M Y; Latif, M A

2015-12-28

To examine the impact of regional and seasonal variations on the incidence and severity of sheath rot, a major seed-borne disease of rice caused by Sarocladium oryzae, data on incidence and severity were collected from 27 selected fields in the Gazipur, Rangpur, Bogra, Chittagong, Comilla, Gopalgonj, Jessore, Manikgonj, and Bhola districts of Bangladesh in rain-fed and irrigated conditions. Cultural variability of 29 pathogen isolates obtained from 8 different locations was studied on potato dextrose agar (PDA) and genetic variability was determined by DNA fingerprinting using variable number tandem repeat-polymerase chain reaction markers. Overall, disease incidence and severity were higher in irrigated rice. Disease incidence and severity were highest in the Bhola district in rain-fed rice and lowest in irrigated rice. Mycelial growth of 29 representative isolates was found to vary on PDA and the isolates were divided into 6 groups. The range of the overall size of conidia of the selected isolates was 2.40-7.20 x 1.20-2.40 μm. Analysis of the DNA fingerprint types of the 29 isolates of S. oryzae, obtained from the amplification reactions, revealed 10 fingerprinting types (FPTs) that were 80% similar. FPT-1 was the largest group and included 13 isolates (44.8%), while FPT-2 was the third largest group and included 3 isolates. Each of FPT-3, 4, 5, and 6 included only 1 isolate. We observed no relationship between cultural and genetic groupings.

Drought resistant rice mutants, characteristics and discussions on possibilities for planting them in some Arab Countries which import rice

International Nuclear Information System (INIS)

Abo-Hegazi, A.M.T.

1994-01-01

A number of drought resistant mutants of rice were produced from ordinary rice varieties being planted in several parts of Egypt through utilization of gamma rays as a mutagen. The mutants have water requirements less than one half of that of their mother varieties. According to official data, authorities in Egypt insure about 18000 M 3 of irrigation water for every hectare (10000 M 2 ) of rice and about 6700 M 3 , 6900 M 3 for every hectare of corn and ground nuts, respectively. Peanuts and corn are summer crops like the drought resistant rice mutants. The mentioned mutants can produce good yield under water requirements very near to that of corn and peanuts. The wide gap in agricultural food stuffs for the Arab Countries (more than 20000 million US $ annually) includes rice imports usually exceeds 700 million US $ per year> Rice imports of Arab Countries such as Saudi Arabia, Yemen, Syria, Libya and the Sudan, reached 180, 47, 21, 16 and 14 million US $ in 1988 as an example. Such countries could make use of the drought resistant rice mutants for plantation on water requirements very near to those of usual summer crops such as corn and peanuts which is significantly less than one half of water requirements of their mother varieties. Some characteristics of such mutants as well as discussions on possibilities for planting them in some of the nominated Arab Countries are presented. However, arrangements for ensuring the minimum water requirements during the growing period irrespective to rain which in many cases did not accord the growing period of the mutants should be taken if such countries wants to make use of the drought resistant rice mutants. The author believe that most if not all requirements of rice of such countries could locally be ensured through planting of the above mentioned rice mutants. In this case, maximizing the efficiency of utilizing the limited water resources of such countries could also be counted as another cause for presenting this

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

Directory of Open Access Journals (Sweden)

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.

An institutional perspective on farmers’ water management and rice production practices in Benin

NARCIS (Netherlands)

Totin, G.G.E.

2013-01-01

This thesis is part of the wider debate about the role of institutions in agricultural innovation processes. It

investigates how institutions shape rice production in inland valleys in Benin. It starts from a scoping study

(prior to this research) on smallholder irrigation in

Differences in the Sensitivity to UVB Radiation of Two Cultivars of Rice (Oryza sativa L.)

OpenAIRE

Jun, Hidema; Hye-Sook, Kang; Tadashi, Kumagai; Institute of Genetic Ecology, Tohoku University; Institute of Genetic Ecology, Tohoku University; Institute of Genetic Ecology, Tohoku University

1996-01-01

The effects of UVB radiation on the growth of two cultivars of Japanese lowland rice (Oryza sativa L.), Sasanishiki and Norin 1, were examined in a phytotron. Supplementation of visible radiation with UVB radiation reduced plant length, tiller number, the fresh and dry weights of the aboveground parts of plants, and the amounts of total leaf nitrogen, chlorophyll, soluble protein and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the eighth leaf, the youngest fully expanded leaf...

Arsenic contamination of soils and agricultural plants through irrigation water in Nepal

Energy Technology Data Exchange (ETDEWEB)

Dahal, B.M. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria); Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Applied Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna (Austria); Environment and Public Health Organization (ENPHO), P.O. Box 4102, Kathmandu (Nepal); Fuerhacker, M. [Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Applied Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna (Austria); Mentler, A. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria); Karki, K.B. [Soil Science Division, Nepal Agricultural Research Council, Khumaltar, Lalitpur (Nepal); Shrestha, R.R. [UN Habitat-Nepal, UN House, Pulchwok, P.O. Box 107, Kathmandu (Nepal); Blum, W.E.H. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria)], E-mail: winfried.blum@boku.ac.at

2008-09-15

This study monitored the influence of arsenic-contaminated irrigation water on alkaline soils and arsenic uptake in agricultural plants at field level. The arsenic concentrations in irrigation water ranges from <0.005 to 1.014 mg L{sup -1} where the arsenic concentrations in the soils were measured from 6.1 to 16.7 mg As kg{sup -1}. The arsenic content in different parts of plants are found in the order of roots > shoots > leaves > edible parts. The mean arsenic content of edible plant material (dry weight) were found in the order of onion leaves (0.55 mg As kg{sup -1}) > onion bulb (0.45 mg As kg{sup -1}) > cauliflower (0.33 mg As kg{sup -1}) > rice (0.18 mg As kg{sup -1}) > brinjal (0.09 mg As kg{sup -1}) > potato (<0.01 mg As kg{sup -1}). - The arsenic content in soil and plants is influenced by the degree of arsenic amount in irrigated water.

Water quality in irrigation and drainage networks of Thessaloniki plain in Greece related to land use, water management, and agroecosystem protection.

Science.gov (United States)

Litskas, Vassilis D; Aschonitis, Vassilis G; Antonopoulos, Vassilis Z

2010-04-01

A representative agricultural area of 150 ha located in a protected ecosystem (Axios River Delta, Thermaikos Gulf-N. Aegean, Greece) was selected in order to investigate water quality parameters [pH, electrical conductivity (EC(w)), NO(3)-N, NH(4)-N, total phosphorus (TP)] in irrigation and drainage water. In the study area, the cultivated crops are mainly rice, maize, cotton, and fodder. Surface irrigation methods are applied using open channels network, and irrigation water is supplied by Axios River, which is facing pollution problems. The return flow from surface runoff and the surplus of irrigation water are collected to drainage network and disposed to Thermaikos Gulf. A 2-year study (2006-2007) was conducted in order to evaluate the effects of land use and irrigation water management on the drainage water quality. The average pH and NO(3)-N concentration was higher in the irrigation water (8.0 and 1.3 mg/L, respectively) than that in the drainage water (7.6 and 1.0 mg/L, respectively). The average EC(W), NH(4)-N, and TP concentration was higher in the drainage water (1,754 muS/cm, 90.3 microg/L, and 0.2 mg/L, respectively) than that in the irrigation water (477.1 muS/cm, 46.7 microg/L, and 0.1 mg/L, respectively). Average irrigation efficiency was estimated at 47% and 51% in 2006 and 2007 growing seasons (April-October), respectively. The loads of NO(3)-N in both seasons were higher in the irrigation water (35.1 kg/ha in 2006 and 24.9 kg/ha in 2007) than those in the drainage water (8.1 kg/ha in 2006 and 7.6 kg/ha in 2007). The load of TP was higher in the irrigation water in season 2006 (2.8 kg/ha) than that in the drainage water (1.1 kg/ha). Total phosphorus load in 2007 was equal in irrigation and drainage water (1.2 kg/ha). Wetland conditions, due to rice irrigation regime, drainage network characteristics, and the crop distribution in the study area, affect the drainage water ending in the protected ecosystem of Thermaikos Gulf.

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.

The assessment of treated wastewater quality and the effects of mid-term irrigation on soil physical and chemical properties (case study: Bandargaz-treated wastewater)

Science.gov (United States)

Kaboosi, Kami

2017-09-01

This study was conducted to investigate the characteristics of inflow and outflow wastewater of the Bandargaz wastewater treatment plant on the basis of the data collection of operation period and the samples taken during the study. Also the effects of mid-term use of the wastewater for irrigation (from 2005 to 2013) on soil physical and chemical characteristics were studied. For this purpose, 4 samples were taken from the inflow and outflow wastewater and 25 quality parameters were measured. Also, the four soil samples from a depth of 0-30 cm of two rice field irrigated with wastewater in the beginning and middle of the planting season and two samples from one adjacent rice field irrigated with fresh water were collected and their chemical and physical characteristics were determined. Average of electrical conductivity, total dissolved solids, sodium adsorption ratio, chemical oxygen demand and 5 days biochemical oxygen demand in treated wastewater were 1.35 dS/m, 707 ppm, 0.93, 80 ppm and 40 ppm, respectively. Results showed that although some restrictions exist about chlorine and bicarbonate, the treated wastewater is suitable for irrigation based on national and international standards and criteria. In comparison with fresh water, the mid-term use of wastewater caused a little increase of soil salinity. However, it did not lead to increase of soil salinity beyond rice salinity threshold. Also, there were no restrictions on soil in the aspect of salinity and sodium hazard on the basis of many irrigated soil classifications. In comparison with fresh water, the mid-term use of wastewater caused the increase of total N, absorbable P and absorbable K in soil due to high concentration of those elements in treated wastewater.

Prone to fix: Resilience of the active nitrogen-fixing rice root microbiome

Science.gov (United States)

Hurek, Thomas; Sabale, Mugdha; Sarkar, Abhijit; Pees, Tobias; Reinhold-Hurek, Barbara

2016-04-01

Due to water consumption, many lowland rice areas in Asia are undergoing a transition that involves adoption of new management strategies, with crop rotations encompassing a non-flooded crop, including maize. Shifting from flooded to non-flooded cropping is likely to affect microbial nitrogen cycling. For analysis of the root-associated microbiome of rice and maize in response to flooding or nitrogen fertilizer, we combine methods of microbial ecology (Next-Generation sequencing of amplicons), and a reductionist approach with pure cultures of the endophytic diazotroph Azoarus sp.. Field plots of the ICON project (Introducing non-flooded crops in rice-dominated landscapes: Impact on Carbon, nitrogen and water budgets) at the International Rice Research Institute in the Philippines were analyzed. Root-associated activity of nitrogenase gene expression was assessed by quantitative RT-PCR of nifH. For rice, expression levels were surprisingly stable, in response to non-flooded versus flooded conditions, or in response to conventional nitrogen fertilizer applications versus lack of N-fertilizer. In contrast, the active diazotrophic population of maize roots was not resistant to N-fertilization, nifH expression strongly decreased. Concordant changes in the diazotrophic resident or active communities were detected by nifH amplicon sequence analysis, based on bacterial DNA or mRNA, respectively. For high-resolution analyses of the endobiome in gnotobiotic culture, we developed a dual fluorescence reporter system for Azoarcus sp. BH72 which allows to quantify and visualize epi- and endophytic gene expression by concfocal microscopy (CLSM). This allowed us to demonstrate sites of active nitrogen fixation (gene expression) in association with rice roots. We confirmed that at low nitrogen fertilizer levels, endophytic nifH gene expression persisted in rice roots, while it was repressed in maize roots. This supports our observation of remarkable stability of nitrogen fixation

Evaluation of sources, rates and methods of zinc fertilizer applications in flooded rice

International Nuclear Information System (INIS)

Sarkar, A.K.; Deb, D.L.

1981-01-01

A pot experiment was conducted using 65 Zn as tracer to evaluate the different sources, levels and methods of zinc fertilization in flooded rice. Results indicated that zinc sulphate was either at par or slightly superior to zincated urea from the point of view of yield and total zinc uptake by rice. The Zndff percent was found to be the highest with zincated urea and the lowest was observed with zinc oxide. 5 and 10 kg/ha levels of zinc were statistically at par in this regard. Among the different methods, surface application and thorough mixing with soil were comparable. Root dipping in 1 percent zinc oxide suspension and application of zinc in irrigation water also indicated high zinc absorption by the rice plant. (author)

Sustainable rice production in the Muda area of Malaysia

International Nuclear Information System (INIS)

Ho Nai Kin; Foong Kam Chong; Kamarudin Dahuli

2002-01-01

The Green Revolution has generated both positive as well as negative effects on the rice agroecosystem in the Muda area. The major obstacles to sustainable rice production are water shortage, natural hazards, disease epidemics, pest outbreaks, urban and industrial development, as well as structural changes in the farming community. The Muda Agricultural Development Authority (MADA) has adopted a proactive approach in addressing these problems. The improvement in management in the Muda area comprises the following strategies: i) Improvement in water use efficiency through intensification of tertiary irrigation systems, ii) Optimisation of drainage water utilisation through recycling, iii) Establishment of a Management Information System to support operational decisions, iv) Conservation of catchment vegetation for sustainable water resources, v) Implementation of Integrated Pest Management programmes, vi) Mobilisation of farmers in dynamic group activities, vii) Integration of farmers participatory experiments in the extension programmes. The above mentioned approaches have contributed to the attainment of high cropping intensity yield enhancement, and sustainability of rice production in the Muda area. (Author)

Water regime-nitrogen fertilizer incorporation interaction: Field study on methane and nitrous oxide emissions from a rice agroecosystem in Harbin, China.

Science.gov (United States)

Dong, Wenjun; Guo, Jia; Xu, Lijun; Song, Zhifeng; Zhang, Jun; Tang, Ao; Zhang, Xijuan; Leng, Chunxu; Liu, Youhong; Wang, Lianmin; Wang, Lizhi; Yu, Yang; Yang, Zhongliang; Yu, Yilei; Meng, Ying; Lai, Yongcai

2018-02-01

Water regime and nitrogen (N) fertilizer are two important factors impacting greenhouse gases (GHG) emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we conducted a two-year field experiment to study the impacts of water regime and N fertilizer on rice yields and GHG emissions in Harbin, China, a cold region located in high latitudes. Our results showed that intermittent irrigation significantly decreased methane (CH 4 ) emission compared with continuous flooding, however, the decrement was far lower than the global average level. The N 2 O emissions were very small when flooded but peaked at the beginning of the disappearance of floodwater. The N fertilizer treatments increased CH 4 emissions at low level (75kgN/ha). But both CH 4 and N 2 O emissions were uninfluenced at the levels of 150kgN/ha and 225kgN/ha. Rice yields increased under intermittent irrigation and were highest at the level of 150kgN/ha. From our results, we recommended that the intermittent irrigation and 150kgN/ha as the ideal water regime-nitrogen fertilizer incorporation for this area to achieve low GHG emissions without impacting rice yields. Copyright © 2017. Published by Elsevier B.V.

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

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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.

Effects of climate change on rice production and strategies for adaptation in southern China

Energy Technology Data Exchange (ETDEWEB)

Jin, Z.; Ge, D.; Chen, H.; Fang, J. [Jiangsu Academy of Agricultural Sciences (China)

1995-12-31

The CERES-rice (Oryza sativa L.) model was calibrated and validated for nine sites in southern China to examine its suitability to model rice production in this area, using agronomic data from more than three successive years. After determining the genetic coefficients for the cultivars, the CERES-rice model was run a second time for the same locations for a time period of 20 to 30 yr. The model used local climate data (1958--1986) and doubled-CO{sub 2} climate change scenarios generated from the Goddard Institute for Space Studies (GISS), Geophysical Fluid dynamics Laboratory (GFDL), and United Kingdom Meteorological Office (UKMO) global climate models (GCMs), with and without supplemental irrigation(to model paddy and upland rice, respectively). The study estimated the potential impacts of climate change on rice production by comparing the base runs with the runs under the three doubled-CO{sub 2} GCM scenarios and it considered the physiological effects of CO{sub 2} on rice growth in each GCM scenario. Finally, the study examined several strategies for adapting to climate change.

Insecticide susceptibility of natural populations of Anopheles coluzzii and Anopheles gambiae (sensu stricto) from Okyereko irrigation site, Ghana, West Africa.

Science.gov (United States)

Chabi, Joseph; Baidoo, Philip K; Datsomor, Alex K; Okyere, Dora; Ablorde, Aikins; Iddrisu, Alidu; Wilson, Michael D; Dadzie, Samuel K; Jamet, Helen P; Diclaro, Joseph W

2016-03-31

The increasing spread of insecticide resistance in malaria vectors has been well documented across sub-Saharan Africa countries. The influence of irrigation on increasing vector resistance is poorly understood, and is critical to successful and ethical implementation of food security policies. This study investigated the insecticide resistance status of An. gambiae (s.l.) mosquitoes collected from the irrigated rice area of Okyereko, a village containing about 42 hectares of irrigated field within an irrigation project plan in the Central Region of Ghana. Large amounts of insecticides, herbicides and fertilizers are commonly used in the area to boost the annual production of the rice. Mosquito larvae were collected and adults were assayed from the F1 progeny. The resistance status, allele and genotype were characterized using WHO susceptibility testing and PCR methods respectively. The An. gambiae (s.l.) populations from Okyereko are highly resistant to DDT and pyrethroid insecticides, with possible involvement of metabolic mechanisms including the elevation of P450 and GST enzyme as well as P-gp activity. The population was mostly composed of An. coluzzii specimens (more than 96 %) with kdr and ace-1 frequencies of 0.9 and 0.2 %, respectively. This study brings additional information on insecticide resistance and the characterization of An. gambiae (s.l.) mosquitoes from Okyereko, which can be helpful in decision making for vector control programmes in the region.

MIRCA2000—Global monthly irrigated and rainfed crop areas around the year 2000: A new high-resolution data set for agricultural and hydrological modeling

Science.gov (United States)

Portmann, Felix T.; Siebert, Stefan; DöLl, Petra

2010-03-01

To support global-scale assessments that are sensitive to agricultural land use, we developed the global data set of monthly irrigated and rainfed crop areas around the year 2000 (MIRCA2000). With a spatial resolution of 5 arc min (about 9.2 km at the equator), MIRCA2000 provides both irrigated and rainfed crop areas of 26 crop classes for each month of the year. The data set covers all major food crops as well as cotton. Other crops are grouped into categories (perennial, annual, and fodder grasses). It represents multicropping systems and maximizes consistency with census-based national and subnational statistics. According to MIRCA2000, 25% of the global harvested areas are irrigated, with a cropping intensity (including fallow land) of 1.12, as compared to 0.84 for the sum of rainfed and irrigated harvested crops. For the dominant crops (rice (1.7 million km2 harvested area), wheat (2.1 million km2), and maize (1.5 million km2)), roughly 60%, 30%, and 20% of the harvested areas are irrigated, respectively, and half of the citrus, sugar cane, and cotton areas. While wheat and maize are the crops with the largest rainfed harvested areas (1.5 million km2 and 1.2 million km2, respectively), rice is clearly the crop with the largest irrigated harvested area (1.0 million km2), followed by wheat (0.7 million km2) and maize (0.3 million km2). Using MIRCA2000, 33% of global crop production and 44% of total cereal production were determined to come from irrigated agriculture.

Detection and assessment of flood susceptible irrigation networks in Licab, Nueva Ecija, Philippines using LiDAR DTM

Science.gov (United States)

Alberto, R. T.; Hernando, P. J. C.; Tagaca, R. C.; Celestino, A. B.; Palado, G. C.; Camaso, E. E.; Damian, G. B.

2017-09-01

Climate change has wide-ranging effects on the environment and socio-economic and related sectors which includes water resources, agriculture and food security, human health, terrestrial ecosystems, coastal zones and biodiversity. Farmers are under pressure to the changing weather and increasing unpredictable water supply. Because of rainfall deficiencies, artificial application of water has been made through irrigation. Irrigation is a basic determinant of agriculture because its inadequacies are the most powerful constraints on the increase of agricultural production. Irrigation networks are permanent and temporary conduits that supply water to agricultural areas from an irrigation source. Detection of irrigation networks using LiDAR DTM, and flood susceptible assessment of irrigation networks could give baseline information on the development and management of sustainable agriculture. Map Gully Depth (MGD) in Whitebox GAT was used to generate the potential irrigation networks. The extracted MGD was overlaid in ArcGIS as guide in the digitization of potential irrigation networks. A flood hazard map was also used to identify the flood susceptible irrigation networks in the study area. The study was assessed through field validation of points which were generated using random sampling method. Results of the study showed that most of the detected irrigation networks have low to moderate susceptibility to flooding while the rest have high susceptibility to flooding which is due to shifting weather. These irrigation networks may cause flood when it overflows that could also bring huge damage to rice and other agricultural areas.

Localized flux maxima of arsenic, lead, and iron around root apices in flooded lowland rice

DEFF Research Database (Denmark)

Williams, Paul N.; Santner, Jakob; Larsen, Morten

2014-01-01

In wetland-adapted plants, such as rice, it is typically root apexes, sites of rapid entry for water/nutrients, where radial oxygen losses (ROLs) are highest. Nutrient/toxic metal uptake therefore largely occurs through oxidized zones and pH microgradients. However, the processes controlling the ...

Disentangling the effect of environmental factors on yield and nitrogen uptake of irrigated rice in Asia

NARCIS (Netherlands)

Jing, Q.; Bouman, B.A.M.; Keulen, van H.; Hengsdijk, H.; Cao, W.; Dai, T.

2008-01-01

Rice yield is the result of the interaction between genotype (cultivar characteristics), environment (climate and soil conditions), and management. Few studies have attempted to isolate the contribution of each of these factors. Here the rice growth model ORYZA2000 was used to analyse the variation

The effect of naturally acidified irrigation water on agricultural volcanic soils. The case of Asembagus, Java, Indonesia

NARCIS (Netherlands)

Los, A.M.D.; Vriend, S.P.; Bergen, M.J.; Gaans, R.F.M.

2008-01-01

Acid water from the Banyuputih river (pH similar to 3.5) is used for the irrigation of agricultural land in the Asembagus coastal area (East Java, Indonesia), with harmful consequences for rice yields. The river water has an unusual composition which is caused by seepage from the acidic Kawah Ijen

Set Up of an Automatic Water Quality Sampling System in Irrigation Agriculture

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Emanuel Heinz

2013-12-01

Full Text Available We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS for stable water isotope analysis (δ2H and δ18O, a reagentless hyperspectral UV photometer (ProPS for monitoring nitrate content and various water level sensors for hydrometric information. The automatic sampling system consists of different sampling stations equipped with pumps, a switch cabinet for valve and pump control and a computer operating the system. The complete system is operated via internet-based control software, allowing supervision from nearly anywhere. The system is currently set up at the International Rice Research Institute (Los Baños, The Philippines in a diversified rice growing system to continuously monitor water and nutrient fluxes. Here we present the system’s technical set-up and provide initial proof-of-concept with results for the isotopic composition of different water sources and nitrate values from the 2012 dry season.

Biodiversity Conservation in Rice Paddies in China: Toward Ecological Sustainability

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Yufeng Luo

2014-09-01

Full Text Available Rice paddies are artificial wetlands that supply people with food and provide wildlife with habitats, breeding areas, shelters, feeding grounds and other services, and rice paddies play an important part in agricultural ecological systems. However, modern agricultural practices with large-scale intensive farming have significantly accelerated the homogenization of the paddy field ecosystem. Modern agriculture mostly relies on chemically-driven modern varieties and irrigation to ensure high production, resulting in the deterioration and imbalance of the ecosystem. Consequently, outbreaks of diseases, insects and weeds have become more frequent in paddy fields. This paper describes the current situation of rice paddy biodiversity in China and analyzes the community characteristics of arthropods and weedy plants. Meanwhile, we discuss how biodiversity was affected by modern agriculture changes, which have brought about a mounting crisis threatening to animals and plants once common in rice paddies. Measures should be focused to firstly preventing further deterioration and, then, also, promoting restoration processes. Ecological sustainability can be achieved by restoring paddy field biodiversity through protecting the ecological environment surrounding the paddy fields, improving paddy cropping patterns, growing rice with less agricultural chemicals and chemical fertilizers, constructing paddy systems with animals and plants and promoting ecological education and public awareness.

Using artificial neural network and satellite data to predict rice yield in Bangladesh

Science.gov (United States)

Akhand, Kawsar; Nizamuddin, Mohammad; Roytman, Leonid; Kogan, Felix; Goldberg, Mitch

2015-09-01

Rice production in Bangladesh is a crucial part of the national economy and providing about 70 percent of an average citizen's total calorie intake. The demand for rice is constantly rising as the new populations are added in every year in Bangladesh. Due to the increase in population, the cultivation land decreases. In addition, Bangladesh is faced with production constraints such as drought, flooding, salinity, lack of irrigation facilities and lack of modern technology. To maintain self sufficiency in rice, Bangladesh will have to continue to expand rice production by increasing yield at a rate that is at least equal to the population growth until the demand of rice has stabilized. Accurate rice yield prediction is one of the most important challenges in managing supply and demand of rice as well as decision making processes. Artificial Neural Network (ANN) is used to construct a model to predict Aus rice yield in Bangladesh. Advanced Very High Resolution Radiometer (AVHRR)-based remote sensing satellite data vegetation health (VH) indices (Vegetation Condition Index (VCI) and Temperature Condition Index (TCI) are used as input variables and official statistics of Aus rice yield is used as target variable for ANN prediction model. The result obtained with ANN method is encouraging and the error of prediction is less than 10%. Therefore, prediction can play an important role in planning and storing of sufficient rice to face in any future uncertainty.

Efficacy of aquatain, a monomolecular film, for the control of malaria vectors in rice paddies.

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Tullu Bukhari

Full Text Available BACKGROUND: Rice paddies harbour a large variety of organisms including larvae of malaria mosquitoes. These paddies are challenging for mosquito control because their large size, slurry and vegetation make it difficult to effectively apply a control agent. Aquatain, a monomolecular surface film, can be considered a suitable mosquito control agent for such breeding habitats due to its physical properties. The properties allow Aquatain to self-spread over a water surface and affect multiple stages of the mosquito life cycle. METHODOLOGY/PRINCIPAL FINDINGS: A trial based on a pre-test/post-test control group design evaluated the potential of Aquatain as a mosquito control agent at Ahero rice irrigation scheme in Kenya. After Aquatain application at a dose of 2 ml/m(2 on rice paddies, early stage anopheline larvae were reduced by 36%, and late stage anopheline larvae by 16%. However, even at a lower dose of 1 ml/m(2 there was a 93.2% reduction in emergence of anopheline adults and 69.5% reduction in emergence of culicine adults. No pupation was observed in treated buckets that were part of a field bio-assay carried out parallel to the trial. Aquatain application saved nearly 1.7 L of water in six days from a water surface of 0.2 m(2 under field conditions. Aquatain had no negative effect on rice plants as well as on a variety of non-target organisms, except backswimmers. CONCLUSIONS/SIGNIFICANCE: We demonstrated that Aquatain is an effective agent for the control of anopheline and culicine mosquitoes in irrigated rice paddies. The agent reduced densities of aquatic larval stages and, more importantly, strongly impacted the emergence of adult mosquitoes. Aquatain also reduced water loss due to evaporation. No negative impacts were found on either abundance of non-target organisms, or growth and development of rice plants. Aquatain, therefore, appears a suitable mosquito control tool for use in rice agro-ecosystems.

Disentangling the role of management, vegetation structure, and plant quality for Orthoptera in lowland meadows.

Science.gov (United States)

Schirmel, Jens; Gerlach, Rebekka; Buhk, Constanze

2017-08-17

Seminatural grasslands provide habitats for various species and are important for biodiversity conservation. The understanding of the diverse responses of species and traits to different grassland management methods is therefore urgently needed. We disentangled the role of grassland management (fertilization and irrigation), vegetation structure (biomass, sward height) and plant quality (protein and fiber content) for Orthoptera communities in lowland hay meadows in Germany. We found vegetation structure to be the most important environmental category in explaining community structure of Orthoptera (species richness, total individuals, functional diversity and species composition). Intensively used meadows (fertilized, irrigated, high plant biomass) were characterized by assemblages with few species, low functional diversity, and low conservation value. Thereby, the relatively moderate fertilizer inputs in our study system of up to ∼75 kg N/ha/year reduced functional diversity of Orthoptera, while this negative effect of fertilization was not detectable when solely considering taxonomic aspects. We found strong support for a prominent role of plant quality in shaping Orthoptera communities and especially the trait composition. Our findings demonstrate the usefulness of considering both taxonomic and functional components (functional diversity) in biodiversity research and we suggest a stronger involvement of plant quality measures in Orthoptera studies. © 2017 Institute of Zoology, Chinese Academy of Sciences.

Promissory rice mutants (Oryza sativa L.) obtained by Gamma Rays induction in Peru

International Nuclear Information System (INIS)

Heros, E.; Gomez, L.

2015-01-01

To improve the available rice cultivars in Peru under irrigated conditions, it was tried the rice seed Amazonas and Capirona, cultivars adapted to irrigated conditions in highland jungle, both characterized for late maturity (140-150 days). The doses were: 150-250-350 Gy that induced mutants with different characteristics to the original cultivar like: early maturity, shorter, high yield and milling quality. In Amazonas cultivar were selected 72 mutants of the M 2 generation with agronomy value and continue in evaluation only the mutant (M35-20). There were applied the same doses of gamma rays with the cultivar Capirona, there is much radiosensitivity at high doses, they were selected two early mutants (MC 35-21 and MC 35-123-3) with an early life cycle days (15 days) than parental cultivar. Two mutants tolerant to salinity (12 dSm). Six mutants are still under evaluation, two of them (MC 25-23-1 and MC 35-45-4) have better yields with performances of 9.1 t ha -1 versus 6.6 t ha -1 . These mutants show lodging and shattering resistance. (Author)

Stakeholder Views, Financing and Policy Implications for Reuse of Wastewater for Irrigation: A Case from Hyderabad, India

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Markus Starkl

2015-01-01

Full Text Available When flowing through Hyderabad, the capital of Telangana, India, the Musi River picks up (partially treated and untreated sewage from the city. Downstream of the city, farmers use this water for the irrigation of rice and vegetables. Treatment of the river water before it is used for irrigation would address the resulting risks for health and the environment. To keep the costs and operational efforts low for the farmers, the use of constructed wetlands is viewed as a suitable option. Towards this end, the paper investigates the interests and perceptions of government stakeholders and famers on the treatment of wastewater for irrigation and further explores the consumer willingness to pay a higher price for cleaner produced vegetables. Full cost recovery from farmers and consumers cannot be expected, if mass scale treatment of irrigation water is implemented. Instead, both consumers and farmers would expect that the government supports treatment of irrigation water. Most stakeholders associated with the government weigh health and environment so high, that these criteria outweigh cost concerns. They also support the banning of irrigation with polluted water. However, fining farmers for using untreated river water would penalize them for pollution caused by others. Therefore public funding of irrigation water treatment is recommended.

Impacts of Climate Change on Water Requirements of Dry Season Boro Rice: Recent Trends and Future Scenarios

Science.gov (United States)

Acharjee, T. K.; Ludwig, F.; Halsema, G. V.; Hellegers, P.; Supit, I.

2017-12-01

The North-West part of Bangladesh is vulnerable to the impacts of climate change, because of dry season water shortage and high water demand for rice cultivation. A study was carried out to understand the impacts of recent climate change (1980-2013) and future consequences (for 2050s and 2080s) on water requirements of Boro rice. The reference crop evapotranspiration (ETo), potential crop water requirement (∑ETC), effective rainfall (ER), potential irrigation requirement for crop evapotranspiration (∑ETC-ER) and net irrigation requirement of Boro rice were estimated in CropWat using observed daily climate data for recent trends and statistically downscaled and bias corrected GCM outputs (five models and two RCPs) for future scenarios. ETo showed a significant decreasing recent trends due to increasing relative humidity and decreasing wind speed and sun shine hours instead of an increase in temperature. However, the strong future increase in temperature will lead to an insignificant increase in ETo. ∑ETC showed a decreasing recent trend and will further decrease in the future because of shortened duration of Boro growth stages as crop's phenological response to increased temperature. The variations in trends of ∑ETC-ER found among different districts, are mainly linked to the variations in trends of changes in effective rainfall. During last three decades, the net irrigation requirement has decreased by 11% at an average rate of -4.4 mm/year, instead of a decreasing effective rainfall, mainly because of high rate of decrease of crop evapotranspiration (-5.9 mm/year). In future, although daily water requirement will increase, the total net irrigation requirement of Boro rice will decrease by 1.6% in 2050s and 7.4% in 2080s for RCP 8.5 scenario on an average for five models and four districts compared to the base period (1980-2013). High variations in projected changes in rainfall bring high uncertainty for future water requirements estimation. Therefore, a

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

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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.

Can arbuscular mycorrhizal fungi improve grain yield, As uptake and tolerance of rice grown under aerobic conditions?

Energy Technology Data Exchange (ETDEWEB)

Li, H. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); Ye, Z.H. [State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Chan, W.F.; Chen, X.W.; Wu, F.Y. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); Wu, S.C. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); School of Environment and Natural Resources, Zhejiang Agriculture and Forestry University, Lin' an, Zhejiang 311300 (China); Wong, M.H., E-mail: mhwong@hkbu.edu.hk [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (Hong Kong); School of Environment and Natural Resources, Zhejiang Agriculture and Forestry University, Lin' an, Zhejiang 311300 (China)

2011-10-15

The effects of arbuscular mycorrhizal fungi (AMF) -Glomus intraradices and G. geosporum on arsenic (As) and phosphorus (P) uptake by lowland (Guangyinzhan) and upland rice (Handao 502) were investigated in soil, spiked with and without 60 mg As kg{sup -1}. In As-contaminated soil, Guangyinzhan inoculated with G. intraradices or Handao 502 inoculated with G. geosporum enhanced As tolerance, grain P content, grain yield. However, Guangyinzhan inoculated with G. geosporum or Handao 502 inoculated with G. intraradices decreased grain P content, grain yield and the molar ratio of grain P/As content, and increased the As concentration and the ratio of grain/straw As concentration. These results show that rice/AMF combinations had significant (p < 0.05) effects on grain As concentration, grain yield and grain P uptake. The variation in the transfer and uptake of As and P reflected strong functional diversity in AM (arbuscular mycorrhizal) symbioses. - Highlights: > Rice/AMF combinations had significant effects on grain As concentration, grain yield and grain P uptake. > Rice colonized with suitable AMF can increase grain yield. > The variation in the transfer and uptake of As and P reflected strong functional diversity in AM symbioses. - Different rice/AMF combinations had very different effects on arsenic and phosphorus uptake.

Can arbuscular mycorrhizal fungi improve grain yield, As uptake and tolerance of rice grown under aerobic conditions?

International Nuclear Information System (INIS)

Li, H.; Ye, Z.H.; Chan, W.F.; Chen, X.W.; Wu, F.Y.; Wu, S.C.; Wong, M.H.

2011-01-01

The effects of arbuscular mycorrhizal fungi (AMF) -Glomus intraradices and G. geosporum on arsenic (As) and phosphorus (P) uptake by lowland (Guangyinzhan) and upland rice (Handao 502) were investigated in soil, spiked with and without 60 mg As kg -1 . In As-contaminated soil, Guangyinzhan inoculated with G. intraradices or Handao 502 inoculated with G. geosporum enhanced As tolerance, grain P content, grain yield. However, Guangyinzhan inoculated with G. geosporum or Handao 502 inoculated with G. intraradices decreased grain P content, grain yield and the molar ratio of grain P/As content, and increased the As concentration and the ratio of grain/straw As concentration. These results show that rice/AMF combinations had significant (p < 0.05) effects on grain As concentration, grain yield and grain P uptake. The variation in the transfer and uptake of As and P reflected strong functional diversity in AM (arbuscular mycorrhizal) symbioses. - Highlights: → Rice/AMF combinations had significant effects on grain As concentration, grain yield and grain P uptake. → Rice colonized with suitable AMF can increase grain yield. → The variation in the transfer and uptake of As and P reflected strong functional diversity in AM symbioses. - Different rice/AMF combinations had very different effects on arsenic and phosphorus uptake.

The limit of irrigation adaption due to the inter-crop conflict of water use under changing climate and landuse

Science.gov (United States)

Okada, M.; Iizumi, T.; Sakamoto, T.; Kotoku, M.; Sakurai, G.; Nishimori, M.

2017-12-01

Replacing rainfed cropping system by irrigated one is assumed to be an effective measure for climate change adaptation in agriculture. However, in many agricultural impact assessments, future irrigation scenarios are externally given and do not consider variations in the availability of irrigation water under changing climate and land use. Therefore, we assess the potential effects of adaption measure expanding irrigated area under climate change by using a large-scale crop-river coupled model, CROVER [Okada et al. 2015, JAMES]. The CROVER model simulates the large-scale terrestrial hydrological cycle and crop growth depending on climate, soil properties, landuse, crop cultivation management, socio-economic water demand, and reservoir operation management. The bias-corrected GCMs outputs under the RCP 8.5 scenario were used. The future expansion of irrigation area was estimated by using the extrapolation method based on the historical change in irrigated and rainfed areas. As the results, the irrigation adaptation has only a limited effect on the rice production in East Asia due to the conflict of water use for irrigation with the other crops, whose farmlands require unsustainable water extraction with the excessively expanding irrigated area. In contrast, the irrigation adaptation benefits maize production in Europe due to the little conflict of water use for irrigation. Our findings suggest the importance of simulating the river water availability and crop production in a single model for the more realistic assessment in the irrigation adaptation potential effects of crop production under changing climate and land use.

Leaf chlorophyll and nitrogen dynamics and their relationship to lowland rice yield for site-specific paddy management

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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

Persistência dos herbicidas imazethapyr e imazapic em solo de várzea sob diferentes sistemas de manejo Persistence of the herbicides imazethapyr and imazapic in irrigated rice soil

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A.F. Kraemer

2009-01-01

Full Text Available A mistura formulada dos herbicidas imazethapyr e imazapic é utilizada para controlar arroz-vermelho em cultivos de arroz irrigado. Entretanto, esses herbicidas podem persistir no solo por longos períodos, causando introxicação ao arroz suscetível cultivado em sucessão. Este trabalho teve como objetivo avaliar o efeito de diferentes manejos de solo, durante a entressafra do arroz, sobre a ação residual do imazethapyr e imazapic, em arroz não tolerante. O residual desses herbicidas causou introxicação no arroz suscetível após um ano da última aplicação dos herbicidas. A introxicação atingiu valores máximos até 25 dias após a emergência (DAE, ocorrendo redução da introxicação após esse período, até praticamente desaparecer (60 DAE. O residual do herbicida alterou o estande de plantas, o número de colmos m-2, o número de panículas m-2 e a altura de plantas, porém não afetou a produtividade de grãos do arroz. O revolvimento do solo diminuiu a atividade do herbicida na camada superficial de solo (0-3 m.The mixture of herbicides imazethapyr and imazapic is used to control red rice in irrigated rice crops. However, such herbicides might persist on the soil for a long period causing phytotoxicity on susceptible rice grown in succession. The objective of this work was to determine the effect of different soil tillage systems during the off-season on the residual phytotoxicity of imazethapyr and imazapic on non tolerant rice. Herbicide residues caused phytotoxicity on susceptible rice with the highest values being registered 25 days after emergence and decreasing after this period until almost disappearing 60 days after emergence. Herbicide residues affected plant stand, number of stems per m², number of panicles per m² and plant height, but did not affect grain yield. Soil movement decreased herbicide activity on the superficial soil layer (0-3 cm.

DENTAL LESIONS IN THE LOWLAND TAPIR (TAPIRUS TERRESTRIS).

Science.gov (United States)

Tjørnelund, Karen B; Jonsson, Lena M; Kortegaard, Hanne; Arnbjerg, Jens; Nielsen, Søren S; Bertelsen, Mads F

2015-06-01

Dental ailments, mandibular swelling, and dentoalveolar abscesses are common in tapirs, but knowledge about prevalence or etiology of these lesions in the Tapiridae family in general, and in lowland tapirs (Tapirus terrestris) in particular, is scarce. A recent study identified resorptive lesions of unknown etiology as a common problem in the Malayan tapir (Tapirus indicus). In order to investigate the type and prevalence of dental lesions occurring in lowland tapirs, and to compare these with findings with the Malayan tapir, skulls and teeth from 46 deceased lowland tapirs were visually and radiographically examined. The specimens were divided into subpopulations according to age (juveniles, young adults, adults) and origin (free-range or captive). Dental lesions were identified in 24% (11/46) of the study population. The most common pathologic findings were complicated dental fractures with associated periapical reaction (15%) and periapical reactions of various degrees without associated detectable dental pathology (13%). All these lesions likely originated from dental trauma. As in Malayan tapirs, juveniles had significantly fewer lesions than adults. This study shows that dental lesions present frequent problems for lowland tapirs, occurring both in captive and in free-ranging individuals, and indicates that increasing age should be considered a risk factor for the development of these lesions. Notably, the predominant dental problems in lowland tapirs and Malayan tapirs are not the same.

The application of parallel wells to support the use of groundwater for sustainable irrigation

Science.gov (United States)

Suhardi

2018-05-01

The use of groundwater as a source of irrigation is one alternative in meeting water needs of plants. Using groundwater for irrigation requires a high cost because of the discharge that can be taken is limited. In addition, the use of large groundwater can cause environmental damage and social conflict. To minimize costs, maintain quality of the environment and to prevent social conflicts, it is necessary to innovate in the groundwater taking system. The study was conducted with an innovation of using parallel wells. Performance is measured by comparing parallel wells with a single well. The results showed that the use of parallel wells to meet the water needs of rice plants and increase the pump discharge up to 100%. In addition, parallel wells can reduce the influence radius of taking of groundwater compared to single well so as to prevent social conflict. Thus, the use of parallel wells can support the achievement of the use of groundwater for sustainable irrigation.

Measurement of flows for two irrigation districts in the lower Colorado River basin, Texas

Science.gov (United States)

Coplin, L.S.; Liscum, Fred; East, J.W.; Goldstein, L.B.

1996-01-01

The Lower Colorado River Authority sells and distributes water for irrigation of rice farms in two irrigation districts, the Lakeside district and the Gulf Coast district, in the lower Colorado River Basin of Texas. In 1993, the Lower Colorado River Authority implemented a water-measurement program to account for the water delivered to rice farms and to promote water conservation. During the rice-irrigation season (summer and fall) of 1995, the U.S. Geological Survey measured flows at 30 sites in the Lakeside district and 24 sites in the Gulf Coast district coincident with Lower Colorado River Authority measuring sites. In each district, the Survey made essentially simultaneous flow measurements with different types of meters twice a day once in the morning and once in the afternoon at each site on selected days for comparison with Lower Colorado River Authority measurements. One-hundred pairs of corresponding (same site, same date) Lower Colorado River Authority and U.S. Geological Survey measurements from the Lakeside district and 104 measurement pairs from the Gulf Coast district are compared statistically and graphically. For comparison, the measurement pairs are grouped by irrigation district and further subdivided by the time difference between corresponding measurements less than or equal to 1 hour or more than 1 hour. Wilcoxon signed-rank tests (to indicate whether two groups of paired observations are statistically different) on Lakeside district measurement pairs with 1 hour or less between measurements indicate that the Lower Colorado River Authority and U.S. Geological Survey measurements are not statistically different. The median absolute percent difference between the flow measurements is 5.9 percent; and 33 percent of the flow measurements differ by more than 10 percent. Similar statistical tests on Gulf Coast district measurement pairs with 1 hour or less between measurements indicate that the Lower Colorado River Authority and U.S. Geological

Evaluation of the effects of mulch on optimum sowing date and irrigation management of zero till wheat in central Punjab, India using APSIM

OpenAIRE

Balwinder-Singh,; Humphreys, E.; Gaydon, D.S.; Eberbach, P.L.

2016-01-01

Machinery for sowing wheat directly into rice residues has become more common in the rice-wheat systems of the north-west Indo-Gangetic Plains of South Asia, with increasing numbers of farmers now potentially able to access the benefits of residue retention. However, surface residue retention affects soil water and temperature dynamics, thus the optimum sowing date and irrigation management for a mulched crop may vary from those of a traditional non-mulched crop. Furthermore, the effects of s...

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.

Application of induced mutations and modern technologies for rice improvement at the Philippine Rice Research Institute (PhilRice)

International Nuclear Information System (INIS)

Padolina, Thelma F.

2015-01-01

The application of mutation techniques, i.e. gamma rays and other physical and chemical mutagens has generated a vast amount of genetic variability and has played a significant role in plant breeding and genetics. The widespread use of mutation techniques in plant breeding programs throughout the world has led to the official release of more than 3000 mutant varieties from different plant species. These varieties provide higher yields, better quality, resistance to diseases and resilience to climate change and variability. In the Philippine Rice Research Institute (PhilRice), classical induced mutagenesis and/or in combination with modern technologies as an important tool in rice breeding have been widely utilized by breeders. These recent advances offered new and exciting challenges for the development of new varieties. Moreover, it has the advantage of free regulatory restrictions imposed on genetically modified organisms. To date, high generation of new varieties, elite lines and pre-breeding materials have been derived from chemical and physical mutagenesis, another culture, in vitro mutagenesis, and molecular marker technologies. Directly benefitting the farmers are three Philippine released varieties: PSB Rc78 developed through gamma ray induction in year 2000; and NSIC Rc272 (2011) and Rc346 (2013) developed by combination of Co60 induction and another culture technology. These varieties are intended for the lowlands. In the current works, diverse mutant lines and pre-breeding materials of different target traits were generated and are now under evaluation as potential varieties and/or for use in the inbred and hybrid breeding programs. These genetic materials are in the background of traditional and modern rice varieties. Accordingly, for inbreds, mutated traits ranged from changes in morphological traits, yield, maturity, grain quality, nutritional traits, abiotic resistance such as heat, salinity, and drought tolerance, biotic resistance such as bacterial

Effects of Chemical Applications to Metal Polluted Soils on Cadmium Uptake by Rice Plant

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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.

Desempenho de genótipos de arroz irrigado cultivados no sistema pré-germinado com inundação contínua Performance of irrigated rice genotypes on a pre-germinated system with continuous flooding

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Enio Marchezan

2004-10-01

days after seeding in order to improve plant establishment. This practice therefore, causes water and nutrient losses and weeds reinfestation. The permanence of water in the field could minimize these problems. Experiments were conducted during the years of 2000/01 till 2002/03 aiming to evaluate the performance of permanent irrigated rice genotypes under flooding, specially for plant lodging, a limiting factor of this management system. The experiments were conducted on a lowland area in a Haplaqualf soil and the treatments were 8, 12 and 15 genotypes in the first, second, and third years, respectively. In the year 1 the mean rice yield was 7279kg ha-1 and IRGA 1572-11-1F-1-4-4 (8279kg ha-1 the most productive genotype. Lodging percentage varied between 0 and 60% and for most treatments in the range from to 0-20%. All genotypes presented some degree of lodging, except El Paso L 144. In the year 2 the mean rice yield was 8492kg ha-1 and the most productive was BRS-Pelota (9282kg ha-1, and no lodging occurred among the tested genotypes. In the year 3, the mean yield was 6202kg ha-1 and was related to a high percentage of the lodging, due to climatic events during seed filling. It was observed that rice yield can be high under permanent flooding but lodging is a limiting factor depending on genotype and environmental conditions.

Countermeasures for heat damage in rice grain quality under climate change

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Satoshi Morita

2016-01-01

Full Text Available Climate change has been an increasingly significant factor behind fluctuations in the yield and quality of rice (Oryza sativa L., particularly regarding chalky (white-back, basal-white, and milky-white grain, immature thin grain, and cracked grain. The development and use of heat-tolerant varieties is an effective way to reduce each type of grain damage based on the existence of each varietal difference. Cultivation methods that increase the available assimilate supply per grain, such as deep-flood irrigation, are effective for diminishing the occurrence of milky-white grains under high temperature and low solar radiation conditions. The application of sufficient nitrogen during the reproductive stage is important to reduce the occurrence of most heat damage with the exception of milky-white grain. In regard to developing measures for heat-induced poor palatability of cooked rice, a sensory parameter, the hardness/adhesion ratio may be useful as an indicator of palatability within a relatively wide air–temperature range during ripening. Methods for heat damage to rice can be classified as either avoidance or tolerance measures. The timing of the measures is further divided into preventive and prompt types. The use of heat-tolerant varieties and late transplanting are preventive measures, whereas the application of sufficient nitrogen as a top dressing and irrigation techniques during the reproductive stage are prompt types which may function to lower the canopy temperature by enhancing evapotranspiration. Trials combining the different types of techniques will contribute towards obtaining more efficient and steady countermeasures against heat damage under conditions of climate change.

Malaria transmission risk variations derived from different agricultural practices in an irrigated area of northern Tanzania.

Science.gov (United States)

Ijumba, J N; Mosha, F W; Lindsay, S W

2002-03-01

Malaria vector Anopheles and other mosquitoes (Diptera: Culicidae) were monitored for 12 months during 1994-95 in villages of Lower Moshi irrigation area (37 degrees 20' E, 3 degrees 21' S; approximately 700 m a.s.l.) south of Mount Kilimanjaro in northern Tanzania. Adult mosquito populations were sampled fortnightly by five methods: human bait collection indoors (18.00-06.00 hours) and outdoors (18.00-24.00 hours); from daytime resting-sites indoors and outdoors; by CDC light-traps over sleepers. Anopheles densities and rates of survival, anthropophily and malaria infection were compared between three villages representing different agro-ecosystems: irrigated sugarcane plantation; smallholder rice irrigation scheme, and savannah with subsistence crops. Respective study villages were Mvuleni (population 2200), Chekereni (population 3200) and Kisangasangeni (population approximately/= 1000), at least 7 km apart. Anopheles arabiensis Patton was found to be the principal malaria vector throughout the study area, with An. funestus Giles sensu lato of secondary importance in the sugarcane and savannah villages. Irrigated sugarcane cultivation resulted in water pooling, but this did not produce more vectors. Anopheles arabiensis densities averaged four-fold higher in the ricefield village, although their human blood-index was significantly less (48%) than in the sugarcane (68%) or savannah (66%) villages, despite similar proportions of humans and cows (ratio 1:1.1-1.4) as the main hosts at all sites. Parous rates, duration of the gonotrophic cycle and survival rates of An. arabiensis were similar in villages of all three agro-ecosystems. The potential risk of malaria, based on measurements of vectorial capacity of An. arabiensis and An.funestus combined, was four-fold higher in the ricefield village than in the sugarcane or savannah villages nearby. However, the more realistic estimate of malaria risk, based on entomological inoculation rates, indicated that exposure to

Determination of rare earth elements in rice by INAA and ICP-MS

International Nuclear Information System (INIS)

Pham Thi Huynh, M.; Chu Pham Ngoc, S.; Carrot, F.; Revel, G.; Dang Vu, M.

1997-01-01

Irrigation of rice plants with a solution of rare earth elements increases both the production capacity and the resistance to disease. Assuming that the treated plants remain expendable, the different parts of plants, root stalk and grain, were analyzed by instrumental neutron activation analysis (INAA) and by mass spectrometry after plasma excitation (ICP-MS). About 40 elements were determined. The results showed that the contamination remained in the roots and was absent in rice grains. The analytical distribution of different elements in different parts of both treated and non-treated plants has given some information concerning the possible effect of the rare earth treatment. The performances of the two analytical methods have been compared. (author)

Genomic prediction accounting for genotype by environment interaction offers an effective framework for breeding simultaneously for adaptation to an abiotic stress and performance under normal cropping conditions in rice

OpenAIRE

Ahmadi, Nourollah; Cao, Tuong-Vi; Valé, Giampiero; Bartholomé, Jérôme; Hassen, Manel

2018-01-01

Developing rice varieties adapted to alternate wetting and drying water management is crucial for the sustainability of irrigated rice cropping systems. Here we report the first study exploring the feasibility of breeding rice for adaptation to alternate wetting and drying using genomic prediction methods that account for genotype by environment interactions. Two breeding populations (a reference panel of 284 accessions and a progeny population of 97 advanced lines) were evaluated under alter...

Evaluation of the ORYZA2000 Rice Growth Model under Nitrogen-Limited Conditions in an Irrigated Mediterranean Environment Evaluación del Modelo de Crecimiento de Arroz ORYZA2000 bajo Condiciones Limitadas de Nitrógeno en un Ambiente Mediterráneo Regado

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Pamela Artacho

2011-03-01

Full Text Available ORYZA2000 is a growth model for tropical lowland rice ( Oryza sativa L. developed by the International Rice Research Institute and Wageningen University. This model has been evaluated extensively in a wide range of environments. However, reports examining japonica cultivars growing in temperate climates are scarce. In this study, ORYZA2000 was calibrated and evaluated using data from experiments carried out in the South-Central area of Chile. These experiments were performed on a japonica rice cultivar growing under an irrigated Mediterranean environment at various N rates. ORYZA2000 was then applied to explore potential yield and grain yield response to N fertilization under likely weather conditions in the major rice-producing area in Chile. ORYZA2000 was sufficiently accurate to simulate grain yield and crop N uptake at the end of the season. Final crop N uptake was simulated with a root mean squared error (RMSE of 20 kg ha-1 (15% and grain yield with a RMSE of 1666 kg ha-1 (19%. However, the prediction of biomass and N uptake of individual organs throughout the season was poor. A long-term simulation study confirmed a potential yield as high as 12 000 kg ha-1 in the Parral area, as well as the existence of a scope for yield increase. The yield response to N fertilization was predicted even at rates of 300 kg ha-1, although a significant probability of low yields was also observed. This trend supports the need to incorporate dynamic N management in Chilean rice production.ORYZA2000 es un modelo para arroz tropical regado desarrollado por el Instituto Internacional de Investigación en Arroz y Universidad de Wageningen, que ha sido evaluado en un amplio rango de ambientes. Sin embargo, los reportes para cultivares japónica creciendo en ambientes templados son escasos. En este estudio, ORYZA2000 fue calibrado y evaluado usando datos de experimentos realizados en el centro-sur de Chile, que incluyeron una variedad japónica cultivada bajo un

Decreasing Agricultural Irrigation has not reversed Groundwater Depletion in the Yellow River Basin

Science.gov (United States)

Kang, Z.; Xie, X.; Zhu, B.

2017-12-01

Agricultural irrigation is considered as the major water use sector accounting for over 60% of the global freshwater withdrawals. Especially in the arid and semiarid areas, irrigation from groundwater storage substantially sustain crop growth and food security. China's Yellow River Basin (YRB) is a typical arid and semiarid area with average annual precipitation about 450 mm. In this basin, more than 52 million hm2 of arable land needs irrigation for planting wheat, cotton, paddy rice etc, and groundwater contributes over one-third irrigation water. However, agricultural irrigation remained a certain level or decreased to some degree due to water-saving technologies and returning farmland to forest projects. Then an interesting question arises: has the groundwater storage (GWS) in YRB kept a consistent variation with the agricultural irrigation? In this study, to address this question, we employed multi-source data from ground measurements, remote sensing monitoring and large-scale hydrological modeling. Specifically, groundwater storage variation was identified using Gravity Recovery and Climate Experiment (GRACE) data and ground observations, and groundwater recharge was estimated based on the Variable Infiltration Capacity (VIC) modeling. Results indicated that GWS in YRB still holds a significant depletion with a rate of about -3 mm per year during the past decade, which was consistently demonstrated by the GRACE and the ground observations. Ground water recharge shows negligible upward trends despite climate change. The roles of different sectors contributing to groundwater depletion have changed. Agricultural irrigation accounting for over 60% of groundwater depletion, but its impact decreased. However, the domestic and the industrial purposes play an increasing role in shaping groundwater depletion.

Rice Production Vulnerability to Climate Change in Indonesia: An Overview on Community-based Adaptation

Science.gov (United States)

Komaladara, A. A. S. P.; Budiasa, I. W.; Ambarawati, I. G. A. A.

2015-12-01

Rice remains to be a major crop and staple food in Indonesia. The task to ensure that rice production meets the demand of a growing population continues to engage the attention of national planners and policy makers. However, the adverse effects of climate change on agriculture production have presented Indonesia with yet another significant challenge. The exposure of rice crops to climate-related hazards such as temperature stress, floods, and drought, may lead to lower yield and self-sufficiency rate. This study explores the vulnerability of rice production to the effects of climate change in Indonesia. Considering the vast geographical span of the country and varying exposure, sensitivity, and adaptive capacity to climate change at regional level, this study emphasize the importance of community-based adaptation. Results from a simulation based on production and climate data from 1984 to 2014 indicates that rice production is sensitive to variation in growing season temperature and precipitation. A projection of these climate factors in 2050 has a significant impact on the major rice crop. To manage the impact of climate change, this study turns to the potential roles of farmer organizations, such as Subak, in adaptation strategies. The Subak in Bali is recognized for its cultural and organizational framework that highlights the sharing of knowledge and local wisdom in rice production. This is demonstrated by its efficient community-based irrigation management system, leading to sustainable rice production. Keywords: rice production, climate change, community-based adaptation, Indonesia

The Effect of Different Levels of Irrigation and Nitrogen Fertilizer on Yield and Water Use Efficiency of Potato in Subsurface Drip Irrigation

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Mohammad Jolaini

2017-06-01

Full Text Available Introduction: After wheat, rice and corn, potato is the fourth most important food plant in the world. In comparison with other species, potato is very sensitive to water stress because of its shallow root system: approximately 85% of the root length is concentrated in the upper 0.3-0.4 m of the soil. Several studies showed that drip irrigation is an effective method for enhancing potato yield. Fabeiro et al. (2001 concluded that tuber bulking and ripening stages were found to be the most sensitive stages of water stress with drip irrigation. Water deficit occurring in these two growth stages could result in yield reductions. Wang et al. (2006 investigated the effects of drip irrigation frequency on soil wetting pattern and potato yield. The results indicated that potato roots were not limited in wetted soil volume even when the crop was irrigated at the highest frequency while high frequency irrigation enhanced potato tuber growth and water use efficiency (WUE. Though information about irrigation and N management of this crop is often conflicting in the literature, it is accepted generally that production and quality are highly influenced by both N and irrigation amounts and these requirements are related to the cropping technique. Researches revealed that nitrogen fertilizers play a special role in the growth, production and quality of potatoes. Materials and Methods: A factorial experiment in randomized complete block design with three replications was carried out during two growing seasons. Studied factors were irrigation frequency (I1:2 and I2:4 days interval and nitrogen fertilizer levels (applying 100 (N1, 75 (N2 and 50 (N3 % of the recommended amount. Nitrogen fertilizer was applied through irrigation water. In each plot two rows with within-and between-row spacing of 45 and 105 cm and 20 m length. The amount of nitrogen fertilizer for the control treatment was determined by soil analysis (N1. In all treatments, nitrogen fertilizer

Improving soil fertility through Azolla application in low land rice: A review

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Purushottam Subedi

2015-04-01

Full Text Available The continuous usages of chemical fertilizers have harmful effects on soil organic matter reserves, soil health and environmental safety. The use of Bio-fertilizers like Azolla not only increases the rice productivity but also improves the long term soil fertility. Azolla is a fast growing aquatic pteridophyte which fixes atmospheric Nitrogen by forming a symbiotic association with the Blue-Green Algae, Anabaena azollae. Azolla is an efficient Nitrogen fixer. It is grown in lowland rice fields because flooded habitat is suitable for it. Under favorable field condition, it fixes atmospheric nitrogen at a rate exceeding that of the Legume-Rhizobium symbiotic relationship. It increases the rice yield equivalent to that produced by 30-60 kg N/ha. As green manure in water logged soil, it enhances the rapid mineralization of nitrogen. It reduces the NH3 volatilization losses through its influence on floodwater pH that leads to the conservation of urea-N in the system to improve the efficiency of N fertilizers. It significantly improves the physical and chemical properties of the soil including improvement in soil microbial activities. It helps in addition of Organic Matter and release of cations such as Magnesium, Calcium and Sodium. The total N, available P and exchangeable K in the soil and N-uptake by rice can be improved. Therefore, Azolla application is considered as a good practice for sustaining soil fertility and crop productivity irrespective of some limitations.

Competição inicial entre Cyperus esculentus e arroz irrigado em condições de casa-de-vegetação Competition between Cyperus esculentus and irrigated rice under green house conditions

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E. A. L. Erasmo

2000-08-01

Full Text Available Com o objetivo de avaliar o efeito competitivo de Cyperus esculentus sobre o crescimento inicial da cultura do arroz irrigado, foi instalado um experimento em casa-devegetação, na Estação Experimental da Faculdade de Agronomia - UNITINS, no munícipio de Gurupi-TO. O delineamento estatístico utilizado foi um fatorial 5x4 com três repetições completamente casualizado. Os tratamentos constaram de cinco períodos de convivência do arroz com C. esculentus (15, 25, 35, 45 e 60 dias após a emergência da cultura e quatro densidades de C. esculentus (0, 2, 4 e 8 tubérculos/vaso, correspondentes a 0; 71; 142 e 286 plantas de C. esculentus por m2, respectivamente. No final de cada período foram avaliados na cultura do arroz os seguintes parâmetros: matéria seca de plantas/vaso; área foliar/planta; matéria seca de perfilhos/vaso; n.º de perfilhos/vaso e altura média de plantas. Os resultados mostraram que o efeito da presença de C. esculentus foi mais marcante nas densidades de quatro e oito tubérculos/vaso a partir dos 35 dias de convivência. O parâmetro mais afetado foi a matéria seca de plantas/vaso, como resultado do decréscimo do número de perfilhos/vaso. A altura das plantas de arroz irrigado não foi afetada pela presença da planta daninha em nenhum período de convivência.With the objective of evaluating the competitive effect of Cyperus esculentus on the growth and production of the culture of irrigated rice, experiments were installed in green house, in the Experimental Station of the School of Agronomy - UNITINS, in Gurupi, State of Tocantins, Brazil. The statistical design used in the experiments was a factorial plot 5x4 with three replications, completely randomized. The treatments consisted of five periods of coexistence of the rice with Cyperus esculentus (15, 25, 35, 45 and 60 days after the emergency - D.A.E, of the rice and four densities of C. esculentus (0, 2, 4 and 8 tuber/pots corresponding to 0; 71; 142 e

Assessment of the irrigation feasibility of low-cost filtered municipal wastewater for red amaranth (Amaranthus tricolor L cv. Surma

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Gokul Chandra Biswas

2015-09-01

Full Text Available Because of the scarcity of clean water, treated wastewater potentially provides an alternative source for irrigation. In the present experiment, the feasibility of using low-cost filtered municipal wastewater in the irrigation of red amaranth (Amaranthus tricolor L cv. Surma cultivation was assessed. The collected municipal wastewater from fish markets, hospitals, clinics, sewage, and kitchens of households in Sylhet City, Bangladesh were mixed and filtered with nylon mesh. Six filtration methods were applied using the following materials: sand (T1; sand and wood charcoal consecutively (T2; sand, wood charcoal and rice husks consecutively (T3; sand, wood charcoal, rice husks and sawdust consecutively (T4; sand, wood charcoal, rice husks, sawdust and brick chips consecutively (T5; and sand, wood charcoal, rice husks, sawdust, brick chips and gravel consecutively (T6. The water from ponds and rivers was considered as the control treatment (To. The chemical properties and heavy metals content of the water were determined before and after the low cost filtering, and the effects of the wastewater on seed germination, plant growth and the accumulation rate of heavy metals by plants were assessed. After filtration, the pH, EC and TDS ranged from 5.87 to 9.17, 292 to 691 µS cm−1 and 267 to 729 mg L−1, respectively. The EC and TDS were in an acceptable level for use in irrigation, satisfying the recommendations of the FAO. However, select pH values were unsuitable for irrigation. The metal concentrations decreased after applying each treatment. The reduction of Fe, Mn, Pb, Cu, As and Zn were 73.23%, 92.69%, 45.51%, 69.57%, 75.47% and 95.06%, respectively. When we considered the individual filtering material, the maximum amount of As and Pb was absorbed by sawdust; Cu and Zn by wood charcoal; Mn and Cu by sand and Fe by gravel. Among the six filtration treatments, T5 showed the highest seed germination (67.14%, similar to the control T0 (77

Genetic improvement of rice (oryza sativa l.) by induced mutations

International Nuclear Information System (INIS)

Suarez, E.; Deus, J. E.; Perez, R.; Alfonso, R.; Hernandez, R.; Avila, J.; Hernandez, J. L.; Puldon, Violeta; Duany, A.; Reinoso, J.; Mesa, H.; Rodriguez, S.

2001-01-01

In 1989 was initiated at Rice Research Institute of Cuba, a mutation breeding programme, in order to obtain new germoplasm with improved characters such as milling quality, earliness, resistance to the Hoja Blanca virus disease and salt tolerance. Seven varieties has been irradiated and two different sources of radiation were used: gamma rays from 60Co and fast neutrons of a 14 MeV neutron generator. In 1995, was released the variety IACuba 23 for low inputs conditions. Another four varieties IACuba 21, IACuba 22, IACuba 27 and IACuba 28 are in validation trials in rice production areas under irrigated condition. The last two have showed resistance to Steneotarsonemus spinki. Also, a group of mutants was selected to be used as parents. These mutants have been used in 953 crosses

Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands

Science.gov (United States)

Douglas, Peter M. J.; Pagani, Mark; Canuto, Marcello A.; Brenner, Mark; Hodell, David A.; Eglinton, Timothy I.; Curtis, Jason H.

2015-01-01

Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800–950 C.E.). Evidence for drought largely derives from the drier, less populated northern Maya Lowlands but does not explain more pronounced and earlier societal disruption in the relatively humid southern Maya Lowlands. Here we apply hydrogen and carbon isotope compositions of plant wax lipids in two lake sediment cores to assess changes in water availability and land use in both the northern and southern Maya lowlands. We show that relatively more intense drying occurred in the southern lowlands than in the northern lowlands during the Terminal Classic period, consistent with earlier and more persistent societal decline in the south. Our results also indicate a period of substantial drying in the southern Maya Lowlands from ∼200 C.E. to 500 C.E., during the Terminal Preclassic and Early Classic periods. Plant wax carbon isotope records indicate a decline in C4 plants in both lake catchments during the Early Classic period, interpreted to reflect a shift from extensive agriculture to intensive, water-conservative maize cultivation that was motivated by a drying climate. Our results imply that agricultural adaptations developed in response to earlier droughts were initially successful, but failed under the more severe droughts of the Terminal Classic period. PMID:25902508

Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands.

Science.gov (United States)

Douglas, Peter M J; Pagani, Mark; Canuto, Marcello A; Brenner, Mark; Hodell, David A; Eglinton, Timothy I; Curtis, Jason H

2015-05-05

Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800-950 C.E.). Evidence for drought largely derives from the drier, less populated northern Maya Lowlands but does not explain more pronounced and earlier societal disruption in the relatively humid southern Maya Lowlands. Here we apply hydrogen and carbon isotope compositions of plant wax lipids in two lake sediment cores to assess changes in water availability and land use in both the northern and southern Maya lowlands. We show that relatively more intense drying occurred in the southern lowlands than in the northern lowlands during the Terminal Classic period, consistent with earlier and more persistent societal decline in the south. Our results also indicate a period of substantial drying in the southern Maya Lowlands from ∼200 C.E. to 500 C.E., during the Terminal Preclassic and Early Classic periods. Plant wax carbon isotope records indicate a decline in C4 plants in both lake catchments during the Early Classic period, interpreted to reflect a shift from extensive agriculture to intensive, water-conservative maize cultivation that was motivated by a drying climate. Our results imply that agricultural adaptations developed in response to earlier droughts were initially successful, but failed under the more severe droughts of the Terminal Classic period.

Lignocellulosic residues for production of electricity, biogas or second generation biofuel: A case study of technical and sustainable potential of rice straw in Mali

DEFF Research Database (Denmark)

Nygaard, Ivan; Dembelé, Filifing; Daou, Ibrahima

2016-01-01

Biomass from agricultural residues, especially lignocellulosic biomass, is not only seen as a sustainable biomass source for the production of electricity, but increasingly as a resource for the production of biogas and second generation biofuel in developing countries. Based on empirical research...... in an irrigated rice-growing area, Office du Niger, in Mali, this article builds scenarios for the sustainable potential of rice straw. The paper concludes that there is great uncertainty regarding the size of the sustainable resources of rice straw available for energy, but that the most likely scenario...

Estruturas automáticas para controle de água nos canais em lavoura de arroz irrigado Automatic structures for water control in channels on irrigated rice crops

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Luís G. H. do Amaral

2005-04-01

Full Text Available O Rio Grande do Sul apresenta a maior área irrigada do Brasil, devido principalmente à lavoura de arroz irrigado por inundação. Um dos fatores que contribuem para reduzir a eficiência de irrigação nessas lavouras é o baixo grau de controle exercido pelas estruturas de distribuição de água. Os objetivos deste trabalho foram projetar e construir dois protótipos de estruturas hidráulicas para controle automático de vazão em canais de irrigação e comparar sua sensibilidade de controle de vazão com a sensibilidade de duas comportas fixas. Os protótipos construídos - uma comporta hidromecânica automática e um regulador automático de vazão - foram instalados à entrada de um canal secundário, juntamente com uma comporta-gaveta e uma comporta-vertedor, que são as estruturas mais utilizadas para controle de vazão no RS. Provocou-se uma variação de 0,20 m na altura da lâmina de água a montante, determinando-se a vazão em cada estrutura. A menor variação de vazão com a alteração da lâmina foi de 5,6%, obtida com o regulador automático de vazão, seguido da comporta-gaveta com 23,7%, da comporta hidromecânica com 30,5%, e da comporta vertedor com 1.177,2%.In Brazil, the State that presents the largest extension of irrigated lands is Rio Grande do Sul, mainly due to rice that grows under flooded conditions. One of the factors that contribute to decrease the efficiency of irrigation is the low degree of control obtained with the structures used on water distribution. The objectives of this work were to design and build two hydraulic structures for automatic flow control on irrigation channels, and to compare the flow control sensitivity of the built prototypes with two types of gates that are widely used in the rice fields at the Rio Grande do Sul State. The constructed prototypes - a hydro-mechanical gate and an automatic flow regulator - were installed at the entrance of a secondary channel, next to a sluice gate and

Radioactive probes as diagnostic tools for rice tungro viruses

International Nuclear Information System (INIS)

Azzam, O.; Arboleda, M.; Reyes. J. de los

1996-01-01

Rice tungro bacilliform (RTBV) and rice tungro spherical viruses (RTSV) are the two viral components responsible for rice tungro disease which has seriously affected the irrigated rice ecosystem in Southeast Asia for the last 30 years. RTBV has an 8 Kb double-stranded DNA circular genome, and it is primarily responsible for induction of symptoms in infected plants. RTSV has a 12 kb single-stranded RNA genome. It does not induce any apparent symptoms in the infected plant, and it is transmitted by greenleafhopper. RTBV depends upon RTSV for its own transmission. The two viruses are limited to the vascular tissue of the rice plant and are present at a low titer. Most of the detection methods used for the identification of these viruses have relied on the virus protein properties and therefore, early detection of the virus activity was not possible. We were interested in evaluating tissue printing, dot blot, and southern techniques for early detection of virus nucleic acids in rice plant using radioactive and non radioactive probes. 32 P-labeled T7 or SP6 RNA polymerase transcripts complementary to the RTBV genome and RTSV coat protein genes were used as probes of the positive stand of both viruses. For nonradioactive probes, RTBV DNA genome was labeled using the ECL detection kit (Amersham). Preliminary results show that viral nucleic acids of RTBV and RTSV could be detected using both labelling systems. Non radioactive probes were comparable in their sensitivity to the radioactive probes. Less than 100 pg of viral DNA was detected in the dot-blot assays. More data will be presented to compare the efficiency and reliability of these two techniques in detecting early virus activity in the rice plant. (author)

Kajian Optimalisasi Sistem Irigasi Rawa (Studi Kasus Daerah Rawa Semangga Kabupaten Merauke Propinsi Papua

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Darwin Pakpahan

2015-10-01

Full Text Available Population growth is increasing, but it is not accompanied by an increase in food needs impartial. Indonesian swamp land potential of about 33.4 million ha, consisting of tidal swamp 20.1 million ha and 13.3 million ha of lowland swamp. The Government has made the development of swamps into agricultural land, including the Semangga swamp area (4,000 ha The cropping pattern of rice (100% - crops (40% – “bero”. The problem faced are; the length is 7-month of dry season and low agricultural production, are therefore likely to swamp irrigation system optimalization. The method used to carry out water balance analysis and performance assessment of irrigation system include; the physical condition of irrigation, the application of the system of planting and water delivery techniques to the use of land for a year, then performed according to the potential land development plan and water resources available. Results of water balance analysis on Semangga Swamp Area existing condition indicate that water deficit occurred during the second growing season crops (May-July and in December. So do the appropriate development plan defined cropping pattern III, namely rice (100% - crops (60% - crops (45% with the addition of a total area of 1,000 ha through the use Kumbe River and Maro River and other water reservoirs to overcome deficits in the availability of water in the dry season that is equal to 2.5m³/s (April to August and October to December, while 6.5m³/s in September, 72.40% irrigation system performance with good category.

137Cs absorption by growing rice planted in pot soil from Qinshan and Daya Bay area

International Nuclear Information System (INIS)

Shang Zhaorong; Yu Fengyi; Lu Zixian

1999-01-01

The pot experiment of growing rice contaminated with 137 Cs solution was designed as follows. (1) The same volume of 137 Cs solution was irrigated into rice soil from Guantang District around Qinshan NPP in seedling stage, booting stage and milk stage respectively with the same Specific Activity (SA) of 370 Bq/g soil , and the rice was sampled after maturity. (2) In the seedling stage, the rice cultured in the soil from Guantang District was irrigated by four different SA of 0.37, 3.7, 37 and 370 Bq/g soil respectively, and sampled after 30, 60 and 90 d. (3) Transfer Factors (TF) of edible parts of rice on five different soils were calculated for three different stage and four different 137 Cs levels. The results show that: 1) TF of Shenzhen soil is the highest with 1.86 in seed and 2.22 in stem and 4.05 in leaf, Changchuanba soil is the lowest with 0.09 in seed and 0.20 in stem and 0.20 in leaf, among the five different soils. 2) TF in milk stage is the highest with 0.46 in seed and 2.29 in stem and 2.87 in leaf, and booting stem is lowest with 0.09 in seed and 0.17 in stem and 0.17 in leaf, among the three different stage. 3) TF of soil with contamination in 0.37 Bq/g soil is the highest with 1.08 in seed and 3.70 in stem and 4.32 in leaf, and the contamination in 37 Bq/g soil is the lowest with 0.06 in seed and 0.10 in stem and 0.14 in leaf, among four different contamination levels

Influence of Seed Priming on Performance and Water Productivity of Direct Seeded Rice in Alternating Wetting and Drying

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Hafeez Ur Rehman

2015-07-01

Full Text Available Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying (DSR-AWD in comparison with direct seeded rice at field capacity (DSR-FC. Seed priming treatments were osmo-priming with KCl (2.2%, CaCl2 (2.2% and moringa leaf extracts (MLE, 3.3% including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with CaCl2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with CaCl2 in DSR-AWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or CaCl2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or CaCl2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation.

Optimized Subsurface Irrigation System: The Future of Sugarcane Irrigation

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M. H. J. P. Gunarathna

2018-03-01

Full Text Available Climate change may harm the growth and yield of sugarcane (Saccharum officinarum L. without the introduction of appropriate irrigation facilities. Therefore, new irrigation methods should be developed to maximize water use efficiency and reduce operational costs. OPSIS (optimized subsurface irrigation system is a new solar-powered automatic subsurface irrigation system that creates a phreatic zone below crop roots and relies on capillarity to supply water to the root zone. It is designed for upland crops such as sugarcane. We investigated the performance of OPSIS for irrigating sugarcane and evaluated its performance against sprinkler irrigation under subtropical conditions. We conducted field experiments in Okinawa, Japan, over the period from 2013 to 2016 and took measurements during spring- and summer-planted main crops and two ratoon crops of the spring-planted crop. Compared with sprinkler irrigation, OPSIS produced a significantly higher fresh cane yield, consumed less irrigation water and provided a higher irrigation water use efficiency. We conclude that OPSIS could be adopted as a sustainable solution to sugarcane irrigation in Okinawa and similar environments.

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.

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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.

A paddy eco-ditch and wetland system to reduce non-point source pollution from rice-based production system while maintaining water use efficiency.

Science.gov (United States)

Xiong, Yujiang; Peng, Shizhang; Luo, Yufeng; Xu, Junzeng; Yang, Shihong

2015-03-01

Non-point source (NPS) pollution from agricultural drainage has aroused widespread concerns throughout the world due to its contribution to eutrophication of water bodies. To remove nitrogen (N) and phosphorus (P) from agricultural drainage in situ, a Paddy Eco-ditch and Wetland System (PEDWS) was designed and built based on the characteristics of the irrigated rice district. A 2-year (2012-2013) field experiment was conducted to evaluate the performance of this system in Gaoyou Irrigation District in Eastern China. The results showed that the reduction in water input in paddy field of the PEDWS enabled the maintenance of high rice yield; it significantly increased irrigation water productivity (WPI), gross water productivity (WPG), and evapotranspiration water productivity (WPET) by 109.2, 67.1, and 17.6%, respectively. The PEDWS dramatically decreased N and P losses from paddy field. Compared with conventional irrigation and drainage system (CIDS), the amount of drainage water from PEDWS was significantly reduced by 56.2%, the total nitrogen (TN) concentration in drainage was reduced by 42.6%, and thus the TN and total phosphorus (TP) losses were reduced by 87.8 and 70.4%. PEDWS is technologically feasible and applicable to treat nutrient losses from paddy fields in situ and can be used in similar areas.

Selectivity of pesticides used in rice crop on Telenomus podisi and Trichogramma pretiosum

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Juliano de Bastos Pazini

2016-09-01

Full Text Available Telenomus and Trichogramma species stand out as agents for the biological control in rice crops, and the main strategy for preserving them is the use of selective pesticides. This study aimed at evaluating the toxicity of pesticides used in irrigated rice crop on Telenomus podisi Ashmead (Hymenoptera: Platygastridae and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae. Adults of these parasitoids were exposed to dry residues of pesticides, in a completely randomized experiment, with 25 treatments (24 pesticides + control and four replications. The insecticides clorantraniliprole, flubendiamide and diflubenzuron and the biological insecticides based on Beauveria bassiana and Metarhizium anisopliae were harmless to T. podisi and T. pretiosum. The harmless herbicides were: 2.4-D amine, profoxydim, quinclorac, ethoxysulfuron and saflufenacil. The fungicide epoxiconazole + kresoxim-methyl was also harmless to these two biological control agents. Therefore, these pesticides are indicated for the integrated pest management, in flooded rice areas.

Toxicity of Pesticide Tank Mixtures from Rice Crops Against Telenomus podisi Ashmead (Hymenoptera: Platygastridae).

Science.gov (United States)

de B Pazini, J; Pasini, R A; Rakes, M; de Armas, F S; Seidel, E J; da S Martins, J F; Grützmacher, A D

2017-08-01

The use of insecticides, herbicides, and fungicides commonly occurs in mixtures in tanks in order to control phytosanitary problems in crops. However, there is no information regarding the effects of these mixtures on non-target organisms associated to the rice agroecosystem. The aim of this study was to know the toxicity of pesticide tank mixtures from rice crops against Telenomus podisi Ashmead (Hymenoptera: Platygastridae). Based on the methods adapted from the International Organisation for Biological and Integrated Control of Noxious Animals and Plants (IOBC), adults of T. podisi were exposed to residues of insecticides, herbicides, and fungicides, individually or in mixture commonly used by growers, in laboratory and on rice plants in a greenhouse. The mixture between fungicides tebuconazole, triclyclazole, and azoxystrobin and the mixture between herbicides cyhalofop-butyl, imazethapyr, imazapyr/imazapic, and penoxsulam are harmless to T. podisi and can be used in irrigated rice crops without harming the natural biological control. The insecticides cypermethin, thiamethoxam, and bifenthrin/carbosulfan increase the toxicity of the mixtures in tank with herbicides and fungicides, being more toxic to T. podisi and less preferred for use in phytosanitary treatments in the rice crop protection.

Rice lands of South and South East Asia, some soil physical aspects

International Nuclear Information System (INIS)

Bhagat, R.M.

2004-01-01

in a lowland-upland (e.g. rice-wheat) situation because of soil shrinkage. Change in the orientation of soil particles in puddled layer brings about changes in soil porosity. The parallel oriented structure produced following puddling from an initially open gel structure, total porosity will decrease. Total pore volume may, however, temporarily increase upon puddling. But an ultimate decline in total porosity is noticed upon puddling in many studies. Depending upon the soil texture and the initial aggregation status at low soil water potential (more negative), water retention in puddled soils is always higher then the non puddle soil. In a long term study on rice straw management in lowland rice - upland wheat system, it was observed that water retention was always higher in plots which were puddle in a previous rice compared to the non puddle plots, even if these were supplied with straw mulch or farm yard manure in the following upland wheat crop. Thermal regimes of air, flood water and soil monitored for diurnal variations in temperature, indicate that for flood water as well as soil, the puddled plots always maintained a higher temperature compared to non puddle plots. Increase in temperature following puddling is attributed to a decrease in percolation rates. In puddled plots water continue to pond on the surface for longer periods compared to non puddled plots resulting in an increase in temperature

How well can we assess impacts of agricultural land management changes on the total greenhouse gas balance (CO2, CH4 and N2O) of tropical rice-cropping systems with biogeochemical models?

Science.gov (United States)

Kraus, David; Weller, Sebastian; Janz, Baldur; Klatt, Steffen; Santabárbara, Ignacio; Haas, Edwin; Werner, Christian; Wassmann, Reiner; Kiese, Ralf; Butterbach-Bahl, Klaus

2016-04-01

Paddy rice cultivation is increasingly challenged by physical and economic irrigation water scarcity. This already results in the trend of converting paddy rice to upland crop cultivation (e.g., maize, aerobic rice) in large parts of South East Asia. Such land management change from flooded lowland systems to well-aerated upland systems drastically affects soil C and N cycling and related emissions of greenhouse gases. Emissions of methane (CH4) are expected to decrease, while emissions of nitrous oxide (N2O) will most likely increase. In addition to such fast evolving 'pollution swapping' it is expected that on longer time scales significant amounts of soil organic carbon (SOC) stocks will be lost in form of carbon dioxide (CO2). Within the DFG-funded research unit ICON (Introducing non-flooded crops in rice-dominated landscapes: Impact on carbon, nitrogen and water cycles), we investigated environmental impacts of land management change from historical paddy rice cultivation to the upland crops maize and aerobic rice at experimental sites at the International Rice Research Institute (IRRI), the Philippines. To present, more than three years of continuous measurement data of CH4 and N2O emissions under different fertilization regimes have been collected. In addition, measurements of SOC contents and bulk densities in different soil horizons allow for an overall very good characterization of the environmental impacts of mentioned land management change. In this contribution we will show how well mentioned land management change effects in tropical agricultural systems can be represented and thus better understood by the help of process-based biogeochemical models. Seasonal emissions of CH4 and N2O are simulated with r2 values of 0.85 and 0.78 and average underestimations of 15 and 14 %, respectively. These underestimations predominantly originate from treatments in which no fertilizer is applied (CH4) as well as uncertainties of soil hydrology (N2O). Long

Pore Water Arsenic Dynamics in Rice Paddies Under Projected Future Climates

Science.gov (United States)

Plaganas, M.; Wang, T.; Muehe, E. M.; Fendorf, S. E.

2016-12-01

Rice is one of the staple crops in the world, with 50% of the global population eating rice daily. Many rice-producing regions of the world are irrigated with groundwater contaminated with arsenic (As), and in particular South and Southeast Asia, where geogenic As is leached into the groundwater. Use of groundwater pervasively high in As leads to subsequent accumulation in paddy soils. Arsenic, a toxic metalloid, also decreases rice productivity and further jeopardizes food security. Hence, rice agriculture is concerned with its productivity in a climate change impacted future and the particular impacts of arsenic on yields. However, past studies do not address the prevalence of As in paddy soils or its fate in the rhizosphere and ultimate impact on the plant. The objective of our study was to determine changes in pore water As dynamics in the rhizosphere of rice plants grown on As-contaminated paddy soil under climate conditions projected for the end of the century. In order to address this objective, we designed greenhouse chambers with today's climate and projected climate conditions for the year 2100, specifically 5°C increase in temperature and doubled concentration of atmospheric CO2. We hypothesize that the effects of climate change with these conditions will increase the mobility of As in the rhizosphere, and thus, decrease rice growth in As-bearing paddies more than, so far, expected. We examined pore water geochemistry including pH and As concentrations, and correlate that to the height of the plants. Furthermore, the dynamics of other elements in the pore water such as carbon, iron, sulfur, manganese, and silica are further evaluated for their effects on rice growth. Arsenic will have an impact on rice production and conditions induced by future climatic conditions need to be considered for food security. Considering that climate change will decrease the global agricultural output, we should urgently consider adapting our agricultural practices to aid

Dental lesions in the lowland tapir (Tapirus terrestris)

DEFF Research Database (Denmark)

Tjørnelund, Karen B.; Jonsson, Lena M.; Kortegaard, Hanne Ellen

2015-01-01

Dental ailments, mandibular swelling, and dentoalveolar abscesses are common in tapirs, but knowledge about prevalence or etiology of these lesions in the Tapiridae family in general, and in lowland tapirs ( Tapirus terrestris ) in particular, is scarce. A recent study identified resorptive lesions...... of unknown etiology as a common problem in the Malayan tapir ( Tapirus indicus ). In order to investigate the type and prevalence of dental lesions occurring in lowland tapirs, and to compare these with findings with the Malayan tapir, skulls and teeth from 46 deceased lowland tapirs were visually...... with associated periapical reaction (15%) and periapical reactions of various degrees without associated detectable dental pathology (13%). All these lesions likely originated from dental trauma. As in Malayan tapirs, juveniles had significantly fewer lesions than adults. This study shows that dental lesions...

Effect of organic fertiliser residues from rice production on nitrogen fixation of soya (Glycine max L. Merrill, Chiang Mai 60 variety

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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.

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

Perception, Mitigation and Adaptation Strategies of Irrigated Paddy Farmer Community to Face Climate Change

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Siska Rasiska Suantapura

2016-06-01

Full Text Available Climate change has a real impact on the condition of agriculture in developing countries, including Indonesia. Irrigated paddy farmers are the ones really feeling the impact of climate change. Therefore, we need to understand the perceptions, mitigation and adaptation strategies of irrigated paddy farmer community to face climate change. The study is conducted in Indramayu and Tasikmalaya Regency in West Java by using descriptive survey method, regression analysis and path analysis through Structural Equation Modelling approach with Lisrel TM 8.5. The results showes that: (1 changes to climate variability affects the productivity of rice; (2 perception of irrigated paddy farmer community on climate change and its affects are influenced by internal and external factors; and (3 adaptation strategy are influenced by internal and external factors, whereas no mitigation strategy. Therefore, mitigation and adaptation strategies with site specific location are very necessary improving climate information services, increasing empowerment of farmers through field schools, and providing the provision of facilities that are practical and adaptive to climate.

SPOT-Based Sub-Field Level Monitoring of Vegetation Cover Dynamics: A Case of Irrigated Croplands

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Olena Dubovyk

2015-05-01

Full Text Available Acquiring multi-temporal spatial information on vegetation condition at scales appropriate for site-specific agricultural management is often complicated by the need for meticulous field measurements. Understanding spatial/temporal crop cover heterogeneity within irrigated croplands may support sustainable land use, specifically in areas affected by land degradation due to secondary soil salinization. This study demonstrates the use of multi-temporal, high spatial resolution (10 m SPOT-4/5 image data in an integrated change vector analysis and spectral mixture analysis (CVA-SMA procedure. This procedure was implemented with the principal objective of mapping sub-field vegetation cover dynamics in irrigated lowland areas within the lowerlands of the Amu Darya River. CVA intensity and direction were calculated separately for the periods of 1998–2006 and 2006–2010. Cumulative change intensity and the overall directional trend were also derived for the entire observation period of 1998–2010. Results show that most of the vector changes were observed between 1998 and 2006; persistent conditions were seen within the study region during the 2006–2010 period. A decreasing vegetation cover trend was identified within 38% of arable land. Areas of decreasing vegetation cover were located principally in the irrigation system periphery where deficient water supply and low soil quality lead to substandard crop development. During the 2006–2010 timeframe, degraded crop cover conditions persisted in 37% of arable land. Vegetation cover increased in 25% of the arable land where irrigation water supply was adequate. This high sub-field crop performance spatial heterogeneity clearly indicates that current land management practices are inefficient. Such information can provide the basis for implementing and adapting irrigation applications and salt leaching techniques to site-specific conditions and thereby make a significant contribution to sustainable

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.

Exploring traditional aus-type rice for metabolites conferring drought tolerance.

Science.gov (United States)

Casartelli, Alberto; Riewe, David; Hubberten, Hans Michael; Altmann, Thomas; Hoefgen, Rainer; Heuer, Sigrid

2018-01-25

Traditional varieties and landraces belonging to the aus-type group of rice (Oryza sativa L.) are known to be highly tolerant to environmental stresses, such as drought and heat, and are therefore recognized as a valuable genetic resource for crop improvement. Using two aus-type (Dular, N22) and two drought intolerant irrigated varieties (IR64, IR74) an untargeted metabolomics analysis was conducted to identify drought-responsive metabolites associated with tolerance. The superior drought tolerance of Dular and N22 compared with the irrigated varieties was confirmed by phenotyping plants grown to maturity after imposing severe drought stress in a dry-down treatment. Dular and N22 did not show a significant reduction in grain yield compared to well-watered control plants, whereas the intolerant varieties showed a significant reduction in both, total spikelet number and grain yield. The metabolomics analysis was conducted with shoot and root samples of plants at the tillering stage at the end of the dry-down treatment. The data revealed an overall higher accumulation of N-rich metabolites (amino acids and nucleotide-related metabolites allantoin and uridine) in shoots of the tolerant varieties. In roots, the aus-type varieties were characterised by a higher reduction of metabolites representative of glycolysis and the TCA cycle, such as malate, glyceric acid and glyceric acid-3-phosphate. On the other hand, the oligosaccharide raffinose showed a higher fold increase in both, shoots and roots of the sensitive genotypes. The data further showed that, for certain drought-responsive metabolites, differences between the contrasting rice varieties were already evident under well-watered control conditions. The drought tolerance-related metabolites identified in the aus-type varieties provide a valuable set of protective compounds and an entry point for assessing genetic diversity in the underlying pathways for developing drought tolerant rice and other crops.

Evaluation of the effects of mulch on optimum sowing date and irrigation management of zero till wheat in central Punjab, India using APSIM.

Science.gov (United States)

Balwinder-Singh; Humphreys, E; Gaydon, D S; Eberbach, P L

2016-10-01

Machinery for sowing wheat directly into rice residues has become more common in the rice-wheat systems of the north-west Indo-Gangetic Plains of South Asia, with increasing numbers of farmers now potentially able to access the benefits of residue retention. However, surface residue retention affects soil water and temperature dynamics, thus the optimum sowing date and irrigation management for a mulched crop may vary from those of a traditional non-mulched crop. Furthermore, the effects of sowing date and irrigation management are likely to vary with soil type and seasonal conditions. Therefore, a simulation study was conducted using the APSIM model and 40 years of weather data to evaluate the effects of mulch, sowing date and irrigation management and their interactions on wheat grain yield, irrigation requirement (I) and water productivity with respect to irrigation (WP I ) and evapotranspiration (WP ET ). The results suggest that the optimum wheat sowing date in central Punjab depends on both soil type and the presence or absence of mulch. On the sandy loam, with irrigation scheduled at 50% soil water deficit (SWD), the optimum sowing date was late October to early November for maximising yield, WP I and WP ET . On the clay loam, the optimum date was about one week later. The effect of mulch on yield varied with seasonal conditions and sowing date. With irrigation at 50% SWD, mulching of wheat sown at the optimum time increased average yield by up to 0.5 t ha -1 . The beneficial effect of mulch on yield increased to averages of 1.2-1.3 t ha -1 as sowing was advanced to 15 October. With irrigation at 50% SWD and 7 November sowing, mulch reduced the number of irrigations by one in almost 50% of years, a reduction of about 50 mm on the sandy loam and 60 mm on the clay loam. The reduction in irrigation amount was mainly due to reduced soil evaporation. Mulch reduced irrigation requirement by more as sowing was delayed, more so on the sandy loam than the clay

Adaptación del arroz riego (Oryza sativa L. en el Caribe colombiano Adaptation of irrigated rice (Oryza sativa L. in the colombian Caribbean

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Hermes Aramendiz Tatis

2011-01-01

Full Text Available En Colombia, el arroz ocupa el primer lugar en seguridad alimentaria, valor económico y generación de empleo entre los cultivos anuales, siendo el sistema bajo riego más importante. El objetivo fue determinar el progreso, estabilidad y adaptabilidad del rendimiento de arroz bajo riego, en cinco departamentos del caribe colombiano. Se utilizaron datos del Ministerio de Agricultura y Desarrollo Rural, correspondiente a los Departamentos de Córdoba, Bolívar, Magdalena, Cesar y Guajira, durante el periodo 1987-2008. La estimación del progreso del rendimiento se realizó a través del análisis de regresión lineal entre los años (variable explicativa y el rendimiento de grano (variable explicada. La estabilidad se determinó a través del coeficiente de variación para tres períodos consecutivos de cinco años y el último de siete. La adaptabilidad, se realizó con el coeficiente de regresión lineal (bi. Los resultados destacan que el progreso en el rendimiento de grano en el Caribe colombiano, osciló entre 1.15% y 3.36% por año y 52.2 y 168.1 kg.ha-1, especialmente en el Departamento de Bolívar (3.36% por año y 168.1 kg.ha-1. La estabilidad, resultó en general alta (CV4.57 para el rendimiento de grano.In Colombia, the rice crop under irrigation system ranks first in food security, economic value and employment offer among annual crops, becoming the most important. The objective of this study was to quantify increasing, stability and adaptability of irrigated rice in five departments of the Colombian Caribbean area. Data from the Ministry of Agriculture and Rural Development for the departments of Cordoba, Bolivar, Magdalena, Cesar and Guajira, during the year period 1987 to 2008 were used. The increasing in yield was determined using the linear regression analysis among years (independent variable and grain yield (dependent variable in each department. The yield stability was determined by the coefficient of variation across of three

Alternate wetting and drying decreases methylmercury in flooded rice (Oryza sativa) systems

Science.gov (United States)

Tanner, K. Christy; Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark C.; Fleck, Jacob; Linquist, Bruce A.

2018-01-01

In flooded soils, including those found in rice (Oryza sativa L.) fields, microbes convert inorganic Hg to more toxic methylmercury (MeHg). Methylmercury is accumulated in rice grain, potentially affecting health. Methylmercury in rice field surface water can bioaccumulate in wildlife. We evaluated how introducing aerobic periods into an otherwise continuously flooded rice growing season affects MeHg dynamics. Conventional continuously flooded (CF) rice field water management was compared with alternate wetting and drying, where irrigation was stopped twice during the growing season, allowing soil to dry to 35% volumetric moisture content, at which point plots were reflooded (AWD-35). Methylmercury studies began at harvest in Year 3 and throughout Year 4 of a 4-yr replicated field experiment. Bulk soil, water, and plant samples were analyzed for MeHg and total Hg (THg), and iron (Fe) speciation was measured in soil samples. Rice grain yield over 4 yr did not differ between treatments. Soil chemistry responded quickly to AWD-35 dry-downs, showing significant oxidation of Fe(II) accompanied by a significant reduction of MeHg concentration (76% reduction at harvest) compared with CF. Surface water MeHg decreased by 68 and 39% in the growing and fallow seasons, respectively, suggesting that the effects of AWD-35 management can last through to the fallow season. The AWD-35 treatment reduced rice grain MeHg and THg by 60 and 32%, respectively. These results suggest that the more aerobic conditions caused by AWD-35 limited the activity of Hg(II)-methylating microbes and may be an effective way to reduce MeHg concentrations in rice ecosystems.

Evaluation on selected dwarf and semidwarf mutants of upland rice

International Nuclear Information System (INIS)

Riyanti Sumanggono, A.M.

1984-01-01

Seratus malam local upland rice variety was irradiated with gamma-rays at doses of O.1, 0.2, 0.3, 0.4 and 0.5 kGy. Observation of radiation effect was carried out on root and shoot length of M 1 seedlings; plant height, panicle length and number of tiller and seed sterility in M 1 plants. Selection for dwarf and semi-dwarf characteristics were done in M 2 plants, and selected again in M 3 . Observation on radiation effect indicated that 'Seratus Malam' seems to be more resistant than the lowland rice varieties. Increasing doses of radiation caused increasing frequency of chlorophyll mutations as well as chlorophyll mutants. Whereas, selection of dwarf or semi-dwarf in M 2 plants seems that mutant and mutation frequencies decreased as the dose increased. Dose of 0.2 kGy was suitable for selection of dwarf or semi-dwarf plants. Plant height could be influenced by environmental condition. Many of the selected M 2 plants were not really dwarf or semi-dwarf mutants. M 3 evaluation of the selected M 2 plants was really beneficial in the mutant selection. (author)

Dynamics of Phenol Degrading-Iron ReducingBacteria{1mm in Intensive Rice Cropping System

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

Field and greenhouse experiments were conducted to investigate theeffects of cropping season, nitrogen fertilizer input and aeratedfallow on the dynamics of phenol degrading-iron reducingbacteria (PD-IRB) in tropical irrigated rice ({ Oryza sativa L.)systems. The PD-IRB population density was monitored at different stagesof rice growth in two cropping seasons (dry and early wet) in acontinuous annual triple rice cropping system under irrigated condition.In this system, the high nitrogen input (195 and 135 kg N ha-1 indry and wet seasons, respectively) plots and control plots receiving noN fertilizer were compared to investigate the effect of nitrogen rate onpopulation size. The phenol degrading-iron reducing bacteria (PD-IRB)were abundant in soils under cropping systems of tropical irrigatedrice. However, density of the bacterial populations varied with ricegrowth stages. Cropping seasons, rhizosphere, and aerated fallow couldaffect the dynamics of PD-IRB. In the field trial, viable counts ofPD-IRB in the topsoil layer (15 cm) ranged between 102 and 108cells per gram of dry soil. A steep increase in viable counts during thesecond half of the cropping season suggested that the population densityof PD-IRB increased at advanced crop-growth stages. Population growth ofPD-IRB was accelerated during the dry season compared to the wet season.In the greenhouse experiment, the adjacent aerated fallow revealed 1-2orders of magnitude higher in most probable number (MPN) of PD-IRB thanthe wet fallow treated plots. As a prominent group of Fe reducingbacteria, PD-IRB predominated in the rhizosphere of rice, since maximumMPN of PD-IRB (2.62108 g-1 soil) was found in rhizospheresoil. Mineral N fertilizer rates showed no significant effect on PD-IRBpopulation density.

Runoff characteristics of water quality from small agricultural watershed having topographical chain and irrigation; Chikei rensa to suiden kangai wo yusuru nogyo shoshu suiiki kara ryushutsusuru suishitsu no tokucho ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Nakasone, H; Kuroda, H; Kubota, K [Ibaraki University, Ibaraki (Japan). School of Agriculture

1996-01-10

An investigation was carried out on characteristics of concentration and load amount of water flowing out from a small watershed with an area of 205 ha which is utilized mostly for agriculture. The basin subjected to the investigation was a district with typical tableland topography in Dejima Village in Ibaraki Prefecture. The land on this tableland in the district is utilized mainly for a truck farm, raising mainly vegetables and fruit trees. However, dry rice fields, which were converted from the truck farms into irrigated rice fields, exist on the tableland in this district. It is known that the dry rice fields have as high water permeability as inconceivable in ordinary paddy rice fields. Paddy fields developing below the tableland are called valley paddy fields, which are ill-drained paddy fields having small downward water permeation. It is an interesting subject to know what effects are given on the quality of runoff water by the topography in this watershed that has such a specific topographical chain as described. Furthermore, the dry rice fields are irrigated from the Dejima water canal taking water from Kasumigaura Lake, whereas large effects are anticipated on the amounts of runoff water and load because of such a large water permeation amount. This paper discusses the characteristics in amounts of runoff water and load in such a watershed as described. 20 refs., 17 figs., 2 tabs.

Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

International Nuclear Information System (INIS)

Al-Ghobari, H.M.; Mohammad, F.S.; El Marazky, M.S.A.

2016-01-01

Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

Energy Technology Data Exchange (ETDEWEB)

Al-Ghobari, H.M.; Mohammad, F.S.; El Marazky, M.S.A.

2016-07-01

Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema) in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

Genetic variability for water deficiency tolerance in upland and lowland rice germplasm and prospects of its transfer to basmati rice varieties (abstract)

International Nuclear Information System (INIS)

Farooq, S.; Iqbal, N.; Arshad, R.

2005-01-01

Rice germplasm consisting of five local basmati (fine grain aromatic) rice cultivars. IR-6, CP-1 (Chinese variety), 19 lines/landraces from WARDA, and 7 varieties/lines from CUBA were tested for tolerance to water deficiency. Material was directly sown in the field blocks maintained at normal flooded conditions (Control) and at 75%, 50% and 25% less water. Fertilizer was applied at the normal recommended doze. Data are collected with reference to plant height, number of leaves and productive tillers, and grain yield. Presence (or otherwise) of any stress protein in selected water deficiency tolerant lines was also studied. Significant variations were observed for all the parameters and in all the material. In 19 (57.6%) entries comprising IR-6, CP-I, material from WARDA and Cuba, number of tillers and leaves were the highest at 50% water compared to the control. In 10 (30.3%) and 8 (24%) entries, plant height increased by 31.7% and 61.3 %, respectively at 25% and 50% water. Only 5 out of 33 entries performed the best with respect to all the three parameters at 25% water. Grain yield in most of the entries (17 out of 33) also increased under 50% water with 9 entries (27.4) simply out yielded the rest under 25% reduced water. Promising among them were WAB 56-104, WAB-56-50 and OS-6. Appearance of some LMW protein fractions of about 40 and 20 kDa was also noticed in these genotypes for the first time. Crossing these genotypes with Basmati varieties, that showed reduction in all the 4 parameters under water deficient conditions, resulted in production of fertile hybrids. Selections in F2 population were made from the plants growing under 50% less water and for plants like of Basmati with early maturity and reduced height. One of the selections also exhibited LMW fractions of 20 kDa stress protein. The association of this fraction with water deficiency tolerance would be tested in M3 generation. We believe that if during this process we are able to reduce 50 % of water

The quiet revolution in Asia's rice value chains.

Science.gov (United States)

Reardon, Thomas; Chen, Kevin Z; Minten, Bart; Adriano, Lourdes; Dao, The Anh; Wang, Jianying; Gupta, Sunipa Das

2014-12-01

There is a rapid transformation afoot in the rice value chain in Asia. The upstream is changing quickly-farmers are undertaking capital-led intensification and participating in burgeoning markets for land rental, fertilizer and pesticides, irrigation water, and seed, and shifting from subsistence to small commercialized farms; in some areas landholdings are concentrating. Midstream, in wholesale and milling, there is a quiet revolution underway, with thousands of entrepreneurs investing in equipment, increasing scale, diversifying into higher quality, and the segments are undergoing consolidation and vertical coordination and integration. Mills, especially in China, are packaging and branding, and building agent networks in wholesale markets, and large mills are building direct relationships with supermarkets. The downstream retail segment is undergoing a "supermarket revolution," again with the lead in change in China. In most cases the government is not playing a direct role in the market, but enabling this transformation through infrastructural investment. The transformation appears to be improving food security for cities by reducing margins, offering lower consumer rice prices, and increasing quality and diversity of rice. This paper discusses findings derived from unique stacked surveys of all value chain segments in seven zones, more and less developed, around Bangladesh, China, India, and Vietnam. © 2014 New York Academy of Sciences.

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.

A Phenology-Based Classification of Time-Series MODIS Data for Rice Crop Monitoring in Mekong Delta, Vietnam

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Nguyen-Thanh Son

2013-12-01

Full Text Available Rice crop monitoring is an important activity for crop management. This study aimed to develop a phenology-based classification approach for the assessment of rice cropping systems in Mekong Delta, Vietnam, using Moderate Resolution Imaging Spectroradiometer (MODIS data. The data were processed from December 2000, to December 2012, using empirical mode decomposition (EMD in three main steps: (1 data pre-processing to construct the smooth MODIS enhanced vegetation index (EVI time-series data; (2 rice crop classification; and (3 accuracy assessment. The comparisons between the classification maps and the ground reference data indicated overall accuracies and Kappa coefficients, respectively, of 81.4% and 0.75 for 2002, 80.6% and 0.74 for 2006 and 85.5% and 0.81 for 2012. The results by comparisons between MODIS-derived rice area and rice area statistics were slightly overestimated, with a relative error in area (REA from 0.9–15.9%. There was, however, a close correlation between the two datasets (R2 ≥ 0.89. From 2001 to 2012, the areas of triple-cropped rice increased approximately 31.6%, while those of the single-cropped rain-fed rice, double-cropped irrigated rice and double-cropped rain-fed rice decreased roughly −5.0%, −19.2% and −7.4%, respectively. This study demonstrates the validity of such an approach for rice-crop monitoring with MODIS data and could be transferable to other regions.

Effects of biochar, waste water irrigation and fertilization on soil properties in West African urban agriculture.

Science.gov (United States)

Häring, Volker; Manka'abusi, Delphine; Akoto-Danso, Edmund K; Werner, Steffen; Atiah, Kofi; Steiner, Christoph; Lompo, Désiré J P; Adiku, Samuel; Buerkert, Andreas; Marschner, Bernd

2017-09-06

In large areas of sub-Saharan Africa crop production must cope with low soil fertility. To increase soil fertility, the application of biochar (charred biomass) has been suggested. In urban areas, untreated waste water is widely used for irrigation because it is a nutrient-rich year-round water source. Uncertainty exists regarding the interactions between soil properties, biochar, waste water and fertilization over time. The aims of this study were to determine these interactions in two typical sandy, soil organic carbon (SOC) and nutrient depleted soils under urban vegetable production in Tamale (Ghana) and Ouagadougou (Burkina Faso) over two years. The addition of biochar at 2 kg m -2 made from rice husks and corn cobs initially doubled SOC stocks but SOC losses of 35% occurred thereafter. Both biochar types had no effect on soil pH, phosphorous availability and effective cation exchange capacity (CEC) but rice husk biochar retained nitrogen (N). Irrigation with domestic waste water increased soil pH and exchangeable sodium over time. Inorganic fertilization alone acidified soils, increased available phosphorous and decreased base saturation. Organic fertilization increased SOC, N and CEC. The results from both locations demonstrate that the effects of biochar and waste water were less pronounced than reported elsewhere.

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

Physiological and Fluorescence Reaction of Four Rice Genotypes to Exogenous Application of IAA and Kinetin under Drought Stress

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Mostafa SALEHIFAR

2017-09-01

Full Text Available To assess the effects of IAA and Kinetin plant growth regulators in order to improve the drought tolerance in rice seedlings (Oryza sativa L., a factorial experiment was carried out based on complete randomized design with three replications. The experimental factors included different rice genotypes [‘Gharib’, ‘Khazar’, ‘Sepidrood’ and ‘IR83750 -131-1’ (‘IR83750’ ], drought stress from 1 to 4 code of the Vergara coding system and control (normal irrigation and growth regulators in three levels (IAA and Kinetin through foliar spraying and non-application as control. The results indicated, under normal irrigation condition together with IAA application, ‘IR83750’ rice had the highest number of tillers and leaf greenness, with mean of 18.27 and 49.46, respectively. The highest amount of leaf relative water content 95.11 percent was related to ‘Sepidrood’. Under drought stress condition, the highest electrolyte leakage (36.59 percent was observed in ‘Gharib’. In drought condition, the highest leaf drying score was related to ‘Gharib’ in both years, but the highest score of leaf rolling index (9 was observed in ‘Gharib’ and ‘Khazar’. The present findings showed that drought stress had harmful effects in all examined genotypes and the impact in susceptible genotypes (‘Gharib’ and ‘Khazar’ was more than ‘IR83750’ and ‘Sepidrood’. Application of growth regulators (IAA and Kin improved conditions for the growth of all genotypes. Therefore, using the tolerant genotypes along with growth regulators can improve the rice growth traits.

Soil CH4 and N2O Emissions from Rice Paddy Fields in Southern Brazil as Affected by Crop Management Levels: a Three-Year Field Study

Directory of Open Access Journals (Sweden)

Tiago Zschornack

2018-05-01

Full Text Available ABSTRACT Rice yield increases in response to improvements in crop management, but the impact on greenhouse gas (GHG emissions in the subtropical region of Southern Brazil remains unknown. A three-year field study was developed aiming to evaluate the impact that an increase in crop management levels (high and very high has on soil methane (CH4 and nitrous oxide (N2O emissions, as compared to the level (medium currently adopted by farmers in Southern Brazil. Differences in crop management included seed and fertilizer rates, irrigation, and pesticide use. The effect of crop management levels on the annual partial global warming potential (pGWP = CH4 × 25 + N2O × 298 ranged from 7,547 to 17,711 kg CO2eq ha−1 and this effect was larger than on the rice grain yield (9,280 to 12,260 kg ha−1, resulting in approximately 60 % higher yield-scaled GHG with the high crop management level compared to the current level. Soil CH4 emissions accounted for 98 % of pGWP in the flooded rice season, whereas N2O prevailed during the drained non-rice season (≈65 %. Although it was impossible to relate emissions to any individual input or practice, soil CH4 emissions in the rice season were linearly related to the biomass produced by the rice crop (p<0.01 and by ryegrass in the previous non-rice season (p<0.1, both of which were possibly related to the supply of labile C for methanogenesis. A future increase in rice yield as a result of the adoption of improved crop management may require additional agricultural practices (e.g., intermittent irrigation to offset the increased GHG emissions.

Percepção e medidas de gestão de riscos por produtores de arroz irrigado na Fronteira Oeste do Rio Grande do Sul Risk perception and risk management measures by irrigated rice growers in Fronteira Oeste, Rio Grande do Sul

Directory of Open Access Journals (Sweden)

Maria Isabel Fernandes Finger

2013-05-01

Full Text Available A produção agrícola apresenta características particulares, se comparada a outras atividades econômicas, sendo uma das mais marcantes a extensão dos riscos aos quais está exposta. O cultivo de arroz (Oryza sativa L. irrigado, embora pareça menos suscetível do que as culturas de sequeiro, também está exposto a riscos. Maior produtor mundial de arroz fora da Ásia, o Brasil tem no Rio Grande do Sul seu principal estado produtor. O objetivo deste trabalho foi analisar como o orizicultor da Fronteira Oeste do Rio Grande do Sul percebe os riscos da sua atividade e quais medidas adota para geri-los. A metodologia empregada envolveu aplicação presencial de questionários a orizicultores, de acordo com uma amostra não probabilística. Os resultados indicaram que os orizicultores atribuem maior relevância aos riscos socioeconômicos do que aos de produção. Evidencia-se, assim, a importância da gestão do negócio pelos orizicultores, para que sua atividade esteja integrada com os demais elos da cadeia produtiva. A redução de custos pode ser uma alternativa para mitigação de riscos de mercado, apontados como os mais relevantes pelos orizicultores. A percepção dos orizicultores sobre riscos e sobre medidas para mitigá-los pode representar a base na formulação de estratégias de gestão de riscos.Agricultural production has many different influencing factors compared to other economic activities. One of the most striking is the extent of the risks to which it is exposed. Irrigated rice (Oryza sativa L. cultivation, although seeming less susceptible than non-irrigated crops, is also exposed to risks. World's largest producer of rice outside Asia, Brazil has the state of Rio Grande do Sul as its main producer. The aim of this study was to analyze how rice farmers in Fronteira Oeste, Rio Grande do Sul realize the risks of their activity and how they manage them. Methodology involved the administration of a questionnaire, according to

Re-Meandering of Lowland Streams

DEFF Research Database (Denmark)

Pedersen, Morten Lauge; Kristensen, Klaus Kevin; Friberg, Nikolai

2014-01-01

We evaluated the restoration of physical habitats and its influence on macroinvertebrate community structure in 18 Danish lowland streams comprising six restored streams, six streams with little physical alteration and six channelized streams. We hypothesized that physical habitats and macroinver...