WorldWideScience

Sample records for rice irrigation schemes

  1. 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

  2. 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)

  3. 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)

  4. 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)

  5. 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

  6. 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

  7. 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)

  8. 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...

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

    Directory of Open Access Journals (Sweden)

    Mwangangi Joseph M

    2010-08-01

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

  10. 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.

  11. 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.

  12. Subsurface drainage of valley bottom irrigated rice schemes in tropical savannah : case studies of Tiefora and Moussodougou in Burkina Faso

    NARCIS (Netherlands)

    Keïta, A.

    2015-01-01

    SUMMARY

    The contrasted global population growth with the multiplication of the constraints to developing new irrigation systems puts a special challenge upon human crop production systems that needs to be taken up.

  13. 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, ...

  14. 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

  15. 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

  16. 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

  17. Climate Change Implications to Irrigated Rice Production in Southern Brazil: A Modelling Approach

    Science.gov (United States)

    Dos Santos, Thiago

    Rice is one of the staple foods for more than three billion people worldwide. When cultivated under irrigated conditions (i.e. lowland rice), rice is one of the most intensive water consumer crops globally. Therefore, representation of rice growth should be integrated into the latest land surface models to allow studies on food security and to ensure that accurate simulations of the bidirectional feedbacks between the land surface and atmosphere take place. In this study, I present a new process-based model for rice fields that includes rice growth and rice irrigation as modules within the Agro-IBIS dynamic agro-ecosystem model. The model includes a series of equations, agricultural management parameters and an irrigation scheme that are specifically tailored for rice crops. The model was evaluated against leaf area index and biomass observations, obtained for one growing season in Rio Grande do Sul state (southern Brazil), and in Los Banos, Philippines. The model accurately captured the temporal dynamics of leaf area index in both the Brazilian and the Philippine sites, and predicted end-of-season biomass with an error of between -9.5% and 11.3% depending on the location and the plant organ. Rice phenology is predicted by the model based on experimentally-derived growth rates, and was evaluated by comparing simulated and observed durations of the four growth phases considered by the model. Agro-IBIS showed a tendency to overestimate the duration of the growth stages between 3% and 16%, but underestimated by 8% the duration of the panicle formation phase in one growing season. The new irrigation model is based on the water balance at the surface and applies irrigation in order to keep the water layer at the paddy field always in the optimum level. A set of climate projections from global climate models under two emission scenarios, and excluding and considering CO2 fertilizations effects, was used to drive the updated Agro-IBIS to estimate the effects of climate

  18. Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation

    Directory of Open Access Journals (Sweden)

    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.

  19. Smallholder irrigation schemes in South Africa: A review of ...

    African Journals Online (AJOL)

    The status and characteristics of the 302 smallholder irrigation schemes found in South Africa are discussed and knowledge on South African smallholder irrigation schemes generated by the Water Research Commission (WRC) over a period of nearly 20 years is reviewed. Themes covered include planning, design and ...

  20. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    NARCIS (Netherlands)

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since

  1. Implications of rural irrigation schemes on household economy. A ...

    African Journals Online (AJOL)

    ... and quality of life as measured through the use of standardised HDI. In light of the above, there is a need to fund and develop more rural irrigation schemes so as to ensure livelihood security and rural development in Zimbabwe. Keywords: Rural livelihood, Poverty, Climate change, Irrigation, Lower Gweru, Extension.

  2. INVENTORY OF IRRIGATED RICE ECOSYSTEM USING POLARIMETRIC SAR DATA

    Directory of Open Access Journals (Sweden)

    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

  3. 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 ...

  4. 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

  5. The use and management of water in the Likangala Irrigation Scheme Complex in Southern Malawi

    Science.gov (United States)

    Mulwafu, Wapulumuka O.; Nkhoma, Bryson G.

    This paper examines the uses and management of water for agriculture in Lake Chilwa catchment area in Zomba district of Southern Malawi. It focuses on the Likangala Rice Irrigation Scheme Complex situated along the Likangala River. The scheme is one of the largest government-run schemes. Established in the late 1960s by the government to meet the growing demand for rice, the scheme contributes greatly to the agricultural industry of the country. Besides, the scheme was established to ensure maximum utilization of Malawi's largest wetland, which, due to its hydromorphic soils and the littoral floodplains, does not favour the production of traditional upland seasonal crops such as maize. The scheme's overdependence on water from the Likangala River has attracted a considerable degree of academic interest in the use and management of the river to ensure that there is equity and efficiency for both productive and domestic users. The paper focuses on four main issues: the historical development of the scheme, the distribution of water to farmers, social relations, and the overall contribution of the scheme towards the social and economic development of the area and the country in general. The paper contends that the growing population of the basin and the increase in the number of formal and informal smallholder farmers, contributes greatly to the growth of competition and conflicts over water, which tends to undermine the economic potential of the scheme. Furthermore, the paper provides clearest indication of the need for a realistic and informed water management policy and strategy to solve the growing problem of social inequity without necessarily compromising the production of rice in the scheme.

  6. Arsenic transport in irrigation water across rice-field soils in Bangladesh

    International Nuclear Information System (INIS)

    Polizzotto, Matthew L.; Lineberger, Ethan M.; Matteson, Audrey R.; Neumann, Rebecca B.; Badruzzaman, A. Borhan M.; Ashraf Ali, M.

    2013-01-01

    Experiments were conducted to analyze processes impacting arsenic transport in irrigation water flowing over bare rice-field soils in Bangladesh. Dissolved concentrations of As, Fe, P, and Si varied over space and time, according to whether irrigation water was flowing or static. Initially, under flowing conditions, arsenic concentrations in irrigation water were below well-water levels and showed little spatial variability across fields. As flowing-water levels rose, arsenic concentrations were elevated at field inlets and decreased with distance across fields, but under subsequent static conditions, concentrations dropped and were less variable. Laboratory experiments revealed that over half of the initial well-water arsenic was removed from solution by oxidative interaction with other water-column components. Introduction of small quantities of soil further decreased arsenic concentrations in solution. At higher soil-solution ratios, however, soil contributed arsenic to solution via abiotic and biotic desorption. Collectively, these results suggest careful design is required for land-based arsenic-removal schemes. -- Highlights: •We analyzed the processes impacting arsenic transport in flowing irrigation water. •Arsenic in Bangladesh rice-field irrigation water varied over space and time. •Arsenic was correlated with Fe, P, and Si in flowing and static water. •Oxidation, adsorption and desorption reactions controlled arsenic concentrations. •Land-based arsenic removal from water will be impacted by hydraulic conditions. -- Arsenic concentrations in flowing and static irrigation water in Bangladesh varied over space and time, suggesting careful design is required for land-based pre-treatment schemes that aim to remove As from solution

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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

  9. Assessment of irrigation schemes in Turkey based on management ...

    African Journals Online (AJOL)

    This suggests that the WUAs-operated schemes are not optimally managed, possibly due to factors such as inappropriate crop pattern and intensity, irrigation infrastructure, lack of an effective monitoring and evaluation system, insufficient awareness among managers and farmers, or unstable administrative structure.

  10. 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.

  11. [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.

  12. 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)

  13. 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

  14. Evaluation of Different Rice Genotypes Tolerance to Saline Irrigation Water

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Year-Round Irrigation Schedule for a Tomato–Maize Rotation System in Reservoir-Based Irrigation Schemes in Ghana

    Directory of Open Access Journals (Sweden)

    Ephraim Sekyi-Annan

    2018-05-01

    Full Text Available Improving irrigation management in semi-arid regions of Sub-Saharan Africa is crucial to respond to increasing variability in rainfall and overcome deficits in current irrigation schemes. In small-scale and medium-scale reservoir-based irrigation schemes in the Upper East region of Ghana, we explored options for improving the traditional, dry season irrigation practices and assessed the potential for supplemental irrigation in the rainy season. The AquaCrop model was used to (i assess current water management in the typical tomato-maize rotational system; (ii develop an improved irrigation schedule for dry season cultivation of tomato; and (iii determine the requirement for supplemental irrigation of maize in the rainy season under different climate scenarios. The improved irrigation schedule for dry season tomato cultivation would result in a water saving of 130–1325 mm compared to traditional irrigation practices, accompanied by approximately a 4–14% increase in tomato yield. The supplemental irrigation of maize would require 107–126 mm of water in periods of low rainfall and frequent dry spells, and 88–105 mm in periods of high rainfall and rare dry spells. Therefore, year-round irrigated crop production may be feasible, using water saved during dry season tomato cultivation for supplemental irrigation of maize in the rainy season.

  17. Doses and application methods of Azospirillum brasilense in irrigated upland rice

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. Matching soil salinization and cropping systems in communally managed irrigation schemes

    Science.gov (United States)

    Malota, Mphatso; Mchenga, Joshua

    2018-03-01

    Occurrence of soil salinization in irrigation schemes can be a good indicator to introduce high salt tolerant crops in irrigation schemes. This study assessed the level of soil salinization in a communally managed 233 ha Nkhate irrigation scheme in the Lower Shire Valley region of Malawi. Soil samples were collected within the 0-0.4 m soil depth from eight randomly selected irrigation blocks. Irrigation water samples were also collected from five randomly selected locations along the Nkhate River which supplies irrigation water to the scheme. Salinity of both the soil and the irrigation water samples was determined using an electrical conductivity (EC) meter. Analysis of the results indicated that even for very low salinity tolerant crops (ECi water was suitable for irrigation purposes. However, root-zone soil salinity profiles depicted that leaching of salts was not adequate and that the leaching requirement for the scheme needs to be relooked and always be adhered to during irrigation operation. The study concluded that the crop system at the scheme needs to be adjusted to match with prevailing soil and irrigation water salinity levels.

  20. CONTROL OF SCHISTOSOMIASIS IN THE GEZIRA IRRIGATION SCHEME, SUDAN.

    Science.gov (United States)

    Amin, Mutamad; Abubaker, Hwiada

    2017-01-01

    This paper analyses the changing patterns of infection with Schistosoma mansoni and S. haematobium in the Gezira Irrigation Scheme, Sudan. Taking a historical perspective, it shows the way in which factors such as ecology, biology, social and economic variables and politics have shaped patterns of infection, and how different kinds of strategies have been developed to control schistosomal infection over time. Wider political and economic issues at both national and international levels have shaped these strategies, influencing the prevalence and intensity of schistosomal infection at a local level. By highlighting the inter-play between the above-mentioned factors, the article reflects on the wisdom of prioritizing community-directed mass drug administration for the control of schistosomiasis in Gezira and elsewhere. The review demonstrates that not all efforts to control schistosomiasis are sustainable. A comprehensive control strategy involving political commitment, community participation and socioeconomic development is important for sustainable control of schistosomal infection.

  1. 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

  2. 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.

  3. 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.

  4. Irrigation-based livelihood challenges and opportunities : a gendered technology of irrigation development intervention in the Lower Moshi irrigation scheme Tanzania

    NARCIS (Netherlands)

    Kissawike, K.

    2008-01-01

    This thesis is a study of a modernised irrigation scheme in Tanzania. It aims to
    understand how irrigation and agricultural technologies have interacted with local
    society to transform production, paying particular attention to gender relations and
    changes for women farmers. The

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    P. Setyanto

    2016-10-01

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

  7. The Reticulation Irrigation Scheme at Sankana, Upper West Region ...

    African Journals Online (AJOL)

    farmers utilizing the irrigation project are food secure. ... The effects of ... Often, lack of maintenance, bad management and financial difficulties decrease the ...... and Mushunje A. (2010), 'Analysis of Irrigation Development Post Fast Track Land ...

  8. Is the Revitalisation of Smallholder Irrigation Schemes (RESIS ...

    African Journals Online (AJOL)

    2013-09-30

    Sep 30, 2013 ... including rainwater harvesting, flood recession, flood water spreading, river ... Smallholder irrigation systems can comprise farmers who use shared or ...... on Irrigation and Drainage, 15-17 November 2006, Aventura. Swadini.

  9. Decentralising Zimbabwe’s water management: The case of Guyu-Chelesa irrigation scheme

    Science.gov (United States)

    Tambudzai, Rashirayi; Everisto, Mapedza; Gideon, Zhou

    Smallholder irrigation schemes are largely supply driven such that they exclude the beneficiaries on the management decisions and the choice of the irrigation schemes that would best suit their local needs. It is against this background that the decentralisation framework and the Dublin Principles on Integrated Water Resource Management (IWRM) emphasise the need for a participatory approach to water management. The Zimbabwean government has gone a step further in decentralising the management of irrigation schemes, that is promoting farmer managed irrigation schemes so as to ensure effective management of scarce community based land and water resources. The study set to investigate the way in which the Guyu-Chelesa irrigation scheme is managed with specific emphasis on the role of the Irrigation Management Committee (IMC), the level of accountability and the powers devolved to the IMC. Merrey’s 2008 critique of IWRM also informs this study which views irrigation as going beyond infrastructure by looking at how institutions and decision making processes play out at various levels including at the irrigation scheme level. The study was positioned on the hypothesis that ‘decentralised or autonomous irrigation management enhances the sustainability and effectiveness of irrigation schemes’. To validate or falsify the stated hypothesis, data was gathered using desk research in the form of reviewing articles, documents from within the scheme and field research in the form of questionnaire surveys, key informant interviews and field observation. The Statistical Package for Social Sciences was used to analyse data quantitatively, whilst content analysis was utilised to analyse qualitative data whereby data was analysed thematically. Comparative analysis was carried out as Guyu-Chelesa irrigation scheme was compared with other smallholder irrigation scheme’s experiences within Zimbabwe and the Sub Saharan African region at large. The findings were that whilst the

  10. Contamination of Dining Tables with Pesticides in Kibirigwi Irrigation Scheme

    International Nuclear Information System (INIS)

    Kimani, V.W; McDermont, J.J

    1999-01-01

    Kibirigwi irrigation scheme is a small holder area in Central Kenya, where the main activity is production of horticultural crops. Pesticides are widely misused. This study investigated the extent of house hold pesticide exposure in 40 randomly selected farms in JUly-August, 1995. Exposure measures collected included pesticide levels on dining table swabs. Fifty coytton clothes measuring 30 cm *30cm were prepared in the laboratory by soaking overnight in methanol. In each of the selected homesteads, the table used for meals was swabbed with the piece of cloth. In the laboratory, the residues chemicals extracted from these swabs using conventional residual analysis procedures and the extracts were analysed by gas liquid chromatography. Information on which pesticide (s) were recently handled in the home and when, were also recorded. Cypermethrin (9/40), malathion (9/40), Diazinon (5/40), dimethoate (4/40), chloropyrifos (4/40) and fenitrothion (1/40) were detected in these samples. The range of individual organophosphate pesticides detected was 0.01-8.7ug/cm 2 of table area and for cypermethrin the range was 0.0024 ng-5.8 ng/cm 2 . It was concluded that farmers and their family members are likely to be contaminated with pesticides from tables either dermally or through contamination of food placed on such tables

  11. Gender and power contestations over water use in irrigation schemes: Lessons from the lake Chilwa basin

    Science.gov (United States)

    Nkhoma, Bryson; Kayira, Gift

    2016-04-01

    Over the past two decades, Malawi has been adversely hit by climatic variability and changes, and irrigation schemes which rely mostly on water from rivers have been negatively affected. In the face of dwindling quantities of water, distribution and sharing of water for irrigation has been a source of contestations and conflicts. Women who constitute a significant section of irrigation farmers in schemes have been major culprits. The study seeks to analyze gender contestations and conflicts over the use of water in the schemes developed in the Lake Chilwa basin, in southern Malawi. Using oral and written sources as well as drawing evidence from participatory and field observations conducted at Likangala and Domasi irrigation schemes, the largest schemes in the basin, the study observes that women are not passive victims of male domination over the use of dwindling waters for irrigation farming. They have often used existing political and traditional structures developed in the management of water in the schemes to competitively gain monopoly over water. They have sometimes expressed their agency by engaging in irrigation activities that fall beyond the control of formal rules and regulations of irrigation agriculture. Other than being losers, women are winning the battle for water and land resources in the basin.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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.

  14. 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.

  15. Increased malaria transmission around irrigation schemes in Ethiopia and the potential of canal water management for malaria vector control

    OpenAIRE

    Kibret, Solomon; Wilson, G Glenn; Tekie, Habte; Petros, Beyene

    2014-01-01

    Background Irrigation schemes have been blamed for the increase in malaria in many parts of sub-Saharan Africa. However, proper water management could help mitigate malaria around irrigation schemes in this region. This study investigates the link between irrigation and malaria in Central Ethiopia. Methods Larval and adult mosquitoes were collected fortnightly between November 2009 and October 2010 from two irrigated and two non-irrigated (control) villages in the Ziway area, Central Ethiopia...

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. Management systems in irrigated rice affect physical and chemical soil properties

    NARCIS (Netherlands)

    Rodrigues de Lima, A.C.; Hoogmoed, W.B.; Pauletto, E.A.; Pinto, L.F.S.

    2009-01-01

    Lowland soils are commonly found in the state of Rio Grande do Sul, Southern of Brazil, where they represent around 20% of the total area. Deficient drainage is the most important natural characteristic of these soils which therefore are mainly in use for irrigated rice (Oriza sativa). Degradation

  1. 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...

  2. 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

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

    Science.gov (United States)

    Chiaradia, Enrico Antonio; Facchi, Arianna; Masseroni, Daniele; Ferrari, Daniele; Bischetti, Gian Battista; Gharsallah, Olfa; Cesari de Maria, Sandra; Rienzner, Michele; Naldi, Ezio; Romani, Marco; Gandolfi, Claudio

    2015-09-01

    The cultivation of rice, one of the most important staple crops worldwide, has very high water requirements. A variety of irrigation practices are applied, whose pros and cons, both in terms of water productivity and of their effects on the environment, are not completely understood yet. The continuous monitoring of irrigation and rainfall inputs, as well as of soil water dynamics, is a very important factor in the analysis of these practices. At the same time, however, it represents a challenging and costly task because of the complexity of the processes involved, of the difference in nature and magnitude of the driving variables and of the high variety of field conditions. In this paper, we present the prototype of an integrated, multisensor system for the continuous monitoring of water dynamics in rice fields under different irrigation regimes. The system consists of the following: (1) flow measurement devices for the monitoring of irrigation supply and tailwater drainage; (2) piezometers for groundwater level monitoring; (3) level gauges for monitoring the flooding depth; (4) multilevel tensiometers and moisture sensor clusters to monitor soil water status; (5) eddy covariance station for the estimation of evapotranspiration fluxes and (6) wireless transmission devices and software interface for data transfer, storage and control from remote computer. The system is modular and it is replicable in different field conditions. It was successfully applied over a 2-year period in three experimental plots in Northern Italy, each one with a different water management strategy. In the paper, we present information concerning the different instruments selected, their interconnections and their integration in a common remote control scheme. We also provide considerations and figures on the material and labour costs of the installation and management of the system.

  4. 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.

  5. Factors affecting farmers' participation in irrigation schemes of the ...

    African Journals Online (AJOL)

    ... those factors affecting farmers' participation in irrigated agriculture at the Lower Niger River Basin Development Authority (LNRBDA) in Kwara State, Nigeria. One hundred and sixty (160) respondents were selected from communities around LNRBDA site at Oke Oyi for this study through a two-stage sampling procedures.

  6. 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.

  7. 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 ...

  8. 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 ...

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Transferability Of DEMETER. A Case Study Of The Irrigation Scheme Of Veiga De Chaves

    Science.gov (United States)

    Baptista, A.; Sousa, V.

    2006-08-01

    DEMETER is a research and demonstration project, designed to assess and demonstrate how the integration of Earth Observation techniques in routine Irrigation Advisory Services can improve efficiency in the use of irrigation water. The objectives of this paper are: (1) to analyze the interest in the feasibility of transferring the DEMETER technology to the irrigation scheme of Chaves: (2) to identify the factors that, in general, favour the usefulness of this technology. The irrigation infrastructure and methods, the size and number of irrigation parcels and the main crops grown at the irrigation scheme of Chaves have been recorded. Also a socio-economic description has been done. Field visits, interviews with the staff of water association, and an inquiry to a sample of 107 farmers were made. The main results are: each farmer pays an area based annual fee, independent of the amount of water used for irrigation; most of the irrigated parcels are of very small size, 0.3 ha in average, mostly irrigated by surface methods; the most representative crops grown are potato, forage maize, and several different horticultural crops; an important part of the production is for self-consumption. The farmers are aging and the new generations prefer other jobs than agriculture. A considerable number of farmers have another job in the nearby cities. The small size of the irrigated parcels limits the use of earth observation technologies to expensive high space resolution images. For the time being, farmers do not feel the need for an irrigation advisory service, manly because there is plenty of water which is not bought proportionally to its use. However, circumstances are changing rapidly and, relatively new for the region, environmental concerns related with irrigation, manly nitrate leaching by excess watering of crops prompts the need for an irrigation advisory service in order to maintain crop production with a more rational use of water. The DEMETER technology could be a

  11. Dealing with drought in irrigated agriculture through insurance schemes: an application to an irrigation district in Southern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, M.; Bielza, J.; Garrido, A.; Iglesias, A.

    2015-07-01

    Hydrological drought is expected to have an increasing impact on both crop and fruit yields in arid and semi-arid regions. Some existing crop insurance schemes provide coverage against water deficits in rain-fed agriculture. The Prevented Planting Program in the USA covers against drought for irrigated agriculture. However, drought insurance for irrigated agriculture is still a challenge for companies and institutions because of the complexity of the design and implementation of this type of insurance. Few studies have attempted to evaluate the risk of loss due to irrigation water scarcity using both stand-alone production functions and crop simulation models. This paper’s contributions are that it evaluates the suitability of AquaCrop for calculating drought insurance premiums for irrigated agriculture and that it discusses contract conditions and insurance design for hydrological drought risk coverage as part of a traditional insurance product, with on-field loss assessment in combination with a trigger index. This method was applied to an irrigation district in southern Spain. Our insurance premium calculation showed that it is feasible to apply this method provided that its data requirements are met, such as a large enough set of reliable small-scale yield and irrigation time series data, especially soil data, to calibrate AquaCrop. The choice of a trigger index should not be underestimated because it proved to have a decisive influence on insurance premiums and indemnities. Our discussion of the contract conditions shows that hydrological drought insurance must comply with a series of constraints in order to avoid moral hazard and basis risk. (Author)

  12. Dealing with drought in irrigated agriculture through insurance schemes: an application to an irrigation district in Southern Spain

    Directory of Open Access Journals (Sweden)

    Jorge Ruiz

    2015-12-01

    Full Text Available Hydrological drought is expected to have an increasing impact on both crop and fruit yields in arid and semi-arid regions. Some existing crop insurance schemes provide coverage against water deficits in rain-fed agriculture. The Prevented Planting Program in the USA covers against drought for irrigated agriculture. However, drought insurance for irrigated agriculture is still a challenge for companies and institutions because of the complexity of the design and implementation of this type of insurance. Few studies have attempted to evaluate the risk of loss due to irrigation water scarcity using both stand-alone production functions and crop simulation models. This paper’s contributions are that it evaluates the suitability of AquaCrop for calculating drought insurance premiums for irrigated agriculture and that it discusses contract conditions and insurance design for hydrological drought risk coverage as part of a traditional insurance product, with on-field loss assessment in combination with a trigger index. This method was applied to an irrigation district in southern Spain. Our insurance premium calculation showed that it is feasible to apply this method provided that its data requirements are met, such as a large enough set of reliable small-scale yield and irrigation time series data, especially soil data, to calibrate AquaCrop. The choice of a trigger index should not be underestimated because it proved to have a decisive influence on insurance premiums and indemnities. Our discussion of the contract conditions shows that hydrological drought insurance must comply with a series of constraints in order to avoid moral hazard and basis risk.

  13. 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.

  14. Irrigation Water Value at Small-scale Schemes: Evidence from the North West Province, South Africa

    NARCIS (Netherlands)

    Speelman, S.; Farolfi, S.; Perret, S.; Haese, D' L.; Haese, D' M.

    2008-01-01

    Insight into the value of water is essential to support policy decision making about investments in the water sector, efficient allocation of water and water pricing. However, information on irrigation water values at small-scale schemes is scarce and in general little attention is paid to the

  15. Simulating the effect of water management decisions on groundwater flow and quality in the Kyzylkum Irrigation Scheme, Kazakhstan

    Science.gov (United States)

    Naudascher, R. M.; Marti, B. S.; Siegfried, T.; Wolfgang, K.; Anselm, K.

    2017-12-01

    The Kyzylkum Irrigation Scheme lies north of the Chardara reservoir on the banks of the river Syr Darya in South Kazakhstan. It was designed as a model Scheme and developed to a size of 74'000 ha during Soviet times for rice and cotton production. However, since the 1990s only very limited funds were available for maintenance and as a result, problems like water logging and salinization of soils and groundwater are now omnipresent in the scheme. The aim of this study was to develop a numerical groundwater flow model for the region in Modflow and to evaluate the effect of various infrastructure investments on phreatic evaporation (a major driver for soil salinization). Decadal groundwater observation data from 2011 to 2015 were used to calibrate the annual model and to validate the monthly model. Scenarios simulated were (partial) lining of main and/or secondary and tertiary canal system, improvement of drainage via horizontal canals or pumps, combinations of these and a joint groundwater-surface-water use scenario. Although the annual average model is sufficient to evaluate the yearly water balance, the transient model is a prerequisite for analysing measures against water logging and salinization, both of which feature strong seasonality. The transient simulation shows that a combination of leakage reduction (lining of canals) and drainage improvement measures is needed to lower the groundwater levels enough to avoid phreatic evaporation. To save water, joint surface water and groundwater irrigation can be applied in areas where groundwater salinity is low enough but without proper lining of canals, it is not sufficient to mitigate the ongoing soil degradation due to salinization and water logging.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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.

  18. 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)

  19. 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.

  20. 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.

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

    Science.gov (United States)

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

    2018-04-01

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

  2. Participatory innovation process for testing new practices for soil fertility management in Chókwè Irrigation Scheme (Mozambique)

    Science.gov (United States)

    Sánchez Reparaz, Maite; de Vente, Joris; Famba, Sebastiao; Rougier, Jean-Emmanuel; Ángel Sánchez-Monedero, Miguel; Barberá, Gonzalo G.

    2015-04-01

    Integrated water and nutrient management are key factors to increase productivity and to reduce the yield gap in irrigated systems in Sub-Saharan Africa. These two elements are affected by an ensemble of abiotic, biotic, management and socio-economic factors that need to be taken into account to reduce the yield gap, as well as farmers' perceptions and knowledge. In the framework of the project European Union and African Union cooperative research to increase Food production in irrigated farming systems in Africa (EAU4Food project) we are carrying out a participatory innovation process in Chókwè irrigation scheme (Mozambique) based on stakeholders engagement, to test new practices for soil fertility management that can increase yields reducing costs. Through a method combining interviews with three farmers' associations and other relevant stakeholders and soil sampling from the interviewed farmers' plots with the organization of Communities of Practices, we tried to capture how soil fertility is managed by farmers, the constraints they find as well as their perceptions about soil resources. This information was the basis to design and conduct a participatory innovation process where compost made with rice straw and manure is being tested by a farmers' association. Most important limitations of the method are also evaluated. Our results show that socio-economic characteristics of farmers condition how they manage soil fertility and their perceptions. The difficulties they face to adopt new practices for soil fertility management, mainly related to economic resources limitations, labour availability, knowledge time or farm structure, require a systemic understanding that takes into account abiotic, biotic, management and socio-economic factors and their implication as active stakeholders in all phases of the innovation process.

  3. 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.

  4. 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.)

  5. 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.

  6. Impact of dams and irrigation schemes in Anopheline (Diptera: Culicidae bionomics and malaria epidemiology

    Directory of Open Access Journals (Sweden)

    Jordi Sanchez-Ribas

    2012-08-01

    Full Text Available Irrigation schemes and dams have posed a great concern on public health systems of several countries, mainly in the tropics. The focus of the present review is to elucidate the different ways how these human interventions may have an effect on population dynamics of anopheline mosquitoes and hence, how local malaria transmission patterns may be changed. We discuss different studies within the three main tropical and sub-tropical regions (namely Africa, Asia and the Pacific and the Americas. Factors such as pre-human impact malaria epidemiological patterns, control measures, demographic movements, human behaviour and local Anopheles bionomics would determine if the implementation of an irrigation scheme or a dam will have negative effects on human health. Some examples of successful implementation of control measures in such settings are presented. The use of Geographic Information System as a powerful tool to assist on the study and control of malaria in these scenarios is also highlighted.

  7. Increased malaria transmission around irrigation schemes in Ethiopia and the potential of canal water management for malaria vector control.

    Science.gov (United States)

    Kibret, Solomon; Wilson, G Glenn; Tekie, Habte; Petros, Beyene

    2014-09-13

    Irrigation schemes have been blamed for the increase in malaria in many parts of sub-Saharan Africa. However, proper water management could help mitigate malaria around irrigation schemes in this region. This study investigates the link between irrigation and malaria in Central Ethiopia. Larval and adult mosquitoes were collected fortnightly between November 2009 and October 2010 from two irrigated and two non-irrigated (control) villages in the Ziway area, Central Ethiopia. Daily canal water releases were recorded during the study period and bi-weekly correlation analysis was done to determine relationships between canal water releases and larval/adult vector densities. Blood meal sources (bovine vs human) and malaria sporozoite infection were tested using enzyme-linked immunosorbent assay (ELISA). Monthly malaria data were also collected from central health centre of the study villages. Monthly malaria incidence was over six-fold higher in the irrigated villages than the non-irrigated villages. The number of anopheline breeding habitats was 3.6 times higher in the irrigated villages than the non-irrigated villages and the most common Anopheles mosquito breeding habitats were waterlogged field puddles, leakage pools from irrigation canals and poorly functioning irrigation canals. Larval and adult anopheline densities were seven- and nine-fold higher in the irrigated villages than in the non-irrigated villages, respectively, during the study period. Anopheles arabiensis was the predominant species in the study area. Plasmodium falciparum sporozoite rates of An. arabiensis and Anopheles pharoensis were significantly higher in the irrigated villages than the non-irrigated villages. The annual entomological inoculation rate (EIR) calculated for the irrigated and non-irrigated villages were 34.8 and 0.25 P. falciparum infective bites per person per year, respectively. A strong positive correlation was found between bi-weekly anopheline larval density and canal water

  8. 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...

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    ANDRE FROES DE BORJA REIS

    2017-01-01

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

  11. 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.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    Anja Schmidt

    Full Text Available Decomposers provide an essential ecosystem service that contributes to sustainable production in rice ecosystems by driving the release of nutrients from organic crop residues. During a single rice crop cycle we examined the effects of four different crop residue management practices (rice straw or ash of burned straw scattered on the soil surface or incorporated into the soil on rice straw decomposition and on the abundance of aquatic and soil-dwelling invertebrates. Mass loss of rice straw in litterbags of two different mesh sizes that either prevented or allowed access of meso- and macro-invertebrates was used as a proxy for decomposition rates. Invertebrates significantly increased total loss of litter mass by up to 30%. Initially, the contribution of invertebrates to decomposition was significantly smaller in plots with rice straw scattered on the soil surface; however, this effect disappeared later in the season. We found no significant responses in microbial decomposition rates to management practices. The abundance of aquatic fauna was higher in fields with rice straw amendment, whereas the abundance of soil fauna fluctuated considerably. There was a clear separation between the overall invertebrate community structure in response to the ash and straw treatments. However, we found no correlation between litter mass loss and abundances of various lineages of invertebrates. Our results indicate that invertebrates can contribute to soil fertility in irrigated paddy fields by decomposing rice straw, and that their abundance as well as efficiency in decomposition may be promoted by crop residue management practices.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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)

  2. Assessment of Growth Enhancement Support Scheme among Rice ...

    African Journals Online (AJOL)

    USER

    result of the findings showed that the scheme had very low performance indices in ... direct fertilizer purchase and distribution, and introduce an alternative system of distribution ... effective delivery of yield-increasing farm input (FRN, 2013). ..... telecommunications service providers, making it difficult to get their packages.

  3. Urinary and intestinal schistosomiasis in the Tono Irrigation Scheme, Kassena/Nankana District, Upper East Region, Ghana

    DEFF Research Database (Denmark)

    Amankwa, J. A.; Bloch, P.; Meyer-Lassen, J.

    1994-01-01

    Human- and snail-related aspects of transmission of urinary and intestinal schistosomiasis were studied in the Tono Irrigation Scheme in northern Ghana. The scheme became operational in 1977. In some schools, prevalences and intensities of both Schistosoma mansoni and S. haematobium infection were...... of S. haematobium takes place in all parts of the irrigation system (lateral canal, night storage dam, main reservoir). Transmission of both S. mansoni and S. haematobium is rather focal and a seasonal pattern of transmission is indicated with peak transmission taking place during the beginning...

  4. Comparison of different methods in estimating potential evapotranspiration at Muda Irrigation Scheme of Malaysia

    Directory of Open Access Journals (Sweden)

    Sobri Harun

    2012-04-01

    Full Text Available Evapotranspiration (ET is a complex process in the hydrological cycle that influences the quantity of runoff and thus the irrigation water requirements. Numerous methods have been developed to estimate potential evapotranspiration (PET. Unfortunately, most of the reliable PET methods are parameter rich models and therefore, not feasible for application in data scarce regions. On the other hand, accuracy and reliability of simple PET models vary widely according to regional climate conditions. The objective of the present study was to evaluate the performance of three temperature-based and three radiation-based simple ET methods in estimating historical ET and projecting future ET at Muda Irrigation Scheme at Kedah, Malaysia. The performance was measured by comparing those methods with the parameter intensive Penman-Monteith Method. It was found that radiation based methods gave better performance compared to temperature-based methods in estimation of ET in the study area. Future ET simulated from projected climate data obtained through statistical downscaling technique also showed that radiation-based methods can project closer ET values to that projected by Penman-Monteith Method. It is expected that the study will guide in selecting suitable methods for estimating and projecting ET in accordance to availability of meteorological data.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. A measure for the efficiency of water use and its determinants, a case study of small-scale irrigation schemes in North-West Province, South Africa

    NARCIS (Netherlands)

    Speelman, S.; Haese, D' M.F.C.; Buysse, J.; Haese, D' L.

    2008-01-01

    This paper analyses the efficiency with which water is used in small-scale irrigation schemes in North-West Province in South Africa and studies its determinants. In the study area, small-scale irrigation schemes play an important role in rural development, but the increasing pressure on water

  7. Learning to Voice? The Evolving Roles of Family Farmers in the Coordination of Large-Scale Irrigation Schemes in Morocco

    Directory of Open Access Journals (Sweden)

    Nicolas Faysse

    2010-02-01

    Full Text Available In Morocco, large-scale irrigation schemes have evolved over the past twenty years from the centralised management of irrigation and agricultural production into more complex multi-actor systems. This study analysed whether, and how, in the context of state withdrawal, increased farmer autonomy and political liberalisation, family farmers currently participate in the coordination and negotiation of issues that affect them and involve scheme-level organisations. Issues related to water management, the sugar industry and the dairy sector were analysed in five large-scale irrigation schemes. Farmer organisations that were set up to intervene in water management and sugar production were seen to be either inactive or to have weak links with their constituency; hence, the irrigation administration and the sugar industry continue to interact directly with farmers in a centralised way. Given their inability to voice their interests, when farmers have the opportunity, many choose exit strategies, for instance by resorting to the use of groundwater. In contrast, many community-based milk collection cooperatives were seen to function as accountable intermediaries between smallholders and dairy firms. While, as in the past, family farmers are still generally not involved in decision making at scheme level, in the milk collection cooperatives studied, farmers learn to coordinate and negotiate for the development of their communities.

  8. 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

  9. Effect of climate change on the irrigation and discharge scheme for winter wheat in Huaibei Plain, China

    Science.gov (United States)

    Zhu, Y.; Ren, L.; Lü, H.

    2017-12-01

    On the Huaibei Plain of Anhui Province, China, winter wheat (WW) is the most prominent crop. The study area belongs to transitional climate, with shallow water table. The original climate change is complex, in addition, global warming make the climate change more complex. The winter wheat growth period is from October to June, just during the rainless season, the WW growth always depends on part of irrigation water. Under such complex climate change, the rainfall varies during the growing seasons, and water table elevations also vary. Thus, water tables supply variable moisture change between soil water and groundwater, which impact the irrigation and discharge scheme for plant growth and yield. In Huaibei plain, the environmental pollution is very serious because of agricultural use of chemical fertilizer, pesticide, herbicide and etc. In order to protect river water and groundwater from pollution, the irrigation and discharge scheme should be estimated accurately. Therefore, determining the irrigation and discharge scheme for winter wheat under climate change is important for the plant growth management decision-making. Based on field observations and local weather data of 2004-2005 and 2005-2006, the numerical model HYDRUS-1D was validated and calibrated by comparing simulated and measured root-zone soil water contents. The validated model was used to estimate the irrigation and discharge scheme in 2010-2090 under the scenarios described by HadCM3 (1970 to 2000 climate states are taken as baselines) with winter wheat growth in an optimum state indicated by growth height and LAI.

  10. 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

  11. 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

  12. Pesticide Application among Farmers in the Catchment of Ashaiman Irrigation Scheme of Ghana: Health Implications

    Directory of Open Access Journals (Sweden)

    Memuna M. Mattah

    2015-01-01

    Full Text Available Pesticide use in modern day agriculture has increased tremendously. Pesticides are used to control pests and weeds, as well as protect crops from postharvest losses; however, their effects on humans and the environment cannot be overstated. This study examined pesticide acquisition, handling, and use among 120 farmers within the catchment of a small urban irrigation scheme. Also, in-depth interviews and focus group discussions were conducted among selected farmers through which further data was collected to augment that of the survey. Twelve types of pesticides, including herbicides, insecticides, and fungicides, were found in use in the study areas. Three main sources of information about pesticides were identified, 43.3% from extension officers, 39.2% from agrochemical dealers, and 10% from colleague farmers. Seventy-five percent (75% of the respondents purchased the pesticides from agrochemical shops. Out of 74 farmers who were observed spraying pesticides on their farms, only 25.7% wore dresses that covered their whole body but without goggles. About sixty-seven percent (66.7% of the farmers whose chemical got finished left the containers on their farms or threw them into the bushes around. The frequency of application was influenced by affordability and size of farm, among others. The study recommended that training of farmers on pesticide handling and use should be intensified.

  13. 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...

  14. 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

  15. 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.

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

    Science.gov (United States)

    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.

  17. 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

  18. 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

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Joko Sujono

    2012-05-01

    Full Text Available Traditional irrigation for paddy rice is the leading of consumer of water, about 80 % of the water resource availabilityused for irrigation purpose. This phenomenon is related to the way how to estimate the crop water requirement where crop coefficient for paddy rice (k (Prosida is always greater than one starting from planting up to nearly harvesting. In this research, a number of water saving irrigations (WSI systems for paddy rice cultivation using pots such asalternate wetting and drying (AWD, shallow water depth with wetting and drying (SWD, semi-dry cultivation (SDC, system of rice intensification (SRI, and  AWD with mulch (AWD-Mul were applied. The amount of irrigated water and when it should be irrigated depend on evapotranspiration rate, soil moisture condition and the WSI system used. For this purpose, daily measurement of the pot weight was carried out. Crop coefficient (k  is then caluculated as a cratio between crop and reference evapotranspiration computed using Penman-Montheit  method. Results show that up to 45 days after transplanting, the k of WSI treatments were around half of the k (Prosida values currently used for computing the water requirement, whereas at the productive stage the k of WSI systems were relatively equal (AWD, SDC to or greater (SRI, SWD than the k (Prosida. Based on the the k values, the AWD and the SDC systems could save much water compared to the SRI or the SWD. Water saving could be increased by applying the AWD with mulch. ABSTRAK Irigasi padi sawah dengan sistem tradisional merupakan sistem irigasi  yang boros air, hampir 80 % sumber air yang ada untuk irigasi. Hal ini tidak terlepas dari perhitungan kebutuhan air tanaman dengan nilai koefisien tanaman (k menurut Standar Perencanaan Irigasi (Prosida selalu lebih besar dari satu mulai dari tanam hingga menjelang panen.Dalam penelitian ini beberapa metoda budidaya padi hemat air seperti alternate wetting and drying (AWD, shallow water depth

  1. Effects of water-saving irrigation practices and drought resistant rice variety on greenhouse gas emissions from a no-till paddy in the central lowlands of China

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ying; Ge, Junzhu; Tian, Shaoyang; Li, Shuya [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Nguy-Robertson, Anthony L. [Center for Advanced Land Management Information Technologies, School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583-0973 (United States); Zhan, Ming, E-mail: zhanming@mail.hzau.edu.cn [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Cao, Cougui, E-mail: ccgui@mail.hzau.edu.cn [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China)

    2015-02-01

    As pressure on water resources increases, alternative practices to conserve water in paddies have been developed. Few studies have simultaneously examined the effectiveness of different water regimes on conserving water, mitigating greenhouse gases (GHG), and maintaining yields in rice production. This study, which was conducted during the drought of 2013, examined all three factors using a split-plot experiment with two rice varieties in a no-till paddy managed under three different water regimes: 1) continuous flooding (CF), 2) flooded and wet intermittent irrigation (FWI), and 3) flooded and dry intermittent irrigation (FDI). The Methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) emissions were measured using static chamber-gas measurements, and the carbon dioxide (CO{sub 2}) emissions were monitored using a soil CO{sub 2} flux system (LI-8100). Compared with CF, FWI and FDI irrigation strategies reduced CH{sub 4} emissions by 60% and 83%, respectively. In contrast, CO{sub 2} and N{sub 2}O fluxes increased by 65% and 9%, respectively, under FWI watering regime and by 104% and 11%, respectively, under FDI managed plots. Although CO{sub 2} and N{sub 2}O emissions increased, the global warming potential (GWP) and greenhouse gas intensity (GHGI) of all three GHG decreased by up to 25% and 29% (p < 0.01), respectively, using water-saving irrigation strategies. The rice variety also affected yields and GHG emissions in response to different water regimes. The drought-resistance rice variety (HY3) was observed to maintain yields, conserve water, and reduce GHG under the FWI irrigation management compared with the typical variety (FYY299) planted in the region. The FYY299 only had significantly lower GWP and GHGI when the yield was reduced under FDI water regime. In conclusion, FWI irrigation strategy could be an effective option for simultaneously saving water and mitigating GWP without reducing rice yields using drought-resistant rice varieties, such as HY3

  2. 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...

  3. 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

  4. 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

  5. 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)

  6. 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.

  7. Nematode Community Composition under Various Irrigation Schemes in a Citrus Soil Ecosystem.

    Science.gov (United States)

    Porazinska, D L; McSorley, R; Duncan, L W; Graham, J H; Wheaton, T A; Parsons, L R

    1998-06-01

    Interest in the sustainability of farming practices has increased in response to environmental problems associated with conventional agricultural management often adopted for the production of herbaceous crops, ornamentals, and fruit crops. Availability of measures of the status of the soil ecosystem is of immediate importance, particularly for environmental assessment and monitoring programs. This study investigated the effects of various irrigation regimes (an example of an agricultural management practice) on the structure of the nematode fauna in a citrus orchard in the sandy ridge area of Central Florida. Ecological measures such as community structure indices, diversity indices, and maturity indices were assessed and related to irrigation intensity. Maturity index was an effective measure in distinguishing differences between irrigation regimes, whereas other indices of community structure were not. Of various nematode genera and trophic groups, only omnivores and the omnivore genera. Aporcelaimellus and Eudorylaimus responded to irrigation treatments.

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

    Science.gov (United States)

    Gao, Xuan

    2017-04-01

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

  9. Effect of timing of joint application of hydroquinone and dicyandiamide on nitrous oxide emission from irrigated lowland rice paddy field.

    Science.gov (United States)

    Li, Xianglan; Zhang, Guangbin; Xu, Hua; Cai, Zucong; Yagi, Kazuyuki

    2009-06-01

    A field experiment was conducted to study the effect of timing of joint application of urease inhibitor hydroquinone (HQ) and nitrification inhibitor dicyandiamide (DCD) on N(2)O emission from irrigated lowland rice paddy field. Four treatments including Treatment CK (the control with urea alone), HQ/DCD-1 (application of HQ and DCD together with fertilizer before transplanting), HQ/DCD-2 (HQ and DCD with fertilizer at tillering stage) and HQ/DCD-3 (HQ and DCD with fertilizer at panicle initiation stage) were designed and implemented separately during rice growth period. Seasonal peaks of N(2)O flux occurred during midseason drainage and significant negative correlation between N(2)O flux and water layer depth was observed (r=-0.69 to -0.75, P<0.01). Mean N(2)O flux was the highest in the control with urea alone, while joint addition of HQ and DCD with urea lowered mean N(2)O flux considerably (P<0.05). Total N(2)O emission during rice growth season in Treatment CK, HQ/DCD-1, HQ/DCD-2 and HQ/DCD-3 was 3.90, 2.98, 1.73 and 3.23kgN(2)O-N ha(-1), respectively. Application of HQ and DCD together with basal fertilizer, tillering fertilizer and panicle initiation fertilizer decreased the total N(2)O emission by 24%, 56% and 17%, respectively, while increased grain yield by 10%, 18% and 6%, respectively. Effect of application of inhibitors on N(2)O emission during the continuous period from incorporation of HQ and DCD to rice harvest was also studied, where results indicating that the highest inhibiting efficiency of inhibitors on N(2)O emission was recorded when HQ and DCD applied with fertilizer at tillering stage.

  10. 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.

  11. PERFORMANCE OF PROMISING HYBRID RICE IN TWO DIFFERENT ELEVATIONS OF IRRIGATED LOWLAND IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Yuni Widyastuti

    2015-06-01

    Full Text Available The hybrid rice program has been established since early 1990’s at the Indonesia Center for Rice Research (ICRR. Twenty-four experimental hybrid rice varieties which have been developed were tested in lowland rice fields in Sukamandi (West Java and Batang (Central Java during the dry season and the rainy season of 2012. Randomized complete block design (RCBD with three replications was used in each location. The results showed that grains yields were affected by locations, seasons, and genotypes. The genotypes x locations x seasons interaction effect was significant; therefore, the best hybrid was different for each location and season. A7/PK36 hybrid has the best performance in Batang during the dry season, while A7/PK40 and A7/PK32 are the best hybrids in the rainy season. In Sukamandi, nine hybrids were identified as better yielder than that of the check cultivar in the dry season, but not so in the rainy season. Using the correlation and path analysis, we found that the number of panicles per hill and the number of filled grains per panicle could be used as selection criteria for yield in hybrid rice.

  12. 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.

  13. Observation and Modelling of Soil Water Content Towards Improved Performance Indicators of Large Irrigation Schemes

    Science.gov (United States)

    Labbassi, Kamal; Akdim, Nadia; Alfieri, Silvia Maria; Menenti, Massimo

    2014-05-01

    Irrigation performance may be evaluated for different objectives such as equity, adequacy, or effectiveness. We are using two performance indicators: IP2 measures the consistency of the allocation of the irrigation water with gross Crop Water requirements, while IP3 measures the effectiveness of irrigation by evaluating the increase in crop transpiration between the case of no irrigation and the case of different levels of irrigation. To evaluate IP3 we need to calculate the soil water balance for the two cases. We have developed a system based on the hydrological model SWAP (Soil Water atmosphere Plant) to calculate spatial and temporal patterns of crop transpiration T(x, y, t) and of the vertical distribution of soil water content θ(x, y, z, t). On one hand, in the absence of ground measurement of soil water content to validate and evaluate the precision of the estimated one, a possibility would be to use satellite retrievals of top soil water content, such as the data to be provided by SMAP. On the other hand, to calculate IP3 we need root zone rather than top soil water content. In principle, we could use the model SWAP to establish a relationship between the top soil and root zone water content. Such relationship could be a simple empirical one or a data assimilation procedure. In our study area (Doukkala- Morocco) we have assessed the consistency of the water allocation with the actual irrigated area and crop water requirements (CWR) by using a combination of multispectral satellite image time series (i,e RapidEye (REIS), SPOT4 (HRVIR1) and Landsat 8 (OLI) images acquired during the 2012/2013 agricultural season). To obtain IP2 (x, y, t) we need to determine ETc (x, y, t). We have applied two (semi)empirical approaches: the first one is the Kc-NDVI method, based on the correlation between the Near Difference Vegetation Index (NDVI) and the value of crop coefficient (kc); the second one is the analytical approach based on the direct application of Penman

  14. Crop water productivity for sunflower under different irrigation regimes and plant spacing in Gezira Scheme, Sudan

    Directory of Open Access Journals (Sweden)

    Eman Rahamtalla Ahmed Elsheikh

    2015-12-01

    Full Text Available Two field experiments with Sunflower on deep cracking soil with heavy clay (vertisol were conducted at Gezira Research Station Farm during two executive winter seasons, in WadMedani, Sudan. The crop was sown in the third week of November and in the first week of December for seasons 2012 and 2013 respectively. The experimental design was split plot design with three replicates. The Sunflower hybrid tested in the study was Hysun 33. The objective of this study was to determine the effect of three different irrigation intervals of 10, 15 and 20 days and two intra-row plant spacings of 30 cm and 40 cm on yield and yield components of Sunflower. The seed yields obtained from the different treatments were in the ranges of 1890-3300 kg/ha and 1590-3290 kg/ha for the first and second season respectively. The corresponding computed on average crop water productivity was in the range of 0.31-0.43 kg/m3. The study clearly indicated that the highest seed yield was obtained when the crop was sown at 40 cm plant spacing and irrigated every 10 days. The highest crop water productivity was achieved from irrigation every15 days in both planting spacings

  15. Ghana - Agriculture - Irrigation

    Data.gov (United States)

    Millennium Challenge Corporation — The Millennium Development Authority (MiDA) financed the construction of a new irrigation scheme in Kpong and the renovation of two irrigation schemes in Botanga and...

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

    Science.gov (United States)

    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

  17. A Simple Scheme for Modeling Irrigation Water Requirements at the Regional Scale Applied to an Alpine River Catchment

    Directory of Open Access Journals (Sweden)

    Pascalle C. Smith

    2012-11-01

    Full Text Available This paper presents a simple approach for estimating the spatial and temporal variability of seasonal net irrigation water requirement (IWR at the catchment scale, based on gridded land use, soil and daily weather data at 500 × 500 m resolution. In this approach, IWR is expressed as a bounded, linear function of the atmospheric water budget, whereby the latter is defined as the difference between seasonal precipitation and reference evapotranspiration. To account for the effects of soil and crop properties on the soil water balance, the coefficients of the linear relation are expressed as a function of the soil water holding capacity and the so-called crop coefficient. The 12 parameters defining the relation were estimated with good coefficients of determination from a systematic analysis of simulations performed at daily time step with a FAO-type point-scale model for five climatically contrasted sites around the River Rhone and for combinations of six crop and ten soil types. The simple scheme was found to reproduce well results obtained with the daily model at six additional verification sites. We applied the simple scheme to the assessment of irrigation requirements in the whole Swiss Rhone catchment. The results suggest seasonal requirements of 32 × 106 m3 per year on average over 1981–2009, half of which at altitudes above 1500 m. They also disclose a positive trend in the intensity of extreme events over the study period, with an estimated total IWR of 55 × 106 m3 in 2009, and indicate a 45% increase in water demand of grasslands during the 2003 European heat wave in the driest area of the studied catchment. In view of its simplicity, the approach can be extended to other applications, including assessments of the impacts of climate and land-use change.

  18. 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

  19. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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

  2. 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.

  3. Systems and rates of aerial application of fungicides in irrigated rice

    Directory of Open Access Journals (Sweden)

    Tânia Bayer

    Full Text Available ABSTRACT The present research studied the performance of flat-fan and hollow-cone nozzles, with application rates of 20 and 30 L ha-1, and rotary disc atomizer with application rates of 10 and 15 L ha-1. The test was conducted with a fungicide spray tank composed of Azoxystrobin + Difenoconazole, in which the density and penetration of droplets into the canopy were evaluated using a water-sensitive paper and the distribution of the active ingredients in the plant was evaluated through the chromatographic analysis. Higher application rates resulted in higher droplet density in the upper stratum of plants. In all treatments, the penetration of the droplets was 26% into the middle stratum and 23% into the lower stratum, in relation to the top of the crop, resulting in an average 25% penetration of droplets into the leaf canopy. The active ingredients were distributed in greater quantity in the upper stratum of the plant. For the same weight, the upper part of the ‘Puitá Inta CL’ rice cultivar has a leaf area 6.4 times larger than the lower part. It was concluded that higher application rate leads to higher droplet density in the upper stratum of the leaf canopy and that all systems and application rates promoted similar penetration of droplets into the canopy.

  4. Tagging microsatellite marker to a blast resistance gene in the irrigated rice cultivar Cica-8

    Directory of Open Access Journals (Sweden)

    Thiago Martins Pinheiro

    2012-09-01

    Full Text Available The rice cultivar Cica-8 exhibit differential reaction to several pathotypes of Magnaporthe oryzae. The objective of the present investigation was to determine the number of alleles involved in the expression of resistance to leaf blast and identify microsatellite markers linked to these alleles. A cross between cultivar Metica-1 and Cica-8 susceptible and resistant, respectively, to pathotype IB-1 (Py1049 was made to obtain F1, F2, BC1:1 and BC1:2 progenies. Greenhouse tests for leaf blast reaction showed that resistance is controlled by a monogenic dominant gene. For testing microsatellite markers, DNA of both resistant and susceptible parents and F1 and F2 populations was extracted. As expected for single dominant gene the F2 populations segregated at a ratio of 3:1. Of the 11 microsatellite markers tested, one marker RM 7102 was found to be closely linked to the resistant allele at a distance of 2.7 cM, in the cultivar Cica-8 to pathotype IB-1.

  5. 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.

  6. 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...

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

    Directory of Open Access Journals (Sweden)

    Alberto Baêta dos Santos

    1999-04-01

    Full Text Available O manejo da água de irrigação e as doses e épocas de aplicação de fertilizantes tornam-se aspectos de extrema importância no êxito do aproveitamento das várzeas para o cultivo de arroz (Oryza sativa L. irrigado ou este seguido de outras espécies. Com o objetivo de comparar distintas formas de manejo de água e de fertilizante potássico no comportamento do arroz irrigado, foram conduzidos experimentos por três anos consecutivos, em um Inceptissolo. Foram estudados os efeitos de manejo de água (MA1 - inundação contínua e MA2 - inundação intermitente seguida de contínua e o modo de aplicação de fertilizante potássico (K1 - na semeadura; K2 - parcelada e K3 - meia dose parcelada. O manejo de água apresentou efeito mais expressivo sobre o comportamento do arroz que o do fertilizante potássico. A inundação contínua durante todo o ciclo da cultura proporcionou maiores rendimentos de grãos, expressando maiores valores dos parâmetros produtivos, e melhorou a qualidade industrial dos grãos. Com esta irrigação, o parcelamento da adubação potássica aumentou o aproveitamento do fertilizante. Os manejos do fertilizante potássico afetaram diferentemente o comportamento da cultura do arroz nas distintas formas de manejo de água.Irrigation water levels and timing of potassium fertilization is extremely important for the use of lowlands for irrigated rice (Oryza sativa L. cultivation in crop rotation. A field experiment was conduced for three consecutive years in Inceptisol to study the effects of water management (WM1 - continuous flooding and WM2 - intermittent flooding followed continuous flooding and mode of potassium fertilizer application (K1 - at sowing; K2 - fractional application and K3 - fractional application of half levels on grain yield and yield components of irrigated rice. Water management presented expressive effect on rice performance as compared to potassium fertilization. Continuous flooding during whole

  8. Formal and informal decision making on water management at the village level: A case study from the Office du Niger irrigation scheme (Mali)

    Science.gov (United States)

    Vandersypen, Klaartje; Keita, Abdoulaye C. T.; Coulibaly, Y.; Raes, D.; Jamin, J.-Y.

    2007-06-01

    Water Users Associations (WUAs) are all too often considered a panacea for improving water management in irrigation schemes. Where grassroots movements are absent, they are usually imposed on farmers by national governments, NGOs, and international donors, without fully considering existing forms of organization. This also happened in the Office du Niger irrigation scheme in Mali, where after a partial irrigation management transfer, WUAs were created to fill the resulting power vacuum. This paper demonstrates that, despite active efforts to organize farmers in WUAs, informal patterns of decision making remain dominant. Given the shortcomings of these informal patterns, WUAs could provide a much-needed platform for institutionalizing collective action, on the condition that farmers accept them. Therefore WUAs should adopt some crucial characteristics of informal patterns of decision making while avoiding their weaknesses. First, making use of the existing authority of village leadership and the central management can improve the credibility of WUAs. Second, allowing flexibility in procedures and rules can make them more appropriate for dealing with collective action problems that are typically temporary and specific. Last, formalizing the current pattern of conflict management and sanctioning might enhance its sphere of action and tackle the current absence of firm engagement with respect to some informal management decisions. In addition, WUAs should represent and be accountable to all farmers, including those residing outside the village community.

  9. The Impact of a Local Development Project on Social Capital: Evidence from the Bohol Irrigation Scheme in the Philippines

    Directory of Open Access Journals (Sweden)

    Hogeun Park

    2017-03-01

    Full Text Available The purpose of this paper is to investigate the connection between local development projects and the residents’ social capital in Bohol, The Philippines. From this perspective, we hypothesized that social behaviors of local farmers are influenced by the availability of canal irrigation due to the collective water management required in irrigated societies. By combining the results of the ultimatum game (UG with a household survey on 245 villagers in Bohol, this paper (1 measures the degree of social capital at the individual level and (2 quantifies the effects of irrigation on social capital by controlling household as well as individual characteristics. Moreover, we employed a Spatial Autoregressive model to explore the spatial effects and social contexts of farmers’ behavioral patterns. The empirical results show that the level of measured social behavior is strongly associated with access to community irrigation water and asset holdings. Additionally, increased physical distance between residents leads to a decrease in social capital, or interdependency, among them. The results suggest that community engagement (e.g., irrigation management committee and turnout service association with local development projects would not only improve agricultural productivity but also enhance social relationships among farmers, highlighting its importance.

  10. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  12. A resting box for outdoor sampling of adult Anopheles arabiensis in rice irrigation schemes of lower Moshi, northern Tanzania

    Directory of Open Access Journals (Sweden)

    Msangi Shandala

    2009-04-01

    Full Text Available Abstract Background Malaria vector sampling is the best method for understanding the vector dynamics and infectivity; thus, disease transmission seasonality can be established. There is a need to protecting humans involved in the sampling of disease vectors during surveillance or in control programmes. In this study, human landing catch, two cow odour baited resting boxes and an unbaited resting box were evaluated as vector sampling tools in an area with a high proportion of Anopheles arabiensis, as the major malaria vector. Methods Three resting boxes were evaluated against human landing catch. Two were baited with cow odour, while the third was unbaited. The inner parts of the boxes were covered with black cloth materials. Experiments were arranged in latin-square design. Boxes were set in the evening and left undisturbed; mosquitoes were collected at 06:00 am the next morning, while human landing catch was done overnight. Results A total of 9,558 An. arabiensis mosquitoes were collected. 17.5% (N = 1668 were collected in resting box baited with cow body odour, 42.5% (N = 4060 in resting box baited with cow urine, 15.1% (N = 1444 in unbaited resting box and 24.9% (N = 2386 were collected by human landing catch technique. In analysis, the house positions had no effect on the density of mosquitoes caught (DF = 3, F = 0.753, P = 0.387; the sampling technique had significant impact on the caught mosquitoes densities (DF = 3, F 37. 944, P Conclusion Odour-baited resting boxes have shown the possibility of replacing the existing traditional method (human landing catch for sampling malaria vectors in areas with a high proportion of An. arabiensis as malaria vectors. Further evaluations of fermented urine and longevity of the urine odour still need to be investigated.

  13. Procedure for rapid determination of δ15N and δ18O values of nitrate: development and application to an irrigated rice paddy watershed.

    Science.gov (United States)

    Yada, Saeko; Nakajima, Yasuhiro; Itahashi, Sunao; Asada, Kei; Yoshikawa, Seiko; Eguchi, Sadao

    2016-01-01

    The dual isotope approach using the stable isotope ratios of nitrate nitrogen (δ(15)N(NO3)) and oxygen (δ(18)O(NO3)) is a strong tool for identifying the history of nitrate in various environments. Basically, a rapid procedure for determining δ(15)N(NO3) and δ(18)O(NO3) values is required to analyze many more samples quickly and thus save on the operational costs of isotope-ratio mass spectrometry (IRMS). We developed a new rapid procedure to save time by pre-treating consecutive samples of nitrous oxide microbially converted from nitrate before IRMS determination. By controlling two six-port valves of the pre-treatment system separately, IRMS determination of the current sample and backflush during the next sample pre-treatment period could be conducted simultaneously. A set of 89 samples was analyzed precisely during a 25-h continuous run (17 min per sample), giving the fastest reported processing time, and simultaneously reducing liquid nitrogen and carrier helium gas consumption by 35%. Application of the procedure to an irrigated rice paddy watershed suggested that nitrate concentrations in river waters decreased in a downstream direction, mainly because of the mixing of nitrate from different sources, without distinct evidence of denitrification. Our procedure should help with more detailed studies of nitrate formation processes in watersheds.

  14. Mobilizing local innovation capacity through a simulation game in a participatory research project on agricultural innovation in El Brahmi irrigation scheme (Tunisia).

    Science.gov (United States)

    Dolinska, Aleksandra; d'Aquino, Patrick; Imache, Amar; Dionnet, Mathieu; Rougier, Jean-Emmanuel

    2015-04-01

    In the framework of the European Union and African Union cooperative research to increase Food production in irrigated farming systems in Africa (EAU4Food project) we conducted a participatory research on the possible innovative practices to increase production of dairy farms in the irrigation scheme El Brahmi in Tunisia in the face of changing economic, political and environmental conditions. Our aim was to find effective research method to stimulate farmers' participation in the innovation process. Although the capacities of farmers in producing knowledge and in innovating are recognized and the shift from the linear model of technology transfer towards more participatory approaches to innovation is postulated, in which the role of researchers changes from providing solutions towards supporting farmers in finding their own solutions, in practice, the position of farmers in shaping innovation practice and process remains weak. After a series of participatory workshops and in-depth interviews with the actors of the local innovation system we developed and tested a simple open simulation game Laitconomie for farmers. The game proved to be effective in increasing our understanding of the system as the farmers were adding new elements and rules while playing, and in mobilizing farmers' knowledge (including tacit knowledge) in the simulated innovation process. The result reported by the participants was learning how to improve farm management, soil fertility management and cow nutrition practices. Some of the participants used the game as a decision support tool. While our game and its scope were modest and mobilized only two types of players (farmers and extension agent), open simulation proved to be a useful tool to analyze a local innovation system. Designing similar type of tools that would mobilize more diverse players and hence have a larger scope can be imagined.

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

    Directory of Open Access Journals (Sweden)

    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

  16. Aplicação de reguladores vegetais na cultura de arroz de terras altas = Effect of vegetal regulators on sprinkler-irrigated highland rice

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Félix Alvarez

    2007-04-01

    Full Text Available O objetivo deste trabalho foi identificar o regulador vegetal e dose mais adequada visando à redução da altura da planta e acamamento e a interferência destes nos componentes da produção e produtividade de grãos de arroz de terras altas irrigado por aspersão. Os tratamentos foram constituídos de três reguladores vegetais e quatro doses. Ocloreto de mepiquat (PIX e o etil-trinexapac (Moddus foram aplicados nas doses 0, 2000, 4000 e 8000 mg L-1 e o paclobutrazol (Paclobutrazol ou Cultar foi aplicado nas doses 0, 1000, 2000 e 4000 mg L-1, do produto comercial. Os reguladores vegetais foram aplicadosno estádio de perfilhamento, utilizando o cultivar Primavera. Constatou-se que a aplicação do etil-trinexapac reduziu a altura da planta e influenciou negativamente os componentes da produção e produtividade de grãos. Não foi identificada uma dose “ideal” que reduzisse a altura da planta e proporcionasse aumento na produtividade de grãos.The present work aims to identify the vegetal regulators and optimum dose to reduce plant height and layering and their influence on production and productivity components in sprinkler-irrigated highland rice grains. Treatments consisted of three vegetal regulators and four doses. Mepiquat chloride (Pix and ethyl-trinexapac (Moddus were applied at doses of 0, 2000, 4000 and 8000 mg L-1, while paclobutrazol (Paclobutrazol was applied at 0, 1000,2000 and 4000 mg L-1, commercial product. The vegetal regulators were applied during the profiling state, utilizing Primavera cultivar. Results showed that ethyl-trinexapac reduced the plant height and influenced negatively grain production and productivity components.No optimum dose was identified to reduce plant height and increase grain productivity.

  17. Assessment of greening and collective participation in the context of agri-environmental schemes: The case of Andalusian irrigated olive groves

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, A. J.; Gómez-Limón, J.A.; Arriaza, M.; Rodríguez-Entrena, M.

    2015-07-01

    Agri-environmental schemes (AES) in irrigated olive groves (IOG) in southern Spain were assessed based on farmers’ preferences toward these schemes. A choice experiment was used in this ex-ante assessment, with the inclusion of some innovative elements, such as collective participation and ecological focus areas (EFA). The results showed that farmers’ mean willingness to accept (WTA) participation in collective rather than individual AES was €124.5/ha. Their mean WTA for an additional 1% of EFA was €64.6/ha, while regarding the use of other agri-environmental practices, they showed a WTA of €6.3/ha and €114.7/ha for an additional 1% in the use of cover crops (CC) in olive grove areas and restrictive management of CC, respectively. These estimates were strongly influenced by farmers’ expectations and socio-economic characteristics, as well as farm management. We obtained that farmers’ expectations of no farm takeover reduce WTA for collective participation, whereas agricultural training and having at least a secondary-school education reduce farmers’ WTA for EFA and restrictive management of the CC, respectively. Conversely, harvesting ground olives increased farmers’ WTA for a high proportion of the area under CC. The analysis of the AES scenarios showed moderately high estimates of total WTA (€101-349/ha), especially when collective participation is required (€225-474/ha). The results supported the argument that there are efficient ways to encourage public goods provision, overcoming trade-offs with private goods provision by identifying the type of joint production. (Author)

  18. Efeito do bentazon e bentazon + dichlorprop na cultura do arroz irrigado e sobre as plantas daninhas Effect of bentazon and bentazon + dichlorprop on irrigated rice and weeds

    Directory of Open Access Journals (Sweden)

    C.A.L. dos Santos

    1979-06-01

    Full Text Available Foi instalado um experimento de campo, em solo barrento, com a finalidade de se verificar o efeito do bentazon e da mistura de bentazon + dichlorprop sobre o desenvolvimento do arroz em cultura irrigada e sobre o controle das plantas daninhas. Os tratamentos utilizados foram os seguintes: bentazon á 0,75-1,00 e1,50 kg/ha; bentazon + dichlorprop a 0,80 + 1,00 e 1,00 + 1,40 kg/ha; propanil a 4,20 kg/ha (tratamento padrão; testemunha capinada e testemunha sem capina. Todas as pulverizações foram realizadas em pósemergência. As plantas daninhas encontradas no experimento foram: capituva - Echinochloa colonum (L Link, tiririca amarela - Cyperus esculentus L., beldroega - Portulaca oleracea L. e carurú comum - Amaranthus viridis L. Bentazon a 1,00 e 1,50 kg/ha e bentazon + dichlorprop a 1,00 + 1,40 kg/ha foram eficientes no controle de P. oleracea, A. viridis e C. esculentus; já a dose menor de bentazon apresentou bons resultados contra P. oleracea e A. viridis, enquanto que a dose menor de bentazon + dichlorprop controlou apenas P. oleracea. Propanil, de uma maneira geral, proporcionou eficiente ação sobre as plantas daninhas. Nas condições em que foi realizado o experimento nenhum dos herbicidas, nas suas respectivas doses, apresentou fitotoxicidade para as plantas de arroz da variedade IAC-435 ou prejudicou a produção da cultura.Bentazon at 0.75 - 1.00 and 1.50 kg/ha a.i ., bentazon + dichlorprop at 0.80 + 1.00 and 1.00 + 1.40 kg and propanil at 4.20 kg were applied in post-emergence on irrigated rice, against the following weeds: Echinochloa colonum (L. Link, Cy-perus esc-ulentus L., Portulaca oleracea L. and Amaranthus viridis L. Bentazon at 1.00 - 1.50 kg and bentazon + dichlorprop at 1.00 + 1.40 kg gave good control of P. oleracea, A. viridis and C. esculentus; bentazon at 0.75 kg controlled P. oleracea and A. viridis; bentazon + dichlorprop at 0.80 + 1.00 kg only showed effeciency for P. oleracea; propanil, in general, gave good

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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)

  1. 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.

  2. Cultivares de arroz irrigado e nutrientes na água de drenagem em diferentes sistemas de cultivos Irrigated rice cultivars and drainnage water nutrient under differnt managements systems

    Directory of Open Access Journals (Sweden)

    Lauro Weber

    2003-02-01

    components of four irrigated rice cultivars under different management systems, as well as, to measure the concentration of nutrients in the initial drainage water. The research was conducted during the 1998/99 growing season on a lowland area on a PLANOSOIL located at the Federal University of Santa Maria-RS, Brazil. The rice cultivars were IRGA 417, EL PASO 144, BRS TAIM and EPAGRI 108. The management systems were: conventional and minimum tillage and pre-germinated and "mix" of pre-germinated and seedlings transplants. The experimental design was a randomized aplit block with four replications. The conventional and minimum tillage were seeded in November 01st, 1998 and the pre-germinated and mix of pre-germinated and seedlings transplants were estabhished in November 18th, 1998. Seed yield was affected by management system except for the cultivar EL PASO 144 that had the same yield regardless treatments. EPAGRI 108 had the highest average yields, 8349kg ha-1. The highest number of panicles per square meter was observed in the pre-germinated and mix pre-germinated systems. The transplanted seedlings had the highest number of seeds per panicles. Regardless the management systems, EL PASO 144 presented thehighest number of seeds per panicle and EPAGRI 108 the heavier seeds. Nutrient concentration in the initial dreinage water was similar in all systems with average N, P, K, Ca, Mg and Fe concentrations of 5.02, 2.06, 10.33, 6.38, 3.51 and 2.56 mg l-1, respectively.

  3. 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)

  4. 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

    Directory of Open Access Journals (Sweden)

    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.

  5. Biochar application mode influences nitrogen leaching and NH3 volatilization losses in a rice paddy soil irrigated with N-rich wastewater.

    Science.gov (United States)

    Sun, Haijun; Min, Ju; Zhang, Hailin; Feng, Yanfang; Lu, Kouping; Shi, Weiming; Yu, Min; Li, Xuewen

    2017-07-11

    Impacts of biochar application mode on nitrogen (N) leaching, ammonia (NH 3 ) volatilization, rice grain yield and N use efficiency (NUE) are not well understood. Therefore, a field experiment was conducted to evaluate those impacts in a rice paddy soil received 225 kg N ha -1 from either urea or N-rich wastewater. One treatment received 10 t ha -1 biochar with the basal fertilization, and the other received same total amount of biochar but split applied with the three split N applications with same ratio as N fertilizer split ratio (40%, 30% and 30%). Results showed that N leaching loads were 4.20-6.22 kg ha -1 . Biochar one-time application reduced N leaching by 23.1%, and biochar split application further reduced N leaching by 32.4%. Total NH 3 volatilization loss was 15.5-24.5 kg ha -1 . Biochar one-time application did not influence the NH 3 volatilization, but biochar split application stimulated the cumulative NH 3 volatilization by 57.7%. Both biochar treatments had no influence on NUE and rice grain yield. In conclusion, biochar application mode indeed influences the N leaching and NH 3 volatilization in rice paddy soils, and biochar one-time application should be recommended for reducing N leaching without increasing NH 3 volatilization.

  6. 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

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. Sistemas de cultivo de arroz irrigado e a compactação de um Planossolo Tillage systems of irrigated rice and compaction of a Planosol

    Directory of Open Access Journals (Sweden)

    Alceu Pedrotti

    2001-04-01

    Full Text Available Em 1993 foi avaliada a compactação de um Planossolo cultivado sob diferentes sistemas de manejo, medindo-se a densidade do solo, por meio do método do anel volumétrico, em três camadas de solo. Os tratamentos consistiram de seis sistemas de manejo, selecionados de um experimento conduzido na Embrapa-Centro de Pesquisa Agropecuária de Clima Temperado, desde 1985. Observaram-se, de maneira geral, valores altos de densidade do solo; na primeira camada de solo (0-10 cm o sistema que apresentou o menor valor foi o cultivo de arroz em plantio direto sob a resteva do azevém e nos sistemas que envolvem maior mobilização do solo (arroz contínuo e rotação arroz-soja-milho os valores de densidade do solo foram maiores em relação aos sistemas de preparo reduzido do solo (azevém x arroz plantio direto e soja x arroz plantio direto. Ocorreu maior compactação, em relação à primeira camada, na camada intermediária (1020 cm, em todos os sistemas de cultivo, exceto no sistema de rotação arroz-soja-milho, no qual não houve diferença de densidade entre as camadas de solo.In 1993, it was evaluated the compaction of a Planosol (Albaqualf submitted to different tillage systems, measuring soil density through the volumetric ring method, in three layers. Treatments consisted of six tillage systems selected from an experiment conducted at Embrapa-Centro de Pesquisa Agropecuária de Clima Temperado, Pelotas, RS, Brazil, since 1985. High soil density values were obtained; in the first layer (0-10 cm, the no-tillage rice cultivation on the rye-grass straw was the system with the lowest value. The systems that involved more soil mobilization (rice continuous and rotation rice-soybeans-maize resulted in higher soil density values compared to the reduced preparing systems (rye-grass x rice in zero tillage and soybean x rice in zero tillage. Compacted structures were identified in the intermediate layer (10-20 cm in all tillage systems, except for the

  9. Irrigation development and management in Ghana: Prospects and ...

    African Journals Online (AJOL)

    ... existing schemes. It is envisaged that irrigation will be seen in its right perspective as a multidisciplinary activity to ensure the success of schemes. There is the need for running a postgraduate programme in irrigation at the KNUST to enhance the nations efforts at developing and managing irrigation projects successfully.

  10. 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

  11. Equipamentos de pulverização aérea e taxas de aplicação de fungicida na cultura do arroz irrigado Spraying equipment and rates of fungicide application in irrigated rice

    Directory of Open Access Journals (Sweden)

    Tânia Bayer

    2011-02-01

    Full Text Available O controle eficiente de doenças na cultura do arroz irrigado depende da seleção correta do equipamento, da taxa de aplicação e da indicação certa do produto químico. O objetivo deste trabalho foi verificar a deposição de gotas na cultura do arroz comparando-se bicos hidráulicos no sistema convencional, eletrostático e atomizador rotativo de disco, em diferentes taxas de aplicação por via aérea; para tanto, foram estudadas a densidade e a penetração de gotas nos estratos médio e inferior, produtividade e rendimento de engenho do arroz. Os tratamentos avaliados foram: bico hidráulico 20 e 30 L ha-1, eletrostático 5 e 10 L ha-1 e atomizador rotativo de disco 6, 10 e 15 L ha-1. Não foram verificadas diferenças de produtividade e os equipamentos bico hidráulico 20 L ha-1 e atomizador rotativo de disco 15 L ha-1 proporcionaram maior rendimento de engenho. Maiores taxas de aplicação usando-se bicos hidráulicos e atomizador rotativo proporcionaram maior penetração e, consequentemente, também maior densidade de gotas nos dois estratos avaliados.The efficient chemical control in irrigated rice depends on the correct selection of equipment, rates of application and correct statement of the chemical product. The objective of this study was to evaluate the hydraulic nozzle equipment, electrostatic system and rotary-disk atomizer for aerial application of fungicides, relating to penetration and density of droplets with application rates and equipment in the middle and lower strata, in addition to the productivity and hulling yield in irrigated rice. The treatments were: nozzle hydraulic 20 and 30 L ha-1, electrostatic system 5 and 10 L ha-1, rotary-disk atomizer 6, 10 and 15 L ha-1. There was no difference in productivity and equipment hydraulic nozzle 20 L ha-1 and rotary-disk atomizer 15 L ha-1 showed a higher hulling yield. On average, higher rates had higher penetration and density in both the evaluated canopy strata.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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

    Directory of Open Access Journals (Sweden)

    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

  15. An intuitionistic fuzzy multi-objective non-linear programming model for sustainable irrigation water allocation under the combination of dry and wet conditions

    Science.gov (United States)

    Li, Mo; Fu, Qiang; Singh, Vijay P.; Ma, Mingwei; Liu, Xiao

    2017-12-01

    Water scarcity causes conflicts among natural resources, society and economy and reinforces the need for optimal allocation of irrigation water resources in a sustainable way. Uncertainties caused by natural conditions and human activities make optimal allocation more complex. An intuitionistic fuzzy multi-objective non-linear programming (IFMONLP) model for irrigation water allocation under the combination of dry and wet conditions is developed to help decision makers mitigate water scarcity. The model is capable of quantitatively solving multiple problems including crop yield increase, blue water saving, and water supply cost reduction to obtain a balanced water allocation scheme using a multi-objective non-linear programming technique. Moreover, it can deal with uncertainty as well as hesitation based on the introduction of intuitionistic fuzzy numbers. Consideration of the combination of dry and wet conditions for water availability and precipitation makes it possible to gain insights into the various irrigation water allocations, and joint probabilities based on copula functions provide decision makers an average standard for irrigation. A case study on optimally allocating both surface water and groundwater to different growth periods of rice in different subareas in Heping irrigation area, Qing'an County, northeast China shows the potential and applicability of the developed model. Results show that the crop yield increase target especially in tillering and elongation stages is a prevailing concern when more water is available, and trading schemes can mitigate water supply cost and save water with an increased grain output. Results also reveal that the water allocation schemes are sensitive to the variation of water availability and precipitation with uncertain characteristics. The IFMONLP model is applicable for most irrigation areas with limited water supplies to determine irrigation water strategies under a fuzzy environment.

  16. 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

    Directory of Open Access Journals (Sweden)

    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.

  17. HARVEST TIME AND PHYSIOLOGIC QUALITY OF SEEDS IN IRRIGATED RICE (Oryza sativa cv. BRS RORAIMA ÉPOCA DE COLHEITA E QUALIDADE FISIOLÓGICA DE SEMENTES EM ARROZ IRRIGADO (Oryza sativa cv. BRS RORAIMA

    Directory of Open Access Journals (Sweden)

    Oscar José Smiderle

    2008-09-01

    Full Text Available

    Harvest time is one of most important factors influencing rice seed characteristics for purpose of either planting or milling. With the objective to determine a proper harvesting  time, irrigated rice seeds of cultivar BRS Roraima were harvested at 15, 22, 29, 36, 43 and 50 days after flowering (DAF, and assessed according to humidity, viability, dry mass of 1,000 seeds, whole grain yield, productivity and storability. Seeds harvested 29 DAF showed high quality and its productivity was equivalent to the subsequent periods. Seeds harvested 50 DAF showed good performance, except for whole grain yield. Harvests 15 and 22 DAF were unsuitable, reducing the physiologic quality of seeds, mill efficiency and high initial humidity. The adequate harvest time for cultivar BRS Roraima is between 29 and 43 DAF, when seeds present higher yield, dry mass, whole grain yield, physiologic quality and storability.

    KEY-WORDS: Physiologic quality; whole grain; humidity.

    A época de colheita é um dos fatores mais importantes que influenciam as características da semente de arroz, seja para semeadura ou para consumo. Com o objetivo de determinar a época adequada de colheita de arroz irrigado, para a cultivar BRS Roraima, sementes foram colhidas aos 15, 22, 29, 36, 43 e 50 dias após o florescimento (DAF e avaliadas quanto à umidade, viabilidade, massa seca de 1.000 sementes, rendimento de grãos inteiros, produtividade e armazenabilidade. As sementes colhidas aos 29 DAF

  18. Chemical composition and structural changes of irrigated rice during storageComposição química e alterações estruturais do arroz irrigado durante o armazenamento

    Directory of Open Access Journals (Sweden)

    Tiago André Kaminski

    2013-06-01

    Full Text Available The effect storage time at different temperatures (0.5, 20 and 35 °C was periodically evaluated in regard to the chemical composition, elongation capacity and viscoamylographic properties of three irrigated rice varieties (BR-IRGA 410, IRGA 416 and IRGA 417 during 180 days. The alterations in the components of the polished grains were significant (P O efeito do tempo de armazenamento em diferentes temperaturas (0,5; 20 e 35°C foi avaliado sobre a composição química, capacidade de elongação e propriedades viscoamilográficas de três variedades de arroz irrigado (BR-IRGA 410, IRGA 416 e IRGA 417, durante 180 dias. As alterações nos componentes dos grãos polidos foram significativas (P<0,05 para o teor de matéria mineral, compostos fenólicos, amilose e amido resistente, com incrementos nos valores encontrados, principalmente em maiores períodos e temperaturas de armazenamento. As variáveis do experimento (variedade do arroz irrigado, tempo e temperatura do armazenamento influenciaram significativamente (P<0,01 nos parâmetros de elongação dos grãos, com aumentos expressivos durante o armazenamento a 35°C e nas propriedades viscoamilográficas, ou seja, observou-se maior viscosidade, resistência à quebra e retrogradação para as amostras com maior teor de amilose e mantidas a 35°C durante o armazenamento. As alterações nos componentes dos grãos, quando significativas (P<0,05, foram bastante discretas e não diretamente relacionadas às significativas alterações (P<0,01 de elongação e viscosidade. A temperatura se mostrou uma variável de grande influência no processo de envelhecimento do arroz, sugerindo a possibilidade do armazenamento deste cereal em maiores temperaturas para conferir qualidade culinária em menor tempo de armazenamento.

  19. Spatio-temporal estimation of consumptive water use for assessment of irrigation system performance and management of water resources in irrigated Indus Basin, Pakistan

    Science.gov (United States)

    Usman, M.; Liedl, R.; Awan, U. K.

    2015-06-01

    Reallocation of water resources in any irrigation scheme is only possible by detailed assessment of current irrigation performance. The performance of the Lower Chenab Canal (LCC) irrigation system in Pakistan was evaluated at large spatial and temporal scales. Evaporative Fraction (EF) representing the key element to assess the three very important performance indicators of equity, adequacy and reliability, was determined by the Surface Energy Balance Algorithm (SEBAL) using Moderate Resolution Imaging Spectroradiometer (MODIS) images. Spatially based estimations were performed at irrigation subdivisions, lower and upper LCC and, whole LCC scales, while temporal scales covered months, seasons and years for the study period from 2005 to 2012. Differences in consumptive water use between upper and lower LCC were estimated for different crops and possible water saving options were explored. The assessment of equitable water distribution indicates smaller coefficients of variation and hence less inequity within each subdivision except Sagar (0.08) and Bhagat (0.10). Both adequacy and reliability of water resources are found lower during kharif as compared to rabi with variation from head to tail reaches. Reliability is quite low from July to September and in February/March. This is mainly attributed to seasonal rainfalls. Average consumptive water use estimations indicate almost doubled water use (546 mm) in kharif as compared to (274 mm) in rabi with significant variability for different cropping years. Crop specific consumptive water use reveals rice and sugarcane as major water consumers with average values of 593 mm and 580 mm, respectively, for upper and lower LCC, followed by cotton and kharif fodder. The water uses for cotton are 555 mm and 528 mm. For kharif fodder, corresponding values are 525 mm and 494 mm for both regions. Based on the differences in consumptive water use, different land use land cover change scenarios were evaluated with regard to savings

  20. Balancing ecosystem services with energy and food security - Assessing trade-offs from reservoir operation and irrigation investments in Kenya's Tana Basin

    Science.gov (United States)

    Hurford, A. P.; Harou, J. J.

    2014-08-01

    Competition for water between key economic sectors and the environment means agreeing allocations is challenging. Managing releases from the three major dams in Kenya's Tana River basin with its 4.4 million inhabitants, 567 MW of installed hydropower capacity, 33 000 ha of irrigation and ecologically important wetlands and forests is a pertinent example. This research seeks firstly to identify and help decision-makers visualise reservoir management strategies which result in the best possible (Pareto-optimal) allocation of benefits between sectors. Secondly, it seeks to show how trade-offs between achievable benefits shift with the implementation of proposed new rice, cotton and biofuel irrigation projects. To approximate the Pareto-optimal trade-offs we link a water resources management simulation model to a multi-criteria search algorithm. The decisions or "levers" of the management problem are volume-dependent release rules for the three major dams and extent of investment in new irrigation schemes. These decisions are optimised for eight objectives covering the provision of water supply and irrigation, energy generation and maintenance of ecosystem services. Trade-off plots allow decision-makers to assess multi-reservoir rule-sets and irrigation investment options by visualising their impacts on different beneficiaries. Results quantify how economic gains from proposed irrigation schemes trade-off against the disturbance of ecosystems and local livelihoods that depend on them. Full implementation of the proposed schemes is shown to come at a high environmental and social cost. The clarity and comprehensiveness of "best-case" trade-off analysis is a useful vantage point from which to tackle the interdependence and complexity of "water-energy-food nexus" resource security issues.

  1. Exploring options for water savings in lowland rice using a modelling approach

    NARCIS (Netherlands)

    Belder, P.; Bouman, B.A.M.; Spiertz, J.H.J.

    2007-01-01

    Water-saving irrigation regimes are needed to deal with a reduced availability of water for rice production. Two important water-saving technologies at field scale are alternately submerged¿nonsubmerged (SNS) and flush irrigated (FI) rice. SNS allows dry periods between submerged soil conditions,

  2. Rendimento do arroz e manejo da irrigação e da palha de azevém no sistema mix de pré-germinado Rice yield and management of irrigation and ryegrass straw on flooded rice in no tillage and water seed system

    Directory of Open Access Journals (Sweden)

    Eduardo González Pinto

    2003-04-01

    limiting factor in many agricultural areas, when high productivity is the objective. Alternative system of crop cultivation using no tillage on flooded water seed system can be used to minimize the problem. Although this system has technical and economical advantages on the production chain, especially on red rice control, anaerobic process of ryegrass straw decomposition may produce toxic substances to rice plants establishment. The objective of this work was to evaluate the effect of different water irrigation management and the amount of ryegrass straw on grain yield and yield components on paddy rice cultivated. The experiment was conducted in greenhouse, during the 1998/99 crop growing season, on Hidromorphy Planosoil, sandy Eutrophic, soil mapping unit "Vacacaí", over ryegrass crop residue at the Federal University of Santa Maria, Santa Maria, RS. The rice cultivar IRGA 417 was used. A completely randomized design factorial (3x3, three water management (with neither vertical nor surface in-out water flow over the soil, with drainage and surface water flow and three amount of ryegrass straw (0.0 t ha-1, 3.43 t ha-1 and 6.86 t ha-1. The data demonstrated that a permanent flooding with neither vertical nor surface in-out water flow reduce dry matter above ground and grain yield when compared to the treatments with drainage and surface in-out water flow. Increasing the amount of ryegrass straw on the no-tillage water seed system, with neither vertical nor surface in-out water flow, on the flooded water the grain yield is reduced.

  3. Diagnosis of regional evaporation by remote sensing to support irrigation performance assessment

    NARCIS (Netherlands)

    Bastiaanssen, W.G.M.; Wal, van der T.; Visser, T.N.M.

    1996-01-01

    Performance assessment indicators, being functions of evaporation, are useful tools to evaluate the actual functioning of an irrigation system. The spatial variability of evaporation in large irrigation schemes makes its determination with conventional point measurements almost impossible. A new

  4. Trash-polluted irrigation: characteristics and impact on agriculture

    Science.gov (United States)

    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.

  5. Performance assessment of smallholder irrigation in the Central Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Halsema, van G.E.; Lencha, B.K.; Assefa, M.; Hengsdijk, H.; Wesseler, J.H.H.

    2011-01-01

    The recent increase in smallholder irrigation schemes in the Central Rift Valley of Ethiopia has been associated with the overexploitation of water resources, while the economic viability of these schemes has been questioned. This paper assesses water use efficiencies of the Haleku Irrigation Scheme

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 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.

  9. 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

  10. Balancing ecosystem services with energy and food security - assessing trade-offs for reservoir operation and irrigation investment in Kenya's Tana basin

    Science.gov (United States)

    Hurford, A. P.; Harou, J. J.

    2014-01-01

    Competition for water between key economic sectors and the environment means agreeing on allocation is challenging. Managing releases from the three major dams in Kenya's Tana River basin with its 4.4 million inhabitants, 567 MW of installed hydropower capacity, 33 000 ha of irrigation and ecologically important wetlands and forests is a pertinent example. This research seeks to identify and help decision-makers visualise reservoir management strategies which result in the best possible (Pareto-optimal) allocation of benefits between sectors. Secondly we seek to show how trade-offs between achievable benefits shift with the implementation of new proposed rice, cotton and biofuel irrigation projects. To identify the Pareto-optimal trade-offs we link a water resources management model to a multi-criteria search algorithm. The decisions or "levers" of the management problem are volume dependent release rules for the three major dams and extent of investment in new irrigation schemes. These decisions are optimised for objectives covering provision of water supply and irrigation, energy generation and maintenance of ecosystem services which underpin tourism and local livelihoods. Visual analytic plots allow decision makers to assess multi-reservoir rule-sets by understanding their impacts on different beneficiaries. Results quantify how economic gains from proposed irrigation schemes trade-off against disturbance of the flow regime which supports ecosystem services. Full implementation of the proposed schemes is shown to be Pareto-optimal, but at high environmental and social cost. The clarity and comprehensiveness of "best-case" trade-off analysis is a useful vantage point from which to tackle the interdependence and complexity of water-energy-food "nexus" challenges.

  11. 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 ...

  12. 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

  13. 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

  14. Rice microstructure

    Science.gov (United States)

    An understanding of plant structure is desirable to obtain a clear idea of the overall impact of a crop. A mature rice plant consists of leafy components (left in the field post-harvest) and paddy rice (collected). The rice plant is supported by a hollow stem (culm) with leaf sheaths attached to nod...

  15. Avaliação do progresso genético obtido em 22 anos no melhoramento do arroz irrigado em Minas Gerais Evaluation of the genetical progress obtained in 22 years on the improvement of irrigated rice in Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia Guimarães Santos

    1999-10-01

    Full Text Available O objetivo deste trabalho foi avaliar o desempenho do programa de melhoramento genético do arroz irrigado, no Estado de Minas Gerais. Foram utilizados os dados de produtividade de grãos dos ensaios comparativos avançados de cultivares e linhagens de arroz irrigado, conduzidos em várias microrregiões do Estado de Minas Gerais, durante o período de 1974/75 a 1995/96. O ganho genético médio obtido em todo o período foi de 33 kg/ha/ano (0,98%, sendo altamente significativo (PThe goal of this work was to evaluate the performance of the genetical improvement program of irrigated rice in the State of Minas Gerais, Brazil. The grain yield data of the advanced comparative trials of both cultivars and lines of irrigated rice, conducted in several regions of the State of Minas Gerais over the period of 1974/75 to 1995/1996 were utilized. The average genetical gain obtained was of 33 kg/ha/year (0.98%, being highly significant (P< 0.01. The 22 year period was subdivided into two phases: at the first phase (1974/75 to 1979/80, a gain of 203 kg/ha/year (6.06% was noticed, which was highly significant, and the second phase (1980/81 to 1995/96 presented a gain of 15 kg/ha/year (0.25% being non significant. The high gain of the first phase is ascribed to the replacement of traditional high size and poor yielding potential for breeding materials such as Inca, BG 90-2 and MG 2. In the second phase of the program, increased attention was given to obtain materials more resistant to diseases and with better grain quality and non-significant gains for yield were obtained.

  16. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation pot...

  17. Irrigation Capability Evaluation of Illushi Floodplain, Edo State, Nigeria

    Directory of Open Access Journals (Sweden)

    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.

  18. Impacts of Irrigation Practices on Groundwater Recharge in Mississippi Delta Using coupled SWAT-MODFLOW Model

    Science.gov (United States)

    Gao, F.; Feng, G.; Han, M.; Jenkins, J.; Ouyang, Y.

    2017-12-01

    The Lower Mississippi River alluvial plain (refers to as MS Delta), located in the northwest state of Mississippi, is one of the most productive agricultural region in the U.S. The primary crops grown in this region are soybean, corn, cotton, and rice. Approximately 80% water from the alluvial aquifer in MS Delta are withdrawn for irrigation, which makes it the most used aquifer in the State. As a result, groundwater level has declined > 6 m since 1970, which threaten the sustainability of irrigated agriculture in this region. The objectives of this study were to: 1) couple the SWAT and MODFLOW then calibrate and validate the incorporated model outputs for stream flow, groundwater level and evapotranspiration (ET) in MS Delta; 2) simulate the groundwater recharge as affected by a) conventional irrigation scheme, b) no irrigation scheme, c) ET based and soil moisture based full irrigation schedules using all groundwater, and d) ET and soil moisture based full irrigation schedule using different percentages of surface and ground water. Results indicated that the coupled model performed well during the calibration and validation for daily stream flow at three USGS gauge stations. (R2=0.7; Nash-Sutcliffe efficiency (NSE) varied from 0.6 to 0.7; Root Mean Square Error (RMSE) ranged from 20 to 27 m3/s). The values of determination coefficient R2 for groundwater level were 0.95 for calibration and 0.88 for validation, their NSE values were 0.99 and 0.93, respectively. The values of RMSE for groundwater level during the calibration and validation period were 0.51 and 0.59 m. The values of R2, NSE and RMSE between SWAT-MODFLOW simulated actual evapotranspiration (ET) and remote sensing evapotranspiration (ET) were 0.52, 0.51 and 28.1 mm. The simulated total average monthly groundwater recharge had lower values of 19 mm/month in the crop season than 30 mm/month in the crop off-growing season. The SWAT-MODFLOW can be a useful tool for not only simulating the recharge in MS

  19. 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.

  20. 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

  1. (SRI) to Increase Rice Water Productivity

    African Journals Online (AJOL)

    Water Productivity: a Case of Mkindo Irrigation Scheme in. Morogoro ... plots in a randomized complete block design (RCBD) with five treatments based on two water application regimes of ..... green, blue and grey water footprint of crops.

  2. 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...

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

    Directory of Open Access Journals (Sweden)

    Masao Kikuchi

    2016-03-01

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

  4. 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.

  5. 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

  6. Collective action and participation in irrigation water management: A ...

    African Journals Online (AJOL)

    A case study of Mooi River Irrigation Scheme in KwaZulu-Natal. Province ..... Seven principal components were extracted using Pearson cor- relations. By applying the ..... OLSON M (1965) The Logic of Collective Action: Public Goods and the.

  7. Uncertainties in modelling the climate impact of irrigation

    Science.gov (United States)

    de Vrese, Philipp; Hagemann, Stefan

    2017-11-01

    Irrigation-based agriculture constitutes an essential factor for food security as well as fresh water resources and has a distinct impact on regional and global climate. Many issues related to irrigation's climate impact are addressed in studies that apply a wide range of models. These involve substantial uncertainties related to differences in the model's structure and its parametrizations on the one hand and the need for simplifying assumptions for the representation of irrigation on the other hand. To address these uncertainties, we used the Max Planck Institute for Meteorology's Earth System model into which a simple irrigation scheme was implemented. In order to estimate possible uncertainties with regard to the model's more general structure, we compared the climate impact of irrigation between three simulations that use different schemes for the land-surface-atmosphere coupling. Here, it can be shown that the choice of coupling scheme does not only affect the magnitude of possible impacts but even their direction. For example, when using a scheme that does not explicitly resolve spatial subgrid scale heterogeneity at the surface, irrigation reduces the atmospheric water content, even in heavily irrigated regions. Contrarily, in simulations that use a coupling scheme that resolves heterogeneity at the surface or even within the lowest layers of the atmosphere, irrigation increases the average atmospheric specific humidity. A second experiment targeted possible uncertainties related to the representation of irrigation characteristics. Here, in four simulations the irrigation effectiveness (controlled by the target soil moisture and the non-vegetated fraction of the grid box that receives irrigation) and the timing of delivery were varied. The second experiment shows that uncertainties related to the modelled irrigation characteristics, especially the irrigation effectiveness, are also substantial. In general the impact of irrigation on the state of the land

  8. 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

    Directory of Open Access Journals (Sweden)

    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

  9. IMPACTS OF CLIMATE CHANGE ON RICE AGRICULTURE IN NIGERIA

    Directory of Open Access Journals (Sweden)

    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

  10. Making Rice Production More Environmentally-Friendly

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

  13. Irrigation et paludisme : un couple infernal?

    Directory of Open Access Journals (Sweden)

    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

  14. Online decision support system for surface irrigation management

    Science.gov (United States)

    Wang, Wenchao; Cui, Yuanlai

    2017-04-01

    Zhanghe Irrigation District (Center China) to manage the required irrigation deliveries. Two years' application indicates that the proposed OIDSS can achieve promising performance for surface irrigation. Historical data of rice growing period in 2014 has been applied to test the OIDSS: it gives out 3 irrigation decisions, which is consistent with actual irrigation times and the forecast irrigation dates are well fit with the actual situations; the corresponding amount of total irrigation decreases by 15.13% compared to those without using the OIDSS.

  15. Root canal irrigants

    OpenAIRE

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are...

  16. IRRIGATION USING SOLAR PUMP

    OpenAIRE

    Prof. Nitin P.Choudhary*1 & Ms. Komal Singne2

    2017-01-01

    In this report the described design of a PV and soil moisture sensor based automated irrigation system is introduced. This project aims to provide a human friendly, economical and automated water pumping system which eliminates the problems of over irrigation and helps in irrigation water optimization and manage it in accordance with the availability of water. Our project not only tries to modernize the irrigation practices and ensure the optimum yield by carefully fulfilling the requirements...

  17. Low cost satellite data for monthly irrigation performance monitoring: benchmarks from Nilo Coelho, Brazil

    NARCIS (Netherlands)

    Bastiaanssen, W.G.M.; Brito, R.A.L.; Bos, M.; Souza, R.A.; Cavalcanti, E.B.; Bakker, M.M.

    2001-01-01

    Irrigation performance indicators can help water managers to understand how an irrigation scheme operates under actual circumstances. The new contribution of remote sensing data is the opportunity to study the crop growing conditions at scales ranging from individual fields to scheme level. Public

  18. Irrigation in endodontic treatment.

    Science.gov (United States)

    Basrani, Bettina

    2011-01-01

    The primary endodontic treatment goal is to optimize root canal disinfection and to prevent reinfection. Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal system. In this review of the literature, various irrigants and the interactions between irrigants are discussed and new delivery systems are introduced.

  19. The dynamics of rice production in Indonesia 1961–2009

    Directory of Open Access Journals (Sweden)

    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.

  20. Communication between irrigation engineers and farmers : the case of project design in North Senegal

    OpenAIRE

    Scheer, S.H.

    1996-01-01

    Introduction

    Irrigation schemes all over the world are often marked by a large number of related problems that have an important human dimension and are too complex to be straightforwardly solved. A starting point of this thesis is that these problems have to be dealt with in a learning process that involves all groups and organizations that are relevant to the irrigation scheme. This thesis explores communication processes between irrigation design engineers and ...

  1. Irrigation water policy analysis using a business simulation game

    Science.gov (United States)

    Buchholz, M.; Holst, G.; Musshoff, O.

    2016-10-01

    Despite numerous studies on farmers' responses to changing irrigation water policies, uncertainties remain about the potential of water pricing schemes and water quotas to reduce irrigation. Thus far, policy impact analysis is predominantly based upon rational choice models that assume behavioral assumptions, such as a perfectly rational profit-maximizing decision maker. Also, econometric techniques are applied which could lack internal validity due to uncontrolled field data. Furthermore, such techniques are not capable of identifying ill-designed policies prior to their implementation. With this in mind, we apply a business simulation game for ex ante policy impact analysis of irrigation water policies at the farm level. Our approach has the potential to reveal the policy-induced behavioral change of the participants in a controlled environment. To do so, we investigate how real farmers from Germany, in an economic experiment, respond to a water pricing scheme and a water quota intending to reduce irrigation. In the business simulation game, the participants manage a "virtual" cash-crop farm for which they make crop allocation and irrigation decisions during several production periods, while facing uncertain product prices and weather conditions. The results reveal that a water quota is able to reduce mean irrigation applications, while a water pricing scheme does not have an impact, even though both policies exhibit equal income effects for the farmers. However, both policies appear to increase the variation of irrigation applications. Compared to a perfectly rational profit-maximizing decision maker, the participants apply less irrigation on average, both when irrigation is not restricted and when a water pricing scheme applies. Moreover, the participants' risk attitude affects the irrigation decisions.

  2. 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.

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. 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.

  5. Traditional Irrigation Management in Betmera-Hiwane, Ethiopia: The Main Peculiarities for the Persistence of Irrigation Practices

    Institute of Scientific and Technical Information of China (English)

    Solomon Habtu; Kitamura Yoshinobu

    2006-01-01

    Traditional irrigation, as part of the ancient agricultural practices in northern Ethiopia (Tigray), has persisted for long time since 500 B.C.,while many newly introduced irrigation projects have usually failed there. The main objective of this study is thus to investigate the peculiarities pertinent to irrigation management and those having contributed for the persistence of traditional irrigation practices for a long period of time. The experience gained from such areas can definitely help make irrigation management system of new irrigation schemes sustainable. Betmera-Hiwane, one of the ancient traditional irrigation areas in Tigray region, was selected for the field study. Direct observations through field visits accompanied by interviews to farmers, local officials, local knowledgeable individuals and higher officials were made. After analyzing the collected primary and secondary information, the main peculiarities that contributed to the persistence of traditional irrigation areas were identified, and they are: the presence of communally constructed local rules, locally designed hydraulic control structures, ownership feeling of the irrigators and accountability of water distributors to the irrigation management, the culture for mobilizing communal resources and the culture of self-initiating local water management strategies.

  6. 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

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. A new concept of irrigation response units for effective management of surface and groundwater resources: a case study from the multi-country Fergana Valley, Central Asia

    KAUST Repository

    Awan, Usman Khalid; Ibrakhimov, Mirzakhayot; Benli, Bogachan; Lamers, John P A; Liaqat, Umar Waqas

    2016-01-01

    When estimating canal water supplies for large-scale irrigation schemes and especially in arid regions worldwide, the impact of all factors affecting the gross irrigation requirements (GIR) are not properly accounted for, which results

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Coil irrigation in sugar cane (Saccharum officinarum

    Directory of Open Access Journals (Sweden)

    Jesús Sánchez Gutiérrez

    2016-01-01

    Full Text Available This study was made at the Basic Seed Bank of the Local Sugar Cane Research Station for the Mideastern Cuba, based in Camaguey, on brown carbonate soil, between 2013 and 12014. Coil irrigation was applied to meet the water requirements for the crop, according to the edafoclimatic conditions and the different phenological phases it has. The Savo method was used to determine useful rain water. Adjustment and complementation of the irrigation program was based on indicators that characterize the exploitation scheme. The machine´s working parameters were determined to meet the water needs, and increase crop´s overall yields. The evaluations and results achieved have contributed to new proposals for management and operation of coil irrigation, and they are important to increase its efficiency.

  11. 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.

  12. 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.

  13. 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.

  14. Armenia - Irrigation Infrastructure

    Data.gov (United States)

    Millennium Challenge Corporation — This study evaluates irrigation infrastructure rehabilitation in Armenia. The study separately examines the impacts of tertiary canals and other large infrastructure...

  15. Influence of Climate Factors on Rice Yields in Cambodia

    Directory of Open Access Journals (Sweden)

    Dek Vimean Pheakdey

    2017-12-01

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

  16. Soma térmica de algumas fases do ciclo de desenvolvimento da escala de COUNCE para cultivares Sul-Brasileiras de arroz irrigado Thermal time of some developmental phases of the COUNCE scale for irrigated rice cultivars grown in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    2007-01-01

    Full Text Available A escala de COUNCE é uma escala de desenvolvimento de arroz recente que vem sendo gradativamente adotada no Brasil. No entanto, a duração das fases em ºC dia dessa escala ainda não está disponível para as cultivares brasileiras de arroz irrigado. Sendo assim, o objetivo deste trabalho foi determinar a soma térmica de algumas fases do ciclo de desenvolvimento da escala de COUNCE para cultivares Sul-Brasileiras de arroz irrigado, utilizando-se diversos métodos de cálculo e diferentes temperaturas cardinais ao longo do ciclo de desenvolvimento. Um experimento a campo foi desenvolvido em Santa Maria, RS, durante dois anos agrícolas (2003/2004 e 2004/2005 e com cinco épocas de semeadura em cada um deles. O delineamento experimental foi o inteiramente casualizado com quatro repetições. Cada repetição consistia de um vaso de 12 litros com 10 plantas. As datas dos estágios de desenvolvimento R2 (aparecimento do colar da folha bandeira e R9 (todos os grãos com casca marrom da escala de COUNCE foram registradas no colmo principal de cinco plantas por vaso. As cultivares utilizadas foram IRGA 421, IRGA 416, IRGA 417, IRGA 420, BR-IRGA 409, BRS 7 TAIM e EPAGRI 109. Considerando-se as temperaturas cardinais de 11 °C, 28 °C e 40 °C, a soma térmica para completar a fase emergência-R2 foi de 700-800 °C dia na cultivar muito precoce, 1000-1400 °C dia nas cultivares precoces e 1300-1700 °C dia nas cultivares médias e tardia, e a soma térmica para completar a fase R2-R9 foi de 400-700 °C dia e sem relação com o ciclo da cultivar.The COUNCE scale is a developmental scale recently proposed for rice and that is being used in Brazil. However, the duration of developmental phases of this scale in degree-days is not available for Brazilian irrigated rice cultivars. Thus, the objective of this study was to determine the thermal time of some developmental phases of the COUNCE scale in irrigated rice cultivars grown in Southern Brazil using

  17. 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.

  18. Crop performance, nitrogen and water use in flooded and aerobic rice

    NARCIS (Netherlands)

    Belder, P.; Bouman, B.A.M.; Spiertz, J.H.J.; Peng, S.; Castañeda, A.R.; Visperas, R.M.

    2005-01-01

    Abstract Irrigated aerobic rice is a new system being developed for lowland areas with water shortage and for favorable upland areas with access to supplementary irrigation. It entails the cultivation of nutrient-responsive cultivars in nonsaturated soil with sufficient external inputs to reach

  19. 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

  20. Influência da aplicação de nitrogênio e fungicida no estádio de emborrachamento sobre o desempenho agronômico do arroz irrigado Effect of nitrogen and fungicide application at booting stage on irrigated rice crop performace

    Directory of Open Access Journals (Sweden)

    Edivaldo Rabaioli Camargo

    2008-01-01

    yield. The objective of this experiment was to evaluate the effect of the nitrogen and fungicide application on booting stage in order to verify photosynthetic area and rice yield. This work was conducted in 2005/2006 in lowland area in Santa Maria, RS, Brazil. The treatments were nitrogen rates (50, 100, and 150 kg ha-1, composing the factor A, and management practices during the booting stage (supplementary application of 30 kg ha-1 nitrogen, fungicide application, and the combination of the previous treatments, besides check treatment, composing the factor D. The treatments were arranged in a randomized experimental block design, in a factorial scheme with four replications. The nitrogen rates promoted differentiated effects in the evaluated characteristics until booting stage (number of stem m-2, leaf area index and SPAD reading. However, there was not verified interaction among the treatments during rice grains filling. The management practices carried out on booting stage did not affect foliar area and senescence, yield and components of rice yield. The low occurrence of diseases, the efficiency of nitrogen utilization and the suitable climatic conditions for rice yield can explain the lack response to the management practices.

  1. Is small-scale irrigation an efficient pro-poor strategy in the upper Limpopo Basin in Mozambique?

    Science.gov (United States)

    Ducrot, Raphaelle

    2017-08-01

    In Sub-Saharan Africa, there is evidence that households with access to small-scale irrigation are significantly less poor than households that do not have access to irrigation. However, private motopumps tend to be distributed inequitably. This paper investigates the success of explicit pro-poor interventions with emphasis on small-scale irrigation in the semi-arid Limpopo Basin in Mozambique. It reveals that high irrigation costs are progressively excluding the poor, who are unable to generate a cash income from other activities they need to fund irrigation. In addition, the operation of collective schemes involving the poor is being jeopardized by the development of private irrigation schemes, which benefit from hidden subsidies appropriated by local elites. This results in unequal access to irrigation, which can cause resentment at community level. This weakens community cohesiveness, as well as communities' capacities for collective action and coordination, which are crucial for collective irrigation.

  2. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    2017-01-01

    . We argue that the effect has historical origins: irrigation allowed landed elites in arid areas to monopolize water and arable land. This made elites more powerful and better able to oppose democratization. Consistent with this conjecture, we show that irrigation dependence predicts land inequality...

  3. Effective colostomy irrigation.

    Science.gov (United States)

    Mazier, W P; Dignan, R D; Capehart, R J; Smith, B G

    1976-06-01

    The ultimate goal of the cone method of colostomy irrigation is to return patients with colostomies to their former role in society with confidence in themselves to the extent that having a colostomy is not considered a handicap. The results have generally been excellent. We believe all patients with stomas should be afforded the opportunity to attempt colostomy irrigation.

  4. 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 ...

  5. Modeled effects of irrigation on surface climate in the Heihe River Basin, Northwest China

    Science.gov (United States)

    Zhang, Xuezhen; Xiong, Zhe; Tang, Qiuhong

    2017-08-01

    In Northwest China, water originates from the mountain area and is largely used for irrigation agriculture in the middle reaches. This study investigates the local and remote impact of irrigation on regional climate in the Heihe River Basin, the second largest inland river basin in Northwest China. An irrigation scheme was developed and incorporated into the Weather Research and Forecasting (WRF) model with the Noah-MP land surface scheme (WRF/Noah-MP). The effects of irrigation is assessed by comparing the model simulations with and without consideration of irrigation (hereafter, IRRG and NATU simulations, respectively) for five growth seasons (May to September) from 2009 to 2013. As consequences of irrigation, daily mean temperature decreased by 1.7°C and humidity increased by 2.3 g kg-1 (corresponding to 38.5%) over irrigated area. The temperature and humidity of IRRG simulation matched well with the observations, whereas NATU simulation overestimated temperature and underestimated humidity over irrigated area. The effects on temperature and humidity are generally small outside the irrigated area. The cooling and wetting effects have opposing impacts on convective precipitation, resulting in a negligible change in localized precipitation over irrigated area. However, irrigation may induce water vapor convergence and enhance precipitation remotely in the southeastern portion of the Heihe River Basin.

  6. 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

  7. (PGMS) rice

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... tics, led us to predict that pollen cell abortion in this type of rice when ... averages of natural day-light-lengths and temperatures were used. A natural long ... blocks were allowed to grow under natural growth conditions (which.

  8. 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.

  9. Dwarf cashew growth irrigated with saline waters

    Directory of Open Access Journals (Sweden)

    Hugo Orlando Carvallo Guerra

    2009-12-01

    Full Text Available The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L. clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC. The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

  10. 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 ...

  11. Expanding the Annual Irrigation Maps (AIM) Product to the entire High Plains Aquifer (HPA): Addressing the Challenges of Cotton and Deficit-Irrigated Fields

    Science.gov (United States)

    Rapp, J. R.; Deines, J. M.; Kendall, A. D.; Hyndman, D. W.

    2017-12-01

    The High Plains Aquifer (HPA) is the most extensively irrigated aquifer in the continental United States and is the largest major aquifer in North America with an area of 500,000 km2. Increased demand for agricultural products has led to expanded irrigation extent, but brought with it declining groundwater levels that have made irrigation unsustainable in some locations. Understanding these irrigation dynamics and mapping irrigated areas through time are essential for future sustainable agricultural practices and hydrological modeling. Map products using remote sensing have only recently been able to track annual dynamics at relatively high spatial resolution (30 m) for a large portion of the northern HPA. However follow-on efforts to expand these maps to the entire HPA have met with difficulty due to the challenge of distinguishing irrigation in crop types that are commonly deficit- or partially-irrigated. Expanding these maps to the full HPA requires addressing unique features of partially irrigated fields and irrigated cotton, a major water user in the southern HPA. Working in Google Earth Engine, we used all available Landsat imagery to generate annual time series of vegetation indices. We combined this information with climate covariables, planting dates, and crop specific training data to algorithmically separate fully irrigated, partially irrigated, and non-irrigated field locations. The classification scheme was then applied to produce annual maps of irrigation across the entire HPA. The extensive use of ancillary data and the "greenness" time series for the algorithmic classification generally increased accuracy relative to previous efforts. High-accuracy, representative map products of irrigation extent capable of detecting crop type and irrigation intensity within aquifers will be an essential tool to monitor the sustainability of global aquifers and to provide a scientific bases for political and economic decisions affecting those aquifers.

  12. Determinants of farmers' participation in collective maintenance of irrigation infrastructure in KwaZulu-Natal

    Science.gov (United States)

    Sharaunga, S.; Mudhara, M.

    2018-06-01

    The decentralization framework and the Dublin Principles on Integrated Water Resource Management (IWRM) emphasize the need for a participatory approach to irrigation water management. This study identifies the factors influencing farmers' decision to, and extent of participation in the maintenance of irrigation infrastructure in KwaZulu-Natal province, South Africa based on cross-section data collected from 320 randomly selected smallholder irrigating farmers. A two-step Heckman regression model was applied in the analysis. It was established that households whose heads were older, block committee members, with larger irrigation plots, good soil quality and experiencing severe irrigation water shortages are more likely to participate in maintenance of irrigation infrastructure. On the other hand, farmers with insecure land tenure and with no access to irrigation water were less likely to make the decision to participate. Farmers who were members of the farming cooperative as well as block committee members and those paying irrigation water costs were likely to intensively participate in maintaining irrigation infrastructure. Therefore, decentralization alone cannot lead to improved irrigation outcomes. Several factors are necessary for households to participate intensively in the maintenance of irrigation infrastructure. Governments should address these challenges before handing irrigation schemes to their beneficiaries.

  13. 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.

  14. Solar-thermal jet pumping for irrigation

    Science.gov (United States)

    Clements, L. D.; Dellenback, P. A.; Bell, C. A.

    1980-01-01

    This paper describes a novel concept in solar powered irrigation pumping, gives measured performance data for the pump unit, and projected system performance. The solar-thermal jet pumping concept is centered around a conventional jet eductor pump which is commercially available at low cost. The jet eductor pump is powered by moderate temperature, moderate pressure Refrigerant-113 vapor supplied by a concentrating solar collector field. The R-113 vapor is direct condensed by the produced water and the two fluids are separated at the surface. The water goes on to use and the R-113 is repressurized and returned to the solar field. The key issue in the solar-thermal jet eductor concept is the efficiency of pump operation. Performance data from a small scale experimental unit which utilizes an electrically heated boiler in place of the solar field is presented. The solar-thermal jet eductor concept is compared with other solar irrigation concepts and optimal application situations are identified. Though having lower efficiencies than existing Rankine cycle solar-thermal irrigation systems, the mechanical and operational simplicity of this concept make it competitive with other solar powered irrigation schemes.

  15. Colour schemes

    DEFF Research Database (Denmark)

    van Leeuwen, Theo

    2013-01-01

    This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation.......This chapter presents a framework for analysing colour schemes based on a parametric approach that includes not only hue, value and saturation, but also purity, transparency, luminosity, luminescence, lustre, modulation and differentiation....

  16. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. A user-oriented and quantifiable approach to irrigation design.

    NARCIS (Netherlands)

    Baars, E.; Bastiaansen, A.P.M.; Menenti, M.

    1995-01-01

    A new user-oriented approach is presented to apply marketing research techniques to quantify perceptions, preferences and utility values of farmers. This approach was applied to design an improved water distribution method for an irrigation scheme in Mendoza, Argentina. The approach comprises two

  20. Wastewater irrigation in Jordan: A mismatch in macro nutrient provision

    NARCIS (Netherlands)

    Boom, S.; Huibers, F.P.; Lier, van J.B.

    2008-01-01

    By using sewage nutrients in irrigation, both the costs for nutrient removal and costs for fertilisers at the farm can be distinctly reduced. The present study describes the wastewater use scheme in the Seil Al-Zarqa and Middle Jordan Valley regions, Jordan. Through field studies, information on

  1. 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

  2. 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…

  3. Drip irrigation using a PLC based adaptive irrigation system

    OpenAIRE

    Shahidian, S.; Serralheiro, R. P.; Teixeira, J. L.; Santos, F. L.; Oliveira, M. R. G.; Costa, J. L.; Toureiro, C.; Haie, Naim; Machado, R. M.

    2009-01-01

    Most of the water used by man goes to irrigation. A major part of this water is used to irrigate small plots where it is not feasible to implement full-scale Evapotranspiration based irrigation controllers. During the growth season crop water needs do not remain constant and varies depending on the canopy, growth stage and climate conditions such as temperature, wind, relative humidity and solar radiation. Thus, it is necessary to find an economic irrigation controller that can adapt the dail...

  4. 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.

  5. 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.

  6. EFFECT OF GROWTH PROMOTOR AND BIOPROTECTOR ON THE DEVELOPMENT OF IRRIGATED RICE AND BROWN SPOT INCIDENCE USO DE PROMOTOR DE CRESCIMENTO E DE BIOPROTETOR NA CULTURA DO ARROZ IRRIGADO E SEU EFEITO SOBRE A INCIDÊNCIA DA MANCHA-DE-GRÃOS

    Directory of Open Access Journals (Sweden)

    Rodrigo Fascin Berni

    2007-09-01

    Full Text Available

    Two experiments were carried out to evaluate the effect of two commercial products, one containing plant-growth promoting rhizobacteria (PGPR and micorrhizae, and the other containing micronutrients and aminoacids, on the development of irrigated rice. One kilogram of the biological product Biosol (trade mark was added to the seeds at sowing time (1kg / ha and the biofertilizer Greensol (trade mark was sprayed by airplane (200 ml / ha in association with fungicides, when 5% of panicles had been emitted. The treatments used were T1: Control; T2: Greensol; T3: Biosol + Greensol and T4: Biosol. Five parameters were evaluated: number of shoots per meter, dry weight 90 days after sowing, grain yield, empty grains percentage and incidence of brown spot disease (Helminthosporium oryzae Breda de Haan. Number of shoots per meter was uniform in all treatments. Grouped analysis indicated superiority of all treatments with Biosol over the control for the parameters of dry weight of plants and roots. Treatments T3 and T4 presented superior yields. In these treatments empty grain percentage was lower than the control. Brown spot severity index indicated that all treatments were better than control and T3 and T4 treatments had the lowest disease index.

    KEY-WORDS: Helminthosporium oryzae; Oryza sativa; disease control; rice.

    Foram conduzidos dois experimentos com o objetivo de avaliar os efeitos de dois produtos comerciais sobre o desenvolvimento da cultura do arroz irrigado e sobre a incidência da mancha-de-grãos causada por Helminthosporium oryzae. Um dos produtos consistia de rizobactérias promotoras de crescimento de plantas (RPCPs e micorrizas (Biosol e o outro era constituído por micronutrientes e amino

  7. 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.

  8. Tradable schemes

    NARCIS (Netherlands)

    J.K. Hoogland (Jiri); C.D.D. Neumann

    2000-01-01

    textabstractIn this article we present a new approach to the numerical valuation of derivative securities. The method is based on our previous work where we formulated the theory of pricing in terms of tradables. The basic idea is to fit a finite difference scheme to exact solutions of the pricing

  9. An assessment of colostomy irrigation.

    Science.gov (United States)

    Laucks, S S; Mazier, W P; Milsom, J W; Buffin, S E; Anderson, J M; Warwick, M K; Surrell, J A

    1988-04-01

    One hundred patients with permanent sigmoid colostomies were surveyed to determine their satisfaction and success with the "irrigation" technique of colostomy management. Most patients who irrigate their colostomies achieve continence. Odors and skin irritation are minimized. The irrigation method is economical, time efficient, and allows a reasonably liberal diet. It avoids bulky appliances and is safe. In appropriately selected patients, the irrigation technique is the method of choice for management of an end-sigmoid colostomy.

  10. 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

  11. 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.

  12. 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.

  13. Multiple-use Management of Irrigation Systems: Technical Constraints and Challenges

    Science.gov (United States)

    Gowing, J.; Li, Q.; Mayilswami, C.; Gunawardhana, K.

    It is now widely recognised that many irrigation systems, originally planned only for irrigation supply, are de facto multiple-use systems. However, the importance of non- irrigation uses (such as bathing, laundry, livestock watering and fishing), to the liveli- hoods of the rural poor has generally been ignored. This has significant implications for irrigation engineers, water resources managers and other decision-makers. An im- proved understanding of competition and complementarity between these uses and irrigation demands is essential for effective multiple-use management of irrigation systems.This paper presents a study of multiple-use management, where the focus is on integrating aquaculture within irrigation systems with and without secondary storage. The Lower Bhavani scheme in South India and Mahaweli System H in Sri- Lanka were selected as representative smallholder irrigation schemes: - The Lower Bhavani scheme comprises a 200km contour canal serving a command area of 78,500ha. Apart from the main dam, there are no storage structures within the irriga- tion system. - Mahaweli System H comprises a command area of 43,000ha served by three main canals. The feature of particular interest in this scheme is the large number of secondary storage structures (known locally as tanks), which are in- tegrated within the canal network. It is apparent from these two sites and from studies elsewhere that non-irrigation uses are important to the livelihoods of the local peo- ple, but these uses are largely opportunistic. The failure to give explicit recognition to non-irrigation uses has important implications for assessments of economic per- formance and water productivity of irrigation systems. However, any attempt to give proper recognition to these alternative uses also has implication for irrigation project management. This paper describes a detailed study of water management in the two irrigation systems. The method of investigation involves in-depth studies in

  14. Hydrological drought index insurance for irrigation districts in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Maestro, T.; Bielza, M.; Garrido, A.

    2016-11-01

    Hydrological droughts are a major risk for irrigated agriculture in many regions of the world. The aim of this article is to propose an insurance tool to help irrigators manage the risk of water scarcity in the framework of the Spanish Crop Insurance System (SCIS). Only the United States Insurance System provides this type of coverage, but has very restrictive conditions. To determine the type of insurance scheme that better fits with the SCIS and to the Spanish irrigated agriculture, an expert panel was held with the participation of all stakeholders involved in crop insurance. Following the expert panel conclusions, an hydrological drought index insurance (HDII) addressed to irrigation districts (ID) is proposed. It would compensate water deficits suffered in the whole ID. We detail the conditions that the ID should fulfill to be eligible for HDII. HDII is applied to the Bardenas Irrigation District V (ID-V) in Spain, and the hedging effectiveness of the instrument is analyzed comparing ID-V’s gross margins with and without the insurance contract. Results suggest that the proposed insurance scheme could provide an effective means of reducing farmers’ vulnerability to water shortages and there is no major impediment for it to be included as a new line in the SCIS. This type of insurance can be generalized to any ID fulfilling the conditions mentioned in this paper. (Author)

  15. Classification and Mapping of Paddy Rice by Combining Landsat and SAR Time Series Data

    Directory of Open Access Journals (Sweden)

    Seonyoung Park

    2018-03-01

    Full Text Available Rice is an important food resource, and the demand for rice has increased as population has expanded. Therefore, accurate paddy rice classification and monitoring are necessary to identify and forecast rice production. Satellite data have been often used to produce paddy rice maps with more frequent update cycle (e.g., every year than field surveys. Many satellite data, including both optical and SAR sensor data (e.g., Landsat, MODIS, and ALOS PALSAR, have been employed to classify paddy rice. In the present study, time series data from Landsat, RADARSAT-1, and ALOS PALSAR satellite sensors were synergistically used to classify paddy rice through machine learning approaches over two different climate regions (sites A and B. Six schemes considering the composition of various combinations of input data by sensor and collection date were evaluated. Scheme 6 that fused optical and SAR sensor time series data at the decision level yielded the highest accuracy (98.67% for site A and 93.87% for site B. Performance of paddy rice classification was better in site A than site B, which consists of heterogeneous land cover and has low data availability due to a high cloud cover rate. This study also proposed Paddy Rice Mapping Index (PMI considering spectral and phenological characteristics of paddy rice. PMI represented well the spatial distribution of paddy rice in both regions. Google Earth Engine was adopted to produce paddy rice maps over larger areas using the proposed PMI-based approach.

  16. Optimized Subsurface Irrigation System: The Future of Sugarcane Irrigation

    Directory of Open Access Journals (Sweden)

    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.

  17. Portable photovoltaic irrigation pumps

    Energy Technology Data Exchange (ETDEWEB)

    Furber, J. D.

    1980-07-01

    Experiences in developing a solar-powered irrigation pump to meet the needs of poor farmers in developing nations are summarized. The design which evolved is small and portable, employing a high-efficiency electric pump, powered by photovoltaic panels. Particular emphasis is placed on how the system works, and on early field problems experienced with the first prototypes. The resolution of these problems and the performance of actual systems in various countries is presented and user responses are noted.

  18. Mathematical model for scheduling irrigation for swamp rice in Port ...

    African Journals Online (AJOL)

    While the mother model indicated that the planted crops will be under severe water stress because the values of their d2 were below the allowable range of water depletion except in weeks 1,7,10,16 and 17 with their d2 values to be; 178.50mm, 181.47mm, 162.11mm, 198.80mm and 187.60mm respectively. Water ...

  19. The impact of irrigated rice on the transmission of schistosomiasis ...

    African Journals Online (AJOL)

    The prevalence and intensity of the infection caused by schistosomiasis and geohelmintiasis were ... high before implementation (Audibert et al., 2001;. Barboza et al., 2012). .... body weight) and with Mebendazole for .... CI = Confidence interval;LRT = lke lihood ratio Test; .... composition of the soil and climatic factors.

  20. Irrigation Suitability Assessment of Effluents From West Kano Rice ...

    African Journals Online (AJOL)

    Choice-Academy

    lake water, and an excess in effluents. The excess nitrates in effluents pollute the lake, but could help as crop .... modelling assessment method proposed in this study can be used to ... economic and environmental impact assessment research ...

  1. 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

  2. [Irrigation in colostomies].

    Science.gov (United States)

    Campo, Juana; Lecona, Ana; Caparrós, M Rosario; Barbero, M Antonia; Javier Cerdán, F

    2002-01-01

    The degree of acceptation of irrigation from a colostomy varies ostensibly from some cases to others, therefore, we study what occurs in our medium, separating those patients which have previously undergone other procedures (Group A) from those patients who have been informed and trained about the immediate postoperative period (Group B). 48 patients, 22 or 46% of these patients were considered not apt for irrigation. Of the 26 to whom this procedure was proposed, 14 or 54% accepted. Of these, 5 or 36% abandoned its use while 9 continued its use; this is 64% of those who accepted this procedure, 35% of those to whom it was proposed and 19% of the total study group. 189 patients. This procedure was not recommended to 95 patients, 50%. Of the 94 patients to whom this procedure was proposed, 65 or 69% accepted. Of these, 22 or 34% abandoned its use while 43 continued its use; this is 66% of those; who accepted this procedure, 46% of those to whom it was proposed and 23% of the total study group. In our medium, the practice of irrigation oscillates between 19 and 23% of patients who have undergone a colostomy, without any significant difference referring to the moment when a patient started this procedure. A first report on this study was submitted in the III National Congress for Nursing in Colostomies.

  3. 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.

  4. 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...

  5. ROOT CANAL IRRIGANTS AND IRRIGATION TECHNIQUES: A REVIEW

    OpenAIRE

    Aniketh; Mohamed; Geeta; Nandakishore; Gourav Kumar; Patrick Timothy; Jayson Mathew; Sahle Abdul

    2015-01-01

    Root canal irrigation is not much emphasised in endodontic therapy. Most articles discussed are on root canal shaping and obturation not much emphasis is given for irrigation. There are many irrigation solutions which are introduced into market. The primary objective of root canal therapy is the ret ention of the pulpless or pulpally involved tooth with its associated periapical tissues in a healthy state. Achievement of this objective requires that the pulpal spaces and con...

  6. 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

  7. 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.

  8. Dissemination of sustainable irrigation strategies for almond and olive orchards via a participatory approach. Project LIFE+IRRIMAN

    Science.gov (United States)

    Garcia-Vila, Margarita; Gamero-Ojeda, Pablo; Ascension Carmona, Maria; Berlanga, Jose; Fereres, Elias

    2017-04-01

    Dissemination of sustainable irrigation strategies for almond and olive orchards via a participatory approach. Project LIFE+IRRIMAN Spain is the world's first and third largest producer of olive oil and almond, respectively. Despite huge efforts in the last years by the production sector towards intensification, cultural issues relative to the traditional rain-fed crop management know how, prevent farmers from adoption of sustainable irrigation management practices. Consequently, even though there has been progress in irrigation management research for these two crops, adoption of modern irrigation techniques by farmers has been slow. Sustainable irrigation strategies for olive and almond orchards are being designed, implemented, validated and disseminated under the framework of the LIFE+ IRRIMAN project, through a participatory approach. The implementation of the LIFE+ IRRIMAN innovative and demonstrative actions has been carried out in an irrigation district of Southern Spain (Genil-Cabra Irrigation Scheme, Andalusia). The approach designed has four phases: i) design and implementation of sustainable irrigation strategies in demonstration farms; ii) dissemination of best irrigation practices which were tested in the initial year throughout the irrigation scheme by the irrigation advisory service; iii) assessment of degree of adoption and re-design of the dissemination strategies; and, iv) based on the results obtained, elaboration of sustainable irrigation guidelines for knowledge transfer in the district at regional and national levels to promote changes in irrigation practices. Participatory approaches have proven to be effective tools for successful irrigation strategies design and diffusion, especially in traditional rain fed crops such as olive and almond trees in the Mediterranean countries. Acknowledgements This work has been funded by the European Union LIFE+ project IRRIMAN (LIFE13 ENV/ES/000539).

  9. 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.

  10. Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance

    NARCIS (Netherlands)

    Benouniche, M.; Kuper, M.; Hammani, A.; Boesveld, H.

    2014-01-01

    The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured

  11. 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)

  12. Soil Salt Distribution and Tomato Response to Saline Water Irrigation under Straw Mulching.

    Directory of Open Access Journals (Sweden)

    Yaming Zhai

    Full Text Available To investigate better saline water irrigation scheme for tomatoes that scheduling with the compromise among yield (Yt, quality, irrigation water use efficiency (IWUE and soil salt residual, an experiment with three irrigation quotas and three salinities of irrigation water was conducted under straw mulching in northern China. The irrigation quota levels were 280 mm (W1, 320 mm (W2 and 360 mm (W3, and the salinity levels were 1.0 dS/m (F, 3.0 dS/m (S1 and 5.0 dS/m (S2. Compared to freshwater, saline water irrigations decreased the maximum leaf area index (LAIm of tomatoes, and the LAIm presented a decline tendency with higher salinity and lower irrigation quota. The best overall quality of tomato was obtained by S2W1, with the comprehensive quality index of 3.61. A higher salinity and lower irrigation quota resulted in a decrease of individual fruit weight and an increase of the blossom-end rot incidence, finally led to a reduction in the tomato Yt and marketable yield (Ym. After one growth season of tomato, the mass fraction of soil salt in plough layer under S2W1 treatment was the highest, and which presented a decline trend with an increasing irrigation quota. Moreover, compared to W1, soil salts had a tendency to move to the deeper soil layer when using W2 and W3 irrigation quota. According to the calculation results of projection pursuit model, S1W3 was the optimal treatment that possessed the best comprehensive benefit (tomato overall quality, Yt, Ym, IWUE and soil salt residual, and was recommended as the saline water irrigation scheme for tomatoes in northern China.

  13. Soil Salt Distribution and Tomato Response to Saline Water Irrigation under Straw Mulching.

    Science.gov (United States)

    Zhai, Yaming; Yang, Qian; Wu, Yunyu

    2016-01-01

    To investigate better saline water irrigation scheme for tomatoes that scheduling with the compromise among yield (Yt), quality, irrigation water use efficiency (IWUE) and soil salt residual, an experiment with three irrigation quotas and three salinities of irrigation water was conducted under straw mulching in northern China. The irrigation quota levels were 280 mm (W1), 320 mm (W2) and 360 mm (W3), and the salinity levels were 1.0 dS/m (F), 3.0 dS/m (S1) and 5.0 dS/m (S2). Compared to freshwater, saline water irrigations decreased the maximum leaf area index (LAIm) of tomatoes, and the LAIm presented a decline tendency with higher salinity and lower irrigation quota. The best overall quality of tomato was obtained by S2W1, with the comprehensive quality index of 3.61. A higher salinity and lower irrigation quota resulted in a decrease of individual fruit weight and an increase of the blossom-end rot incidence, finally led to a reduction in the tomato Yt and marketable yield (Ym). After one growth season of tomato, the mass fraction of soil salt in plough layer under S2W1 treatment was the highest, and which presented a decline trend with an increasing irrigation quota. Moreover, compared to W1, soil salts had a tendency to move to the deeper soil layer when using W2 and W3 irrigation quota. According to the calculation results of projection pursuit model, S1W3 was the optimal treatment that possessed the best comprehensive benefit (tomato overall quality, Yt, Ym, IWUE and soil salt residual), and was recommended as the saline water irrigation scheme for tomatoes in northern China.

  14. Irrigation water management: Basic principles and applications

    OpenAIRE

    Ella, Victor B.

    2007-01-01

    This presentation defines the term, irrigation, as well as explains the common methods of irrigation in attempt to define the fundamental principles needed to wisely design an irrigation system. It outlines a typical drip irrigation set-up, and discusses management of an irrigation system, including water volume application suggestions. LTRA-5 (Agroforestry and Sustainable Vegetable Production)

  15. 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.

  16. Agriculture Irrigation and Water Use

    OpenAIRE

    Bajwa, Rajinder S.; Crosswhite, William M.; Hostetler, John E.; Wright, Olivia W.; United States Department of Agriculture, Economic Research Service

    1992-01-01

    The 17 Western States, plus Arkansas, Florida, and Louisiana, account for 91 percent of all U.S. irrigated acreage, with the Western States alone contributing over 85 percent. This report integrates data on the distribution, characteristics, uses, and management of water resources from a wide variety of data sources. The report includes charts and tables on water use in irrigation; farm data comparing selected characteristics of irrigated and nonirrigated farms; and data on water applicatio...

  17. Estrutura fitossociológia de um fragmento natural de floresta inundável em área de orizicultura irrigada, município de Lagoa da Confusão, Tocantins Phytosociologial structure of a natural fragment of floodplain forest in area of irrigated rice cultivation, municipal district of Lagoa da Confusão, Tocantins, Brazil

    Directory of Open Access Journals (Sweden)

    Elizabeth Rodrigues Brito

    2006-10-01

    , inserted in area of irrigated rice cultivation. For the phytosociological survey, all the tree/shrub individuals with perimeter at 1.30m (PBH > 15 cm were sampled. On the whole, 807 individuals, 35 families and 70 species were sampled. The species with higher VC, in descending order, were Hirtella racemosa Lam., Qualea multiflora Mart. and Cecropia pachystachya Trécul. The richest families in species were Fabaceae (9, Vochysiaceae (6, Annonaceae and Malvaceae (4. The Shannon diversity index (H' was 3.44. The distribution of diameter classes showed an inverted "J" curve, with most of the individuals being in the first class.

  18. Irrigation management of sigmoid colostomy.

    Science.gov (United States)

    Jao, S W; Beart, R W; Wendorf, L J; Ilstrup, D M

    1985-08-01

    Questionnaires were sent to 270 patients who had undergone abdominoperineal resection and sigmoid colostomy at the Mayo Clinic, Rochester, Minn, during the ten years from 1972 to 1982; 223 patients returned their questionnaires with evaluable data. Sixty percent of the patients were continent with irrigation, and 22% were incontinent with irrigation. Eighteen percent had discontinued irrigation for various reasons. The proportion continent was higher in women, younger patients, and previously constipated patients. A poorly constructed colostomy may cause acute angle, parastoma hernia, stomal prolapse, or stenosis and thus be the cause of failure of irrigation.

  19. 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.

  20. Rice peasants and rice research in Colombia

    NARCIS (Netherlands)

    Spijkers, P.A.N.M.

    1983-01-01

    Rice has been grown as a food crop in Latin America from early colonial times. In Colombia rice became a prominent subsistence crop especially on the north coast where it has been grown since the 17th century, sometimes also as a commercial crop. During the last twenty years there has been a sharp

  1. 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.

  2. Assessment of Irrigation Water Quality and Suitability for Irrigation in ...

    African Journals Online (AJOL)

    A number of factors like geology, soil, effluents, sewage disposal and other environmental conditions in which the water stays or moves and interacts are among the factors that affect the quality of irrigation water. This study was conducted to determine the quality and suitability of different water sources for irrigation purpose ...

  3. Effect of irrigation on heavy metals content of wastewater irrigated ...

    African Journals Online (AJOL)

    There is an urgent need to educate farmers on the dangers of the presence of heavy metals in soils as well as the quality of irrigation water especially if it comes from tanning industries for increased crop production. Accordingly, soil and irrigation wastewater study was conducted to assess the concentrations of heavy ...

  4. 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

  5. Geothermal rice drying unit in Kotchany, Macedonia

    International Nuclear Information System (INIS)

    Popovski, K.; Dimitrov, K.; Andrejevski, B.; Popovska, S.

    1992-01-01

    A geothermal field in Kotchany (Macedonia) has very advantageous characteristics for direct application purposes. Low content of minerals, moderate temperature (78C) and substantial available geothermal water flow (up to 300 1/s) enabled the establishment of a district heating scheme comprising mainly agricultural and industrial uses. A rice drying unit of 10 t/h capacity was installed 8 years ago, using the geothermal water as the primary heat source. A temperature drop of 75/50C enables the adaptation of conventional drying technology, already proven in practice in the surrounding rice growing region. Water to air heat exchanger and all necessary equipment and materials are of local production, made of copper and carbon steel. The use of such drying units is strongly recommended for the concrete district heating scheme because it offers a very simple geothermal application and enables improvement in the annual heating load factor without high investments in geothermal water distribution lines

  6. 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

  7. Additive operator-difference schemes splitting schemes

    CERN Document Server

    Vabishchevich, Petr N

    2013-01-01

    Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

  8. How Patients Experience Antral Irrigation

    Directory of Open Access Journals (Sweden)

    Karin Blomgren

    2015-01-01

    Full Text Available Background Antral irrigation earlier had an important role in the diagnosis and treatment of rhinosinusitis. Nowadays, it is often considered too unpleasant. However, the experience of patients of this procedure has been very seldom evaluated. Nor has the effect on pain in rhinosinusitis been evaluated. The aim of this study was to evaluate patients’ experience of discomfort and pain during antral irrigation. We also assessed facial pain caused by rhinosinusitis before the procedure and pain soon after the procedure. Methods Doctors and 121 patients completed their questionnaires independently after antral irrigation in a university clinic, in a private hospital, and at a communal health center. Results Patients experienced mild pain during antral irrigation (mean and median visual analog scale score: <3. Their experience of pain during antral irrigation was closely comparable to pain during dental calculus scaling. Facial pain assessed before antral irrigation decreased quickly after the procedure. Conclusions Antral irrigation was well tolerated as an outpatient procedure. The procedure seems to relieve facial pain caused by the disease quickly. The role of antral irrigation in the treatment of acute rhinosinusitis will need further investigation.

  9. Irrigation management in organic greenhouse

    NARCIS (Netherlands)

    Voogt, W.; Balendonck, J.; Berkelmans, R.; Enthoven, N.

    2017-01-01

    Irrigation in protected cultivation is essential due to the absence of natural precipitation. High evapotranspiration, due to higher temperature and prolonged cropping period, requires ample an adequate supply of water. The water supply in a greenhouse is solely carried out by irrigation and thus

  10. Scintigraphic assessment of colostomy irrigation.

    Science.gov (United States)

    Christensen, P.; Olsen, N.; Krogh, K.; Laurberg, S.

    2002-09-01

    OBJECTIVE: This study aims to evaluate colonic transport following colostomy irrigation with a new scintigraphic technique. MATERIALS AND METHODS: To label the bowel contents 19 patients (11 uncomplicated colostomy irrigation, 8 complicated colostomy irrigation) took 111In-labelled polystyrene pellets one and two days before investigation. 99mTc-DTPA was mixed with the irrigation fluid to assess its extent within the bowel. Scintigraphy was performed before and after a standardized washout procedure. The colon was divided into three segments 1: the caecum andascending colon; 2: the transverse colon; 3: the descending and sigmoid colon. Assuming ordered evacuation of the colon, the contribution of each colonic segment to the total evacuation was expressed as a percentage of the original segmental counts. These were added to reach a total defaecation score (range: 0-300). RESULTS: In uncomplicated colostomy irrigation, the median defaecation score was 235 (range: 145-289) corresponding to complete evacuation of the descending and transverse colon and 35% evacuation of the caecum/ascending colon. In complicated colostomy irrigation it was possible to distinguish specific emptying patterns. The retained irrigation fluid reached the caecum in all but one patient. CONCLUSION: Scintigraphy can be used to evaluate colonic emptying following colostomy irrigation.

  11. Are There Infinite Irrigation Trees?

    Science.gov (United States)

    Bernot, M.; Caselles, V.; Morel, J. M.

    2006-08-01

    In many natural or artificial flow systems, a fluid flow network succeeds in irrigating every point of a volume from a source. Examples are the blood vessels, the bronchial tree and many irrigation and draining systems. Such systems have raised recently a lot of interest and some attempts have been made to formalize their description, as a finite tree of tubes, and their scaling laws [25], [26]. In contrast, several mathematical models [5], [22], [10], propose an idealization of these irrigation trees, where a countable set of tubes irrigates any point of a volume with positive Lebesgue measure. There is no geometric obstruction to this infinitesimal model and general existence and structure theorems have been proved. As we show, there may instead be an energetic obstruction. Under Poiseuille law R(s) = s -2 for the resistance of tubes with section s, the dissipated power of a volume irrigating tree cannot be finite. In other terms, infinite irrigation trees seem to be impossible from the fluid mechanics viewpoint. This also implies that the usual principle analysis performed for the biological models needs not to impose a minimal size for the tubes of an irrigating tree; the existence of the minimal size can be proven from the only two obvious conditions for such irrigation trees, namely the Kirchhoff and Poiseuille laws.

  12. 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.

  13. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Irrigating The Environment

    Science.gov (United States)

    Adamson, D.

    2017-12-01

    Water insecurity and water inequality are international issues that reduce economic growth. Countries are adopting alternative approaches to rebalance the share of water between all users to mitigate economic loss for this and future generations. However, recent reforms have struggled to provide the necessary arguments to obtain political protection of the process. In the absence of proof, rent-seeking arguments have challenged the benefit of restoring environmental flows by arguing that policy design fails to maximise the environmental benefits. This is a problem in Australia's Murray-Darling Basin (MDB), where despite establishing 3,200GL of environmental water, the policy is still under threat. Applied water economic policy advice fails, when it does not deal with uncertainty. The state-contingent analysis approach can map how individual decision makers can adapt to alternative states of water supply (i.e. drought, normal and wet) by reallocating inputs to obtain state-described outputs. By modelling changes to the states, or the frequency of the states occurring, climate change can modelled, and decision management responses explored. By treating the environment as another set of production systems, lessons learnt from managing perennial and annual agricultural production systems during the Millennium Drought in the MDB can be applied to explore the limits of irrigating the environment. The demand for water by a production system is a combination of state-general (must be irrigated every year e.g. perennial crop or permanent wetland) and state specific inputs (irrigate in response to the realise state). In simple terms, the greater the component of state-general water requirements a production system has, the less resilience it has when water supply is highly variable and if water is not available then production systems are irreversibly lost. While production systems that only need state-allocable water can adapt to alternative levels of scarcity without

  16. Choosing soil management systems for rice production on lowland soils in South Brazil

    NARCIS (Netherlands)

    Lima, A.C.R.; Hoogmoed, W.B.

    2009-01-01

    Lowland soils are commonly found in the state of Rio Grande do Sul, Southern of Brazil, where they represent around 20% of the total area of the state. Deficient drainage is the most important natural characteristic of these soils which therefore are mainly in use for flood-irrigated rice (Oriza

  17. 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, ...

  18. 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...

  19. 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

  20. 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

  1. 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

  2. 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.

  3. Assessment of irrigation performance: contribution to improve water management in a small catchment in the Brazilian savannas

    Science.gov (United States)

    Rodrigues, Lineu; Marioti, Juliana; Steenhuis, Tammo; Wallender, Wesley

    2010-05-01

    systems, one microirrigation system and three center pivots schemes. Field evaluations used the method advocated by Keller and Bliesner and conducted during farmer scheduled irrigation. Soil samples were taken before irrigations to investigate adequacy of water applied. Since the irrigation water management and the uniformity of water distribution are the two major factors used to define the quality of irrigation, the following criteria for uniformity was used: i) Localized irrigations (distribution uniformity - UD) - excellent (90% management criteria, in agricultural basins, once irrigation water becomes limiting and reduces basin water productivity.

  4. 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...

  5. Sensing technologies for precision irrigation

    CERN Document Server

    Ćulibrk, Dubravko; Minic, Vladan; Alonso Fernandez, Marta; Alvarez Osuna, Javier; Crnojevic, Vladimir

    2014-01-01

    This brief provides an overview of state-of-the-art sensing technologies relevant to the problem of precision irrigation, an emerging field within the domain of precision agriculture. Applications of wireless sensor networks, satellite data and geographic information systems in the domain are covered. This brief presents the basic concepts of the technologies and emphasizes the practical aspects that enable the implementation of intelligent irrigation systems. The authors target a broad audience interested in this theme and organize the content in five chapters, each concerned with a specific technology needed to address the problem of optimal crop irrigation. Professionals and researchers will find the text a thorough survey with practical applications.

  6. 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

  7. Colostomy irrigation: are we offering it enough?

    Science.gov (United States)

    Woodhouse, Fran

    This article discusses the use of irrigation for suitable colostomists and reasons why it can have a very positive effect on lifestyle. While it is evidence-based it also includes anecdotal tips from patients who irrigate. The suitability of patients to irrigate and ways to 'get started' with irrigation are discussed.

  8. Evaluation model development for sprinkler irrigation uniformity ...

    African Journals Online (AJOL)

    use

    Sprinkle and trickle irrigation. The. Blackburn Press, New Jersey, USA. Li JS, Rao MJ (1999). Evaluation method of sprinkler irrigation nonuniformity. Trans. CSAE. 15(4): 78-82. Lin Z, Merkley GP (2011). Relationships between common irrigation application uniformity indicators. Irrig Sci. Online First™, 27 January. 2011.

  9. Wireless sensor networks for irrigation management

    Science.gov (United States)

    Sustaining an adequate food supply for the world's population will require advancements in irrigation technology and improved irrigation management. Site-specific irrigation and automatic irrigation scheduling are examples of strategies to deal with declining arable land and limited fresh water reso...

  10. Condensation irrigation a system for desalination and irrigation

    International Nuclear Information System (INIS)

    Lindblom, J.; Nordell, B

    2006-01-01

    condensation irrigation is a system for both desalination and irrigation. The principles is that humidified air is let into an underground horizontal pipe system, where the air is cooled by the ground and humidity falls out as fresh water. The humidification could e.g. be achieved by evaporation of seawater in solar stills or any other heat source. By using drainage pipes for underground air transportation the water percolates into the soil, thereby irrigating the land. This study focuses on drinking water production, which means that humid air is led into plan pipes where the condensed water is collected at the pipe endings. Numerical simulations gave a study-state diurnal mean water production of 1.8 kg per meter of pipe over a 50 m pipe. Shorter pipes result in a greater mean production rate. Since the heat transfer of drainage pipes would be greater, current study indicates that condensation irrigation is a promising method for desalination and irrigation. Performed studies in condensation irrigation started at LTU in 2003. Current paper reports the initial theoretical work on the system.(Author)

  11. 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.

  12. 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

  13. Adaptive management of irrigation and crops' biodiversity: a case study on tomato

    Science.gov (United States)

    De Lorenzi, Francesca; Alfieri, Silvia Maria; Basile, Angelo; Bonfante, Antonello; Monaco, Eugenia; Riccardi, Maria; Menenti, Massimo

    2013-04-01

    We have assessed the impacts of climate change and evaluated options to adapt irrigation management in the face of predicted changes of agricultural water demand. We have evaluated irrigation scheduling and its effectiveness (versus crop transpiration), and cultivars' adaptability. The spatial and temporal variations of effectiveness and adaptability were studied in an irrigated district of Southern Italy. Two climate scenarios were considered: reference (1961-90) and future (2021-2050) climate, the former from climatic statistics, and the latter from statistical downscaling of general circulation models (AOGCM). Climatic data consist of daily time series of maximum and minimum temperature, and daily rainfall on a grid with a spatial resolution of 35 km. The work was carried out in the Destra Sele irrigation scheme (18.000 ha. Twenty-five soil units were identified and their hydrological properties were determined (measured or estimated from texture through pedo-transfer functions). A tomato crop, in a rotation typical of the area, was considered. A mechanistic model of water flow in the soil-plant-atmosphere system (SWAP) was used to study crop water requirements and water consumption. The model was calibrated and validated in the same area for many different crops. Tomato crop input data and model parameters were estimated on the basis of scientific literature and assumed to be generically representative of the species. Simulations were performed for reference and future climate, and for different irrigation scheduling options. In all soil units, six levels of irrigation volumes were applied: full irrigation (100%), deficit irrigation (80%, 60%, 40%, 20%), no irrigation. From simulation runs, indicators of soil water availability were calculated, moreover the marginal increases of transpiration per unit of irrigation volume, i.e. the effectiveness of irrigation (ΔT/I), were computed, in both climate scenarios. Indicators and marginal increases were used to

  14. 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

  15. 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...

  16. Rice (Oryza) hemoglobins

    Science.gov (United States)

    Hemoglobins (Hbs) corresponding to non-symbiotic (nsHb) and truncated (tHb) Hbs have been identified in rice (Oryza). This review discusses the major findings from the current studies on rice Hbs. At the molecular level, a family of the nshb genes, consisting of hb1, hb2, hb3, hb4 and hb5, and a sin...

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

    Directory of Open Access Journals (Sweden)

    Tamrin Abdullah

    2015-08-01

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

  18. Biodiversity Conservation in Rice Paddies in China: Toward Ecological Sustainability

    Directory of Open Access Journals (Sweden)

    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.

  19. 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.

  20. 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.

  1. Morphophysiology of guava under saline water irrigation and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Idelfonso L. Bezerra

    Full Text Available ABSTRACT The aim of this study was to evaluate the growth of grafted guava cv. ‘Paluma’ subjected to different concentrations of salts in irrigation water and nitrogen (N fertilization. The plants were transplanted to 150 L lysimeters and under field conditions at the Science and Agri-food Technology Center of the Federal University of Campina Grande, in the municipality of Pombal - PB. The experiment was conducted in randomized block design in a 5 x 4 factorial scheme, with three replicates, and the treatments corresponded to five levels of electrical conductivity of irrigation water - ECw (0.3; 1.1; 1.9; 2.7 and 3.5 dS m-1 and four N doses (70, 100, 130 and 160% of the N dose recommended for the crop. The doses equivalent to 100% corresponded to 541.1 mg of N dm-3 of soil. Irrigation water salinity above 0.3 dS m-1 negatively affects the number of leaves, leaf area, stem diameter, dry phytomass of leaves, branches and shoots . A significant interaction between irrigation water salinity and N fertilization was observed only for the number of leaves and leaf area at 120 days after transplanting. N dose above 70% of the recommendation (378.7 mg N dm-3 soil did not mitigate the deleterious effects caused by salt stress on plant growth.

  2. Pricing Unmetered Irrigation Water under Asymmetric Information and Full Cost Recovery

    Directory of Open Access Journals (Sweden)

    Alban Lika

    2016-12-01

    Full Text Available The objective of this study is to define an efficient pricing scheme for irrigation water in conditions of unmetered water use. The study is based on a principal-agent model and identifies a menu of contracts, defined as a set of payments and share of irrigated area, able to provide incentives for an efficient use of the resource by maximizing social welfare. The model is applied in the case study of the Çukas region (Albania where irrigation water is not metered. The results demonstrate that using a menu of contracts makes it possible to define a second best solution that may improve the overall social welfare derived from irrigation water use compared with the existing pricing structure, though, in the specific case study, the improvement is small. Furthermore, the results also suggest that irrigation water pricing policy needs to take into account different farm types, and that appropriate contract-type pricing schemes have a potential role in providing incentives to farmers to make irrigation choices to the social optimum.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. performance evaluation of sprinkler irrigation system at mambilla

    African Journals Online (AJOL)

    HOD

    ratio (DPR), irrigation productivity (IP), labour requirements and water quality. Standard procedure was ... The exchangeable cations analysis of Kakara irrigation ... Keywords: Tea, irrigation System, Performance Evaluation. 1. INTRODUCTION.

  8. 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.

  9. 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.

  10. 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)

  11. Influence of ethyl-trinexapac on 15N accumulation and distribution and on highland rice yield

    International Nuclear Information System (INIS)

    Alvarez, Rita de Cassia Felix; Crusciol, Carlos Alexandre Costa; Alvarez, Angela Cristina Camarim; Trivelin, Paulo Cesar Ocheuze; Rodrigues, Joao Domingos

    2007-01-01

    The high rice grain yields ensured by sprinkler irrigation have encouraged the use of higher fertilizer doses, mainly the nitrogen fertilizers. However, an improper management of nitrogen fertilization may result in plant lodging. Application of plant regulators may redirect assimilates to grain production while limiting the vegetative growth. This study aimed to: evaluate the influence of the growth regulator Ethyl-trinexapac on plant growth parameters and on 15 N accumulation and distribution in the whole plant and plant components, and determine the contribution of nitrogen taken up in different developmental stages in panicle formation, yield components and rice yield. The experiment was carried out under controlled greenhouse conditions. The treatments consisted of application or not of a plant growth regulator (0 and 200 g active ingredient ha-1 of ethyl-trinexapac) at four plant development stages (beginning to end of tillering; end of tillering and flower differentiation; flower differentiation to flowering; flowering until physiological maturation). The experimental design was arranged in random blocks, in a 2 x 4 factorial scheme, with three replications. The plants were placed in a group of 48 pots. In a group of 24 pots with nutrient solution containing 15 NH 4 SO 4 , plants were collected and separated in parts in the beginning of each pre-established plant development stage and at the end of each stage. In a second group (24 pots), pre-labeled plants were left to grow in nutrient solution with 14 NH 4 SO 4 and harvested at the end of each cycle in order to access 15 N redistribution.. The growth regulator reduced plant height and 15 N accumulation in the panicle and promoted redistribution of the absorbed 15 N, and increased accumulated 15 N in root, stem+sheats and leaves. The contribution of absorbed 15 N to panicle formation in each stage increased with the plant development, though in a lower proportion in the presence of the growth regulator

  12. Food security, irrigation, climate change, and water scarcity in India

    Science.gov (United States)

    Hertel, T. W.; Taheripour, F.; Gopalakrishnan, B. N.; Sahin, S.; Escurra, J.

    2015-12-01

    This paper uses an advanced CGE model (Taheripour et al., 2013) coupled with hydrological projections of future water scarcity and biophysical data on likely crop yields under climate change to examine how water scarcity, climate change, and trade jointly alter land use changes across the Indian subcontinent. Climate shocks to rainfed and irrigated yields in 2030 are based on the p-DSSAT crop model, RCP 2.6, as reported under the AgMIP project (Rosenzweig et al., 2013), accessed through GEOSHARE (Villoria et al, 2014). Results show that, when water scarcity is ignored, irrigated areas grow in the wake of climate change as the returns to irrigation rise faster than for rainfed uses of land within a given agro-ecological zone. When non-agricultural competition for future water use, as well as anticipated supply side limitations are brought into play (Rosegrant et al., 2013), the opportunity cost of water rises across all river basins, with the increase ranging from 12% (Luni) to 44% (Brahmaputra). As a consequence, irrigated crop production is curtailed in most regions (Figure 1), with the largest reductions coming in the most water intensive crops, namely rice and wheat. By reducing irrigated area, which tends to have much higher yields, the combined effects of water scarcity and climate impacts require an increase in total cropped area, which rises by about 240,000 ha. The majority of this area expansion occurs in the Ganges, Indus, and Brahmari river basins. Overall crop output falls by about 2 billion, relative to the 2030 baseline, with imports rising by about 570 million. The combined effects of climate change and water scarcity for irrigation also have macro-economic consequences, resulting in a 0.28% reduction in GDP and an increase in the consumer price index by about 0.4% in 2030, compared the baseline. The national welfare impact on India amounts to roughly 3 billion (at 2007 prices) in 2030. Assuming a 3% social discount rate, the net present value of the

  13. Irrigation in dose assessments models

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla; Barkefors, Catarina [Studsvik RadWaste AB, Nykoeping (Sweden)

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  14. Irrigation in dose assessments models

    International Nuclear Information System (INIS)

    Bergstroem, Ulla; Barkefors, Catarina

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  15. Developing a Hybrid Solar/Wind Powered Drip Irrigation System for Dragon Fruit Yield

    Science.gov (United States)

    Widiastuti, I.; Wijayanto, D. S.

    2017-03-01

    Irrigation operations take a large amount of water and energy which impact to total costs of crop production. Development of an efficient irrigation supplying precise amount of water and conserving the use of energy can have benefits not only by reducing the operating costs but also by enhancing the farmland productivity. This article presents an irrigation method that promotes sustainable use of water and energy appropriate for a developing tropical country. It proposes a drip irrigation system supported by a combined solar-wind electric power generation system for efficient use of water in dragon fruit cultivation. The electric power generated is used to drive a water pump filling a storage tank for irrigating a 3000 m2 dragon fruit yield in Nguntoronadi, Wonogiri, Indonesia. In designing the irrigation system, the plant’s water requirement was identified based on the value of reference evapotranspiration of the area. A cost/benefit analysis was performed to evaluate the economic feasibility of the proposed scheme. The installation of this solar and wind drip irrigation helps provide sufficient quantity of water to each plant using renewable energy sources which reduce dependence on fossil fuel.

  16. Economic assessment at farm level of the implementation of deficit irrigation for quinoa production in the Southern Bolivian Altiplano

    Directory of Open Access Journals (Sweden)

    J. Cusicanqui

    2013-10-01

    Full Text Available In the Southern Bolivian Altiplano recent research has suggested to introduce deficit irrigation as a strategy to boost quinoa yields and to stabilize it at 2.0 ton ha-1. In this study we carried out an economic assessment of the implementation of deficit irrigation at farm level using a hydro-economic model for simulating profit for quinoa production. As input of the model we worked with previously developed farms typology (livestock, quinoa and subsistence farms, simulated quinoa production with and without irrigation using AquaCrop model, and calculated yield response functions for four different climate scenarios (wet, normal, dry and very dry years. Results from the hydro-economic model demonstrate that maximum profit is achieved with less applied irrigated water than for maximum yield, and irrigated quinoa earned more profit than rainfed production for all farms types and climate scenarios. As expected, the benefits of irrigation under dry and very dry climate conditions were higher than those under normal and wet years, and benefits among farms types were higher for quinoa farms. In fact, profit of irrigated quinoa might be stabilized at around BOB 6500 ha-1 (about USD 920 compared with the huge differences found for rainfed conditions for all climate scenarios. Interestingly, the economic water productivity, expressed in terms of economic return for amount of applied irrigated water (BOB mm-1, reached the highest values with intermediate and low level of water availability schemes of deficit irrigation for all climate scenarios.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Regulations of irrigation on regional climate in the Heihe watershed, China, and its implications to water budget

    Science.gov (United States)

    Zhang, X.

    2015-12-01

    In the arid area, such as the Heihe watershed in Northwest China, agriculture is heavily dependent on the irrigation. Irrigation suggests human-induced hydro process, which modifies the local climate and water budget. In this study, we simulated the irrigation-induced changes in surface energy/moisture budgets and modifications on regional climate, using the WRF-NoahMP modle with an irrigation scheme. The irrigation scheme was implemented following the roles that soil moisture is assigned a saturated value once the mean soil moisture of all root layers is lower than 70% of fileld capacity. Across the growth season refering from May to September, the simulated mean irrigation amount of the 1181 cropland gridcells is ~900 mm, wihch is close to the field measurments of around 1000 mm. Such an irrigation largely modified the surface energy budget. Due to irrigation, the surface net solar radiation increased by ~76.7 MJ (~11 Wm-2) accouting for ~2.3%, surface latent and senbile heat flux increased by 97.7 Wm-2 and decreased by ~79.7 Wm-2 respectively; and local daily mean surface air temperature was thereby cooling by ~1.1°C. Corresponding to the surface energy changes, wind and circulation were also modified and regional water budget is therefore regulated. The total rainfall in the irrigation area increased due to more moisture from surface. However, the increased rainfall is only ~6.5mm (accounting for ~5% of background rainfall) which is much less than the increased evaporation of ~521.5mm from surface. The ~515mm of water accounting for 57% of total irrigation was transported outward by wind. The other ~385 mm accounting for 43% of total irrigation was transformed to be runoff and soil water. These results suggest that in the Heihe watershed irrigation largely modify local energy budget and cooling surface. This study also implicate that the existing irrigation may waste a large number of water. It is thereby valuable to develope effective irrigation scheme to

  19. Communication between irrigation engineers and farmers : the case of project design in North Senegal

    NARCIS (Netherlands)

    Scheer, S.H.

    1996-01-01

    Introduction

    Irrigation schemes all over the world are often marked by a large number of related problems that have an important human dimension and are too complex to be straightforwardly solved. A starting point of this thesis is that these problems have to be dealt

  20. A Matter of Relationships : Actor-Networks of Colonial Rule in the Gezira Irrigation System, Sudan

    NARCIS (Netherlands)

    Ertsen, M.W.

    2016-01-01

    In the first half of the 20th century, colonial rulers, a British firm and Sudanese farmers changed the Gezira Plain in Sudan into a large-scale irrigated cotton scheme. Gezira continues to be in use up to date. Its story shows how the abstract concept 'development' is shaped through the agency of

  1. 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.

  2. 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.

  3. 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.

  4. 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)

  5. Sustainable irrigation in fruit trees

    Directory of Open Access Journals (Sweden)

    Cristos Xiloyannis

    2010-09-01

    Full Text Available Water management in fruit growing, particularly in areas with high water deficit, low rainfall and limited availability of water for irrigation should aid to save water by: i the choice of high efficiency irrigation methods and their correct management; ii the proper choice of the specie, cultivar and rootstock to optimise plant water use; iii the proper choice of the architecture of the canopy and it’s correct management in order to improve water use efficiency; iv the application of regulated deficit irrigation at growth stages less sensitive to water deficit; v strengthening the role of technical assistance for a rapid transfer of knowledge to the growers on the sustainable use of water in fruit growing.

  6. Sustainable irrigation in fruit trees

    Directory of Open Access Journals (Sweden)

    Cristos Xiloyannis

    Full Text Available Water management in fruit growing, particularly in areas with high water deficit, low rainfall and limited availability of water for irrigation should aid to save water by: i the choice of high efficiency irrigation methods and their correct management; ii the proper choice of the specie, cultivar and rootstock to optimise plant water use; iii the proper choice of the architecture of the canopy and it’s correct management in order to improve water use efficiency; iv the application of regulated deficit irrigation at growth stages less sensitive to water deficit; v strengthening the role of technical assistance for a rapid transfer of knowledge to the growers on the sustainable use of water in fruit growing.

  7. [Continent colostomy and colon irrigation].

    Science.gov (United States)

    Kostov, D; Temelkov, T; Kiriazov, E; Ivanov, K; Ignatov, V; Kobakov, G

    2000-01-01

    The authors have studied a functional activity of a continent colostomy at 20 patients, undergone an abdomeno-perineal extirpation of rectum and carried out periodic colonirrigations, during a period of 6 months. A conus type, closed irrigating system has been used. The degree of an incontinency at patients has been compared before and after the beginning of the colonirrigations. The irrigating procedures have reduced spontaneous defications at patients during a week 28 times and have improved the quality of life significantly. The application of colostomy bags has been restricted in 8 (40%) patients. An intraluminal ultrasonographic investigation has been done at 12 (60%) patients at the end of 6 month irrigating period. No changes of the ultrasonographic image of the precolostomic segment of colon has been observed.

  8. Atividade residual de (imazethapyr+imazapic para sorgo granífero (Sorghum bicolor semeado em rotação com o arroz irrigado Field persistence of (imazethapyr+imazapic to grain sorghum (Sorghum bicolor planted in rotation after irrigated rice

    Directory of Open Access Journals (Sweden)

    J.J.O Pinto

    2009-12-01

    áveis ao sorgo cultivado em safra subsequente ao arroz.The objective of this research was to evaluate the field persistence of the herbicide Only (imazethapyr+imazapic, to grain sorghum, planted in rotation after one, two or three years of Clearfield® (CL rice. The field study was carried out at Universidade Federal de Pelotas, Capão do Leão, state of Rio Grande do Sul. Clearfield rice was established as the main crop, Italian ryegrass as a succession crop and grain sorghum, as a rotation crop after CL rice. Except for the first rice crop, all the other cultures were planted as no-till rice. Ryegrass plants were burned down in every experiment using glyphosate (760 g a.e. ha-1. The experimental design was a factorial with treatments arranged in a complete randomized design, with four replications, where factor A was the number of CL rice seasons and B was the herbicide rate. The rice cultivar was IRGA 422 CL, and the herbicide treatments were Only (imazethapyr+imazapic at 0; (75+25; (112.5+37.5 and (150+50 g ha-1. Adjuvant Dash was added to the herbicide at 0.5% v/v. The experiments were labeled as A1, A2 or A3, respectively, for one, two or three years of CL rice. Grain sorghum, cv. BR 304, was planted as a bioindicator of herbicide residue. The following parameters were evaluated: plant population, plant height; above ground biomass, 1000-grain weight and grain yield. As for grain sorghum plant height and 1000-seed weight, an interaction was observed between the different environments (years of CL rice and herbicide rate (imazethapyr+imazapic. For the other parameters, only effect for herbicide rat was detected. The results suggested that all grain sorghum parameters were affected by the herbicides (imazethapyr+ imazapic in the soil. Grain sorghum injury increased with herbicide rate. In conclusion, grain sorghum, planted in rotation with rice is affected by the residue of the herbicide Only (imazethapyr+imazapic applied to Clearfield® rice.

  9. 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)

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

    Science.gov (United States)

    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

  11. AGROCLIMATIC DETERMINANTS OF IRRIGATION NEEDS

    Directory of Open Access Journals (Sweden)

    Leszek Łabędzki

    2016-05-01

    Full Text Available The paper is a review of the so far used in Poland methods and criteria for assessing the needs of irrigation for planning purposes, the assessment because of the agroclimatic conditions and taking into account the soil water retention. Irrigation needs of the most are determined taking into account crop water deficits. This is the factor that is characterized by a shortage of precipitation in relation to the water requirements of crops. Some methods use only the meteorological parameters that determine the state of the atmosphere-soil-plant system, and some also take into account soil water retention and its availability for plants.

  12. 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.

  13. 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.

  14. Modernisation Strategy for National Irrigation Systems in the Philippines: Balanac and Sta. Maria River Irrigation Systems

    NARCIS (Netherlands)

    Delos Reyes, M.L.F.

    2017-01-01

    This book examines the nature and impact of irrigation system rehabilitation on increasing the actual area irrigated by the publicly funded canal irrigation systems of the Philippines. It proposes a system diagnosis approach for the development of a more appropriate and climate-smart irrigation

  15. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands

  16. Participatory Irrigation Management and Irrigation Water Use Efficiency in Maize Production: Evidence from Zhangye City, Northwestern China

    Directory of Open Access Journals (Sweden)

    Qing Zhou

    2017-10-01

    Full Text Available Water has become increasingly scarce in northwestern China due to climate change, economic growth and burgeoning population. Improving agriculture water use efficiency is of strategic significance in promoting socio-economic water productivity for arid and semi-arid inland river basins. Based on the household-level data collected in Zhangye City, which is located in the middle reaches of Heihe River Basin (HRB in northwestern China, irrigation water use efficiency (IWUE of maize is estimated based on stochastic frontier analysis. The impacts of influential factors, especially the participatory irrigation management (PIM through water user associations (WUAs, on IWUE were further examined. Results show that the estimated average Technical efficiency (TE and IWUE of maize production are 0.74 and 0.24, respectively. The participation level in irrigation management is very low, with only 40% of the respondents participating in WUA meetings. In addition, most have a relatively superficial understanding of the roles and management scheme of WUAs. Empirical results show that though significantly positive, the magnitude of the impact of PIM on IWUE is relatively small. Households that participated in WUA meetings achieved only 0.002% higher IWUEs than those have never participated in. WUAs are not operating with their designed objectives. Consequently, reform of the traditional management form of WUAs to make them more transparent, fair, and extensively participated in among farmers is in urgently need. In addition, we also find that water price, source of irrigation water, irrigation technology adoption and famers’ education level and farming experience also have significant positive impacts on IWUE.

  17. GSM BASED IRRIGATION CONTROL AND MONITORING SYSTEM

    OpenAIRE

    GODFREY A. MILLS; STEPHEN K. ARMOO; AGYEMAN K. ROCKSON; ROBERT A. SOWAH; MOSES A. ACQUAH

    2013-01-01

    Irrigated agriculture is one of the primary water consumers in most parts of the world. With developments in technology, efforts are being channeled into automation of irrigation systems to facilitate remote control of the irrigation system and optimize crop production and cost effectiveness. This paper describes an on-going work on GSM based irrigation monitoring and control systems. The objective of the work is to provide an approach that helps farmers to easily access, manage and regulate ...

  18. Measuring Transpiration to Regulate Winter Irrigation Rates

    Energy Technology Data Exchange (ETDEWEB)

    Samuelson, Lisa [Auburn University

    2006-11-08

    Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.

  19. Comparative efficiency of trickle and furrow irrigation

    International Nuclear Information System (INIS)

    Hanif, M.; Qureshi, R.H.; Sandhu, G.R.

    1976-01-01

    Comparison of furrow and trickle methods of irrigation to know their relative efficiency with respect to water applied and fertilizer used on tomatoes, cauliflower and lettuce as test crops using canal water, showed a significant saving of about 44 and 41 per cent respectively for irrigation water and fertilizer applied with trickle as compared to furrow irrigation. Trickle irrigated crops also showed a better response as regards the rate of survival, crop growth and time of maturity

  20. 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.

  1. 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.

  2. Cooking quality of upland and lowland rice characterized by different methods

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. Newer Root Canal Irrigants in Horizon: A Review

    Directory of Open Access Journals (Sweden)

    Sushma Jaju

    2011-01-01

    Full Text Available Sodium hypochloride is the most commonly used endodontic irrigant, despite limitations. None of the presently available root canal irrigants satisfy the requirements of ideal root canal irrigant. Newer root canal irrigants are studied for potential replacement of sodium hypochloride. This article reviews the potential irrigants with their advantages and limitations with their future in endodontic irrigation.

  5. 21 CFR 876.5895 - Ostomy irrigator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ostomy irrigator. 876.5895 Section 876.5895 Food... DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5895 Ostomy irrigator. (a) Identification. An ostomy irrigator is a device that consists of a container for fluid, tubing with a cone-shaped...

  6. 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

  7. 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.

  8. Transfer of gaseous iodine from atmosphere to rough rice, brown rice and polished rice

    International Nuclear Information System (INIS)

    Sumiya, Misako; Uchida, Shigeo; Muramatsu, Yasuyuki; Ohmomo, Yoichiro; Yamaguchi, Shuho; Obata, Hitoshi.

    1987-01-01

    Experiments were carried out in order to obtain information required for establishing transfer coefficients of gaseous iodine (I 2 ) to rough rice, brown rice and polished rice. The gaseous iodine deposited on young rice plants before the heading period was scarcely found in the rough rice harvested at the full ripe stage. The biological half life of iodine in hull, however, was much slower than that in leaves of 14 days. The translocation of iodine from leaves and stalks to rough rice was not clearly recognized. Therefore, it was deduced that iodine found in brown rice mainly should originate from that deposited on the hull. The distribution ratios of iodine between rough rice and brown rice, and between brown rice and polished rice were 100:4 and 100:30 on 100 grains basis, respectively. If average normalized deposition velocity (V d(m) ) or derived deposition velocity (V s ) are given, the transfer coefficients of gaseous iodine to rough rice (TF r ), brown rice (TF b ) and polished rice (TF p ) could be calculated. (author)

  9. Speed control variable rate irrigation

    Science.gov (United States)

    Speed control variable rate irrigation (VRI) is used to address within field variability by controlling a moving sprinkler’s travel speed to vary the application depth. Changes in speed are commonly practiced over areas that slope, pond or where soil texture is predominantly different. Dynamic presc...

  10. Position paper : Whole bowel irrigation

    NARCIS (Netherlands)

    2004-01-01

    Whole bowel irrigation (WBI) should not be used routinely in the management of the poisoned patient. Although some volunteer studies have shown substantial decreases in the bioavailability of ingested drugs, no controlled clinical trials have been performed and there is no conclusive evidence that

  11. 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

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

    Directory of Open Access Journals (Sweden)

    Yoo J. H.

    2013-04-01

    Full Text Available Pot experiment using metal polluted soils was conducted to investigate the effects of lime, iron and sulfur on changes in Cd availability and uptake by rice plant. Drainage and irrigation of water were performed to develop redox changes like field cultivation. Iron chloride and sodium sulfate solutions were applied to the pots in the middle of growth period of rice plant. Reactive metal pool in heavily polluted soils was slightly decreased after treatments with lime, iron chloride, sodium sulfate and combination of these chemicals. However, cadmium uptake by rice plant was significantly different across the treatments and the extent of Cd pollution. For highly polluted soils, more Cd reduction was observed in iron chloride treatments. Cd content in polished rice for iron chloride and (iron chloride+organic matter treatments was only 16-23% and 25-37% compared to control and liming, respectively. Treatment of (iron chloride+sulfate rather increased Cd content in rice. For moderately polluted soils, Cd reduction rate was the order of (OM+iron chloride > iron chloride > lime. Other treatments including sulfate rather increased Cd content in rice maximum 3 times than control. It was proposed to determine the optimum application rate of iron for minimizing hazardous effect on rice plant.

  13. 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

  14. Finite Boltzmann schemes

    NARCIS (Netherlands)

    Sman, van der R.G.M.

    2006-01-01

    In the special case of relaxation parameter = 1 lattice Boltzmann schemes for (convection) diffusion and fluid flow are equivalent to finite difference/volume (FD) schemes, and are thus coined finite Boltzmann (FB) schemes. We show that the equivalence is inherent to the homology of the

  15. Prevalence of Rice Yellow Mottle Virus (RYMV) on Rice Plants ...

    African Journals Online (AJOL)

    Abstract. Incidence of Rice yellow mottle virus (RYMV) on rice plants (ofada) grown in two local government areas (LGAs) of Ogun State had been evaluated during a two year field survey. Six month old rice plants were observed for symptom expression and leaf samples collected for serological indexing. Of the 60 leaf ...

  16. 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.

  17. Modernized Irrigation Technologies in West Africa

    Directory of Open Access Journals (Sweden)

    Hakan Büyükcangaz

    2017-12-01

    Full Text Available Crop production in West Africa is mostly dependent upon rainfed agriculture. Irrigation is a vital need due to uneven distribution of rainfall and seasonality of water resources. However, management and sustainability of irrigation are under risk due to notably weak database, excessive cost, unappropriate soil or land use, environmental problems and extreme pessimism in some quarters since rainfed agriculture is seen as potentially able to support the present population. This paper focuses on modernized irrigation technologies and systems that utilize less water. Information about irrigation systems in Ghana and Liberia were gathered through: 1 Irrigation development authorities in both countries, by reviewing past literatures, online publications, reports and files about irrigation in West Africa, specifically Ghana and Liberia; 2 International Food Policy Research Institute (IFPRI; 3 Collation of information, reports and data from Ghana Irrigation Development Authority (GIDA and 4 International Water Management Institute (IWMI. The result shows that both countries have higher irrigation potential. However, the areas developed for irrigation is still a small portion as compare to the total land available for irrigation. On the other hand, as seen in the result, Liberia as compare to Ghana has even low level of irrigation development.

  18. Modeling irrigation behavior in groundwater systems

    Science.gov (United States)

    Foster, Timothy; Brozović, Nicholas; Butler, Adrian P.

    2014-08-01

    Integrated hydro-economic models have been widely applied to water management problems in regions of intensive groundwater-fed irrigation. However, policy interpretations may be limited as most existing models do not explicitly consider two important aspects of observed irrigation decision making, namely the limits on instantaneous irrigation rates imposed by well yield and the intraseasonal structure of irrigation planning. We develop a new modeling approach for determining irrigation demand that is based on observed farmer behavior and captures the impacts on production and water use of both well yield and climate. Through a case study of irrigated corn production in the Texas High Plains region of the United States we predict optimal irrigation strategies under variable levels of groundwater supply, and assess the limits of existing models for predicting land and groundwater use decisions by farmers. Our results show that irrigation behavior exhibits complex nonlinear responses to changes in groundwater availability. Declining well yields induce large reductions in the optimal size of irrigated area and irrigation use as constraints on instantaneous application rates limit the ability to maintain sufficient soil moisture to avoid negative impacts on crop yield. We demonstrate that this important behavioral response to limited groundwater availability is not captured by existing modeling approaches, which therefore may be unreliable predictors of irrigation demand, agricultural profitability, and resilience to climate change and aquifer depletion.

  19. Irrigation Water Quality for Leafy Crops: A Perspective of Risks and Potential Solutions

    Directory of Open Access Journals (Sweden)

    Ana Allende

    2015-07-01

    Full Text Available There is increasing evidence of the contribution of irrigation water in the contamination of produce leading to subsequent outbreaks of foodborne illness. This is a particular risk in the production of leafy vegetables that will be eaten raw without cooking. Retailers selling leafy vegetables are increasingly targeting zero-risk production systems and the associated requirements for irrigation water quality have become more stringent in regulations and quality assurance schemes (QAS followed by growers. Growers can identify water sources that are contaminated with potential pathogens through a monitoring regime and only use water free of pathogens, but the low prevalence of pathogens makes the use of faecal indicators, particularly E. coli, a more practical approach. Where growers have to utilise water sources of moderate quality, they can reduce the risk of contamination of the edible portion of the crop (i.e., the leaves by treating irrigation water before use through physical or chemical disinfection systems, or avoid contact between the leaves and irrigation water through the use of drip or furrow irrigation, or the use of hydroponic growing systems. This study gives an overview of the main problems in the production of leafy vegetables associated with irrigation water, including microbial risk and difficulties in water monitoring, compliance with evolving regulations and quality standards, and summarises the current alternatives available for growers to reduce microbial risks.

  20. Irrigation Water Quality for Leafy Crops: A Perspective of Risks and Potential Solutions

    Science.gov (United States)

    Allende, Ana; Monaghan, James

    2015-01-01

    There is increasing evidence of the contribution of irrigation water in the contamination of produce leading to subsequent outbreaks of foodborne illness. This is a particular risk in the production of leafy vegetables that will be eaten raw without cooking. Retailers selling leafy vegetables are increasingly targeting zero-risk production systems and the associated requirements for irrigation water quality have become more stringent in regulations and quality assurance schemes (QAS) followed by growers. Growers can identify water sources that are contaminated with potential pathogens through a monitoring regime and only use water free of pathogens, but the low prevalence of pathogens makes the use of faecal indicators, particularly E. coli, a more practical approach. Where growers have to utilise water sources of moderate quality, they can reduce the risk of contamination of the edible portion of the crop (i.e., the leaves) by treating irrigation water before use through physical or chemical disinfection systems, or avoid contact between the leaves and irrigation water through the use of drip or furrow irrigation, or the use of hydroponic growing systems. This study gives an overview of the main problems in the production of leafy vegetables associated with irrigation water, including microbial risk and difficulties in water monitoring, compliance with evolving regulations and quality standards, and summarises the current alternatives available for growers to reduce microbial risks. PMID:26151764

  1. Nutrition of Tithonia diversifolia and attributes of the soil fertilized with biofertilizer in irrigated system

    Directory of Open Access Journals (Sweden)

    Matheus M. Reis

    Full Text Available ABSTRACT The fertilization with biofertilizer associated with the use of irrigation favors nutrient uptake by plants and soil chemical properties; however, these effects are little studied in Tithonia diversifolia in semiarid regions. This study evaluated the effect of doses of bovine biofertilizer and irrigation on accumulation of nutrients in the leaves of Tithonia diversifolia plants and on soil chemical attributes. The study was carried out from December 3, 2014 to November 28, 2015, and arranged in a 2 x 5 factorial scheme, consisting of five doses of bovine biofertilizer (0, 40, 80, 120 and 160 m3 ha-1, combined with and without irrigation. The experiment was set in a randomized block design, using three replicates. Irrigation promoted increased accumulation of N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu and B in leaves of Tithonia diversifolia in the first cutting. However, the high bicarbonate concentration in the irrigation water and the occurrence of rainfall during the second crop increased the accumulation of Cu in the leaves of Tithonia diversifolia under rainfed condition, compared with irrigated plants. The increase in biofertilizer doses contributed to the increment of base saturation and the contents of organic matter, P and K in soil.

  2. Organic cultivation of onion under castor cake fertilization and irrigation depths

    Directory of Open Access Journals (Sweden)

    Gabriel Alves Botelho de Mello

    2017-11-01

    Full Text Available Two experiments were carried out to evaluate the effects that different doses of castor bean (0, 200, and 300 g m-2 and irrigation levels (204, 224, 278, and 321 mm in 2014, and 278, 302, 397, and 444 mm in 2015 have on both the productivity and quality of onion bulbs. In the experiments, the experimental design was randomized blocks (4 x 3 factorial scheme, with five replicates. Irrigation management was performed using a Simplified Irrigation Device (SID in response to soil water tension in the treatment of highest irrigation depth. The following variables were evaluated: plant dry biomass (PDB, bulb dry biomass (BDB, total yield (TY, mean bulb fresh weight (MBFW, mean bulb dry weight (MBDW, mean bulb diameter (MBD and water use efficiency (WUE. The highest irrigation depths positively influenced the mean production of onion bulbs, regardless of the applied dose of castor cake. The doses of castor cake positively influenced the production of onion bulbs when higher irrigation depths were applied.

  3. Irrigation Water Quality for Leafy Crops: A Perspective of Risks and Potential Solutions.

    Science.gov (United States)

    Allende, Ana; Monaghan, James

    2015-07-03

    There is increasing evidence of the contribution of irrigation water in the contamination of produce leading to subsequent outbreaks of foodborne illness. This is a particular risk in the production of leafy vegetables that will be eaten raw without cooking. Retailers selling leafy vegetables are increasingly targeting zero-risk production systems and the associated requirements for irrigation water quality have become more stringent in regulations and quality assurance schemes (QAS) followed by growers. Growers can identify water sources that are contaminated with potential pathogens through a monitoring regime and only use water free of pathogens, but the low prevalence of pathogens makes the use of faecal indicators, particularly E. coli, a more practical approach. Where growers have to utilise water sources of moderate quality, they can reduce the risk of contamination of the edible portion of the crop (i.e., the leaves) by treating irrigation water before use through physical or chemical disinfection systems, or avoid contact between the leaves and irrigation water through the use of drip or furrow irrigation, or the use of hydroponic growing systems. This study gives an overview of the main problems in the production of leafy vegetables associated with irrigation water, including microbial risk and difficulties in water monitoring, compliance with evolving regulations and quality standards, and summarises the current alternatives available for growers to reduce microbial risks.

  4. Digging, Damming or Diverting? Small-Scale Irrigation in the Blue Nile Basin, Ethiopia

    Directory of Open Access Journals (Sweden)

    Irit Eguavoen

    2012-10-01

    Full Text Available The diversity of small-scale irrigation in the Ethiopian Blue Nile basin comprises small dams, wells, ponds and river diversion. The diversity of irrigation infrastructure is partly a consequence of the topographic heterogeneity of the Fogera plains. Despite similar social-political conditions and the same administrative framework, irrigation facilities are established, used and managed differently, ranging from informal arrangements of households and 'water fathers' to water user associations, as well as from open access to irrigation schedules. Fogera belongs to Ethiopian landscapes that will soon transform as a consequence of large dams and huge irrigation schemes. Property rights to land and water are negotiated among a variety of old and new actors. This study, based on ethnographic, hydrological and survey data, synthesises four case studies to analyse the current state of small-scale irrigation. It argues that all water storage options have not only certain comparative advantages but also social constraints, and supports a policy of extending water storage 'systems' that combine and build on complementarities of different storage types instead of fully replacing diversity by large dams.

  5. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Science.gov (United States)

    2010-01-01

    ... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... Milled Rice Principles Governing Application of Standards § 868.310 Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice...

  6. 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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  9. Extraction of rice bran oil from local rice husk

    International Nuclear Information System (INIS)

    Anwar, J.; Zaman, W.; Salman, M.; Jabeen, N.

    2006-01-01

    Rice Bran Oil is widely used in pharmaceutical, food and chemical industries due to its unique properties and high medicinal value. In the present work, extraction of rice bran oil from different samples of rice husk collected from local rice shellers by solvent extraction method has been studied. Experiments were conducted using a soxhelt apparatus, to extract rice bran oil using hexane, petroleum ether, ethanol and methanol as the solvents and the yields obtained under different conditions were compared. Batch extraction tests showed that the rate of extraction decreases with time and the solution approaches saturation at an exponential rate. (author)

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

    Directory of Open Access Journals (Sweden)

    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

  11. Phosphorus absorption in drip irrigation

    International Nuclear Information System (INIS)

    Guennelon, R.; Habib, R.

    1979-01-01

    Introducing the use of solute phosphate with drip irrigation may be an unsatisfying practice on account of the very weak mobility of PO 4 anion. Nevertheless P can move down to 30-40 cm depth by following the saturated flux along earth-worms holes or crakes, or by displacement in very narrow structural porosity, even in heavy soils. In this case roots cannot easily absorb PO 4 from soil solution, as soon as the soil is quite saturated. On the other hand, it seems that P absorption occurs very quickly and easily when the implantation of 32 P tagged solution is carried out at the border of zone which is concerned by the irrigation effects [fr

  12. Managing Water Resources for Environmentally Sustainable Irrigated Agriculture in Pakistan

    OpenAIRE

    Muhammad Afzal

    1996-01-01

    Pakistan’s agriculture is almost wholly dependent on irrigation and irrigated land supplies more than 90 percent of agricultural production. Irrigation is central to Pakistan’s economy. Massive investments in irrigation contributed to the development of one of the largest Indus Basin Irrigation System. Despite heavy budgetary inputs in irrigation system, it is facing shortage of resources and suffering from operational problems. The sustainability of irrigated agriculture is threatened due to...

  13. Introducing non-flooded crops in rice-dominated landscapes: Impact on carbon, nitrogen and water budgets

    Science.gov (United States)

    Jauker, Frank; Wassmann, Reiner; Amelung, Wulf; Breuer, Lutz; Butterbach-Bahl, Klaus; Conrad, Ralf; Ekschmitt, Klemens; Goldbach, Heiner; He, Yao; John, Katharina; Kiese, Ralf; Kraus, David; Reinhold-Hurek, Barbara; Siemens, Jan; Weller, Sebastian; Wolters, Volkmar

    2013-04-01

    Rice production consumes about 30% of all freshwater used worldwide and 45% in Asia. Turning away from permanently flooded rice cropping systems for mitigating future water scarcity and reducing methane emissions, however, will alter a variety of ecosystem services with potential adverse effects to both the environment and agricultural production. Moreover, implementing systems that alternate between flooded and non-flooded crops increases the risk of disruptive effects. The multi-disciplinary DFG research unit ICON aims at exploring and quantifying the ecological consequences of altered water regimes (flooded vs. non-flooded), crop diversification (irrigated rice vs. aerobic rice vs. maize), and different fertilization strategies (conventional, site-specific, and zero N fertilization). ICON particularly focuses on the biogeochemical cycling of carbon and nitrogen, green-house gas (GHG) emissions, water balance, soil biotic processes and other important ecosystem services. The overarching goal is to provide the basic process understanding that is necessary for balancing the revenues and environmental impacts of high-yield rice cropping systems while maintaining their vital ecosystem services. To this aim, a large-scale field experiment has been established at the experimental farm of the International Rice Research Institute (IRRI, Philippines). Ultimately, the experimental results are analyzed in the context of management scenarios by an integrated modeling of crop development (ORYZA), carbon and nitrogen cycling (MoBiLE-DNDC), and water fluxes (CMF), providing the basis for developing pathways to a conversion of rice-based systems towards higher yield potentials under minimized environmental impacts. In our presentation, we demonstrate the set-up of the controlled large-scale field experiment for simultaneous assessment of carbon and nitrogen fluxes and water budgets. We show and discuss first results for: - Quantification and assessment of the net-fluxes of CH4

  14. 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.

  15. IRRIGATION OF ORNAMENTAL PLANT NURSERY

    Directory of Open Access Journals (Sweden)

    Eduardo de Aguiar do Couto

    2013-01-01

    Full Text Available Airports consume significant amounts of water which can be compared to the volume consumed by mid-size cities, thus practices aimed at reducing water consumption are important and necessar y. The objective of this study was to assess the reuse potential of sewage effluent produced at a mid-size international airport for nursery irri gation. The sewage treatment system consisted of a facultative pond followed by a constructed wetland, which were monitored during one hydrological year a nd the parameters COD, pH, solids, nitrogen, phosphorus and Escherichia coli we re analyzed. Removal efficiencies of 85% and 91% were achieved for C OD and solids, respectively. Removal efficiencies for ammonia nitrogen a nd total phosphorus were 77% and 59%, respectively. In terms of E. coli concen tration, the treated effluent met the recommendations by the World Health Organization for reuse in irrigation with the advantage of providing high levels of residual nutrient. The ornamental species Impatiens walleriana was irrigated with treated sewage effluent and plant growth characteristics were evalua ted. The experiment showed that reuse can enhance plant growth without signi ficantly affecting leaf tissue and soil characteristics. This study highlighted th e importance of simple technologies for sewage treatment especially in count ries which still do not present great investment in sanitation and proved that effluent reuse for landscape irrigation can provide great savings of water and financial resources for airport environments.

  16. Gasification of rice husks

    Energy Technology Data Exchange (ETDEWEB)

    Marzetti, P. (ENEA, Rome (Italy). Dipt. Fonti Alternative e Risparmio Energetico)

    The paper outlines the thermochemical processes and equipment involved in the gasification of rice husks. An assessment is made of the feasibility (availability, technology requirements, economics of production and marketing) of this renewable energy source. Results, reported here in tabular form, of experimental trials at an Italian pilot plant (producing, with the use of 165 kg/h of rice husks, 350,000 kcal/h of gas with a conversion yield of 70%) indicated good feasibility. More research is required to improve the combustion qualities of the final product.

  17. Processing Methods of Alkaline Hydrolysate from Rice Husk

    Directory of Open Access Journals (Sweden)

    Olga D. Arefieva

    2017-07-01

    Full Text Available This paper devoted to finding processing methods of alkaline hydrolysate produced from rice husk pre-extraction, and discusses alkaline hydrolysate processing schemed and disengagement of some products: amorphous silica of various quality, alkaline lignin, and water and alkaline extraction polysaccharides. Silica samples were characterized: crude (air-dried, burnt (no preliminary water treatment, washed in distilled water, and washed in distilled water and burnt. Waste water parameters upon the extraction of solids from alkaline hydrolysate dropped a few dozens or thousand times depending on the applied processing method. Color decreased a few thousand times, turbidity was virtually eliminated, chemical oxygen demanded about 20–136 times; polyphenols content might decrease 50% or be virtually eliminated. The most prospective scheme obtained the two following solid products from rice husk alkaline hydrolysate: amorphous silica and alkaline extraction polysaccharide. Chemical oxygen demand of the remaining waste water decreased about 140 times compared to the silica-free solution.

  18. Scheme Program Documentation Tools

    DEFF Research Database (Denmark)

    Nørmark, Kurt

    2004-01-01

    are separate and intended for different documentation purposes they are related to each other in several ways. Both tools are based on XML languages for tool setup and for documentation authoring. In addition, both tools rely on the LAML framework which---in a systematic way---makes an XML language available...... as named functions in Scheme. Finally, the Scheme Elucidator is able to integrate SchemeDoc resources as part of an internal documentation resource....

  19. 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...

  20. Declining groundwater level caused by irrigation to row crops in the Lower Mississippi River Basin, Current Situation and Trends

    Science.gov (United States)

    Feng, G.; Gao, F.; Ouyang, Y.

    2017-12-01

    The Mississippi River is North America's largest river and the second largest watershed in the world. It flows over 3,700 km through America's heartland to the Gulf of Mexico. Over 3 million hectares in the Lower Mississippi River Basin represent irrigated cropland and 90 percent of those lands currently rely on the groundwater supply. The primary crops grown in this region are soybean, corn, cotton, and rice. Increased water withdrawals for irrigating those crops and stagnant recharging jeopardize the long-term availability of the aquifer and place irrigation agriculture in the region on an unsustainable path. The objectives of this study were to: 1) analyze the current groundwater level in the Lower Mississippi River Basin based on the water table depth observed by Yazoo Mississippi Delta Joint Water Management District from 2000 and 2016; 2) determine trends of change in groundwater level under conventional and groundwater saving irrigation management practices (ET or soil moisture based full irrigation scheduling using all groundwater or different percentages of ground and surface water). The coupled SWAT and MODFLOW model was applied to investigate the trends. Observed results showed that the groundwater level has declined from 33 to 26 m at an annual decrease rate of 0.4 m in the past 17 years. Simulated results revealed that the groundwater storage was decreased by 26 cm/month due to irrigation in crop season. It is promising that the groundwater storage was increased by 23 cm/month, sometimes even 60 cm/month in crop off-growing season because of recharge from rainfall. Our results suggest that alternative ET or soil moisture based groundwater saving irrigation scheduling with conjunctive use of surface water is a sustainable practice for irrigated agriculture in in the Lower Mississippi River Basin.

  1. 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.

  2. 75 FR 43958 - Turlock Irrigation District and Modesto Irrigation District; Notice of Application for Amendment...

    Science.gov (United States)

    2010-07-27

    ... to the Turlock Irrigation District's Tuolumne Substation; (2) 23-mile-long, 69-kV Don Pedro-Hawkins Line extending from the Don Pedro switchyard to the Turlock Irrigation District's Hawkins Substation...

  3. Effect of low-cost irrigation methods on microbial contamination of lettuce irrigated with untreated wastewater

    DEFF Research Database (Denmark)

    Keraita, Bernard; Konradsen, Flemming; Drechsel, P.

    2007-01-01

    OBJECTIVE: To assess the effectiveness of simple irrigation methods such as drip irrigation kits, furrow irrigation and use of watering cans in reducing contamination of lettuce irrigated with polluted water in urban farming in Ghana. METHODS: Trials on drip kits, furrow irrigation and watering...... cans were conducted with urban vegetable farmers. Trials were arranged in a completely randomised block design with each plot having all three irrigation methods tested. This was conducted in both dry and wet seasons. Three hundred and ninety-six lettuce, 72 soil, 15 poultry manure and 32 water samples...... were analysed for thermotolerant coliforms and helminth eggs. RESULTS: Lettuce irrigated with drip kits had the lowest levels of contamination, with, on average, 4 log units per 100 g, fewer thermotolerant coliforms than that irrigated with watering cans. However, drip kits often got clogged, required...

  4. Introduction: Panda or Hydra? The untold stories of drip irrigation

    NARCIS (Netherlands)

    Kuper, M.; Venot, J.P.; Zwarteveen, M.; Venot, J.P.; Kuper, M.; Zwarteveen, M.

    2017-01-01

    Irrigated areas in the world are witnessing a transformation from open canal systems to more ‘modern’ irrigation methods such as drip irrigation that convey water through closed pipe systems. Initially associated with hi-tech irrigated agriculture, drip irrigation is now being used by a wide range

  5. 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.

  6. Rice as commodity and anti-commodity

    NARCIS (Netherlands)

    Richards, P.

    2016-01-01

    On the Upper West Africa coast rice belongs to two species — African rice (Oryza glaberrima Steud.) and Asian rice (Oryza sativa L.). African rice was domesticated in the region, perhaps three millennia ago, from a presumed wild ancestor, O. barthii. Asian rice was introduced via trans-Saharan

  7. Saline water irrigation for crop production

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, P.O. - Phulwari Sharif, Patna (India); [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Singh, S S; Singh, S R [Directorate of Water Management Research, Indian Council of Agricultural Research (ICAR), Walmi Complex, P.O. - Phulwari Sharif, Patna (India)

    2001-05-01

    Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation.

  8. Saline water irrigation for crop production

    International Nuclear Information System (INIS)

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

    2001-05-01

    Salinity is one of agriculture's most complex production problems. Excessive salts from irrigation water or high water tables can severely limit crop production. Years of saline water irrigation on poorly drained soils can eventually make economic crop production impossible. About 10% of all land are affected by salinity problems. They occur in every continent in different proportions, more frequently in arid and semi-arid areas. This paper discusses a range of problems related to use of saline water for crop irrigation

  9. Diseases of wild rice

    Science.gov (United States)

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

  10. Promising rice mutants

    International Nuclear Information System (INIS)

    Hakim, L.; Azam, M.A.; Miah, A.J.; Mansur, M.A.; Akanda, H.R.

    1988-01-01

    Two induced mutants namely, Mut NS 1 (tall) and Mut NS 5 (semi-dwarf) derived from rice variety Nizersail were evaluated for various agronomic characters at four locations in Bangladesh. Both the mutants matured about three weeks earlier and yielded significantly higher than the parent variety Nizersail. (author). 3 tabs., 9 refs

  11. 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.

  12. Multiresolution signal decomposition schemes

    NARCIS (Netherlands)

    J. Goutsias (John); H.J.A.M. Heijmans (Henk)

    1998-01-01

    textabstract[PNA-R9810] Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This report proposes a general axiomatic pyramid decomposition scheme for signal analysis

  13. Senegal - Irrigation and Water Resource Management

    Data.gov (United States)

    Millennium Challenge Corporation — IMPAQ: This evaluation report presents findings from the baseline data collected for the Irrigation and Water Resources Management (IWRM) project, which serves as...

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

    Science.gov (United States)

    Kukusamude, C.; Kongsri, S.

    2017-10-01

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

  15. Adaptive protection scheme

    Directory of Open Access Journals (Sweden)

    R. Sitharthan

    2016-09-01

    Full Text Available This paper aims at modelling an electronically coupled distributed energy resource with an adaptive protection scheme. The electronically coupled distributed energy resource is a microgrid framework formed by coupling the renewable energy source electronically. Further, the proposed adaptive protection scheme provides a suitable protection to the microgrid for various fault conditions irrespective of the operating mode of the microgrid: namely, grid connected mode and islanded mode. The outstanding aspect of the developed adaptive protection scheme is that it monitors the microgrid and instantly updates relay fault current according to the variations that occur in the system. The proposed adaptive protection scheme also employs auto reclosures, through which the proposed adaptive protection scheme recovers faster from the fault and thereby increases the consistency of the microgrid. The effectiveness of the proposed adaptive protection is studied through the time domain simulations carried out in the PSCAD⧹EMTDC software environment.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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)

  18. 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.

  19. Automation of irrigation systems to control irrigation applications and crop water use efficiency

    Science.gov (United States)

    Agricultural irrigation management to slow water withdrawals from non-replenishing quality water resources is a global endeavor and vital to sustaining irrigated agriculture and dependent rural economies. Research in site-specific irrigation management has shown that water use efficiency, and crop p...

  20. Factors affecting irrigant extrusion during root canal irrigation: a systematic review

    NARCIS (Netherlands)

    Boutsioukis, C.; Psimma, Z.; van der Sluis, L.W.M.

    2013-01-01

    The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

  1. Radiation disinfestation of Basmati rice

    International Nuclear Information System (INIS)

    Rao, V.S.; Gholap, A.S.; Adhikari, H.R.; Nair, P.M.

    1994-01-01

    Effect of low dose γ-radiation on prepackaged Basmati rice was studied in order to achieve disinfestation of rice. Basmati rice procured from local market was repacked in 1 kg pouches made from high density polyethylene (HDP) and biaxially oriented polypropylene: low density polyethylene (BOPP/LDP) laminate and irradiated at doses from 0.25-1.0 kGy. Within one month of storage at room temperature, unirradiated (control) Basmati rice developed heavy infestation. No infestation was observed in any of the irradiated samples even at 0.25 kGy and the rice could be stored for 6 months in a clean state. Irradiation (at 0.25 kGy) did not alter the moisture content of the rice. Likewise, no significant change was noted due to irradiation in the functional properties of rice such as swelling index and water absorption and in total volatile components responsible for flavour of Basmati rice. In organoleptic evaluation, no significant difference was found between the acceptability of irradiated (0.25 kGy) and control rice. These results are significant in view of the high export potential of Basmati rice and the transit losses at present due to infestation. (author). 24 refs., 5 tabs., 1 fig

  2. Properties of a clay soil from 1.5 to 3.5 years after biochar application and the impact on rice yield

    NARCIS (Netherlands)

    Carvalho, M.T.M.; Madari, B.E.; Bastiaans, L.; Oort, van P.A.J.; Leal, W.G.O.; Heinemann, A.B.; Silva, da M.A.S.; Maia, A.H.N.; Parsons, D.; Meinke, H.

    2016-01-01

    We assessed the impact of a single application of wood biochar on soil chemical and physical properties and aerobic rice grain yield on an irrigated kaolinitic clay Ferralsol in a tropical Savannah. We used linear mixed models to analyse the response of soil and plant variables to application

  3. 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

  4. Irrigation as an Historical Climate Forcing

    Science.gov (United States)

    Cook, Benjamin I.; Shukla, Sonali P.; Puma, Michael J.; Nazarenko, Larissa S.

    2014-01-01

    Irrigation is the single largest anthropogenic water use, a modification of the land surface that significantly affects surface energy budgets, the water cycle, and climate. Irrigation, however, is typically not included in standard historical general circulation model (GCM) simulations along with other anthropogenic and natural forcings. To investigate the importance of irrigation as an anthropogenic climate forcing, we conduct two 5-member ensemble GCM experiments. Both are setup identical to the historical forced (anthropogenic plus natural) scenario used in version 5 of the Coupled Model Intercomparison Project, but in one experiment we also add water to the land surface using a dataset of historically estimated irrigation rates. Irrigation has a negligible effect on the global average radiative balance at the top of the atmosphere, but causes significant cooling of global average surface air temperatures over land and dampens regional warming trends. This cooling is regionally focused and is especially strong in Western North America, the Mediterranean, the Middle East, and Asia. Irrigation enhances cloud cover and precipitation in these same regions, except for summer in parts of Monsoon Asia, where irrigation causes a reduction in monsoon season precipitation. Irrigation cools the surface, reducing upward fluxes of longwave radiation (increasing net longwave), and increases cloud cover, enhancing shortwave reflection (reducing net shortwave). The relative magnitude of these two processes causes regional increases (northern India) or decreases (Central Asia, China) in energy availability at the surface and top of the atmosphere. Despite these changes in net radiation, however, climate responses are due primarily to larger magnitude shifts in the Bowen ratio from sensible to latent heating. Irrigation impacts on temperature, precipitation, and other climate variables are regionally significant, even while other anthropogenic forcings (anthropogenic aerosols

  5. improving of irrigation management: a learning based approach

    African Journals Online (AJOL)

    p2333147

    Irrigation farms are small businesses and like any other business, the managers or ... human factors and constraints that impact on the adoption of irrigation ... Informal interaction with other irrigation farmers and social networks played a ...

  6. How Governance Regimes Shape the Implementation of Water Reuse Schemes

    Directory of Open Access Journals (Sweden)

    Jos Frijns

    2016-12-01

    Full Text Available The governance dimensions of water reuse scheme development and operation, such as policies and regulatory frameworks, and public involvement and stakeholder collaboration, can serve to both facilitate and constrain wider adoption of water reuse practices. This paper explores the significance and underlying structure of the key governance challenges facing the water reuse sector in Europe. It presents empirical evidence from interviews and focus group sessions conducted at four water reuse schemes: an indirect potable reuse scheme at Torreele (Belgium, the urban reuse of treated municipal wastewater at the London Olympic Park (United Kingdom and at Sabadell (Spain, and the reuse of agro-industrial effluent for irrigation at Capitanata (Italy. The findings underscore the importance of clarity in policy arrangements around water reuse, as well as of the financial competitiveness of reuse projects compared to alternative water supply options. Operators of water reuse schemes expressed a preference for water quality standards, which focus on appropriateness for use rather than over-emphasise the waters’ origin so that unnecessary treatment and costs can be avoided. Positive public support was widely acknowledged as an important factor in the success or failure of water reuse schemes. We conclude that constructive institutional relationships underpin many of the challenges faced by reuse scheme operators and that greater emphasis should be given to building confidence and gaining trust in water service providers through early identification of how governance regimes shape the viability of new schemes.

  7. Assesing the suitability of water for irrigation theoretical and practical approach

    International Nuclear Information System (INIS)

    Hannan, A.; Javad, M.A.; Arif, M.; Rashid, A.

    2006-01-01

    Forced by the surface water shortage and prevalent drought like conditions in the country the farmers have started exploiting groundwater resource. On the other hand, seventy percent of the groundwater being marginal to unfit is a threat to the sustainability of irrigated agriculture. The judicious groundwater exploitation and application has also become imperative in context of ever increasing demographic pressure on soil, crop and water resources. Different classes of irrigation waters established by various research scientists / organizations within the country or abroad are not ultimate under all conditions but these serve as general guidelines. In some cases brackish water requires only minor modification under existing irrigation and ogronomic practices, while in most of the cases it requires major changes regarding type of crops grown, method of water application and the use of soil and water amendments. Therefore, before recommending water for irrigation. Soil characteristics, water management practices, drainage condition of the filed and climatic events must be taken into account as waters generally classified unsuitable for irrigation can be used successfully to grow crops without long term hazardous consequences to crops or soils. This can be attempted simply with the use of improved farming and management practices. Use of brackish water for irrigation may increase the resource base for irrigated agriculture in Pakistan. This article reviews various water classification schemes, salinity-crop yield interrelation with detailed discussion on brackish water application and associated problems. The article also covers a number of management options so as to mitigate the problem and sustain food security in the country. (author)

  8. Physiology of ‘Paluma’ guava under irrigation with saline water and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Evandro Manoel da Silva

    2017-05-01

    Full Text Available The use of saline water in irrigation causes osmotic and toxic effects and nutritional imbalance in plants, leading to morphophysiological modifications in the leaves and compromising the production of photosynthetic pigments, which negatively reflects in the growth and development of the crops. Hence, this study aimed to evaluate the effect of irrigation water salinity on the content of photosynthetic pigments and leaf morphophysiology of guava seedlings cv. ‘Paluma’ under nitrogen (N fertilization. A randomized block design was used, testing five levels of irrigation water electrical conductivity - ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1 and four N doses (541.1, 773.0, 1,004.9, and 1,236.8 mg of N dm-3 of soil in a 5 x 4 factorial scheme with three replicates and five plants per plot. The contents of photosynthetic pigments in the leaves of the guava seedlings cv. ‘Paluma’ were inhibited by the increase in irrigation water salinity at 190 days after emergence, and the salt stress was lessened with the N dose of 1,004.9 mg dm-3 up to an ECw level of 1.2 dS m-1. Leaf morphophysiology of guava seedlings was not compromised by irrigation water salinity up to 1.5 dS m-1, and the highest values were obtained in plants fertilized with 541.1 mg of N dm-3.

  9. A comparative analysis of the impacts of climate change and irrigation on land surface and subsurface hydrology in the North China Plain

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Guoyong; Tang, Qiuhong; Huang, Maoyi; Leung, Lai-Yung R.

    2015-02-01

    The Community Land Model 4.0 (CLM4) was used to investigate and compare the effects of climate change and irrigation on terrestrial water cycle. Three climate change scenarios and one irrigation scenario (IRRIG) were simulated in the North China Plain (NCP), which is one of the most vulnerable regions to climate change and human perturbations in China. The climate change scenarios consist of (1) HOT (i.e. temperature increase by 2oC); (2) HOTWET (same with HOT but with an increase of precipitation by 15%); (3) HOTDRY (same with HOT but with a decrease of precipitation by 15%). In the IRRIG scenario, the irrigation scheme was calibrated to simulate irrigation amounts that match the actual irrigation amounts and irrigation was divided between surface water and groundwater withdrawals based on census data. Our results show that the impacts of climate change were more widespread while those of irrigation were concentrated only over the agricultural regions. Specifically, the mean water table depth was simulated to decline persistently by over 1 m annually due to groundwater exploitation during the period of 1980-2000, while much smaller effects were induced by climate change. Although irrigation has comparable effects on surface fluxes and surface soil moisture as climate change, it has much greater effects on water table depth and groundwater storage. Moreover, irrigation has much larger effects on the top layer soil moisture whereas increase in precipitation associated with climate change exerts more influence on lower layer soil moisture. This study emphasizes the need to accurately account for irrigation impacts in adapting to climate change.

  10. Growth, Yield and WUE of Drip and Sprinkler Irrigated Okra Grown On Sandy Soil Under Semi-Arid Conditions in Southeast Ghana

    DEFF Research Database (Denmark)

    Plauborg, Finn

    Vegetable production systems at the Keta sand spit, Southeast Ghana, are typically managed with excessive amounts of irrigation water and fertilizers on sandy soils with low inherent water and nutrient retention capacities. The shallow groundwater which is the primary irrigation water resource...... is prone to salinization from the Keta lagoon, the Atlantic Ocean and brackish water underneath (Kortatsi and Agyeku, 1999). To ensure the sustainability of vegetable production at the Keta spit, introduction of water saving irrigation systems and improved irrigation management schemes are important. Thus......, the main aim of our study was to explore the water sa ving potential of drip irrigation in order to save the shallow groundwater from over exploitation. A two season study (minor dry season, 2011 and major dry season, 2012) were carried out to determine the okra crop response to the following treatments: 1...

  11. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    Science.gov (United States)

    Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y.

    2015-12-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET / Y). The management practices are four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)), four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation), and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments in Israel, Spain, Italy and the UK, respectively; wet, normal and dry years; three soil types (sand, sandy loam and silty clay loam); and three crops (maize, potato and tomato). The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is 8-10 % if we change from the reference to drip or SSD, 13 % when changing to OML, 17-18 % when moving to drip or SSD in combination with OML, and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow

  12. Threshold Signature Schemes Application

    Directory of Open Access Journals (Sweden)

    Anastasiya Victorovna Beresneva

    2015-10-01

    Full Text Available This work is devoted to an investigation of threshold signature schemes. The systematization of the threshold signature schemes was done, cryptographic constructions based on interpolation Lagrange polynomial, elliptic curves and bilinear pairings were examined. Different methods of generation and verification of threshold signatures were explored, the availability of practical usage of threshold schemes in mobile agents, Internet banking and e-currency was shown. The topics of further investigation were given and it could reduce a level of counterfeit electronic documents signed by a group of users.

  13. Study of Rice Marketing System in Iran

    OpenAIRE

    Feizabadi, Yaser

    2011-01-01

    Rice comes second after wheat in Iran`s food consumption economy. Rising population and recent growth in GDP has made Iran one of the greatest rice importer countries all over the world. That is why rice marketing has always been a controversial issue in Iran`s agricultural economics. To study rice marketing system in Iran, this paper aims to calculate rice marketing margin, market efficiency and marketing cost coefficient in seaside Mazandaran province( where 70 percent of domestic rice prod...

  14. Ecological investigation of application of pesticides in rice fields

    International Nuclear Information System (INIS)

    Nouri, J.; Arjomandi, R.; Bayat, H.

    2000-01-01

    Among several pests of rice as one of the main agricultural products in Iran, rice borer, C hilo sarsaparilla is one of the most important pests of this crop. Use of pesticides coincided with the occurrence of this pest in the northern region of Iran in 1972. At present in order to control this pest, more than 12000 tones of pesticides granules are used annually. Ecological effects of pesticides application and the use of Trichograma sp. as a natural enemy, for assessing the impacts of pesticides in environments, especially on different living organisms on the plant, in irrigation water, and in 5 cm depth of surface soil, were investigated in two regions of Amol, named Osk. Mahalleh and Capik Field of Tashbandan. Results indicated that the two treatments were not different on crop loss. One the contrary, in the pesticide treatment, there was a considerable dec tease in the population of living organisms, particularly, no organism was observed in 5 cm depth of surface soil. It is recommended that in order to maintain the balance of environment, the use of chemicals for controlling rice borer must be with extreme care, only in the inevitable was with the use of principles of Integrated Pest Management

  15. 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)

  16. 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.

  17. 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

  18. A preliminary study on the uptake of radioiodine by rice plants from soil

    International Nuclear Information System (INIS)

    Uchida, Shigeo; Muramatsu, Yasuyuki; Sumiya, Misako; Ohmomo, Yoichiro; Yamaguchi, Shuho.

    1989-01-01

    In an atmospheric discharge of radioiodines, direct deposition of the nuclides onto leaf surface must be the most significant pathway from the environment to man. However, 129 I reaches man through several pathways because of its long half life of 1.6 x 10 7 years. Root uptake of 129 I is one of the most important pathways of this nuclide. In Japan, rice is thought to be the most critical crop on the pathway. In this paper, uptake of radioiodine from irrigation water by rice plant was investigated. Rice plants, Oryza sativa cv. Nihonbare, were grown under flooded condition in Wagner pots containing soil collected in Tokai-mura. Iodine-131 was added as a tracer into the surface water in the pots at three different growing stages, heading, dough-ripe and yellow-ripe stages, respectively, and the plants were cultivated until the harvest time in a plant growth chamber. At the harvest time, concentration of 131 I in each organ of rice plant was measured with a NaI scintillation counter. The profile of 131 I in the soil was also investigated. The results obtained are as follows; (1) Activities of 131 I in leaf blade and sheath of lower part were generally higher than those of upper part. Compared to the 131 I activity of the flag leaf, the ratios of the activity in rachis-branch, hull and brown rice were 1.0-0.5, 0.1 and 1-5 x 10 -3 , respectively. These may suggest that iodine taken up by the roots scarcely re-translocated into rice. (2) Ratio of 131 I in brown rice and hull was about 1 : 4. (3) Activity ratio ('concentration of 131 I in brown rice'/'average concentration of that in the soil' during 6 days uptake experiment.) was 4-5 x 10 -4 . (author)

  19. 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.

  20. Modelling human agency in ancient irrigation

    NARCIS (Netherlands)

    Ertsen, M.W.

    2011-01-01

    Human activity is key in understanding ancient irrigation systems. Results of short term actions build up over time, affecting civilizations on larger temporal and spatial scales. Irrigation systems, with their many entities, social and physical, their many interactions within a changing environment

  1. Technical efficiency of irrigated vegetable production among ...

    African Journals Online (AJOL)

    This study was carried out to analyse the technical efficiency of irrigated vegetable production among smallholder farmers in the guinea savannah, Nigeria, and determine the cost and returns on irrigated vegetable production. Two-stage sampling technique was used, purposive selection of two states and three Local ...

  2. Prospects and Constraints of Household Irrigation Practices ...

    African Journals Online (AJOL)

    Constraints and prospects of hand dug wells related to household irrigation were assessed in Hayelom watershed (~1045 ha), by evaluating groundwater suitability for irrigation, soil quality and impact of intervention. 181 hand dug wells have come into existence in the watershed due to intervention and benefiting about ...

  3. Using Automation to Improve Surface Irrigation Management

    Science.gov (United States)

    In the Lower Mississippi Water Resource Area (WRA 08), also called the Mid-South, 2 million ha of cropland (80% of the irrigated farmland) employ surface irrigation, almost equally divided between furrow (52%) and controlled flooding (48%). Because Mid-South farmers experience less-than-optimal surf...

  4. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    Boutsioukis, C.; van der Sluis, L.W.M.; Basrani, B.

    2015-01-01

    Syringe irrigation remains a widely used irrigant delivery method during root canal treatment. An interdisciplinary approach involving well-established methods from the field of fluid dynamics can provide new insights into the mechanisms involved in cleaning and disinfection of the root canal system

  5. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    Boutsioukis, Christos; van der Sluis, Lucas; Basrani, Bettina

    2015-01-01

    This book reviews the available information on bacterial disinfection in endodontics, with emphasis on the chemical treatment of root canals based on current understanding of the process of irrigation. It describes recent advances in knowledge of the chemistry associated with irrigants and delivery

  6. A scintigraphic study of colostomy irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Shinji; Fujii, Hisao; Nakano, Hiroshige (Nara Medical Univ., Kashihara (Japan))

    1991-09-01

    Colostomy irrigation was investigated by colonoscintigraphy. Twelve rectal cancer and one sigmoid colon cancer patients were examined. The tepid water whose volume was determined by barium enema was mixed with {sup 99m}Tc-DTPA. Dynamic scanning was started on commencement of colostomy irrigation. The sampling time was 3 seconds and scanning was performed for 30 minutes. The mean volume of remnant colon as measured by barium enema was 650 ml. The mean number of mass movements was 4.3. The mean evacuation time was 11 minutes 56 seconds and the mean half emptying time was calculated to be 9.5 minutes. The evacuation time in the patients who underwent colostomy irrigation for more than 2 years was greater than that in the patients who underwent irrigation for less than 2 years. Colonic motility was thought to have weakened. The half emptying time and the number of mass movements in the patients whose irrigation water went into the terminal ileum was more than that in the patients whose irrigation water was within the colon and cecum. Irrigation water which went into the terminal ileum was caused evacuation after the contents of the remnant colon were washed out. In conclusion, patients should have their colostomy irrigated with the tepid water, volume is determined by barium enema. Furthermore single infusion of the water is recommended. (author).

  7. A scintigraphic study of colostomy irrigation

    International Nuclear Information System (INIS)

    Yasuda, Shinji; Fujii, Hisao; Nakano, Hiroshige

    1991-01-01

    Colostomy irrigation was investigated by colonoscintigraphy. Twelve rectal cancer and one sigmoid colon cancer patients were examined. The tepid water whose volume was determined by barium enema was mixed with 99m Tc-DTPA. Dynamic scanning was started on commencement of colostomy irrigation. The sampling time was 3 seconds and scanning was performed for 30 minutes. The mean volume of remnant colon as measured by barium enema was 650 ml. The mean number of mass movements was 4.3. The mean evacuation time was 11 minutes 56 seconds and the mean half emptying time was calculated to be 9.5 minutes. The evacuation time in the patients who underwent colostomy irrigation for more than 2 years was greater than that in the patients who underwent irrigation for less than 2 years. Colonic motility was thought to have weakened. The half emptying time and the number of mass movements in the patients whose irrigation water went into the terminal ileum was more than that in the patients whose irrigation water was within the colon and cecum. Irrigation water which went into the terminal ileum was caused evacuation after the contents of the remnant colon were washed out. In conclusion, patients should have their colostomy irrigated with the tepid water, volume is determined by barium enema. Furthermore single infusion of the water is recommended. (author)

  8. Irrigation scheduling with the neutron probe

    International Nuclear Information System (INIS)

    Travers, P.

    1987-01-01

    The operational theory of the neutron probe is briefly outlined and its application and uses discussed in relation to determination of soil compaction and irrigation scheduling. Graphic examples are given of alluvial soil moisture profiles and how this information can be used to improve trickle irrigation in vineyards. 3 refs., 7 figs

  9. Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions

    Science.gov (United States)

    Mozo, Sandra; Llena, Carmen

    2012-01-01

    Introduction: Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. Objective: The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. Methods: This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. Results: The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layer and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation. Key words:Ultrasonic irrigation, ultrasound, smear layer, endodontics. PMID:22143738

  10. Impact of improved operation and maintenance on cohesive sediment transport in Gezira Scheme, Sudan

    NARCIS (Netherlands)

    Osman, I.S.E.

    2015-01-01

    Summary

    Efficient operation and maintenance of irrigation schemes are needed for improving the hydraulic performance of the canals, enhancing the crop yields and insuring sustainable production. There is a great need to enhance the researches and for a variety of tools such as

  11. Techno-Economic Evaluation of Solar Irrigation Plants Installed in Bangladesh

    Directory of Open Access Journals (Sweden)

    Najmul Hoque

    2016-02-01

    Full Text Available In the summer season, irrigation sector in Bangladesh suffers a lot due to the country wide electricity crisis. Solar pump offers a clean and simple alternative to the conventional fuel fired engine or grid electricity driven pump in this regard to resolve the issue. In this paper, the techno-economic analyses of solar irrigation plants installed in Bangladesh are evaluated.  It was observed that systems were running around 70% to 80% of the rated power which was quite acceptable. A 10 hp pump was able to pump 600 liter of water per minute which was also satisfactory to irrigate the land. Average operating time was found to be 8 hour/day. It was found that the overall efficiency of the systems were in between 11.39% to 16.52% whereas the typical average value of lit/Wp/year was 9200. On the other hand, the cost of irrigation to cultivate paddy in 0.161 hectares’ land for one season was 1,750 BDT by solar irrigation which was found to be lower than that of other available modes. This charge for grid electricity based irrigation was about 3,000 to 3500 BDT per 0.161 hectares’ and 2,300 to 2,600 BDT per 0.161 hectares’ for diesel engine based irrigation. According to the current financial scheme (15% equity investment, 35% credit support and remaining 50% from government through IDCOL the average value of payback period was 5.43 years, NPV in the range from 7 to 15% and IRR was 18%. By considering 100% equity investment, however, these projects were not economically attractive. The payback period for this case was about 18 years. Study also revealed that each solar irrigation plant reduces 42.8 kg of CO2 emission per day compare to diesel engine operated pump and 2566.24 kg/day compared to grid electricity operated pump. A comprehensive effort from the Government as well as from all the stakeholders is required for further expansion of solar irrigation plants in Bangladesh. Article History: Received Sept 05, 2015; Received in revised form

  12. In vitro assessment on the impact of soil arsenic in the eight rice varieties of West Bengal, India.

    Science.gov (United States)

    Bhattacharya, Piyal; Samal, Alok C; Majumdar, Jayjit; Banerjee, Satabdi; Santra, Subhas C

    2013-11-15

    Rice is an efficient accumulator of arsenic and thus irrigation with arsenic-contaminated groundwater and soil may induce human health hazard via water-soil-plant-human pathway. A greenhouse pot experiment was conducted on three high yielding, one hybrid and four local rice varieties to investigate the uptake, distribution and phytotoxicity of arsenic in rice plant. 5, 10, 20, 30 and 40 mg kg(-1) dry weights arsenic dosing was applied in pot soil and the results were compared with the control samples. All the studied high yielding and hybrid varieties (Ratna, IET 4094, IR 50 and Gangakaveri) were found to be higher accumulator of arsenic as compared to all but one local rice variety, Kerala Sundari. In these five rice varieties accumulation of arsenic in grain exceeded the WHO permissible limit (1.0 mg kg(-1)) at 20 mg kg(-1) arsenic dosing. Irrespective of variety, arsenic accumulation in different parts of rice plant was found to increase with increasing arsenic doses, but not at the same rate. A consistent negative correlation was established between soil arsenic and chlorophyll contents while carbohydrate accumulation depicted consistent positive correlation with increasing arsenic toxicity in rice plant. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Nicaragua - Rice and Banana Farmers

    Data.gov (United States)

    Millennium Challenge Corporation — This report is an impact evaluation of two components of the Rural Business Development Program (RBD) in Nicaragua, specifically the components benefitting rice and...

  16. [Irrigants and intracanal medicaments in endodontics].

    Science.gov (United States)

    Zehnder, Matthias; Lehnert, Birgit; Schönenberger, Kathrin; Waltimo, Tuomas

    2003-01-01

    Modern, biologic root canal therapy should be performed with suitable irrigating solutions and intracanal medicaments. The goal of endodontic treatment is to free the treated tooth from infection and prevent reinfection as thoroughly as possible by means which do not put the organism at risk. In this review of the literature, an evidence-based concept for irrigation and medication of root canal systems is presented. Irrigants and medicaments are discussed with respect to their antimicrobial, tissue-dissolving and endotoxin-decontaminating capacity in relation to their systemic toxicity. Recent findings pertaining to interactions of root canal medicaments and irrigating solutions and their impact on a sound irrigating and medicating concept are discussed.

  17. CSR schemes in agribusiness

    DEFF Research Database (Denmark)

    Pötz, Katharina Anna; Haas, Rainer; Balzarova, Michaela

    2013-01-01

    of schemes that can be categorized on focus areas, scales, mechanisms, origins, types and commitment levels. Research limitations/implications – The findings contribute to conceptual and empirical research on existing models to compare and analyse CSR standards. Sampling technique and depth of analysis limit......Purpose – The rise of CSR followed a demand for CSR standards and guidelines. In a sector already characterized by a large number of standards, the authors seek to ask what CSR schemes apply to agribusiness, and how they can be systematically compared and analysed. Design....../methodology/approach – Following a deductive-inductive approach the authors develop a model to compare and analyse CSR schemes based on existing studies and on coding qualitative data on 216 CSR schemes. Findings – The authors confirm that CSR standards and guidelines have entered agribusiness and identify a complex landscape...

  18. Tabled Execution in Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Willcock, J J; Lumsdaine, A; Quinlan, D J

    2008-08-19

    Tabled execution is a generalization of memorization developed by the logic programming community. It not only saves results from tabled predicates, but also stores the set of currently active calls to them; tabled execution can thus provide meaningful semantics for programs that seemingly contain infinite recursions with the same arguments. In logic programming, tabled execution is used for many purposes, both for improving the efficiency of programs, and making tasks simpler and more direct to express than with normal logic programs. However, tabled execution is only infrequently applied in mainstream functional languages such as Scheme. We demonstrate an elegant implementation of tabled execution in Scheme, using a mix of continuation-passing style and mutable data. We also show the use of tabled execution in Scheme for a problem in formal language and automata theory, demonstrating that tabled execution can be a valuable tool for Scheme users.

  19. Sorghum and rice: Mali

    International Nuclear Information System (INIS)

    2003-01-01

    Agriculture is the mainstay of the Malian economy and yet cereal imports absorb 6.5% of GDP. Food self-sufficiency is therefore a national priority. The Joint FAO/IAEA Division is supporting a programme to improve local varieties of sorghum and rice by using nuclear techniques to develop new cultivars that will produce higher yields under Mali's semi-arid climatic conditions. (IAEA)

  20. Evaluating statistical cloud schemes

    OpenAIRE

    Grützun, Verena; Quaas, Johannes; Morcrette , Cyril J.; Ament, Felix

    2015-01-01

    Statistical cloud schemes with prognostic probability distribution functions have become more important in atmospheric modeling, especially since they are in principle scale adaptive and capture cloud physics in more detail. While in theory the schemes have a great potential, their accuracy is still questionable. High-resolution three-dimensional observational data of water vapor and cloud water, which could be used for testing them, are missing. We explore the potential of ground-based re...

  1. Gamma spectrometry; level schemes

    International Nuclear Information System (INIS)

    Blachot, J.; Bocquet, J.P.; Monnand, E.; Schussler, F.

    1977-01-01

    The research presented dealt with: a new beta emitter, isomer of 131 Sn; the 136 I levels fed through the radioactive decay of 136 Te (20.9s); the A=145 chain (β decay of Ba, La and Ce, and level schemes for 145 La, 145 Ce, 145 Pr); the A=47 chain (La and Ce, β decay, and the level schemes of 147 Ce and 147 Pr) [fr

  2. Scheme of energy utilities

    International Nuclear Information System (INIS)

    2002-04-01

    This scheme defines the objectives relative to the renewable energies and the rational use of the energy in the framework of the national energy policy. It evaluates the needs and the potentialities of the regions and preconizes the actions between the government and the territorial organizations. The document is presented in four parts: the situation, the stakes and forecasts; the possible actions for new measures; the scheme management and the regional contributions analysis. (A.L.B.)

  3. Diversity of some endophytic fungi associated with rice black bug Paraeucosmetus pallicornis on rice plant

    OpenAIRE

    Nur, Amin; La Daha; Nurariaty, Agus; Ade, Rosmana; Muh., Fadlan

    2015-01-01

    A new rice insect pest was sighted in some rice producing areas of South Sulawesi Province, Indonesia. This pest is rice black bugs Paraeucosmetus pallicornis. The research aimed to isolation of fungi associated with rice black bugs Paraeucosmetus pallicornis, so as to know the cause of a bitter taste to the rice. The isolation of the fungi consist of three kinds of treatment, namely rice black bugs without sterilization, with sterilization and rice black bugs cut and sterilized. The resul...

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

    Science.gov (United States)

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

    2017-12-01

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

  5. 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.

  6. Socio-economic analysis of rice production in Ghana: Agenda for ...

    African Journals Online (AJOL)

    Ghana Journal of Agricultural Science ... that had resulted in closure of some irrigation schemes, including those at Dawhenya and Weija, difficulties in accessing credit, use of pooryielding seed varieties, inappropriate agronomic practices, limited mechanisation, poor processing methods, and poor marketing strategies.

  7. 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

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Broken rice kernels and the kinetics of rice hydration and texture during cooking.

    Science.gov (United States)

    Saleh, Mohammed; Meullenet, Jean-Francois

    2013-05-01

    During rice milling and processing, broken kernels are inevitably present, although to date it has been unclear as to how the presence of broken kernels affects rice hydration and cooked rice texture. Therefore, this work intended to study the effect of broken kernels in a rice sample on rice hydration and texture during cooking. Two medium-grain and two long-grain rice cultivars were harvested, dried and milled, and the broken kernels were separated from unbroken kernels. Broken rice kernels were subsequently combined with unbroken rice kernels forming treatments of 0, 40, 150, 350 or 1000 g kg(-1) broken kernels ratio. Rice samples were then cooked and the moisture content of the cooked rice, the moisture uptake rate, and rice hardness and stickiness were measured. As the amount of broken rice kernels increased, rice sample texture became increasingly softer (P hardness was negatively correlated to the percentage of broken kernels in rice samples. Differences in the proportions of broken rice in a milled rice sample play a major role in determining the texture properties of cooked rice. Variations in the moisture migration kinetics between broken and unbroken kernels caused faster hydration of the cores of broken rice kernels, with greater starch leach-out during cooking affecting the texture of the cooked rice. The texture of cooked rice can be controlled, to some extent, by varying the proportion of broken kernels in milled rice. © 2012 Society of Chemical Industry.

  11. The Haitian Rice Tariff

    Directory of Open Access Journals (Sweden)

    Mats Lundahl

    2016-04-01

    Full Text Available Se ha argumentado que los problemas agríco-las de Haití derivan de la tarifa del arroz de a mediados de los años noventa. Antes, supues-tamente, Haití fue autosuficiente, abastecida por su producción doméstica. Después de la reducción, el mercado haitiano se inundó en importaciones de arroz barato de los EEUU, lo cual despojó a los campesinos de sus fincas, convirtiendolos en migrantes internos, hacia los empleos de bajo pago de las ciudades. El artículo rechaza ese argumento y demuestra que es falso. La malnutrición fue un fenómeno extendido en Haití mucho antes de la reducción de la tarifa del arroz, la cual tampoco tuvo un gran impacto en la importación y la producción doméstica del arroz. Lo que sí impulsó el aumento de las importaciones fue el crecimiento de la población. También el artículo argumenta que un aumento de la tarifa del arroz no solucionará el problema de la alimentación que sufre Haití. English: It has been argued that Haiti’s agricultural problems derive from the reduction of the rice tariff in the mid-1990s. Before that Haiti was allegedly able to meet its food needs by domestic production. After the reduction the Haitian market was swamped by imports of cheap American rice which drove the farmers off their lands and forced them to migrate to low-wage industrial jobs in the cities. The article demonstrates that the argument is false. Malnutrition was widespread in Haiti long before the rice tariff reduction, and the latter did not have much of an impact on rice imports and domestic production. Instead, the main driving force behind imports appears to be population growth. It is also shown that an increase of the rice tariff will not solve Haiti’s food problem.

  12. Scheduling of Irrigation and Leaching Requirements

    Directory of Open Access Journals (Sweden)

    Amer Hassan Al-haddad

    2015-03-01

    Full Text Available Iraq depends mainly on Tigris and Euphrates Rivers to provide high percentage of agricultural water use for thousands years. At last years, Iraq is suffering from shortage in water resources due to global climate changes and unfair water politics of the neighboring countries, which affected the future of agriculture plans for irrigation, added to that the lack of developed systems of water management in the irrigation projects and improper allocation of irrigation water, which reduces water use efficiency and lead to losing irrigation water and decreasing in agricultural yield. This study aims at studying the usability of irrigation and leaching scheduling within the irrigating projects and putting a complete annual or seasonal irrigation program as a solution for the scarcity of irrigation water, the increase of irrigation efficiency, lessening the salinity in the projects and preparing an integral irrigation calendar through field measurements of soil physical properties and chemical for project selected and compared to the results of the irrigation scheduling and leaching with what is proposed by the designers. The process is accomplished by using a computer program which was designed by Water Resources Department at the University of Baghdad, with some modification to generalize it and made it applicable to various climatic zone and different soil types. Study area represented by large project located at the Tigris River, and this project was (Al-Amara irrigation project. Sufficient samples of project's soil were collected so as to identify soil physical and chemical properties and the salinity of soil and water as well as identifying the agrarian cycles virtually applied to this project. Finally, a comparison was conducted between the calculated water quantities and the suggested ones by the designers. The research results showed that using this kind of scheduling (previously prepared irrigation and leaching scheduling with its properties

  13. Optimization of modern irrigation for biosaline agriculture

    International Nuclear Information System (INIS)

    Shahid, S.A.; Hasbini, B.

    2007-01-01

    Supplementation water is a must to offset the water requirement to produce profitable crops in most arid and semiarid zones, where fresh water resources are insufficient to meet the pressure of irrigated agriculture. This necessitates the use of poor quality water resources. These waters if not properly managed and used can cause serious soil related problems (salinity, sodicity, destruction of soil structure) in addition to decline in crop yields. Biosaline agriculture (using saline water on saline soils to grow salt-tolerant crops) becomes the only option for the farmer when both soil and water resources are saline and the water resource is scarce. In this regards key design considerations must be taken into account when irrigating with salty waters to optimize water uses and to reduce subsequent soil salinity development. Sprinkler irrigation systems are commonly used in irrigation of large-scale irrigational production systems. However they tend to concentrate salts on the leaves of plants. For this reason discharge and degree of overlap between consecutive sprinkler heads, are key design parameters when applying salty waters. Trickle irrigation is the most efficient system and is gaining importance in the GCC countries in the agriculture and landscape irrigation. The objective of this study was to optimize modern irrigation systems through development of design standards for drip (emitters spacing) and sprinkler irrigation systems (single head jet and overlapping) by applying saline water. The effect of emitter spacing (drip) and overlapping (sprinkler) were tested for the formation of salt contours in soil. The leaching ratio (LR) is the overall soil sanity within rhizosphere divided by the average irrigation water salinity. In this study LR is used to evaluate the effectiveness of irrigation systems in developing soil sanity. From the present investigations it is concluded that when using saline water for irrigation, the soil sanity development can be

  14. Autoradiographic study on moisture distribution in pearl-barley and in rice grain

    International Nuclear Information System (INIS)

    Sakharov, Eh.V.; Koz'mina, E.P.; Troitskaya, E.Ya

    1975-01-01

    The dependence of some structural details of the pearl-barley and rice endosperm on the internal moisture distribution is found. The general scheme of the study is shown. The curves of the local moisture distribution in the pearly-barley and rice kernel are plotted according to the radiography data. Moisture distribution over the whole section of the rice kernel is relatively constant at 85 deg C after ten minutes of moisture. Whereas moisture of pearl-barley kernel is only approaching the center of kernel by the time the moisture content increases to 1.5-2%. The slow moisture transfer in the pearl-barley kernel makes the cooking period three times longer as that of the rice

  15. Nutritional test of rice in rats

    International Nuclear Information System (INIS)

    Horii, Masaji; Yoshikawa, Seiji

    1980-01-01

    Behaviors on N derived from rice were followed up by means of 15 N-labeled rice. In the first test, the single unpolished rice diet and the diet of rice and bean lecithin (4.5%) produced urinary excretion of 10 - 12% of 15 N, and that of rice and mannan from devil's tongue (3%), 16 - 20%. The single unpolished rice diet showed slightly more urinary excretion of 15 N, and the other 2 diets showed a similar proportion of 15 N in 3 days. The results indicated that the diet containing mannan from devil's tongue resulted in a poor N absorption by rice, a large quantity of N being excreted over a long period of time. This suggested differences and time lags in the excretion of rice N into the stool and urine depending on the diet constitution. With the unpolished rice diet, a small quantity of rice protein was not absorbed, but was excreted. In the 2nd test with 15 N-polished rice, the urinary excretion rate was 11.44% for a single rice diet, 11.16% for a mixed diet of rice and bean (1:1 in protein), 10.99% for rice and egg yolk, 9.66% for rice, bean and egg yolk and 8.10% for rice and bean lecithin. This decrease in urinary excretion indicated a corresponding increase in absorption of rice protein. (Chiba, N.)

  16. Nucleus management with irrigating vectis

    Directory of Open Access Journals (Sweden)

    Srinivasan Aravind

    2009-01-01

    Full Text Available The main objective in modern cataract surgery is to achieve a better unaided visual acuity with rapid post-surgical recovery and minimal surgery-related complications. Early visual rehabilitation and better unaided vision can be achieved only by reducing the incision size. In manual small incision cataract surgery (MSICS, incision is between 5.5 to 7 mm. Once the nucleus is prolapsed into the anterior chamber, it can be extracted through the tunnel. Nucleus extraction with an irrigating vectis is a very simple technique, which combines mechanical and hydrostatic forces to express out the nucleus. This technique is time-tested with good results and more than 95% of nuclei in MSICS are extracted in this way offering all the merits of phacoemulsification with the added benefits of having wider applicability, better safety, shorter learning curve and lower cost.

  17. 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 Aut