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Not AvailableRice is the staple food for half of the world’s population, and rice farming is a livelihood for millions of farmers in Asia. In India, it provides an individual with 32% of the total calorie and 24% of the total protein daily. This crop is mostly grown in puddled soil by transplanting, and flood irrigation is practised by farmers. Water or irrigation input to transplanted rice typically ranges from 1000 to 2000 mm depending upon the growing season, climatic condition, soil type and hydrological conditions. Facing water scarcity and climate change, reducing water requirement of this crop is a challenge. Out of 42.75 million hectare (m ha) rice area, only 25.12 m ha is under irrigation. Regarding water resources, depletion of groundwater is alarming in the north Indian states. On the other hand, it is under-utilized in eastern India. Microirrigation, i.e. sprinkler and drip methods have been used with the aim of minimizing water use and enhancing water use efficiency of rice. In addition, evidence-based scientific understandings on microirrigation for rice have been elucidated in this article. The potential of drip or sprinkler irrigation to rice on water saving as well as scientific insight and critical appraisal have been expounded on reasons of yield reduction. This comprehensive treatise would facilitate the formulation of strategies or policies on efficient management of water or irrigation for rice cultivation.Not Availabl

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Not AvailableABSTRACT Achieving higher productivity in irrigated rice production is becoming ever-more important. A modified ricecultivation method, the System of Rice Intensification (SRI), recommends keeping rice fields moist but unflooded during the crop’s vegetative stage, usually with alternate-wetting-and-drying (AWD), then maintaining shallow flooding during the post-vegetative stage of crop growth. However, no evidence is available on how flooding paddy fields continuously vs. alternately during the post-vegetative stage under SRI might influence the crops’ physiology, root growth, grain yield, and water productivity. Field experiments were conducted to investigate the impacts of two alternative crop management systems, namely, SRI and conventional management practice (CMP) under different water management treatments during the vegetative stage [continuous flooding (CF) vs. AWD] and then during post-vegetative stage: CF vs. AWD @ 1-DAD (days after disappearance of ponded water), 3-DAD or 5-DAD. SRI practices, compared to CMP methods, significantly improved plants’ root growth and xylem exudation rate, leaf area index and light interception by the crop canopy, plus photosynthesis rate at the grain-filling stage, resulting in higher grain yield. Overall, this modified method of rice crop management produced 58% higher grain yield with 16% less water. Across all water management treatments, significantly more grain was produced per unit of water applied with SRI management (6.3 kg ha-mm−1 ) compared to CMP (3.3 kg grain ha-mm−1 ). The highest grain yield with SRI (6.2 t ha−1 ), and the greatest water productivity (6.7 kg ha-mm−1 ) were obtained with SRI and 3-DAD post-vegetative irrigation. With CMP, highest grain yield (4.1 t ha−1 ) and water productivity (3.5 kg ha-mm−1 ) were with 1-DAD irrigation. Differences measured in plants’ response to modified management practices and alternative irrigation schedules indicated how phenotypic and physiological performances can be improved for a given genotype. Combining changes in crop and water management can improve water productivity as well as grain yield.Not Availabl

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Not AvailableWe studied the effect of rearing densities of Pacific white shrimp,Litopenaeus vannameiin three densities withthree replicate treatments [T1: 0.4 million post - larvae (PL) ha−1,T2: 0.5 million PL ha−1,T3: 0.6 million PLha−1] and water cutback approach on rearing environment, water use efficiency, water footprint and productionperformance. Conditional water exchange was carried out based on water quality parameters. Water qualitysuitability index was very good (7.5–9.0) up to 13th, 10th and 5th week of culture in T1,T2and T3, respectively;which was attributed to rearing density, smaller - sized shrimp and low early feed input. Optimum rearing densityof 50 PL m - 2(T2) led to total water use of 3.25 × 104m3. It was seeming as a way to improve shrimp pro - ductivity (10.58 t ha−1120 d−1), consumptive water use index (1.72 m3kg - 1biomass), total water footprint(1229 m3t−1biomass) and net consumptive water productivity (USD 1.28 m - 3). L.vannameiculture with low tomoderate water exchange as in T2, helped uphold water quality suitable for the shrimp growth, improved wateruse efficiency (0.58 kg biomass m - 3water), minimized sediment load (45.3 m3t - 1biomass), effluent outputs(0.63 × 104m3), pumping cost (USD 30.1 t−1biomass produced), and ratio of output value to the cost of cul - tivation (1.97). Thefindings and advancement in knowledge would offer the basis to augment shrimp rearingefforts and the water management approaches will help in preventing the production of waste and effluent while increasing water use efficiency and production performanceNot Availabl

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Not AvailableCommand area development and management strategies were attempted in Nagpur minor canal in a coastal district of Puri, Odisha (India) under Puri canal system. Benchmarking of the irrigation system was carried out considering domains of system performance, agricultural productivity and financial aspects. Under system performance, the results revealed that seasonal irrigation water supply per unit command area is 73% less than the designed supply of 20970 m3 ha-1. Under agricultural productivity for paddy crop as expressed in market based output versus supplied water was computed as 18% less, when it is computed as Rs. 9.9 m3 (considering MSP of paddy Rs. 1410 q-1 during 2015-16; average crop yield of 3.9 t ha-1 and actual water supply of 5565 m3 ha-1). Similarly, under financial performance expressed as cost - recovery ratio was obtained as 0.1 only. The irrigation efficiency under surface irrigation methods (check basin, furrow and raised bed furrow) in different crops was observed to the tune of 35-60% which could be improved up to 80–90% using pressurized irrigation (pipe conveyance, drip irrigation and sprinkler irrigation) in upper, middle and tail reach of the minor. The results of the study reveal that the use of pressurized irrigation, which could increase the irrigation efficiency and water productivity is one of the potential options for sustainable crop production in water scarce canal command area of coastal Odisha.Not Availabl