Water balance simulation and economic analysis for optimal size of on-farm reservoir

摘要: Rainfed rice in eastern India suffers frequent moisture stress leading to severe yield reduction due uncertainty of rainfall coupled with inadequate field level rainwater conservation structures. Construction the on-farm reservoir (OFR) is an alternative for storage excess from diked during monsoon season followed by its reuse as supplemental irrigation same and pre-sowing mustard winter season. For determining optimum size OFR, water balance model cropped fields (both mustard) well OFR was developed along economic analysis. Simulation study revealed that 12% farm area having 2 m depth trapezoidal section would be optimal rice-mustard cropping system. The above-mentioned provides benefit cost ratio (BCR), internal rate return (IRR) pay back period (PBP) 1.23, 15.5% 15 yr, respectively dry year. Values BCR, IRR PBP average year were simulated 1.22, 15% respectively, those wet 1.21, 14.8% 16 respectively. To justify investment system, experiments conducted three years. observed experiment found 1.17,