Integrated farming approach for runoff recycling systems in humid plateau areas of eastern India

Regions having undulating terrain are predominantly rainfed and have a poor productivity level. As the traditional irrigation systems, viz. canal irrigation and tubewell irrigation are not feasible due to topographical, geological and hydrological constraints, rainwater harvesting has been found to have potential of being an irrigation water resource which can provide full irrigation in conjunction with rainfall to a transplanted rice based two crop rotation. Utilization of stored water in both monsoon and post-monsoon season crops increases the efficiency of the system which is evident from higher water yield-storage capacity ratio of 1.75. The evaluation of a rain water harvesting system has shown that integrated farming approach of utilizing the system enhances the economics of the system. While the B–C ratio with only crop was 1.89, it increased to 2.27 if horticultural crops are taken on the embankment of the tank. It further increased to 2.80 when fish culture is taken up in the stored water. There is possibility of its increasing to more than 3.0 if duckery is also taken up. Extrapolating these results, benefit cost analysis has been done for other two site conditions where the seepage loss is between 6 and 10 mm/day and seepage loss is more than 10 mm/day and therefore lining is required.