Enhancing economic water productivity under on farm reservoirs in diversified rainfed cropping systems

A long term study was done to assess the impact of on farm reservoirs (OFR) on oil seedand cereal based cropping systems with vegetables (okra, tomato and carrot) in semi-aridalfisol of southern Telangana region. Two supplemental irrigation (SI) depths (30 and 50 mm)from OFR with raingun system were studied for assessing the water productivity andprofitability of the technology in these cropping systems. Cropping system using sole cropof groundnut or maize, later was found to be more profitable (3 times) with 50 mm SI in2 critical growth stages having annualized net benefit (ANB) of $ 971 - 998 / ha andeconomic productivity (EP) of 31 Cents / m3 under different capacities of OFR (500-1500m3). In rainy season with single filling of OFR and deficit irrigation of 30 mm SI,maize+tomato was found to be more profitable (ANB: $ 1659 - 2325 / ha and EP: 37 - 51Cents / m3) as compared to sole crop or with okra. During rainy season and post-rainy seasonwith second filling of OFR at SI depth of 30 mm, maize+tomato+carrot was the mostprofitable option (ANB: $ 2544 - 3012 / ha and EP: 37 - 45 Cents/ m3) as compared to anyother combination of the crops. The study revealed that the best economical crop combinationunder deficit irrigation of 30 mm will make the rainfed agriculture more remunerative withOFR technology with efficient use of surface water.