Effect of irrigation regime and varietal selection on the yield, water productivity, energy indices and economics of rice production in the lower Gangetic Plains of Eastern India

Water is the major environmental constraint for sustainable rice cultivation. A field experiment was conducted during 2016 and 2017 to evaluate the effects of three irrigation methods viz., continuous ponding (CP), alternate wetting and drying (AWD) and saturation (SAT)) and three popular local rice varieties (IET-4786, IR-36 and GB-1) laid out in a factorial randomized block design with three replications on growth, yield, water and energy productivity and economics of winter rice grown at farmers’ field. Results of the study showed that all the growth parameters, yield attributes and yield were significantly higher in CP followed by AWD method. Among the varieties, GB-1 was superior in both CP and AWD conditions to produce higher yields and yield variables than IET-4786 and IR-36. Crop water productivity (CWP) was found maximum in SAT regime followed by AWD while GB-1 as well as followed by IET-4786 displayed highest CWP among rice varieties. Energy use efficiency (EUE) and economics were higher in AWD with GB-1 followed by CP with GB-1. AWD irrigation coupled with GB-1 variety was the best treatment combination for deriving higher grain yield with maximum water saving, CWP, EUE and benefit-cost ratio. •Limited irrigation coupled with HYV rice improves yield, yield components and water productivity•Variety GB-1 in continuous flooding condition results in maximum grain yield, CWP, EUE and economics.•Variety GB-1 in AWD condition is techno-economical alternative for deriving higher yield, CWP, and EUE under water scarce.•A predictive water-yield production function model for rice has been developed.•Managing optimum irrigation and HYV rice can assure higher production, quality produce and marketability.