Irrigation water productivity of rice grown with resource conservation technologies

Abstract

Rice being one of the biggest users of world’s developed fresh water resources, the agricultural scientists are facing a big challenge to improve its irrigation water productivity (WPIW) so as to arrest the declining surface and ground water resources. Different resource conservation technologies (RCTs) are being developed and evaluated for their suitability both in submerged and aerobic system of rice production. This paper highlights the irrigation water use when practising the resource conservation technologies under different irrigation scenarios. The intermittent irrigation scheduling on the basis of soil matric tension (16 kPa at 20 cm depth) could save irrigation water by 30%. Growing of puddle transplanted rice (PTR) on raised beds does not help save irrigation water when similar irrigation schedules are followed in both in direct seeded rice (DSR) and PTR with full furrow-depth of irrigation water. Applying water with half furrow depth could help in improving irrigation water productivity. The water balance for direct-seeded rice needs to be computed under differential irrigation scenarios to achieve highest irrigation water productivity.