Improving Grain Yield, Water Productivity, and Savings of Paddy Rice Production under Regulated Deficit Irrigation (DI) Management through the System of Rice Intensification (SRI) Practices
Keywords:
Improving, System of Rice Intensification, Grain Yield, Water Productivity, Irrigation Water Savings, Paddy Rice Cultivation, Deficit Irrigation IntervalAbstract
A study on improving the grain yield, water productivity and savings of paddy rice production under regulated deficit
irrigation management through the SRI Practices was carried out and the best suitable deficit irrigation regime compared
to Conventional farming method was identified. A total of 12 treatments consisting of four SRI Water Application Levels
and three levels of irrigation intervals at different growth stages were conducted. The performance of those treatments in
terms of grain yield, water productivity and savings were compared to the conventional farming system. The study
revealed that on average, SRI treatments which involved Alternate Wetting and Drying cycles has significantly improved
water productivity by 100 – 200 % relative to conventional farming systems that involve continuous flooding. In contrast
to the conventional farming system in the current study, SRI practice increased rice yield by about 74.7 %, 68.5 % and 53.8
% at irrigation intervals of 3, 4, and 2-days respectively. The average mean of SRI Irrigation water savings with respect to
conventional method varied from 29.4 % to 54.6 %. 25% and 50% deficit water application at vegetative and grain filling
stages at 4-day intervals under SRI (T and T ) were statistically similar and significantly higher with 54.6 % and 52.1 %12 11
respectively, while the least value of 29.5 % was recorded for T (no deficit). Generally, the most suitable deficit irrigation1
regime compared to conventional farming method were at 25 %, 50 % and 75 % at 3-days irrigation intervals and were
capable of producing 11.93 t/ha, 11.71 t/ha and 11.37 t/ha of paddy rice, which were 81 %, 77 % and 72 % respectively
higher than conventional practice. These treatments also showed 51 %, 48 % and 44 % irrigation water savings and water
productivity of 178 %, 206 % and 233 %, respectively.