Study on effect of alternate wetting and drying irrigation practices on growth and yield of rice under SRI

Field experiments were laid out in the wetlands of Agricultural College and Research Institute, Coimbatore during Rabi season of 2013–14 and 2014- 15 to study the effect of Alternate Wetting and Drying Irrigation practices on growth, yield attributes and grain yield of SRI rice. Nine AWDI treatments were tested along with SRI and conventional rice irrigation methods in Randomized Block Design, replicated thrice. The AWDI levels tested were irrigation at different depletions viz., 10, 15 and 20 cm below soil surface with their combinations. In both seasons, irrigation at 10cm depletion from 7 days after transplanting upto 10 days prior to harvest was found to be superior than other AWDI practices which recorded the highest water use efficiency of 6.82 and 6.27 kg/ha-mm and grain yield of 6352 and 6441 kg/ha during rabi 2013–14 and 2014–15 seasons respectively. SRI method gave comparable yields with AWDI at 10cm depletion, but the water used was higher than that of AWDI at 10 cm depletion. This AWDI practice resulted in 22.1 and 19.5 per cent of water saving during 2013–14 and 2014–15.