fiEffect of Irrigation Management and Transplanting Date on the Rice Production and Water Productivity

Water supply via irrigation and other water sources during the rice-growing season is vital for obtaining reasonable yield. The present study was carried out to investigate the dual-interacted effects of different irrigation intervals and transplanting dates on the yield, yield components, and water productivity of rice (Hashemi cultivar). The study was conducted in a three replicated randomized complete block design (RCBD) with the split-plot arrangement in two growing seasons (spring and summer) of 2016 and 2017 at Rice Research Institute of Iran, Rasht. The main factor was irrigation at four levels (full flooding, 5-, 10-, and 15-day irrigation intervals), and the second factor was three transplanting dates (April 21st, May 11th(,) and May 31s(t)). The productivity of irrigation water (WPI) and irrigation water + precipitation (WPI+R) was reported in terms of grain yield and biomass. The highest paddy yield was observed in flooding treatment (4271 kg per hectare) and the irrigation intervals of 5, 10, and 15 days with 3844, 3196, and 3264 kg/ha were in the next rank, respectively. According to the biomass yield, 15-day irrigation interval and flooding irrigation had the highest and lowest water irrigation productivity, respectively. In the study of different transplanting dates, the highest paddy yield (3795 and 3820 kg/ha, respectively) was observed on the May 11th, and May 31st transplanting dates, and the highest water productivity based on paddy and biomass yield was obtained in the April 21st transplanting date. Regarding grain and biomass yield of rice, water productivity, and water use, the five-day irrigation treatment resulted in the best crop grain and biomass yield on April 21st transplanting date.