Effect of the Amount of Water and Nitrogen on Water Productivity, Yield, and Yield Components in Two Different Rice Cultivation Methods

Rice cultivation in Iran is dominantly under submerged condition, which requires plenty of water, nitrogen fertilizer application, very difficult and laborious land preparation, along with high labor costs. In order to assess the effects of different rice cultivation methods on increasing water productivity and to find a suitable method of water and nitrogen application, an experiment was carried out in Rice Research Institute of Iran, Amol (RRII), in 2014. The experimental layout was split-split plot with 3 replications, using Keshvari rice variety. Two land preparation methods i.e. with and without puddling, were the main factors, while four levels of irrigation application were the sub-factors, with sub-sub plots allocated to four levels of nitrogen application (N0, N80, N120, N160 kg/ha) . The results showed that the effect of rice cultivation method on water use and water productivity (WP), and the effects of irrigation and nitrogen on yield-related traits, water use and WP were statistically significant at %1 level. The new cultivation technique -aerobic cultivation method- saves water use and increases WP, respectively, as much as 27.95% and 29.11%.With the increasing The application of nitrogen, increased yield and WP, in the form of linear equation. Applying 130% of Class A pan evaporation and nitrogen 120 kg was optimal yield and saving water and nitrogen, respectively 8.9% and 33%.