Spatial Water Productivity for Rice Production in Chainat Province

Abstract

The spatial water productivity for rice production in Chainat province was assessed using the DSSAT-CERES model. Two rice production systems—irrigated system [IRR] and rain-fed [RAIN] system—were considered. Forty-eight cropping seasons (1970-2017) were simulated using daily time step. The results revealed that the rice water use [ET+P] attained 700 mm in the irrigated system, while it used approximately 500 mm in the rain-fed system. Irrigation increased the dry grain yield of 14% (from 714 kg·rai^-1 [RAIN] to 803 kg·rai^-1 [IRR]). Water productivity with respect to transpiration (WP_T) [yield/transpiration] ranged from 2.5 to 2.6 kg·m^-3 and water productivity with respect to total evapotranspiration (WP_ET) [yield/evapotranspiration] was of 1.0 kg·m^-3. Irrigation practice and the soil properties, low hydraulic conductivity and high organic matter, can contribute the rice yield and its stability.