Application of the WRF-DSSAT Modeling System for Assessment of the Nitrogen Fertilizer Used for Improving Rice Production in Northern Thailand

The cultivation of rice under irrigation provides fundamental sustenance for nearly half of the world’s population. Rice yields need to increase in order to maintain the rapidly growing population and meet growing food requirements. In this research, we applied the coupled atmospheric–crop model, which is based on the WRF and CERES-Rice models, to find the appropriate nitrogen fertilizer level for improving rice yield in northern Thailand. The model was conducted from June to December in 2011 and 2015. To evaluate the model’s capability, the output from the model, including meteorological data (i.e., precipitation and temperature) and rice production, was compared to actual observation data. The modeling system showed an acceptable level of output for statistical examination; for example, the R 2 values were 0.93, 0.76, and 0.97 for precipitation, temperature, and rice production, respectively. To assess the optimization of the nitrogen fertilizer level, we designed nine experiments: control cases and other cases that were multiplied by a factor of 2–10 times the nitrogen fertilizer levels. The model suggested that we can produce substantial rice yields by increasing nitrogen fertilizer levels by 12 kg/ha.