Estimating the optimum dose of nitrogen fertilizer with climatic conditions on improving Boro rice (Oryza sativa) yield using DSSAT-Rice crop model

This study was conducted at Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh using the DSSAT-Rice crop model for estimating the nitrogen fertilizer dose of the rice varieties BRRI dhan 28, BRRI dhan 29 and BR16. Three different varieties such as CL448, Basmati-515 and KS-282 were used to calibrate the model. The research used 2 years (2020–2021) weather data and soil data of different layers (0–60 cm). Four different nitrogen fertilizer treatments i.e., nitrogen (N) @ 50 kg/ha; N @ 100 kg/ha; and N @ 150 kg/ha along with control (no nitrogen) were used for running the simulation process. Result showed that BRRI dhan 29 was the best performed variety and the yield was 6000 kg/ha @ 150 kg/ha N fertilizer treatment. In addition, 1:1 graph showed highest simulated grain yield observed 6050 kg/ha with 150kg/ha N fertilizer treatment for BRRI dhan 29. RMSE, nRMSE and d stat values showed tiller number, grain weight, leaf area index and harvest index had excellent performance with the simulated data for the 150 kg N fertilizer treatments. The study revealed that DSSAT crop model could be useful to estimate optimum N dose to obtain the best variety with climate changing.