The Comparison of DSSAT-CERES and AquaCrop Models for Wheat Under Water–Nitrogen Interactions

ABSTRACT

A comparison was made between the recently used crop models (DSSAT-CERES and AquaCrop), based on high accuracy, to simulate wheat growth under different water and nitrogen levels. Hence, four irrigation treatments (rainfed, irrigate at 50% and 75% of field capacity (FC), and irrigate at 100% of FC) were considered as the main factor with three nitrogen fertilizer levels as the sub-main factor (viz. non-fertilizer, 100 kg N ha⁻¹, and 200 kg N ha⁻¹) during 2014–2016. Model efficiency (E), Wilmott’s index of agreement (d), Root Mean Square Error (RMSE), and Normalized Root Mean Square Error (NRMSE) were used to test the model performance. AquaCrop model was calibrated to simulate the grain and biomass yield with the prediction error statistics of 0.87 < E < 0.90, 0.24 < RMSE < 0.36 t ha⁻¹, 6 < NRMSE < 7.2%, and 0.90 < d < 0.93, respectively. Subsequently, the CERES model was calibrated and the performance was in line (0.88 < E < 0.93, 0.92 < d < 0.96, 0.19 < RMSE < 0.34 t ha⁻¹, and 5.7 < NRMSE < 5.8%), respectively. Upon validation, E was 0.89 and 0.91; d was 0.93 and 0.96, RMSE was 0.25 and 0.21 t ha⁻¹, and NRMSE was 6.4 and 5.9 for grain yield by AquCrop and CERES models for all treatments, respectively. Overall, the simulation results by the DSSAT model were relatively more accurate than the AquaCrop model. But, considering the low required input data, the AquaCrop model is recommended for wheat yield simulation in the conditions of unavailability of equipment and crop data.

KEYWORDS:

• AquaCrop model
• calibration
• CERES
• validation
• wheat

Highlights

• DSSAT-CERES and AquaCrop model were calibrated and validated for wheat crop, biomass, and grain yield under different irrigation water regimes and nitrogen fertilizer levels.

• The simulation results by the DSSAT model were slightly more accurate than the AquaCrop model for wheat under varying irrigation water and nitrogen levels.

Considering the low requirement input data for wheat yield simulation by the AquaCrop model, so this model is more suitable than the DSSAT model in conditions of lack of data in developing and undeveloped countries.