Evaluating Animo Model for Predicting Nitrogen Leaching in Rice and Wheat

Nitrogen (N) leaching could be a serious problem for coarse-textured soils. Various models are created to simulate N leaching in coarse-textured soils, but their testing is required to evaluate the accuracy of simulations. This study evaluated the Soil Water Atmosphere Plant (SWAP) and Agricultural NItrogen MOdel (ANIMO) models to predict soil water content and N leaching. Calibration was performed with soil water content data from wheat crop and validation was conducted with NO3-N and NH4-N concentrations data from rice crop of the same field. Hydraulic and various other N rate constants were calibrated using the PEST (Parameter EStimation Technique) model. The calibration of the SWAP model showed differences between measured and predicted soil water content at different soil depths were less than 2/5th of the measured absolute error (MAE). The calibration of the ANIMO model showed relatively large differences between measured and predicted NO3-N concentrations that could be attributed to erratic values of NO3-N concentrations found in the soil profiles. The validation of ANIMO model showed that differences between measured and predicted NH4-N concentrations at different soil depths were less than 2/5th of the MAE and R-2 was greater than 0.76. These results suggest that SWAP/ANIMO model has the potential to predict N leaching in rice and wheat crops in testing environments and their performance could be further improved with the availability of more field data.