Evaluation of crop yield and soil water estimates using the EPIC model for the Loess Plateau of China

Since 2000, a database of crop and soil parameters, and meteorological data and so on, has been set up for the EPIC model, based on long-term experimental data and on-the-spot investigated data. The model parameters have been repeatedly revised and verified by data assimilation methods, so the EPIC model can be adopted for the grassland and grain-crop field systems in the Loess Plateau of China. All relevant results showed that the water contents with winter wheat, spring maize, alfalfa and A. adsurgen can be well estimated using the EPIC model (the RMSEs were 20.4 mm, 49.5 mm, 191.92 mm and 136.70 mm, respectively); the simulated winter wheat and spring maize grain yield and the simulated dry forage yield of alfalfa and A. adsurgen were acceptable within the estimation precision (the RMSEs were 0.899 t/hm2, 0.803 t/hm2, 1.89 t/hm2 and 1.06 t/hm2, respectively).