Simulation of sprinkler irrigation water uniformity impact on corn yield

In a previous work, the spatial and temporal wind effects on corn yield were analysed using Ador-Crop (based on the FAO crop model CropWat) and a solid set sprinkler irrigation model. The combined model could explain only 25% of the variability of measured yield. The objective of this work was to evaluate the predictive capacity of two more ad¬vanced crop models (EPICphase and DSSAT) when coupled to the solid set sprinkler irrigation model. EPICphase ex¬plained 44% of total dry mater (TDM) and grain yield (GY) variability when measured irrigation was used. The com¬bination of EPICphase and the solid set sprinkler irrigation model explained better the variability of TDM than that of GY (42% and 35%, respectively), although the error in the estimation of GY with the coupled model was higher than when measured irrigation doses were considered (1.55 t ha-1 vs. 1.22 t ha1). The DSSAT model explained 39% and 38% of the variability in TDM and GY, respectively, when measured irrigation data was used. When DSSAT was considered in the coupled model, better results were obtained for TDM (R2 = 41%) than GY (R2 = 31%). The EPIC¬phase model simulated grain yield more accurately than the DSSAT model because it produced a better prediction of the maximum LAI. The combination of the sprinkler irrigation model with the EPICphase or DSSAT models simula¬ted crop growth and yield more accurately than when combined with the Ador-Crop model.