AquaCrop Model Calibration and Evaluation in Irrigation Management for Main Grains

Due to water resources shortage, especially in arid and semiarid region, deficit irrigation is one of main managements for achieving maximum production. In recent years, many crop models are developed for simulation of crop growth and yield in various fields and irrigation managements. These models can simulate crop growth and crop yield. AquaCrop model is a pervasive model and is developed by FAO that can be used in growth simulating and modeling of many crops. In this study, Capability of the AquaCrop 3.1 and 5 in deficit irrigation management of important grains (wheat, barley and corn) in Shoor river basin has been investigated. At the first the model should be calibrated. Calibration of crop parameters such as rootzone depth, maximum canopy and periods of each growing cycle are main crop parameters that must be calibrated. Then, the calibrated model has been validated. RMSE and EF indexes were obtained 286.6 Kg/ha and 0.91 Kg/ha for wheat, 233.9 Kg/ha and 0.94 for barely, 444.4 Kg/ha and 0.98 (for the 2000 year data) and 796.3 Kg/ha and 0.95 for corn (for the 2001 year data), respectively by Aquacrop 3.1. RMSE indexes were 265.0, 198.1, 430.8 and 780.4 and EF indexes were 0.94, 0.96, 0.99 and 0.98 for wheat, barely, corn for the 2000 and 2001 year data, respectively by AquaCrop 5. These results show AquaCrop 5 have more accuracy due to salinity consideration. So AquaCrop 5 is suggested when there is salinity in soil and water resources or crop is sensetive to salinty.