Estimation of Actual Evapotranspiration and Net Irrigation Water Requirement for Strategic Agricultural Crop in Moghan Plain Using AquaCrop Model

The common methods for estimation of evapotranspiration and water requirement are generally based on the ideal and without stresses conditions. In field conditions, different stresses such as salinity, dryness, temperature, soil fertility and other field managements effect on evapotranspiration and water requirement. In this study, AquaCrop model is used for estimation of real evapotranspiration and water requirement in Moghan Plain. The results showed that the evapotranspiration and water requirement of this model is less than the Cropwat model, which is due to consideration of the region conditions such as soil moisture, salinity, fertility and other field managements by AquaCrop model. The Cropwat model only consider climate condition. According to the results obtained from the AquaCrop model, in comparison with the Cropwat model, water requirements of Wheat, Barley and Maize were reduced about 41, 69 and 790 m3/ha, respectively. Also the evapotranspiration and water requirement of the AquaCrop model were compared with NetWat. These parameters of AquaCrop are higher for wheat and maize, and for less barley data. NetWat data has a low degree of reliability, due to being old of weather data.