nvestigating root water uptake amount in chickpea under deficit irrigation conditions using different models

Accurate estimation of root water uptake is essential for irrigation management and yield prediction. In this study, impact of deficit irrigationon water uptake amount was studied in two macro models(Feddes; Van Genuchten) and one micro model (Van Lier) using greenhouse data of chickpea. Irrigation treatments included five irrigation levels of 120, 100, 80, 60, and 40 percent of water requirement. To estimate potential water uptake, 120% treatment was used. Also 100% and 80% treatments were used for calibration of the models and 60% and 40% treatments for validation of the models. Hydraulic parameters of soil and root water uptake for each of the models were estimated utilizing GLUE method. The results of calibration stage indicated Van Genuchten model is able to simulate root water uptake well, as the parameters of R2, NS, NRMSE, MAE, ME, and dare 0.935, 0.91, 5.51, 0.42, 0.92, 0.95, respectively. The values in validation stage are 0.872, 0.82, 11.73,0.6, 0.82, 0.9, respectively. The findings also showed the micro model presented by Van Lier has the weakest function due to very simplifying assumptions (considering fixed root diameter and disregarding root tolerance).