Field Evaluation and SALTMED Model Performance for Cyclic Use of Saline and Fresh Water

Regarding increased limitations on fresh water availability in agriculture and the necessity of finding solutions for management of unconventional waters, some scenarios for using saline water were assessed for forage maize. SALTMED model, as an integrated approach, can be used for a variety of irrigation systems, soil types, soil stratifications, crops, water management strategies (blending or cyclic), leaching requirements, and water quality. In this study, SALTMED model was evaluated in condition of the frequency of salt water with fresh water for forage maize. Three salinity levels i.e. 0.4 (as control treatment), 3.5, and 5.7 dS/m, were used in this research. Irrigation was carried out using tape (drip irrigation) with separate control in each plot. Crop yield (based on biomass) was considered as a parameter to evaluate the model for nine different treatments (regarding saline and fresh water application). The results showed that the performance of the model in prediction of the crop yield was satisfactory. The relative errors between the observed and the predicted data were between 0.0 and 24.7%. Moreover, there was a good correlation (coefficient of determination= 0.79) between the observed and predicted crop yield values. Statistical test also indicated that there was no significant difference between the observed and predicted values. Thus, SALTMED model could be a useful tool for on-farm water management and predicting crop yield.