The Effect of Different Saline Irrigation Regimes on the Yield of Grain Sorghum and Yield Simulation using SWAP Model

Due to the dry climate and limitation of fresh water resources, using fresh and salt water is a solution for crop production under salinity conditions. This study was conducted at Isfahan University of Technology as a randomized complete block design with three replications and five irrigation management treatments in 2014. The treatments included irrigation with saline water (with the salinity of 5 dS/m, based on the relative yield of 75%), irrigation with fresh water (municipal water), alternate irrigation (irrigation with saline water and the next irrigation with fresh water), conjunctive irrigation (half of irrigation with saline water and the other one with fresh water) and irrigation with fresh water to reach the raceme stage, and irrigation with saline water. The maximum wet yield, dry yield and grain yield were related to the fresh water treatment with 4.14, 2.45 and 0.588 kg/m2 and the minimum values were obtained for water their water treated with 1.34, 0.765 and 0.0957 kg/m2 respectively. The conjunctive treatment had the highest yield after fresh water treatment. The various statistical indices showed that this model could be used for sorghum in Isfahan. The determination coefficient for yield was 0.65.The priority of model for yield simulation was salt water at the last stage, alternate irrigation, saline water, conjunctive irrigation and fresh water treatments, respectively.