Effect of conjunctive irrigation on soil salinity and herbal elements of sorghum and simulation of output salt uesing SWAP model

Reduction of water resources in arid and semi-arid areas requires the application of management methods to achieve optimal performance. With the logical application of saline water as a source of irrigation water, we can supply a part of the crop water requirement (Hamdy, A., Abdel-Dayem, S. and Abu-Zeid, M., 1993), using various applicable management techniques. The optimal management is, in turn, considered as the use of conjunctive irrigation. Two commonly used solutions include mixing salty and fresh water to obtain water with the optimal salinity; and also the periodic application of fresh and salty water (Amer, 2010; Aslam, & Prathapar, 2006). In effect, salt mainly enters the surface layers of the soil through irrigation and the solute moves vertically from the unsaturated to the saturated zone and towards the groundwater. In turn, the SWAP model is often used to simulate the solute transfer in soil. However, field measurement of the solute concentration changes is very difficult in soil profiles. A simulation model can, thus, be used to estimate the accumulation of solutes in the soil profiles. (Van Dam, Huygen, & Wesseling, 1997)