Effect of Leaching Method and Water and Drainage Water Application Order on Desalinization and Desodification of Heavy Soils

Application of drainage water with appropriate management for saline soil reclamation is one of the suggested methods for reuse of drainage water. This research was carried out with the aim of investigating the effect of water and drainage water applying method (mixing before applying or applying in turn) and also the effect of leaching method (intermittent or continuous) on desalinization and desodification of Heavy textured soils of southern Khuzestan province. Leaching experiments were carried out applying 120 cm of water in 1.5 m × 1.5 m plots. Five leaching treatments were D1F1 and D2F2, which respectively consisted of 1-2 times applying of “Salman Farsi sugar cane agro-industry “drainage water with a salinity of 9.0 dS/m, and then, in the same manner, Karoun river water with a  salinity of 2.61 dS/m was applied to the plots. Also, M1, M2, and M4 treatments, in which respectively a mixture of water and drainage water with a salinity of 6.0 dS/m, were applied to the plots by continuous leaching and intermittent leaching with two breaks and intermittent leaching with four breaks. The remaining salts in the soil in M1 and M2 treatments in 0-30 cm soil top layer were 17% and 24%, respectively, and the sodium absorption ratio in these treatments was 57.5% and 24.7% higher than the M4 treatment, which indicates a positive effect of increasing the number of discontinuities in the desalinization and desodification processes.