Determination of leaching efficiency coefficient for desalinization of saline and sodic soil in Veis area, Khuzistan province

Leaching of soluble salts from soil profile could be done as the most appropriate method to emend and reclaim saline and sodic soils. Determination of appropriate depth of leaching water to reclaim this type of soils for optimal management of water and soil resources seems to be necessary. For this reason in this study three different leaching methods including continuous ponding, intermittent ponding and sprayer leaching have been performed on saline and sodic soils in Veis area, Khuzistan. This evaluation was performed as an experiment on natural and intact soil columns with 1 meter height and 15 cm diameter (by pushing polyethylene pipe from upper part of excavated profile wall to the lower part vertically). Soil columns with primary salinity average of 14.13 dS/m, four layers 25 cm thick with clay loam and loam texture, and silt loam texture for the last two layers (from top to bottom) were used. Soil columns were treated with Karun of river water feed canal with 2.86 dS/m salinity in four different depths including 25, 50, 75 and 100 cm during experiment. Which was transferred through canals after each treatment of leaching depths, the columns were removed from leaching. At the end, experimental model was presented for each leaching method. . Exponential model in continuous ponding method was considered as the best model based on better correlation coefficient and lowestandard error. However, intermittent ponding method showed lower water consumption for soil desalinization and better leaching efficiency coefficient corresponding to soil texture of the area. Due to the shortage of water in the present condition and considering the leaching efficiency coefficient which is between 0.33 and 0.35 in different consecutive soil layers from top to bottom, intermittent ponding method will be appropriate for the studied area.