Effect of Leaching Method and Water Quality on Desalinization of Heavy Soils

Huge amount of drainwater is disposing of operating Irrigation and drainage networks in Khuzestan, SW Iran, that needs to manage. One of the low risk manners of reusing drainwater is use it for saline land reclamation. To investigate the effects of leaching methods and water quality on desalinization of clay soils of this area, leaching experiments were done in 1.5×1.5 meter Plots in “Salman Farsi” sugarcane agro industry, South Khuzestan. Complete combination of three different water qualities; 2.7 dS/m (fresh water from Karun River), 6.0 and 9.0 dS/m (mixture of agro industries drainwater and Karun River water) and tow leaching method; continuous (application of 120cm of water) and intermitting (application of four 30 cm of water with five days interruptions) in six treatments and three replications based on complete randomized blocks design were experimented. Results shown that using drainwater with the quality of 6.0 or 9.0 dS/m could reduce the use of fresh water for desalinization by intermitting leaching up to 72 or 51 percent, respectively. The difference between soil saturation extracts due to applying different water qualities were more in deeper soil layers, also the difference between continuous and intermittent leaching were increase by applying more saline water. In heavy soil, advantage of intermitting leaching method to continuous one is limited to low evaporation condition.