One of the most important problems related to sustainable agriculture in arid and semi-arid regions is lack of sufficient water resources. The use of wastewater with proper irrigation management is a practical method to solve this problem. The use of wastewater for irrigation causes problems such as salinity and sodicity of agricultural lands which reduces crop yield and area under cultivations. One of the practical methods to reduce the salinity and sodicity of agricultural lands is to mix better quality water with saline irrigation water and apply it for irrigation using proper leaching requirement. To date, there is little study about mixing wastewaters or irrigation water with different salinities and application of these mixed water for irrigation of corn using different leaching fractions. Therefore, the objective of this study was to investigate the effects of different irrigation water and wastewater salinities and sodicities, on corn yield and soil chemical characteristics using soil columns. Three irrigation water salinities of 1, 4.7 and 9 dS/m and three leaching fractions of 0, 15 and 30 % were applied. Two different factorial experiments with completely randomized design one for irrigation water and one for wastewater were carried out with three replications for each treatment at College of Agriculture, Isfahan University of Technology. The results showed that the increase of irrigation water salinity and irrigation water sodicity increases the soil salinity and sodicity and decreases the corn yield. The treatment of mixture of wastewaters with salinities of 1 and 9 dS/m, as compared to the treatment of wastewater with salinity of 9 dS/m and sodium adsorption ratio of 13.1 percent, reduces soil salinity and sodium adsorption ratio significantly and increases corn yield by nearly twice. The treatment of mixing irrigation water with salinities of 1 and 9 dS/m, as compared to the treatment of irrigation water with salinity of 9 dS/m decreases the soil salinity and sodium adsorption ratio of upper layer of soil 43 and 45 percent, respectively, and increases corn yield 45 percent. For all treatments the sodium adsorption ratio for 0-10 cm of soil layer was higher than other soil layers. The leaching fraction of 15 and 30 percent, reduce soil salinity of 0-10 cm of soil layer 11 and 36 percent and increase corn yield 33 and 75 percent, respectively. If acidity of irrigation water and soil at beginning of the experiment be the same, the leaching levels have no significant effect on soil pH. With proper irrigation management, and with proper leaching fractions, the saline wastewaters can be applied for irrigation and can be used as an irrigation source. Keywords: Irrigation water salinity, Wastewater, Leaching and Corn yield
