Salinity management for irrigation with saline-sodic wastewater under corn cultivation

Abstract

Water scarcity is one the main problems of sustainable agriculture. One way to overcome this problem is to use wastewaters for irrigation. To determine the effect of salinity and sodicity of municipal wastewater as irrigation water and leaching application, on some of common soil chemical properties and consequently on growth performance of corn, a soil column experiment was conducted with sandy clay loam soil. Nine treatments including wastewaters with three different salinity levels: 1, 4.7 (blending of 1 and 9 dS/m wastewaters with 1:1 ratio), 9 dS/m, and three levels of leaching fractions: 0, 15 and 30 percent were arranged in a factorial experiment with three replication. Results show that at first and last layer of the soil, the effect of 30 percent leaching on soil salinity (ECe) was statistically significant only for irrigation with 9 dS/m wastewater. Application of the 15 and 30 percent leaching fraction for irrigation with 4.7 dS/m wastewater (SAR = 8.2) significantly reduced soil SAR at first layer of the soil. The application 30 percent leaching fraction significantly increased corn dry yield for irrigation with all of three wastewaters. There was no significant difference between effects of irrigation with 4.7 dS/m wastewater with the 15 and 30 percent leaching fraction and irrigation with 1 dS/m wastewater with 0 and 15 percent leaching fraction on IWUE. Results show that with combination of leaching method and reduction wastewater salinity through blending of wastewaters for irrigation with saline sodic wastewater, high corn biomass can be achieved, without any significant difference in comparison with non-saline or non-sodic wastewater.