Effect of Barley Cultivation on the Reducing of Soil Salinity Amount, under Different Levels of Salinity and Irrigation

The possibility of modification the saline lands by planting the salt-resistant crops, prevents the production of wastewater and drainage costs. In this study, the possibility of modifying saline soils by planting barley at different irrigation levels and soil salinity, was investigated. Salinity treatments included 6(S1), 9.5(S2) and 13(S3) (dS.m-1) and irrigation treatments included the amount of 100(I1), 75(I2) and 50(I3) percent based on the barley water requirement. This research was done as a factorial experiment in a completely randomized design with three replications. Due to increasing soil salinity (from S1 to S3) at irrigation levels of I1, I2 and I3, the amount of evapotranspiration was reduced to 25.5, 30.6 and 36 percent, respectively. The amount of reduced soil salinity in S1, S2 and S3 treatments were equal to 4.34, 6.88 and 9.42 (in I1 treatment), 3.76, 4.92 and 6.08 (in I2 treatment) and 3.64, 3.58 and 3.52 dS.m-1 (in I3 treatment), respectively. Low irrigation reduced the soil modification efficiency. Also, increasing the soil salinity in low irrigation treatments had a high effect on this work. Due to drought stress, the amount of soil modification efficiency decreased to 16% (in S1 treatment), 48% (in S2 treatment) and 62.6% (in S3 treatment). However, at full irrigation level, increasing the soil salinity (up to S3 treatment) did not had effect on the soil modification efficiency. Regression functions were used to estimate the final soil salinity, by the initial soil salinity and irrigation level. The exponential model had the best fit between the two variables of EC_f/EC_i and I_i/I_1 . The overall result showed that achieving to the highest soil modification efficiency and optimal modeling, required to the full irrigation of the crop.