Investigation the Possibility of Using Saline Water in Drip Irrigation for Lands Sustainability

Abstract

Using of saline water for irrigation of crops is known as a strategy of on-farm irrigation water management. In this study, the cyclic using of saline and fresh water and its effect on soil salinity were investigated. Field experiments were carried out in randomized complete block design under drip irrigation for maize crop with 9 treatments. The treatments were based on alternative irrigation management of saline and fresh water use on three salinity levels 0.4, 3.5 and 5.7 dS/m and freshwater application in every one, three and five saline water application (1:1, 3:1 and 5:1, respectively). The results showed that in 1:1 management, soil salinity at the end of growing season compared with the beginning of growing season did not change considerably (reducing of 1.0% and 17.9% for 1S1:1F and 1S2:1F). In 3S2:1F and 5S2:1F treatments, the amount and frequency of fresh water was not enough to remove salts from the soil and at the end of growing season, salt accumulation was seen in soil profile (increasing of 39.0% and 46.2% in soil salinity). In 3S1:1F and 5S1:1F treatments, soil salinity increased 17.9% and 31.6%, respectively, while increasing of soil salinity in S1 treatment was 40.7%. Thus, by 4 irrigations with fresh water in 3S1:1F treatment and 2 irrigations with fresh water in 5S1:1F treatment, reducing of 22.8% and 9.1% in soil salinity was seen in compared with S1 treatment.