Water and salt distribution in coastal saline soil after infiltration of melt-water of saline water ice with different sodium adsorption ratio

A laboratory soil column experiment was conducted to investigate water and salt distribution in coastal saline soil after saline ice melt-water infiltration. A salinity of 10 g·L^-1 was designed with three variants of saline sodium adsorption ratios (SAR, i. e., 5, 10 and 30) as source water in the experiment, with fresh water as the control. The results showed that both the salinity and SAR levels of melt-water were extremely higher in the initial melt-water than in subsequent melt-waters. The infiltration rate and depth of the saline ice melt-water were higher than those of the control, and increased with the increasing SAR. Soil water content was lower in the 0~10 cm soil layer than in the deep soil after saline ice melt-water infiltration, which resulted in salt content in deep soil was higher than that in surface soil. The depth of soil desalinization was higher under saline ice treatments than the control. Soil water content in the 0~10 cm soil layer was higher in low SAR than in high SAR saline ice treatment. The reverse was, however, noted in the 10~45 cm soil layer. Salt content in the surface soil was lower in low SAR than in high SAR saline ice treatment. Average water and salt contents in 0~10 cm soil layer were 30.3% and 1.1 g·kg^-1 respectively under treatment of SAR 5 saline water. They were lower than in other treatments. To compare effects of saline ice melt-water irrigation with direct saline water irrigation, a simulated column experiment was conducted by using water with 10 g·L^-1 salt and SAR 10. The results showed that compared with the direct saline water irrigation treatment, the saline ice melt-water irrigation treatment presented better soil desalinization effect.