Effect of initial soil water content and bulk density on the infiltration and desalination of melting saline ice water in coastal saline soil

Abstract

AbstractLaboratory experiments were conducted to investigate the infiltration of melting saline ice water into coastal saline soil with different initial water contents and bulk densities, together with the redistribution of water, salt and salt leaching after infiltration. Three water contents (5, 10 and 15% at a soil bulk density of 1.3 g cm−3) and three bulk density levels (1.2, 1.3 and 1.4 g cm−3 of air‐dry soil) of saline soil were used, with salt‐free ice comprising the control treatment. The results showed that the depth of infiltration with treatment by saline ice was greater than that of salt‐free ice, and increased as the initial soil water content and bulk density decreased. After infiltration, the soil water content in the upper soil layers increased with increasing initial soil water contents and bulk densities. This trend was reversed in the deeper soil layers. After infiltration of the melting ice water, the saline ice treatment resulted in a smaller soil salt content than the salt‐free ice treatment. The salt contents in the upper soil layers decreased with decreasing initial soil water contents and bulk densities. The largest rate of desalting was observed following infiltration of the melting saline ice water into the coastal saline soil with the smallest soil water content and bulk density. These results indicate that although a similar infiltration process was observed when the melting saline ice water and direct saline water infiltrated the saline soil with different soil water contents and bulk densities, the desalting effect of infiltration of the melting saline ice water was greater than that of infiltration of direct saline water and melting salt‐free ice water. Smaller initial water content and bulk density favoured salt leaching under the infiltration of melting saline ice water.Highlights We evaluated infiltration and soil desalination under melting saline ice into saline soil Rate of infiltration and depth increased with decreasing initial soil water content and bulk density. Soil water content in the top soil layer increased with increasing initial water content and bulk density. Rate of desalting increased with decrease in initial water content and bulk density under infiltration of melting saline ice water.