Effect of brackish water irrigation on water and salt movement in repellent soils

The existence of soil water-repellency had impacts on crop yields. In order to study soil water and salt movements of water-repellent soils irrigated by brackish water, laboratory soil column infiltration experiments were conducted. Impacts of different mineralization degrees and different water-repellency degrees on the movements of soil water and soil salt were compared for two soil textures. The variations of soil water-repellency during infiltration were also discussed. The results showed that infiltration ability of non-water-repellent soils increased with the increase of mineralization degrees. Both the infiltration rates of wettable and repellent soils could be simply fitted by Kostiakov equation. For the water repellent soils, the infiltration ability was largest at mineral degree of 1g/L, but decreased with the increase of mineralization degree when mineralization degree were larger than 1g/L. There was good linear relationship between cumulative infiltration and the wetting front distance when irrigated by brackish water. Soil water content and soil salt content at the same depth of the water repellent soil profiles were smaller than those of the wettable soil profiles. To some extent, soil water repellency was caused after irrigated by brackish water. This work indicated that brackish water irrigation had some impacts on distributions of soil water and soil salt as well as water-repellency of salinized soil.