Abstract:Saline water irrigation is one of the effective measures for relieving the crisis of agricultural water utilization. Sand and saline-alkali soils were selected and were added with hydrophobic materials. CaCl2 solution with mineral degrees of 0, 1, 3 and 6 g/L were used for laboratory column infiltration experiments, in order to compare the effects of irrigation water quality on the distributions of soil water, soil salt and soil water repellency. The results showed that the curves of cumulative infiltration, wetting front and infiltration rate for sand 1 and wettable saline-alkali soil were all smooth after saline water irrigation. But those for sand 2 and hydrophobic saline-alkali soil were not so smooth, and their infiltration process were much slower than those of sand 1 and wettable saline-alkali soil. The increase of irrigation water mineral degree affected the infiltration process of saline-alkali soil more than that of sand. Philip model and Kostiakov equation were both good for fitting the infiltration curves of wettable soils. After saline water irrigation, the water drop penetration time (WDPT) along the profile increased both for sand 1 and san 2, but the maximal increment was only 3.6 s. The increment of WDPT for saline-alkali soil was obvious and the maximal increment value was 19 s. The increase of irrigation mineral degrees affected electrical conductivity, concentration of Ca2+ and concengtration of Cl-. In conclusion, this study indicated that saline water irrigation affected not only the distributions of soil water and salt, but also that of hydrophobicity.
