Abstract: Soil-water characteristic curves (SWCCs) of saline silt with different salt contents were measured by the filter paper and pressure plate methods. The influence of salt contents on the SWCCs was discussed. It was concluded from the experimental results that the variation in salt content in silt has little effect on matric suction; the difference between total and matric suctions measured by the filter paper increases with increasing salt content; and the difference is greater than osmotic suction of the pure saline solution with the same salt concentration due to the adsorption of the surface of soil grains to the solution; and the matric SWCC measured by the filter paper method is between the drying curve and the wetting curve. The calibration curve of Whatman No.42 filter paper was measured by the vapor equilibrium method for total suction at the high suction range; and thus the measured accuracy of total suction is improved at that range.

Key words: chlorine saline soil, soil-water characteristic curve (SWCC), salt content, pressure plate method, filter paper method