Experimental of disk infiltration characteristics with different soil salt contents

The characteristics of soil water infiltration to different salt contents soils are the basis for accurate acquiring soil hydraulic parameters. Based on the infiltration experiments using a disc infiltrometer, the characteristics of the soil water movement under the different negative heads (-1, -3, -6, -9 and -12 cm) for 4 soils with different soil salt contents were analyzed. The results showed that with the decrease of the negative head, the parameters including the sorptivity, the steady infiltration rate, the unsaturated hydraulic conductivity and the macroscopic capillary length decreased to different extents. As the soil salt contents increased, the steady infiltration rates and unsaturated hydraulic conductivity increased. The parameters in Garder exponential model for unsaturated hydraulic conductivity was determined according to the experimental data at different negative water pressure heads, which could provide a reference for estimating hydraulic parameters of salinity soils.