Water and salt movement under saline water irrigation in soil with clay interlayer

The existence of clay interlayer in soils had impacts on water and salt movement and distribution. In order to study water and salt movement in soils with clay interlayer irrigated by saline water, the field experiment of saline water irrigation was conducted. A corresponding model was also used to forecast the cumulating trend of soil salt. The experiment results showed that when there was clay interlayer existed in the soil, soil water and salt could be hindered evidently. In upper soil layers (0-40 cm), the content of soil water and salt increased with increasing salinity. In bottom layers (80-120 cm), however, the content of soil water and salt had less relationship with salinity of water. The maximum rate of salt accumulation in 0-70 cm soil layers was 65.7% after leaching in winter and soil salt was partly detained in upper soil layers. The salinity prediction showed that there were soil salinization trends for 4 g/L and 5 g/L treatments after irrigating continuously for 5 years. Long term irrigation with saline water of the salinity higher than 3 g/L was not feasible in soil with clay interlayer and does?serious harm?to soil environment seriously.