Investigation of soil erosion on terraced fields near Yanting, Sichuan Province, China, using caesium-137

Much of the agricultural land in the Central Hills area of the Sichuan Basin is at risk from soil erosion by water. An investigation of rates and patterns of soil erosion on agricultural land near Yanting was undertaken using the caesium-137 technique. Erosion of the upper parts of sloping fields was found to be severe, with rates of the order of 20 to 50 t ha" year". However, infield deposition and sediment retrieval from field ditches has led to low net soil loss from the fields with rates of the order of 1 to 6 t ha" year". These data suggest that traditional soil conservation strategies are providing effective protection of much of the cultivated land, but the high potential for soil erosion must be recognized if any change is made in land use or management.