Characteristics of nutrient loss from surface runoff of terraced orchards under different scales

In order to study the nutrient loss from surface runoff in terraced orchards at different scales, the field experiments under two typical rainfalls and two different scales（Scheme 1: runoff plot scale, Scheme 2: natural slope scale）were performed to investigate characteristics of the runoff, sediment yield, and N and P transfer process in Soil Conservation Ecological Science and Technology Demonstration Park in Jiangxi province from April to September in 2011. The results showed that the runoff and sediment yield per unit area in Scheme 2 were fairly smaller than that in scheme 1, which accounted for 23.09%, 13.63% of that in Scheme 1 under moderate rain, and 27.49%、13.72% of that in Scheme 1 under heavy rain. The processes of runoff and sediment yields of Scheme 1 and Scheme 2 were basically similar along with changes of the intensity of rainfall. The nutrition loss was mainly in the initial stage, and homogeneously stable in the later stage.