Abstract: Ten experimental plots different in land use were set up to study characteristics of soil erosion and nutrient loss under natural precipitation in Zhangjiachong Watershed.The experiment lasted one year.Results show that the maximum annual runoff and the maximum soil erosion occurred in the plot of orange orchard on a terraced slope and the minimum runoff did in the plot of orange orchard on terraces with hedgerows,and the minimum soil erosion in the plot of grain cropland on a slope.The plot of grain cropland on a slope with hedgerows was the highest in loss of total nitrogen and total phosphorous,which amounted to 23.29 and 1.02 kg·hm-2,respectively,while the plot of orange orchard on a slope the least in loss of total nitrogen and total phosphorous,which amounted to 9.50 and 0.15 kg· hm^-2,respectively.It is,thus recommended that in agricultural watersheds similar to the studied one,it is advisable to grow orange in sloping fields,but the land use patterns of growing grain crops on slopes with hedgerows and oranges on terraces slopes are not appropriate to extrapolate.

Key words: experimental plot, soil erosion, runoff, nutrient