Soil erosion and agricultural non-point source pollution is one of the key eco-environment problems for uplands agriculture in the Three Gorges Region.Biological methods

characterized by little cost

easy for operation

and effective quickly

should be suggested to alleviate the eco-environment problem.Substitute crop of perennial alfalfa and Contour Hedgerow Technology were tested in this research on the effect of reducing soil

nitrogen and phosphorus losses from upland of purple soil.Five treatment plots were set up

and the runoff

sediment

nitrogen and phosphorus losses through sediment by each rainfall event were monitored for each plot from January 19

2002 to November 27

2004.The treatments are perennial alfalfa

ryegrass rotates with soybean

wheat rotates with peanut and Toona sinensis Roem contour hedgerow

wheat rotates with peanut and alfalfa contour hedgerow

and wheat rotates with peanut.The research showed that annually 68.00%~81.80% of the regional precipitation distributed from April to September

and most of the soil erosion

nitrogen and phosphorus losses occured at this period.Substitute perennial alfalfa and contour hedgerow technology are effective in reducing soil erosion and sedimentary nitrogen and phosphorus losses.