Abstract: A run-off plot method combined with the rare earth elements tracing technique was used to study effects of contour grass hedgerows on control of soil erosion and surface run-off and spatial distribution of soil erosion on slope land in red soil hill regions of South China. Five different patterns of contour grass were planted for the experiment. It was found that soil losses from the run-off plots were obviously affected by rainfall. In run-off plots with contour grass hedgerows established, regardless of pattern, mean soil loss and surface run-off was significantly lower than in CK (bare land)(P<0.05). Among the five patterns of grass hedgerows, the one of double-row Ophiopogon japonicas was the most effective in controlling soil erosion and surface run-off. So the plot was the lowest in mean soil erosion and surface run-off, being 4 047 g and 1 554 L, respectively, while CK was the highest, being 19 793 g and 2 403 L, respectively. It was also found that through quadratic linear fitting using a model that differences existed between treatments in marginal value of soil loss as a result of variation of surface runoff. The middle and down slopes were the major source of sediments, contributing nearly 85% to the total soil loss. Although the grass hedgerows changed the soil re-distribution through sedimentation within the slope, they did not have any obvious effect on spatial distribution patterns of soil erosion on the slope.

Key words: contour grass hedgerow, soil erosion, surface run-off, rare earth element tracing