Tillage practices

which change the soil surface structure

lead to different soil erosion characteristics on the tilled surfaces compared to the smooth surface. The objective of this study was to analyze soil and water loss on the tilled surfaces in rainfall-erosion processes based on the simulated rainfall experiments. Experiment results would be used for evaluating the soil and water conservation benefit of the projects of return steep slope land to forestry. Tillage practices in this study included shallow hoeing (SH)

deep hoeing (DH) and contour ploughing (CP). A smooth surface (SS) was served as control measure. Rainfall intensities were 60

90 and 120 mm/h and rainfall duration was 80 min for three rainfall intensities. Results showed that: （1) On the tilled steep slope

three tillage practices delayed the beginning of surface runoff during the rainfall of 60 and 90 mm/h intensities

but no significant difference was found in surface runoff initiation time between SH and SS

and between DH and SS during the rainfall of 120 mm/h intensity; （2) The cumulative production flow of CP was lower than the SS under three rainfall intensities

but no obvious regularity in size of the cumulative production flow for SH and DH treatments compared with SS; （3) In rainfall of 120 mm/h intensity

the flow sediment concentration of slope with tillage practices was higher than SS

leading soil sediment from three tilled slopes was 2 ~ 5 times of SS. Therefore

on the tilled and bare steep slope

when the rainfall intensity is larger

the tillage practices not only fail to reduce soil erosion

instead will increase.