| Abstract | Two experimental sites were established in Ningnan County (Tanguanyao and Masangping), Sichuan Province, China, to evaluate the effects of contour hedgerows on runoff and control of soil erosion. Five treatments with three replications were used; the treatments were: T1- farmer's practice (without hedgerows and with fertilizer); T2- Leucaena lecocephala hedgerow + annual crops without fertilizer; T3- L. leucocaphala hedgerow + annual crops with fertilizer; T4- Tephrosia candida hedgerow + annual crops with fertilizer; and T5- L. leucocephala hedgerows + mulberry trees with fertilizer. Results showed that the contour hedgerow system was very effective in controlling runoff. Three years after contour hedgerow establishment, runoff was reduced to 26-31% of that under farmer's practice at Tanguanyao. In Masangping, L. leucocephala were more effective than T. candida hedgerows in reducing runoff. The contour hedgerows were very effective in reducing soilerosion. Compared to farmer's practice, soil loss in plots with contour headgerow was down to 2.5% of that from control plots 3-4 years after hedgerow establishment at both project sites. The gradient of alleys in plots with hedgerows reduced from 17 deg to around 7 deg after seven years of cultivation at the Tanguanyao site, and from 23 deg to around 11 deg at the Masangping site after five years of cultivation. At Tanguanyao, more than 80% of the runoff and more than 90% of soil loss occurred from June to August. At Masangping, only 40% of the runoff occurred from June to August, and 60% from September to October; but 78% of total soil loss occurred from June to August. |