| Abstract: | Experimental observations on soil loss under different tillage methods were conducted on sloping farmland with purple soil in rolling area of central Sichuan Province. The observation results indicated that when sweet potato and corn were interplanted on farmland with 10° of slope gradient in rainy season, we had the order of soil loss amount: vertical ridge tillage >smooth slope tillage> contour ridge tillage >horizontal ridge tillage with earth fenders >horizontal terraced pot tillage. Horizontal ridge tillage with earth fenders and horizontal terraced pot tillage were two simple practical tillage methods, which Were also beneficial to soil conserving and yield increasing. Crop cover degree had obvious correlation with soil loss amount of sloping farmland.In vertical ridge tillage at slope gradient 109, when crop cover degree decreased from 100% to 0(bare land), the runoff amount and soil erosion amount per unit precipitation erosive force increased 9 and 2 times seperately. Thereforce, adopting intercropping and interplanting, increasing crawling crop can efficiently decrease soil loss from sloping farmland. |
