1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, 712100,Yangling, Shaanxi, China; 2. Innovative Experimental College, Northwest A&F University, 712100, Yangling, Shaanxi, China; 3. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Natural Resources and Environment, Northwest A&F University, 712100,Yangling, Shaanxi, China
Abstract:Simulated rainfall experiments were conducted to study the effects of maize straw buffers laid on different slope positions in preventing rill erosion on loess slope. Experimental treatments include two slope positions (4.5 -5.5 m and 6.5 -7.5 m distance to the top) under a single simulated rainfall and two successive simulated rainfalls with the rainfall intensity of 100 mm/ h and slope gradient of 20毅. The results showed that under different maize straw buffer treatments, total erosion amount decreased by 7.3% -14.2%, rill erosion amount by 11.0% - 30.6%, sediment concentration by 3.4% - 15.0% and proportion of rill erosion to total erosion amount by 5.5% - 128%, respectively. Among all treatments, the best way to prevent rill erosion under the single simulated rainfall was to establish maize straw buffer in the middle slope (at 4.5 - 5.5 m distance to the top); the total erosion amount, rill erosion amount, sediment concentration, rill horizon density and rill average depth decreased by 14.2%,30.6%, 11.6%, 12.9% and 21.9%, respectively. Under two successive simulated rainfalls, maize straw buffer should be established at the lower slope (6.5 - 7.5 m distance to the top) for better prevention effect; the total erosion amount, rill erosion amount, sediment concentration, rill horizon density and rill average depth decreased by 13.5%, 25.0%, 5.5%, 15.5% and 16.3%, respectively.