黑土坡耕地横坡垄作对减少径流及土壤有机碳流失的作用

东北黑土坡耕地受土壤侵蚀和习惯顺坡耕作措施的影响,水土流失严重,土壤有机碳含量呈逐年下降趋势.针对东北黑土坡耕地不同垄作措施水土流失及土壤有机碳变化特征不明确的问题,采用田间定位试验的方法,探究了顺坡垄作和横坡垄作对坡耕地水土流失及土壤有机碳变化的影响.结果表明:(1)横坡垄作相对于顺坡垄作能显著减少径流总量97.1％...

Effects of Ridge Planting on Reducing Runoff and Soil Organic Carbon Loss in Black Soil Slope

Losses of nutrients, water and soil was serious in black soil sloping farmlands in Northeast China, and the soil organic carbon (SOC) decreased year by year due to soil erosion and conventional longitudinal ridge-tillage. However, the characteristics of water and soil losses, and the changes in soil organic carbon under different tillage methods remain unclear. This study explored the impact of longitudinal ridge-tillage and cross-ridge tillage practices on losses of water and soil, and the changes in SOC from sloping farmland based on field experiments. Results showed that:(1) Compared with the longitudinal ridge-tillage, cross-ridge tillage significantly reduced the surface runoff and sediment losses by 97.1% and 93.1%, respectively, showing a strong interception of surface runoff and sediment. (2) The cross-ridge tillage could reduce the losses of SOC and dissolved organic carbon (DOC) from the sloping farmland by 99.9% and 99.3%, respectively, and shoulder and back of the slope were two main positions of SOC sequestration, where 98.8% of SOC and 94.4% of DOC were sequestrated. (3) The cross-ridge tillage significantly increased the yield of spring maize, especially at the shoulder (by 21.2%) and back (by 19.4%) positions (both p<0.05), based on a 3-year cross-ridge tillage. Therefore, compared with the conventional longitudinal ridge-tillage, the cross-ridge tillage is a multi-win practice to reduce soil erosion and SOC losses, and increase the productivity, which can serve as a conservation measure for the protection of black soil sloping farmlands in Northeast China.