Abstract: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.