Interrelationship among slope steepness, tillage practice and rainfall properties with surface runoff and soil loss on Mollisols in Northeast China

Soil erosion and rainfall-induced runoff are well studied yet remain somewhat unpredictable from one natural rainfall to the next, due to interactions between erosion parameters. This study quantified the relationship between annual (2011-2016) and individual (2016) rain events with overland flow (runoff) and soil loss in China's northern 'corn-belt'. Two tillage practices and slopes were evaluated (no-till and conventional till, 5 degrees and 7 degrees slopes). Results showed 54 rainfall events for a total of 394 mm precipitation ranging between May and October 2016. Runoff occurred 13 times in the conventional till with 7 degrees slope, accounting for 25.9% of the precipitation volume and caused 15.6 t ha(-1) erosion. It occurred twice in the no-till with 5 degrees slope plot and caused 0.2 t ha(-1) erosion., Thus the no-till with 5 degrees slope treatment is the best tillage system to protect soil in Mollisols in Northeast China. Broad analysis coupled with a detail review of three rainfall events demonstrates that water either runs off plots quickly or rapidly infiltrates while sediment moves in a pulsing manner.