Agricultural Conservation Management (ACM) is increasingly advocated to reduce losses of nutrition from farming lands, especially with agricultural watershed and subwatershed perspectives. Within agricultural watershed scale, different crop coverage has different nutrient precipitation runoff non-point source load properties because of their spatial topography heterogeneity and variable fertilization demands. The objective of this study was to assess the reduction efficiency of an ACM on nitrogen non-point source load from small agricultural watershed, in the black soil region, northeast of ch...