Author(s): Zhaoxia Zeng; Xiaoli Liu; Qiuwen Chen; Baiqing Tie
Linked Author(s): Qiuwen Chen
Keywords: Gricultural watershed; Agricultural conservation management; SWAT model; Nitrogen; Black soil region
Abstract: 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 china, where present typical gentle hilly landscapes, using the Soil and Water Assessment Tool (SWAT). Results showed that SWAT model performed well in calculating runoff (ENS=0. 58), NO3-N (ENS=0. 47) and total N (ENS=0. 69) loads. The calibrated and validated model was used to evaluate the effects of spatial adjustment of crops plantation on NO3-N and total N loads through land use pattern scenario analysis according to crop different fertilization demand and surface runoff nitrogen loss characteristics. Result showed that crops plantation spatial adjustment as an effective ACM strategy can reduce NO3-N and total N loads by 9. 5% and 10. 7% , respectively. It was apparent that within small watershed scale, crops plantation spatial regulation according to their fertilizer demand, nutrition loads properties and locations as an ACM can effectively decrease non-point source pollution from agricultural watershed, and can provide useful information for targeted water quality management for surface runoff receptor water body.