Characteristics of N and P Loss in the Soil of Purple Sloping Farmland at Different Fertilization Levels

Using the "Winter Wheat-Summer Maize" model and the plot runoff monitoring method, we studied the characteristics of nitrogen and phosphorus loss in the soil sediment of purple sloping farmland under five conditions, including control,combined manure / fertilizer application, chemical fertilizer, high intensity chemical fertilizer, and cross ridge farming. The results showed that the nutrient content of the surface soil increased, to some extent. Furthermore, the nutrients were enriched in the sediment for all groups. The degree of sediment nutrient enrichment of cross ridge farming was less great compared to longitudinal farming. For the combined manure / fertilizer application, the ratio of effective nutrients was larger than that of total nutrients; whereas, for the chemical fertilizer group, the ratio of effective nutrients was significantly smaller. At all fertilization levels, sediment loss only accounted for 0. 34% ~ 6. 21%. 78. 80% ~ 84. 83% of the total phosphorus loss occurred in the sediment, and the phosphorus loss was largely in the sediment. The relative loss factor of nitrogen was the largest for the chemical fertilizer group, followed by the cross ridge farming group, the high intensity chemical fertilizer group, and the combined manure / fertilizer application group. The relative loss factor of phosphorus was the largest for the high intensity chemical fertilizer group, followed by the cross ridge farming group, the chemical fertilizer group, and the combined manure / fertilizer application group.