Abstract:To study the law of nitrogen loss on slope under different fertilizer types (urea, chicken manure) and different dosages (349.6, 174.8 kg/hm2), the artificial simulated rainfall test method was used to explore the reasons for the difference in nitrogen loss between the two, and to elaborate the effects of fertilizer application rate on nitrogen loss. The results showed that the slope nitrogen loss after fertilization was mainly in the form of total nitrogen loss in sediment, accounting for 78.16%~93.46%. The concentration of runoff nitrate nitrogen was higher than that of runoff ammonium nitrogen, and the loss of total nitrogen in runoff was mainly in the form of nitrate nitrogen loss. The amount accounted for 38.53%~48.62% of the total nitrogen loss in runoff. The type of fertilizer had no obvious effect on the total nitrogen concentration of the slope sediment. The nitrate nitrogen concentration and the ammonium nitrogen concentration of the silt treated with chicken manure were higher. The equal nitrogen application of chicken manure could reduce the concentration of total nitrogen, nitrate nitrogen and ammonium nitrogen in slope runoff, by 68.64%~74.23%, 70.09%~72.54%, 27.90%~39.45%, respectively. Equal-nitrogen chicken manure replacing urea could reduce the total nitrogen loss on slope surface by 11.07%~15.81%, and reduce the total nitrogen loss in runoff by 70.55%~73.36%. Increasing the amount of nitrogen applied on slopes would increase the concentration of nitrogen loss, and the total amount of nitrogen loss would also increase by 6.00%~11.00%. The full amount of chicken manure instead of half the amount of urea would reduce the total nitrogen loss on the slope by 10.40%. When applying nitrogen fertilizer in agriculture, the application rate should be selected reasonably with the low rate and high frequency. Try to choose organic fertilizer instead of traditional nitrogen fertilizer to reduce the nitrogen concentration in surface runoff. The water and soil conservation should be done well to reduce the threat to the environment caused by the large amount of nitrogen in soil erosion.