| In recent years,the problem of non-point pollution in agriculture has become increasingly serious in China,It is great significance to study the response of nitrogen and phosphorus loss to different nutrient management measures for the prevention and control of agricultural non-point pollution.The field plot test method was adopted in this experiment with 7 treatments of no fertilization treatment（CK,control）and treatments which with different amounts of organic and inorganic fertilizers（N0,fertilization without fertilizer nitrogen;CON,fertilization by habit of farmers;OPT,optimized fertilization;OPT+N,increased nitrogen application according to optimized fertilization;OPT+P,increased phosphate application according to optimized fertilization;OPT+NPK,increased nitrogen,phosphate and potassium application according to optimized fertilization）.The effects of different nutrient management measures on vegetable growth,nitrogen and phosphates loss through surface runoff in perennial vegetable field of cabbage-cabbage-eggplant were studied.The preliminary results were as follows:1.Vegetable yield increased at beginning and then stabilized with the increase of nitrogen fertilizer application.Vegetable yield did not increase with phosphates application.Economic yields of leaf vegetable tended to zero due to no fertilize application in long-term.2.Nitrogen in surface runoff was dominated by soluble total nitrogen,soluble total nitrogen was dominated by mineral nitrogen,and mineral nitrogen was dominated by nitrate under different nutrient management measures.The concentrations of total nitrogen,soluble total nitrogen,nitrate and ammonium nitrogen in the surface runoff of perennial vegetables ranged from 3.80 to 43.98,1.93 to 42.45,0.15 to 23.56 and 0.05 to 12.92mg·L-1,respectively.Nitrogen concentrations in surface runoff were increased with nitrogen application.The risk of excessive nitrate nitrogen in runoff increased with nitrogen fertilizer application.The annual loss of total nitrogen of each treatment from low to high was as follows:CK(46.1 kg·hm-2);N0(57.6 kg·hm-2);OPT(72.4kg·hm-2);CON(73.7kg·hm-2);OPT+P(74.7kg·hm-2);OPT+N(83.6kg·hm-2);OPT+NPK(96.4kg·hm-2).Nitrogen loss load in all form and the proportion of soluble total nitrogen and nitrate nitrogen in surface runoff were significantly increased by chemical nitrogen fertilizer application.3.Phosphates in surface runoff was dominated by soluble total phosphorus,soluble total phosphorus was dominated by phosphates in orthophosphate.The concentration ranges of total phosphorus,soluble total phosphorus and phosphates in orthophosphate in the surface runoff of perennial vegetables were 0.045-4.712,0.007-3.151 and 0.007-2.678 mg·L-1,respectively,under different nutrient management measures.Phosphates application increased the concentration of total phosphorus,soluble total phosphorus and phosphates in orthophosphate in the runoff solution.The annual loss of total phosphorus of each treatment from low to high was as follows:CK(1.18 kg·hm-2);OPT(9.02 kg·hm-2);OPT+N(9.48 kg·hm-2);N0(10.2 kg·hm-2);OPT+NPK(11.9 kg·hm-2);OPT+P(12.6 kg·hm-2);CON(14.9 kg·hm-2).Phosphates application increased the fluxes of total phosphorus,soluble total phosphorus and phosphates in orthophosphate in the runoff solution.4.The loss coefficients of total nitrogen of each treatment from low to high were:CON（2.04%）、OPT+N（2.22%）、OPT（2.57%）、OPT+P（2.79%）、OPT+NPK（2.98%）、N0（3.19%）.The loss coefficients of total phosphorus of each treatment from low to high were:OPT（2.12%）、OPT+N（2.24%）、OPT+NPK（2.24%）、OPT+P（2.38%）、N0（2.44%）、CON（3.72%）.Based on the comprehensive analysis of vegetable yield,fertilizer input and loss load caused by nitrogen and phosphates fertilizer application,and economic and environmental benefits,optimizing fertilization treatment was a relatively reasonable fertilization scheme for nutrient management of perennial vegetable field. |
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