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为粮田耕地污染监控预警及污染控制提供技术支持,以北京市房山区小麦/玉米轮作为研究对象,采用陶土头负压法,通过2年的田间小区对比试验,以不施肥处理为对照,分析比较优化施肥和常规施肥对淋溶液水质的影响,并测算不同施肥处理的排污系数。研究结果表明:不同的施肥处理氮素淋溶量占总养分淋溶的76%~82%,氮素淋溶中以硝态氮为主,占总氮素淋溶的60%~70%,最高可达到90%;在氮磷钾养分施入量相同的情况下,优化施肥处理在不同程度上降低了养分淋溶量,可使总氮淋溶量减少23%~31%,总磷淋溶量减少32%~46%,硝态氮淋溶量减少22%~36%,在降雨量大时,优化施肥处理可明显减少铵态氮的淋溶;经测算,小麦/玉米轮作农田耕地排污系数(产出每公斤农产品养分淋溶排出量)常规施肥处理总氮、总磷、铵态氮及硝态氮的排放量分别为687.2、3.25、0.22、440 mg,优化施肥处理的排放量分别为348、0.87、0.38、205.9 mg。
In order to provide technical support for monitoring and early warning of pollution caused by arable land in arable land and pollution control, taking the wheat / corn steamer in Fangshan District of Beijing as the research object, with the potter’s head negative pressure method, through 2 years of field plot comparative experiment, The effects of optimized fertilization and conventional fertilization on the leaching solution quality were analyzed and compared, and the sewage disposal factors of different fertilization treatments were calculated. The results showed that leaching amount of N fertilizer accounted for 76% ~ 82% of the total nutrient leaching in different fertilization treatments, nitrate nitrogen was the main nitrogen leaching, accounting for 60% ~ 70% of total nitrogen leaching, The maximum can reach 90%; Under the condition of the same amount of nitrogen, phosphorus and potassium nutrients applied, the optimized fertilization treatment reduced the leaching amount of nutrients to varying degrees, which can reduce the leaching of total nitrogen by 23% -31% The amount of leaching decreased by 32% -46% and the amount of nitrate leaching decreased by 22% -36%. When the rainfall was large, the optimized fertilization treatment could significantly reduce the leaching of ammonium nitrogen. According to the calculation, the wheat / corn rotation Emission factors (nutrient leaching of output per kg of agricultural products) The total nitrogen, total phosphorus, ammonium nitrogen and nitrate nitrogen of conventional fertilization were 687.2, 3.25, 0.22 and 440 mg respectively, and the discharge of optimized fertilization Respectively 348,0.87,0.38,205.9 mg.