太湖重污染区麦季养分输入与流失规律研究

Nutrient Inputs and Runoff Losses during Wheat Season in Highly-contaminated Zone of Taihu Lake Region

为了识别太湖流域重污染区典型麦季污染物流失规律,以田间单元为研究对象,研究了麦季不同施肥处理条件下营养元素的输入和流失与降雨的关系。结果表明,大气湿沉降和施肥输入氮素190.23 kg/hm2,磷素19.12 kg/hm2;优化施肥-秸秆还田处理条件下COD、总氮和总磷平均流失量均小于常规施肥处理,而小麦产量有一定增加,说明采用深施化肥可以降低营养元素的流失,而秸秆还田措施对小麦产量的增加有一定帮助;径流流失中氮的形态以硝态氮为主,硝氮、氨氮平均浓度分别占总氮浓度的85.8%和4.84%,所以重污染区农田径流污染应着重考虑硝态氮的处理。文章研究结果可为太湖流域重污染区农田径流流失的治理提供基础性支撑。

To identify the loss rule of typical pollutants during wheat season in highly contaminated zone of Taihu Lake area,relationship between input and loss of nutrient and rainfall under different fertilization treatment conditions in field units were studied.Results showed that nitrogen and phosphorus were input of 190.23 kg/hm2 and 19.12 kg/hm2 respectively through wet atmospheric deposition and fertilizing.Average losses of COD,TN,TP under the optimal fertilization and wheat straw returning were all less than that of general fertilization treatment.However,wheat yield increased which indicated that taking agricultural measures of fertilizer-deep-ploughing can reduce the loss of nutrients and straw manure had a good effect on increasing wheat yield.Main form of nitrogen in the loss of runoff is nitrate nitrogen.Average concentrations of nitrate nitrogen and ammonia nitrogen accounted for 85.8% and 4.84% of total nitrogen concentration.Treatment of nitrate nitrogen of field runoff contamination should be mainly considered in highly contaminated area.Results would provide basic support on treatment of filed runoff in highly contaminated area of Taihu Lake.