稻麦轮作农田氮素流失及控制对策研究

通过2年的田间定位监测和采样分析,研究上海稻麦轮作农田氮素流失特征及对水环境的影响。结果表明,施肥对稻季地表排水、麦季径流和渗漏水中氮素流失影响显著。在粮食生产过程中过量施肥和不合理的水肥管理是土壤氮素流失的主要原因。适当减少氮肥用量,可减少农田氮素流失,且对产量影响不大。因此,改进传统的施肥模式,加快制定农业非点源污染的相关法律法规,对控制农田氮化肥流失污染和提高农业经济效益,具有十分重要的意义。

Nitrogen loss in rice-wheat cropping farmland and its control measures

The characteristics of nitrogen loss in rice-wheat cropping farmland and the impact on water environment in Shanghai were studied through the two-year location monitoring of farmland and the sample analysis.The results showed that the application of nitrogen fertilizer had a notable impact on the N loss of the farmland due to the drainage in rice season and the rain runoff and leakage water in wheat season,and excessive fertilizer application and irrational management of water and fertilizer in the grain production were main reasons for nitrogen loss.Appropriately reducing amount of N fertilizer application could reduce the N loss in the farmland and nearly not affect the crop yields.And so it has an important meaning to improve conventional practice of applying fertilizer and constitute laws and regulations on the control of non-point source pollution.