中文摘要：

农田氮素损失是造成农业非点源污染的主要原因之一,其中由于大量施用氮肥引起的土壤氮素淋溶损失又是农田氮素损失的重要途径。针对农业不同种植条件下氮素损失控制难题,本文通过田间试验研究集约化种植和常规种植两种土地利用方式下,土壤硝态氮迁移特征及动态变化规律,来评估不同农业种植方式对地下水污染的潜在风险。结果表明：集约化种植区施肥量和灌溉量较大,硝态氮的淋失浓度明显大于常规种植园,土壤硝态氮浓度随时间和空间变化也最为显著。集约化种植区的地下水污染程度远远大于常规种植区,集约化种植葡萄园地下水中的硝态氮含量平均值11.2mg/L,是常规种植区平均值1.35 mg/L的8倍,集约化种植区过量施肥增大了土壤硝态氮的淋失风险,对生态环境构成了潜在的污染威胁。研究结果可为农业集约化种植区防治农业非点源污染和优化田间管理措施提供科学依据。

英文摘要：

Nitrogen loss from farmland is one of the main contributors to agricultural non-point source pollution.Nitrogen leaching loss due to excessive fertilization is the major nitrogen loss.A laboratory experiment and field monitoring were conducted to investigate nitrate nitrogen leaching dynamics under extensively agricultural systems and local management.Results showed that soil nitrate concentration did not change frequently in the intensive planting areas and in the conventional planting areas,but both changing ranges were greater.Monitoring results of field experiment indicated that the difference of groundwater nitrate-nitrogen content in three typical planting areas was distinct;nitrate nitrogen average content of greenhouse vine intensive planting base was the highest among three typical planting areas,being up to 11.2mg/L.However,nitrate nitrogen content of vegetable intensive planting areas and conventional planting farmland were 4.02mg/L and 1.35mg/L respectively.It further suggested that nitrate nitrogen average content in intensive planting areas had large varied amplitude and higher over standard rate,and excessive irrigation and fertilization had caused groundwater environment pollution.The study is also believed to be useful in formulating management strategies for an extensively planting farmland to reduce diffusive pollution from agricultural activities.