小麦-玉米轮作区地下水硝态氮含量的研究

目的]为确定河北省地下水硝态氮污染情况。方法]选择山前平原的小麦-玉米轮作区为主要调查区域,采集120个地下水样,测定其硝态氮含量并分析其分布特征及污染原因。结果]120个样点地下水均检测到硝态氮,平均硝态氮含量为4.03mg/L。山前平原区浅层地下水总体质量较好,无大面积污染。地下水埋深及施氮量对地下水硝态氮含量都有明显的影响。各样点间硝态氮含量变异很大,含量最高的样点在新乐县(23.94mg/L),含量最低的样点在辛集市(0.09mg/L)。新乐县有部分样点硝态氮污染明显,正定、栾城两县都有一定浓度的硝态氮积累,这表明农田面源污染对地下水质有较大威胁。结论]该研究为河北平原地区的饮水安全以及农业面源污染的治理提供了科学依据。

Study on the Nitrate Nitrogen Content in the Groundwater of Wheat-corn Rotation Region in Hebei Plain

Objective The aim of the research was to confirm the pollution condition of nitrate nitrogen in the groundwater of Hebei province.Method Selecting the wheat-corn rotation region in the piedmont plain as main investigation regions,120 groundwater samples were collected to determine the nitrate nitrogen content and analyze its distribution characteristics and pollution reasons.Result Nitrate nitrogen was detected in the groundwater of 120 sampling sites and the average content of nitrate nitrogen was 4.03 mg/L.The quality of the shallow-layer groundwater in piedmont plain region was better as a whole and had not pollution in wide area.Both Groundwater depth and the application amount of nitrogen had obvious effects on the nitrate nitrogen content in the groundwater.The nitrate nitrogen content had great variation among different sampling sites,the sampling site of the highest content lay in Xinle county(23.94 mg/L)and the sampling site of the lowest content lay in Xinji city(0.09 mg/L).Some sampling sites in Xinle county had obvious nitrate nitrogen pollution,Zhengding county and Luancheng county had certain concentration of nitrate nitrogen accumulation,which indicated that farmland non-point source pollution had greater threat to the quality of groundwater.Conclusion The research provided scientific basis for the drinking water safety in the regions of Hebei plain and the treatment of agricultural non-point source pollution.