中文摘要：

以宁夏青铜峡灌区田间土壤中非点源污染物（总氮、硝氮、氨氮和盐分）作为研究对象,对土壤剖面进行分析。结果表明：表层土壤中各类污染物含量变化较大,基本上以60 cm深度为分界线,下层变化较小,而且作物生长期前后土壤中不同深度各类污染物含量变化与灌溉过程、施肥强度等关系密切;土壤中三氮含量变化幅度呈硝氮〉氨氮〉全氮的趋势,总氮在10月份的含量高于5月份,氨氮、硝氮在10月份的含量低于5月份。盐分在水田土壤中的含量变化幅度要高于旱田。

英文摘要：

Agricultural non-point source pollution is becoming the major cause of the environment deterioration.It has been researched in our country since 1980＇s,and now it becomes a research hotpot.An experiment was done to study non-point source pollutants from field soil in Qingtongxia irrigation area,Ningxia.Based on this experiment,we tried to find out TN,NO3^--N,NH＋4-N and salt content changes in soil profile.The result showed that：（1）The content of various pollutants in surface soil changed greatly,and changed less in deeper soil,which the boundary line is a depth of 60cm basically in soil.Besides,before and after the crop growth period,its content changes in different soil layers had a close relation with the process of irrigation,fertilization intensity and other factors.（2）The content change rate of three kinds of nitrogen was in the tendency of NO3^--〉NNH4^＋-N〉TN,and the content of TN in October was higher than that in May and the case of NH＋4-N and NO3^--N was just the opposite.The rate of salt in paddy field was higher than that in dry field.