中文摘要：

在淮河上游重要支流沙颍河流域分布于不同土壤类型的77个代表样点进行表层及深层土壤样品采集,分析土壤氮组成、空间分布特征及其影响要素,以期为优化农业生产管理措施和保护水生态环境提供参考.分析结果表明：沙颍河流域表层土壤氮密度为0.02~0.42kg·m-2,80%以上区域处于0.20~0.30kg·m-2之间,平均值高于深层土壤,是土壤氮的主要赋存区域.有机质及降雨量是影响研究区域土壤氮累积的主要因素,富含有机质的冲洪积沉积区域的砂姜黑土表层平均氮密度较高,超过0.28kg·m-2;氮肥施用量大、水肥条件好、土壤有机质含量丰富的水浇地及地下水埋深较深区域表层土壤氮密度高;降雨量与表层土壤氮密度呈显著负相关（R2=-0.58,P〈0.05）,与深层土壤氮密度呈显著正相关（R2=0.69,P〈0.05）.

英文摘要：

In this study,the soil nitrogen composition,spatial distribution and influencingfactors were investigated by analyzing samples at 77 sampling locations representative of different soil types in Shaying river basin,an important upstream tributary of the Huaihe River Basin,to provide reference for agricultural management optimization and water ecological environment protection.The results showed that：nitrogen density of surface soil ranges from 0.02to0.42kg·m-2,and 80% of the area has a density of 0.20~0.30kg·m-2,the average value is higher than deep soil,the main part of soil nitrogen load.Soil nitrate density isclosely related to the sedimentary environment.The deposition of organic-rich alluvial source of caliche nodule black soil resulted in its high nitrogen density in surface soil,more than 0.28kg·m-2.At the same time,surface soil nitrogen density in areas with more fertilizer,areas with low groundwater table,as well as irrigated farm land with good water condition and high soil organic matter content,were all relatively high.Precipitation has a significant negative correlation with nitrogen density of surface soil,but a remarkable positive correlation with that of deep soil.