农业小流域“田-沟”系统氮素时空变化分析  

Analysis of temporal and spatial variation of nitrogen in field-ditch system of small agricultural watershed

作　　者：张展羽[1,2] 陈晶晶[1,2] 张文祥[2] 司涵[1,2] 

机构地区：[1]南方地区高效灌排与农业水土环境教育部重点实验室,江苏南京210098 [2]河海大学水利水电学院,江苏南京210098

出　　处：《排灌机械工程学报》2013年第1期61-65,共5页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51179050);农业部公益性行业科研专项经费资助项目(200903001-05)

摘　　要：为研究农业小流域尺度上氮素的时空变化趋势,以夏作期内位于南京市溧水县白马镇的典型农业小流域为研究对象,通过野外监测和室内化验分析相结合,探讨了小流域内土壤氮素含量的时空变化,并分析了排水沟道中氮素质量浓度的时空分布特征.结果表明:夏作期小流域内土壤3种形态氮素质量分数时间上存在一定差异性,土壤全氮质量分数呈先增大后减小趋势,土壤硝态氮、铵态氮质量分数均呈总体减小趋势,降幅分别为37.1%,60.9%;小流域土壤全氮质量分数空间上分布趋势为中部较高,四周较低,南部相对于北部质量分数较大.夏作期排水沟道中总氮、硝态氮、铵态氮平均质量浓度依次为3.54,0.81,0.59 mg/L;在排水沟道的迁移过程中,3种形态氮素质量浓度均是沟道出口处大于沟道入口处.A typical agricultural small watershed in summer season in Lishui county, Nanjing city was specified as a study model to explore the temporal and spatial variation trend of nitrogen in the small watershed. The temporal and spatial variation of soil nitrogen in the watershed was investigated by in- situ observation, indoor laboratory analysis and statistics regression, eventually the distribution charac- teristics of nitrogen concentration in the drainage ditch were clarified. It was turned out that the profiles of three forms of soil nitrogen content against time show some differences, namely, the total soil total nitrogen content gets the maximum at a time instance, but both the soil nitrate nitrogen and ammonium nitrogen are subject to a steady decrease and the maximum declines are 37.1% and 60.9%. In the central area of the watershed the soil total nitrogen content is the highest, meanwhile the total nitrogen in the southern area is higher than that in the northern part. The averaged concentrations of the total nitrogen, nitrate nitrogen and ammonium nitrogen are 3.54, 0.81,0.59 mg/L in the drainage ditch during summer. In water migration process in the ditch, the concentrations of three forms of nitrogen at the outlet of the ditch are always higher that those at the entrance.

关 键 词：氮素 田沟系统 小流域 时空变化 土壤 

分 类 号：S276.1[农业科学—农业水土工程]