滇池北岸居民-农田混合区域农田土壤氮素空间分布特征研究.doc

农业环境科学学报 2010,29(8):1618-1623 Journal of Agro-Environment Science 滇池北岸居民－农田混合区域农田土壤氮素 空间分布特征研究 陆海燕 1，2，胡正义 1，2，张瑞杰 1，逄玉万 1，殷小锋 1，吴永红 1 （1.中国科学院南京土壤研究所，土壤与农业可持续发展国家重点实验室，南京 210008；2.中国科学院研究生院，北京 100049）  摘  要：土壤氮含量空间分布特征对评价氮迁移风险和合理施肥具有重要意义。以滇池北岸大清河流域下游 46.7 hm2 韭菜田与花卉 地为对象，于 2006 年 8 月通过网格法（40 m ×（80～90）m）布点采集 112 个表层土样，研究了土壤氮素空间变异特征。结果表明，调查 区土壤 TN 为 1.28～6.17 g·kg-1（均值 3.36 g·kg-1）、NO3--N 为 3.7～691.7 mg·kg-1（均值 89 mg·kg-1）。调查区东北部韭菜种植区由于接受 生活污水、养殖废水，土壤总氮含量最高，而西南部韭菜、花卉种植区土壤总氮含量相对较低，高浓度养殖和生活污水的排放是导致 土壤总氮含量空间分布差异的主要原因；土壤硝氮含量则以西南部花卉大棚区最高，不同的种植方式（花卉大棚栽培）是土壤硝氮含 量差异的主要原因。夏季高温多雨，花卉揭棚将增加土壤硝酸盐淋溶/径流的迁移风险，蔬菜田块土壤氮矿化也可能加剧土壤氮的淋 溶/径流迁移。因此，在滇池流域湖滨区居民生活污水、养殖污水的排放，作物种植方式与布局，对农田氮的迁移及水体污染具有重要 的影响。 关键词：滇池；氮；蔬菜地；花卉地；空间变异；面源污染 中图分类号：X833 文献标志码：A 文章编号：1672-2043(2010)08-1618-06  Spatial Variability of Nitrogen in Soils in Farmland Adjacent Suburban Villages at Northern Bank of Dianchi Lake LU Hai-yan1,2, HU Zheng-yi1,2, ZHANG Rui-jie1, PANG Yu-wan1, YIN Xiao-feng1，WU Yong-hong1 （1.State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; 2.College of Resources and Environment, Graduate University of Chinese Academy of Sciences, Beijing 100049, China） Abstract：Information about the spatial variability of nitrogen（N）in soils is required for assessing N loss from farmland to water body, and developing rational N fertilizer management practices. In the present investigation, total of 112 top soil samples in a regular grid of 40 m × （80~90）m were collected from 46.7 hm2 farmlands located at the lower reach of Daqinghe on Dianchi northern bank in Aug. 2006. Soil total N ranged from 1.28 g·kg-1 to 6.17 g·kg-1 with an average of 3.36 g·kg-1, and from 3.7 mg·kg-1 to 691.7 mg·kg -1 with an average of 88.7 mg· kg-1 for NO3-N. Geostatistics analysis of these data demonstrated that spatial variability of soil total N, soil NO 3-N were obvious. The high soil total N appeared at northeast leek fields, which could be sewag