西南岩溶农业区典型土地利用对土壤氮素特征的影响  

Effects of Typical Land Use Types on Soil Nitrogen Characteristics in Karst Agricultural Areas of Southwest China

作　　者：田雨桐 韩志伟[1,2] 赵然[1] 田永著 罗广飞 杨淼 TIAN Yutong;HAN Zhiwei;ZHAO Ran;TIAN Yongzhu;LUO Guangfei;YANG Miao(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025;Key Laboratory of Karst Georesources and Environment,Ministry of Education,Guiyang 550025)

机构地区：[1]贵州大学资源与环境工程学院,贵阳550025 [2]喀斯特地质资源与环境教育部重点实验室,贵阳550025

出　　处：《中国农学通报》2022年第33期89-96,共8页Chinese Agricultural Science Bulletin

基　　金：贵州省人才基地建设项目“喀斯特地区地球关键带表生污染过程及防控途径”(RCJD2018-21);贵州省国内一流学科建设项目“贵州省国内生态学一流学科建设项目”(GNYL[2017]007)。

摘　　要：为探究岩溶地区不同土地利用类型对土壤氮素特征的影响,阐明土壤氮素在不同土地利用类型、不同深度下的迁移特征及影响因素,以花溪河流域中凯掌水库周边不同利用类型的土壤(草地、河滨带、水田、旱地)为研究对象,测定了土壤的基本理化性质、全氮、硝态氮及铵态氮含量,分析了岩溶地区不同土地利用状态下土壤不同形态氮素空间分布特征、氮素的组成比例以及氮素与各环境因子的相关关系。结果表明:研究区农用地(水田、旱地)土壤全氮含量均值高于非农用地(草地、河滨带)垂直方向上呈“表聚”现象,整体呈随深度增加而减少的特征;硝态氮受农业活动影响,农用地含量要高于非农用地,在垂直方向上在农用地中变化幅度较大,整体呈随着深度而减少的趋势;铵态氮含量在不同土地利用类型下差异不大,在垂直剖面上整体较为稳定;对比硝态氮及铵态氮在无机氮中的占比,表明研究区土壤无机氮主要以铵态氮为主;研究区各环境因子中土壤有机质含量与各氮素呈极显著正相关关系(P<0.01),土壤pH与氮素呈显著负相关(P<0.05)。农用地土壤氮素含量普遍高于非农用地,不同土地利用类型对氮素分布具有显著影响。To investigate the influence of different land use types on soil nitrogen characteristics in karst area and clarify the migration characteristics and influencing factors of soil nitrogen under different land use types and depths, we took different types of soil(grassland, riverside zone, paddy field and dry land) around Kaizhang reservoir in Huaxi River Basin as the research objects, measured the basic physical and chemical properties of soil, the contents of total nitrogen, nitrate nitrogen and ammonium nitrogen, and analyzed the spatial distribution characteristics of different forms of soil nitrogen under different land use conditions in karst area,the composition proportion of nitrogen and the correlation between nitrogen and various environmental factors.The results showed that the average content of soil total nitrogen in agricultural land(paddy field and dry land)was higher than that in non-agricultural land(grassland and riverside zone), showing‘surface accumulation’in the vertical direction and a decrease with the soil depth increase as a whole. Affected by agricultural activities, the content of nitrate nitrogen in agricultural land was higher than that in non-agricultural land. In the vertical direction, the content of nitrate nitrogen in agricultural land changed greatly, and the overall trend decreased with soil depth. The content of ammonium nitrogen had little difference under different land use types, and was relatively stable in the vertical section. Comparing the proportion of nitrate nitrogen and ammonium nitrogen in inorganic nitrogen, it showed that the soil inorganic nitrogen in the study area was mainly ammonium nitrogen. There was a very significantly positive correlation between soil organic matter content and nitrogen in the study area(P<0.01), and there was a significantly negative correlation between soil pH and nitrogen(P<0.05). In summary, the soil nitrogen content of agricultural land is generally higher than that of non-agricultural land, and different land use types have a sig

关 键 词：岩溶农业区 氮素组成 土地利用方式 影响因素 空间分布 

分 类 号：X53[环境科学与工程—环境工程]