自然红壤坡地氮素在地表径流-土壤水系统迁移转化规律试验研究  

Experiment Study of Nitrogen Transformation and Transport onNatural Slope with Red soil in the Surface-subsurface System

作　　者：马千禧 韩旭东 刘昭 朱焱[1] MA Qian-xi;HAN Xu-dong;LIU Zhao;ZHU Yan(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,Hubei Province,China;Jiangxi Provincial Key Laboratory of Soil Erosion and Prevention,Nanchang 330029,Jiangxi Province,China;Jiangxi Academy of Water Science and Engineering,Nanchang 330029,Jiangxi Province,Chinal)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [2]江西省土壤侵蚀与防治重点实验室,江西南昌330029 [3]江西省水利科学院,江西南昌330029

出　　处：《中国农村水利水电》2024年第4期88-96,110,共10页China Rural Water and Hydropower

基　　金：国家重点研发计划课题项目(2021YFD1900805-02)。

摘　　要：目前对红壤坡地氮素流失的试验研究主要集中在人工土槽装置中监测径流和壤中流氮素,缺乏在野外自然坡情况下氮素在径流-壤中流及土壤中迁移转化过程的整体研究。为了探究天然红壤坡地氮素在地表径流-土壤水系统中的迁移转化规律,在江西水土保持生态科技园开展了3次坡地人工降雨氮素流失试验,对不同坡面及土壤初始条件下人工降雨过程中地表径流、壤中流及土壤水分状况与氮素(硝态氮和铵态氮)浓度进行了监测和分析。结果表明,初始坡面粗糙截流能力强,能减少地表径流产流量,但会导致硝态氮大量渗入土壤,造成硝态氮随土壤水的下移。自然坡地土壤中的大孔隙和土壤空间变异性是导致壤中流的主要原因,壤中流硝态氮浓度显著高于地表径流硝态氮浓度,导致壤中流硝态氮流失占比较高,第一次试验中硝态氮壤中流流失占比超过50%。相比较而言,壤中流与地表径流铵态氮浓度均较小,与铵态氮在土壤中较强的吸附能力有关。历次试验中,土壤硝态氮和铵态氮沿顺坡方向空间变异性较大,随时间变化无一致性规律,除受到坡面水力特征影响外,还受到土壤温度的影响。Current study of nitrogen loss in the slope with red soil mainly focuses on its transport processes in the runoff and soil interflow with the equipment of artificial soil tank.Few experiments were carried out to monitor the nitrogen transport processes both in the surface and subsurface system on the natural slope.To investigate the nitrogen loss processes in the surface-subsurface system on the slope with red soil,three experiments with different soil surface coverage and soil moisture conditions were carried out in Ecological Science and Technology Park of Water Conservation in Jiangxi Province, China. The runoff, interflow, soil moisture and temperature and the nitrogen concentra⁃tion( nitrate-N and ammonia-N) were measured in each experiment. The results show that the rough soil surface intercepts rainfall water anddecreases the runoff flow, but it causes more nitrate-N infiltrate to soil and move downward with soil water. In natural slope, the existence ofmacro pores and the strong soil spatial variability are the main reasons for the interflow in soil. The nitrogen concentration in the interflow wasobviously more than that in the runoff, which caused the large portion of nitrogen loss by interflow. During the first experiment, the nitrogenloss by interflow accounted for more than 50% of total nitrogen loss. In comparison, the ammonia-N concentration in the interflow and runoffwere smaller than those of nitrate-N due to its high adsorption effect by soil. The soil nitrate-N and ammonia-N exhibited high spatial varia⁃tion along the slope. There was no consistent rule of the variation over time, which was impacted by various factors, such as soil temperatureand surface soil hydraulic.

关 键 词：自然坡地 壤中流 地表径流 土壤氮素 氮素迁移转化 

分 类 号：TV93[水利工程—水利水电工程] S27[农业科学—农业水土工程]