Sources and transport of nitrate constrained by the isotopic technique in a karst catchment: an example from Southwest China

	Sources and transport of nitrate constrained by the isotopic technique in a karst catchment: an example from Southwest China
	Fu-Jun Yue; Si-Liang Li; Cong-Qiang Liu
	2015
发表期刊	Hydrological Processes
卷号	29 期号:8 页码:1883-1893
摘要	The concentration and isotopic composition of nitrate were analyzed to improve an understanding of nitrate sources and transformation processes in a typical karstic agricultural field in the Houzhai catchment, Guizhou Province, Southwest China. The results revealed that no distinct spatial pattern of content and isotopic composition of nitrate exists in this karst catchment. Nitrate in surface stream (SFS) had slightly lighter isotopic composition and lower concentration compared with nitrate in subterranean stream (STS) during the dry season. Concentrations of SFS nitrate increased to concentrations similar to those of STS during the wet season. The isotopic values indicated that nitrate were mainly impacted by manure sources during the dry season and influenced by a mix of chemical fertilizer and manure during the wet season. The denitrification rates were roughly estimated based on the isotopic compositions of nitrate after considering volatilization and ignoring assimilation. The calculated result showed that approximately one fifth of nitrate load was removed by denitrification in the catchment. Annual nitrate flux from the outlets accounted for 14.2% of applied total fertilizers used in the catchment, approximately 85% of total transported flux from the catchment in the wet season. Furthermore, chemical weathering processes were enhanced by using nitrogen fertilizer because liberated protons and enhanced HCO3- flux were produced through by nitrification.
关键词	Dry Season Nitrogen Fertilizers Hydrology Streams Weat
学科领域	环境地球化学
收录类别	SCI
语种	英语
文献类型	期刊论文
条目标识符	http://ir.gyig.ac.cn/handle/352002/5941
专题	环境地球化学国家重点实验室_环境地球化学国家重点实验室_期刊论文环境地球化学国家重点实验室
推荐引用方式 GB/T 7714	Fu-Jun Yue,Si-Liang Li,Cong-Qiang Liu. Sources and transport of nitrate constrained by the isotopic technique in a karst catchment: an example from Southwest China[J]. Hydrological Processes,2015,29(8):1883-1893.
APA	Fu-Jun Yue,Si-Liang Li,&Cong-Qiang Liu.(2015).Sources and transport of nitrate constrained by the isotopic technique in a karst catchment: an example from Southwest China.Hydrological Processes,29(8),1883-1893.
MLA	Fu-Jun Yue,et al."Sources and transport of nitrate constrained by the isotopic technique in a karst catchment: an example from Southwest China".Hydrological Processes 29.8(2015):1883-1893.