气候变化领域集成服务门户(CCPortal): NO3- sources and circulation in the shallow vadose zone in the edge of Dunhuang Mingsha sand dunes in an extremely arid area of Northwestern China

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DOI	10.1016/j.catena.2017.11.012
	NO3- sources and circulation in the shallow vadose zone in the edge of Dunhuang Mingsha sand dunes in an extremely arid area of Northwestern China
	Qi, Shi; Ma, Jinzhu; Feng, Qi; Liu, Fei; He, Jianhua; Shu, Heping; Jia, Bing
发表日期	2018
ISSN	0341-8162
EISSN	1872-6887
卷号	162
英文摘要	The unsaturated zone is a significant feature of the nitrogen cycle in arid areas connecting atmospheric precipitation and surface water to groundwater. To measure NO3-, Cl-, and NH4+ concentrations, precipitation samples (39.9592 degrees N, 94.3302 degrees E) were collected at the western edge of the Mingsha sand dunes. Soil profiles were taken along the northern edge of the dunes to determine NO3- and Cl- concentrations and delta O-80-NO3- and delta N-15-NO3- levels in soil water. The mNO(3)(-)/Cl-, mNH(4)(+)/Cl- and NH4+-N/NO3--N values in precipitation showed seasonal variations, reflecting the influence of distinct anthropogenic sources. The delta N-15-NO3- and delta(ONO3-)-O-18 of the LT profile ranged from 2.38 to 7.84 parts per thousand and 14.72 to 57.5 parts per thousand, respectively, and that of GC profile ranged from - 1.36 to 2.35 parts per thousand and 5.07 to 21.3 parts per thousand, respectively. These results suggest that the main sources of vadose zone nitrogen in the profiles are NO3- fertilizer and NH4+ in fertilizer and precipitation, all of which are influenced by agricultural sources. Obvious nitrification and the mixing of different sources were noted, but the profiles showed no evidence of denitrification. The findings of this study show that migration of NO3- and Cl- in the desert vadose zone is influenced by heavy rainfall events, vegetation, and evaporation. Heavy rainfall events promote leaching of NO3- and Cl- into the deep vadose zone, while evaporation at the surface prevents leaching and vegetation hinders the downward migration of NO3- and Cl-. Migration of NO3--N and Cl-1 in sand dunes is affected by the solute gradient concentration difference of the soil water, moving from areas of higher concentrations to lower concentration. The NO3--N and Cl- accumulations were 1.02 kg N ha(-1) and 3.45 kg ha(-1), respectively, throughout autumn. These were larger than could be attributed to the input flux of atmospheric precipitation, especially in the near-surface soil layer, likely illustrating the influence of atmospheric dry deposition.
关键词	Atmospheric deposition Unsaturated zone Nitrate Circulation Mingsha sand dunes
学科领域	Geology; Agriculture; Water Resources
语种	英语
WOS研究方向	Geosciences, Multidisciplinary ; Soil Science ; Water Resources
来源期刊	CATENA
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/112001
作者单位	Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Key Lab Ecohydrol Inland River Basin, Lanzhou 730000, Gansu, Peoples R China
推荐引用方式 GB/T 7714	Qi, Shi,Ma, Jinzhu,Feng, Qi,et al. NO3- sources and circulation in the shallow vadose zone in the edge of Dunhuang Mingsha sand dunes in an extremely arid area of Northwestern China[J]. 中国科学院西北生态环境资源研究院,2018,162.
APA	Qi, Shi.,Ma, Jinzhu.,Feng, Qi.,Liu, Fei.,He, Jianhua.,...&Jia, Bing.(2018).NO3- sources and circulation in the shallow vadose zone in the edge of Dunhuang Mingsha sand dunes in an extremely arid area of Northwestern China.CATENA,162.
MLA	Qi, Shi,et al."NO3- sources and circulation in the shallow vadose zone in the edge of Dunhuang Mingsha sand dunes in an extremely arid area of Northwestern China".CATENA 162(2018).