气候变化领域集成服务门户(CCPortal): Stable isotopes as an effective tool for N nutrient source identification in a heavily urbanized and agriculturally intensive tropical lowland basin

CCPortal

DOI	10.1007/s10533-020-00663-w
	Stable isotopes as an effective tool for N nutrient source identification in a heavily urbanized and agriculturally intensive tropical lowland basin
	Luu T.N.M.; Do T.N.; Matiatos I.; Panizzo V.N.; Trinh A.D.
发表日期	2020
ISSN	0168-2563
起始页码	17
结束页码	35
卷号	149 期号:1
英文摘要	We present the application of dual stable isotope analyses of NO3 (δ15N-NO3 and δ18O-NO3) to provide a comprehensive assessment of the provenance, partitioning, and conversion of nitrate across the Day River Basin (DRB), Vietnam, which is heavily impacted by agriculture and urbanization. Stable isotope compositions of river water δ18O-H2O, in addition to their δ15N-NO3 and δ18O-NO3 signatures, were sampled at 12 locations in the DRB. Sample collection was conducted during three different periods to capture changes in regional weather and agricultural fertilization regimes; April (the dry season and key fertilization period), July (the rainy season and another key fertilization period) and October (the rainy season with no regional fertilization). Ranges of NO3 stable isotopes are − 7.1 to + 9.2‰ and − 3.9 to + 13.2‰ for δ18O and δ15N, respectively. Interpretation of the stable isotope data characterizes 4 main sources of NO3 in the DRB; (1) nitrified urea fertilizer derived from an intensive agricultural irrigation network, (2) soil and groundwater leaching from within the basin (3) manure and sewage inputs (which is more prevalent in downstream river sections) and (4) upstream inflow from the Red River which discharges into the Day River through the Dao River. We applied a mixing model for the DRB consisting of 4 variables, representing these 4 different sources. The partition calculation shows that during the fertilization and rainy period of July, more than 45% of river NO3 is derived from nitrified urea sources. During the other sampling periods (April and October), manure and sewage contribute more than 50% of river NO3 and are derived from the middle portion of the DRB, where the Day River receives domestic wastewater from the Vietnamese capital, Hanoi. Stable isotope data of O and N reveal that nitrification processes are more prevalent in the rainy season than in dry season and that this predominantly takes place in paddy field agricultural zones. In general, data demonstrate that nitrate loss in the DRB is due to denitrification which takes place in polluted stretches of the river and dominates in the dry season. This study highlights that (i) domestic waste should be treated prior to its discharge into the Day River and (ii) the need for better catchment agricultural fertilization practices as large portions of fertilizer currently discharge into the river, which greatly impacts regional water quality. © 2020, Springer Nature Switzerland AG.
英文关键词	Biological assimilation; Denitrification; Dual stable isotopes; Nitrification; Vietnam
语种	英语
scopus关键词	denitrification; domestic waste; dry season; fertilizer application; groundwater pollution; intensive agriculture; leaching; nitrogen; paddy field; sewage disposal; source identification; stable isotope; urban area; Day Basin; Hanoi; Red River [Asia]; Viet Nam
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/153150
作者单位	Institute of Chemistry, Vietnam Academy of Science and Technology, A18, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Viet Nam; Electric Power University of Vietnam, 235 Hoang Quoc Viet, Cau Giay, Hanoi, Viet Nam; Isotope Hydrology Section, International Atomic Energy Agency, Vienna International Centre, PO Box 100, Vienna, 1400, Austria; School of Geography, Centre for Environmental Geochemistry, University of Nottingham, University Park, Nottingham, NG27 2RD, United Kingdom; Nuclear Training Center, Vietnam Atomic Energy Institute, 140 Nguyen Tuan, Thanh Xuan, Hanoi, Viet Nam
推荐引用方式 GB/T 7714	Luu T.N.M.,Do T.N.,Matiatos I.,et al. Stable isotopes as an effective tool for N nutrient source identification in a heavily urbanized and agriculturally intensive tropical lowland basin[J],2020,149(1).
APA	Luu T.N.M.,Do T.N.,Matiatos I.,Panizzo V.N.,&Trinh A.D..(2020).Stable isotopes as an effective tool for N nutrient source identification in a heavily urbanized and agriculturally intensive tropical lowland basin.Biogeochemistry,149(1).
MLA	Luu T.N.M.,et al."Stable isotopes as an effective tool for N nutrient source identification in a heavily urbanized and agriculturally intensive tropical lowland basin".Biogeochemistry 149.1(2020).