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DOI	10.5194/hess-23-1355-2019
	Sources and fate of nitrate in groundwater at agricultural operations overlying glacial sediments
	Bourke S.A.; Iwanyshyn M.; Kohn J.; Jim Hendry M.
发表日期	2019
ISSN	1027-5606
起始页码	1355
结束页码	1373
卷号	23 期号:3
英文摘要	Leaching of nitrate (NO3-) from animal waste or fertilisers at agricultural operations can result in NO3- contamination of groundwater, lakes, and streams. Understanding the sources and fate of nitrate in groundwater systems in glacial sediments, which underlie many agricultural operations, is critical for managing impacts of human food production on the environment. Elevated NO3- concentrations in groundwater can be naturally attenuated through mixing or denitrification. Here we use isotopic enrichment of the stable isotope values of NO3- to quantify the amount of denitrification in groundwater at two confined feeding operations overlying glacial sediments in Alberta, Canada. Uncertainty in δ15NNO3 and δ18ONO3 values of the NO3- source and denitrification enrichment factors are accounted for using a Monte Carlo approach. When denitrification could be quantified, we used these values to constrain a mixing model based on NO3- and Cl- concentrations. Using this novel approach we were able to reconstruct the initial NO3-N concentration and NO3-N-Cl- ratio at the point of entry to the groundwater system. Manure filtrate had total nitrogen (TN) of up to 1820 mg L-1, which was predominantly organic N and NH3. Groundwater had up to 85 mg L-1 TN, which was predominantly NO3-. The addition of NO3- to the local groundwater system from temporary manure piles and pens equalled or exceeded NO3- additions from earthen manure storages at these sites. On-farm management of manure waste should therefore increasingly focus on limiting manure piles in direct contact with the soil and encourage storage in lined lagoons. Nitrate attenuation at both sites is attributed to a spatially variable combination of mixing and denitrification, but is dominated by denitrification. Where identified, denitrification reduced agriculturally derived NO3- concentrations by at least half and, in some wells, completely. Infiltration to groundwater systems in glacial sediments where NO3- can be naturally attenuated is likely preferable to off-farm export via runoff or drainage networks, especially if local groundwater is not used for potable water supply. © 2019 Author(s).
语种	英语
scopus关键词	Agriculture; Ammonia; Chlorine compounds; Denitrification; Fertilizers; Glacial geology; Groundwater; Isotopes; Manures; Mixing; Nitrates; Piles; Potable water; Sediments; Waste management; Water supply; Agricultural operations; Drainage networks; Enrichment factors; Feeding operations; Glacial sediments; Groundwater system; Isotopic enrichment; Monte Carlo approach; Groundwater pollution; concentration (composition); denitrification; drinking water; food production; glacial deposit; groundwater; groundwater pollution; lake pollution; nitrate; pollutant source; runoff; spatial variation; stable isotope; streamwater; waste management; Alberta; Canada; Animalia
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159733
作者单位	Bourke, S.A., Department of Geological Sciences, University of Saskatchewan, Saskatchewan, SK S7N5C9, Canada, School of Earth Sciences, University of Western Australia, Crawley, WA 6009, Australia; Iwanyshyn, M., Natural Resources Conservation Board, Calgary, AB T2P0R4, Canada; Kohn, J., Alberta Agriculture and Forestry, Irrigation and Farm Water Branch, Edmonton, AB T6H5T6, Canada; Jim Hendry, M., Department of Geological Sciences, University of Saskatchewan, Saskatchewan, SK S7N5C9, Canada
推荐引用方式 GB/T 7714	Bourke S.A.,Iwanyshyn M.,Kohn J.,et al. Sources and fate of nitrate in groundwater at agricultural operations overlying glacial sediments[J],2019,23(3).
APA	Bourke S.A.,Iwanyshyn M.,Kohn J.,&Jim Hendry M..(2019).Sources and fate of nitrate in groundwater at agricultural operations overlying glacial sediments.Hydrology and Earth System Sciences,23(3).
MLA	Bourke S.A.,et al."Sources and fate of nitrate in groundwater at agricultural operations overlying glacial sediments".Hydrology and Earth System Sciences 23.3(2019).