Recovery of groundwater N_{2spiinf;o at the soil surface and its contribution to total N}2spiinf;o emissions

authored by: Daniel Weymann, Reinhard Well, Carolin von der Heide, Jürgen Böttcher, Heiner Flessa, Wilhelmus H.M. Duijnisveld
Abstract: Production and accumulation of the major greenhouse gas nitrous oxide (N₂O) in surface groundwater might contribute to N₂O emissions to the atmosphere. We report on a ¹⁵N tracer study conducted in the Fuhrberger Feld aquifer in northern Germany. A K¹⁵NO₃ tracer solution (60 atom%) was applied to the surface groundwater on an 8 m² measuring plot using 45 injection points in order to stimulate production of ¹⁵N₂O by denitrification and to detect its contribution to emissions at the soil surface. Samples from the surface groundwater, from the unsaturated zone and at the soil surface were collected in regular intervals over a 72-days period. Total N₂O fluxes at the soil surface were low and in a range between -7.6 and 29.1 μg N₂O-N m^-2 h^-1. ¹⁵N enrichment of N₂O decreased considerably upwards in the profile. In the surface groundwater, we found a ¹⁵N enrichment of N₂O between 13 and 42 atom%. In contrast, ¹⁵N enrichment of N₂O in flux chambers at the soil surface was very low, but a detectable ¹⁵N enrichment was found at all sampling events. Fluxes of groundwater-derived ¹⁵N-N₂O were very low and ranged between 0.0002 and 0.0018 kg N₂O-N ha^-1 year^-1, indicating that indirect N₂O emissions from the surface groundwater of the Fuhrberger Feld aquifer occurring via upward diffusion are hardly significant. Due to these observations we concluded that N₂O dynamics at the soil-atmosphere interface is predominantly governed by topsoil parameters. However, highest ¹⁵N enrichments of N₂O throughout the profile were obtained in the course of a rapid drawdown of the groundwater table. We assume that such fluctuations may enhance diffusive N₂O fluxes from the surface groundwater to the atmosphere for a short time.
Organisation(s): Institute of Soil Science
Section Soil Biophysics
External Organisation(s): University of Göttingen
Johann Heinrich von Thünen Institute, Federal Research Institute for Rural Areas, Forestry and Fisheries
Federal Institute for Geosciences and Natural Resources (BGR)
Type: Article
Journal: Nutrient cycling in agroecosystems
Volume: 85
Pages: 299-312
No. of pages: 14
ISSN: 1385-1314
Publication date: 10.2009
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Agronomy and Crop Science, Soil Science
Electronic version(s): https://doi.org/10.1007/s10705-009-9269-4 (Access: Open)

BibTeX

@article{4f51c7ad2eb142148e2110a325dd3034,
title = "Recovery of groundwater N2spiinf;o at the soil surface and its contribution to total N2spiinf;o emissions",
abstract = "Production and accumulation of the major greenhouse gas nitrous oxide (N2O) in surface groundwater might contribute to N2O emissions to the atmosphere. We report on a 15N tracer study conducted in the Fuhrberger Feld aquifer in northern Germany. A K15NO3 tracer solution (60 atom%) was applied to the surface groundwater on an 8 m2 measuring plot using 45 injection points in order to stimulate production of 15N2O by denitrification and to detect its contribution to emissions at the soil surface. Samples from the surface groundwater, from the unsaturated zone and at the soil surface were collected in regular intervals over a 72-days period. Total N2O fluxes at the soil surface were low and in a range between -7.6 and 29.1 μg N2O-N m-2 h-1. 15N enrichment of N2O decreased considerably upwards in the profile. In the surface groundwater, we found a 15N enrichment of N2O between 13 and 42 atom%. In contrast, 15N enrichment of N2O in flux chambers at the soil surface was very low, but a detectable 15N enrichment was found at all sampling events. Fluxes of groundwater-derived 15N-N2O were very low and ranged between 0.0002 and 0.0018 kg N2O-N ha-1 year-1, indicating that indirect N2O emissions from the surface groundwater of the Fuhrberger Feld aquifer occurring via upward diffusion are hardly significant. Due to these observations we concluded that N2O dynamics at the soil-atmosphere interface is predominantly governed by topsoil parameters. However, highest 15N enrichments of N2O throughout the profile were obtained in the course of a rapid drawdown of the groundwater table. We assume that such fluctuations may enhance diffusive N2O fluxes from the surface groundwater to the atmosphere for a short time.",
keywords = "N-Labeling, Denitrification, Nitrate, Nitrous oxide fluxes, Stable isotopes, Surface groundwater",
author = "Daniel Weymann and Reinhard Well and {von der Heide}, Carolin and J{\"u}rgen B{\"o}ttcher and Heiner Flessa and Duijnisveld, {Wilhelmus H.M.}",
note = "Funding information: Acknowledgments We thank the German Research Foundation for funding this research project. Modification of the gas probes, the instrumentation of the measuring field and sampling would not have been possible without the help of G. Benseler, G. Klump, and F. Trienen. We thank I. Ostermeyer, K. Schmidt and L. Szwec as well as R. Langel (Centre for Stable Isotope Research and Analysis at the University of G{\"o}ttingen) for always reliable assistance during the laboratory efforts.",
year = "2009",
month = oct,
doi = "10.1007/s10705-009-9269-4",
language = "English",
volume = "85",
pages = "299--312",
journal = "Nutrient cycling in agroecosystems",
issn = "1385-1314",
publisher = "Springer Netherlands",
number = "3",
}

Recovery of groundwater N2spiinf;o at the soil surface and its contribution to total N2spiinf;o emissions

Recovery of groundwater N_{2spiinf;o at the soil surface and its contribution to total N}2spiinf;o emissions