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| Titel |
Isotope fractionations factors of N2O production and reduction by denitrification: a. Laboratory incubation studies using N2O reductase inhibition |
| VerfasserIn |
Reinhard Well, Daniel Weymann, Dominika Lewicka-Szczebak, Lena Rohe, Heinz Flessa |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250079356
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| Zusammenfassung |
| Isotopologue signatures of N2O such as δ18O, average δ15N (δ15Nbulk) and 15N site
preference (SP = difference in δ15N between the central and peripheral N positions of the
asymmetric N2O molecule) can be used to constrain the atmospheric N2O budget and to
characterize N2O turnover processes. However, the use of this approach to study N2O
dynamics in soils requires knowledge of isotopologue fractionation factors (É) for the various
partial processes involved, e.g. N2O production by nitrification or denitrification, and N2O
reduction by denitrification.
Here we present results from laboratory incubations of soils and aquifer material to
determine Égf N2O production (Éprod) and N2O reduction to N2 (Éred) during denitrification.
Éprod for δ18O, δ15Nbulk and SP was obtained by anaerobic incubation of NO3- amended
soils when N2O reduction was inhibited by 10 kPa acetylene. Éred of the respective
signatures was derived by comparing treatments with and without inhibition of N2O
reduction. We investigated samples from 4 mineral soils, one organic soil and from a sandy
aquifer. The mineral soils were incubated under unsaturated conditions in closed or
open systems, the organic and aquifer samples as homogenized slurries in a closed
system.
Results of fractionation factors, process rates and incubation conditions will be
presented and discussed in view of previous studies and theoretical considerations. |
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