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| Titel |
Nitrogen turnover of three different agricultural soils determined by 15N triple labelling |
| VerfasserIn |
Sebastian R. Fiedler, Kristina Kleineidam, Nicol Strasilla, Steffen Schlüter, Jan Reent Köster, Reinhard Well, Christoph Müller, Nicole Wrage-Mönnig |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250151429
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| Publikation (Nr.) |
 EGU/EGU2017-16012.pdf |
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| Zusammenfassung |
| To meet the demand for data to improve existing N turnover models and to evaluate the effect
of different soil physical properties on gross nitrogen (N) transformation rates, we
investigated two arable soils and a grassland soil after addition of ammonium nitrate
(NH4NO3), where either ammonium (NH4+), or nitrate (NO3−), or both pools have been
labelled with 15N at 60 atom% excess (triple 15N tracing method). Besides NH4+, NO3− and
nitrite (NO2−) contents with their respective 15N enrichment, nitrous oxide (N2O) and
dinitrogen (N2) fluxes have been determined.
Each soil was adjusted to 60 % of maximum water holding capacity and pre-incubated at
20˚ C for two weeks. After application of the differently labelled N fertilizer, the soils were
further incubated at 20˚ C under aerobic conditions in a He-N2-O2 atmosphere (21 % O2, 76
He, 2% N2) to increase the sensitivity of N2 rates via the 15N gas flux method. Over a 2
week period soil N pools were quantified by 2 M KCl extraction (adjusted to pH
7 to prevent nitrite losses) (Stevens and Laughlin, 1995) and N gas fluxes were
measured by gas chromatography in combination with IRMS. Here, we present the
pool sizes and fluxes as well as the 15N enrichments during the study. Results are
discussed in light of the soil differences that were responsible for the difference
in gross N dynamics quantified by the 15N tracing model Ntrace (Müller et al.,
2007).
References
Müller, C., T. Rütting, J. Kattge, R.J. Laughlin, and R.J. Stevens, (2007) Estimation of
parameters in complex 15N tracing models by Monte Carlo sampling. Soil Biology &
Biochemistry. 39(3): p. 715-726.
Stevens, R.J. and R.J. Laughlin, (1995) Nitrite transformations during soil extraction with
potassium chloride. Soil Science Society of America Journal. 59(3): p. 933-938. |
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