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| Titel |
Dynamic (redox) interfaces in soils - Carbon turnover in microbial food webs and impact on soil organic matter |
| VerfasserIn |
E. Cyrus, A. Miltner, M. Kästner |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250023273
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| Zusammenfassung |
| Abstract
The stabilization of soil organic matter (SOM) in soil is related to the interaction of
organic compounds with interfaces, in particular those with mineral surfaces. For continuous
stabilization of C, we hypothesize that dynamic interfaces are needed which can be created in
soil by variations in water content and redox potential. Therefore, these factors are crucial
for organic compound transformation by microbes in soil and their effects will be
studied.
In our experiments, hexadecane and phenanthrene will be used as representative examples
of aliphatic and aromatic compounds, respectively. Their transformation in soil and how this
is affected by water content and redox potential will be studied in isotope tracer
experiments.
The effect of different water contents and redox potentials as well as the effect of redox
potential oscillations on their transformation will be studied in batch experiments with
constant or oscillating water contents and redox conditions. Screening experiments with
14C-labeled hexadecane revealed particularly interesting combinations of water content and
redox potential. In soil column experiments, we will study the transformation of the same
compounds in a gradient of water content and redox potential.
The data will reveal the distribution of the compound-derived C on mineralization,
biomass formation and SOM related residue formation. They will also provide information
on the flux of the C in microbial food webs related to the activity of selected functional genes. |
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