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| Titel |
Investigation of biogeochemical interface development by a short-term incubation experiment using 15N and 13C labeled litter |
| VerfasserIn |
C. Vogel, K. Heister, F. Buegger, A. Bannert, I. Kögel-Knabner |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250067743
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| Zusammenfassung |
| Fraction studies with isotopes such as 15N and 13C imply the possibility to get a process-oriented understanding about litter-derivated carbon and nitrogen movement through various soil pools and the development of biogeochemical interfaces. The aim of our study was to follow the organic matter turnover and the formation of organo-mineral associations to get insight in the formation of biogeochemical interfaces over different time steps.
To mimic an agricultural topsoil system, sieved soil (< 2 mm) was homogenized with litter (< 200 µm) before water addition and weekly during the course of the experiment. The litter composed of 13C and 15N labeled maize and potato mixed in a relation of 1:1 and added in a proportion of 1:10 to the soil. The experiments were performed in three independent replicates and additional treatments with non-labeled litter as control. After litter addition, the soils were incubated for 42 days under defined conditions in a 14 °C room at a water holding capacity of 60 %. For this, the columns were moistened in a two days interval. Samples were taken in 5 time steps, directly after litter addition and then after 1, 7, 21 and 42 days. The isotopic nitrogen and carbon composition of the bulk soil and the soil fractions were monitored using an isotope ratio mass spectrometer after a combined density and particle-size fraction.
First results show that 13C is mineralized relatively quickly with a half-time of 12 days, by contrast 15N remained more or less constant. The detection of 15N and 13C enrichment in organo-mineral associations after 3 weeks indicates the rapid development of newly formed interface which could have an influence on the stabilization of organic substances. |
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