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| Titel |
Contributions of root and shoot derived-C to soil organic matter throughout an agricultural soil profile assessed by compound-specific 13C analysis |
| VerfasserIn |
Mercedes Mendez-Millan, Marie-France Dignac, Cornelia Rumpel, Daniel P. Rasse, Sylvie Derenne |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250040810
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| Zusammenfassung |
| The turnover of soil organic matter (SOM) is generally studied in the topsoil horizons, where
the highest concentrations of organic carbon (OC) are found. Subsoils, although containing
lower amounts of organic carbon compared to topsoils, greatly contribute to the total carbon
stocks within a soil profile. An increase in SOM aliphaticity was observed during
SOM degradation, and also down the soil profile, suggesting that the stable pool of
SOM is enriched in aliphatic structures. These alkyl-C structures might mainly
derive from cutins and suberins, two biomacromolecules, which contain biomarkers
specific for shoot and root plant biomass. The aim of this study was to use cutin and
suberin structural units to follow the incorporation of plant biomass originating
from roots and shoots throughout an agricultural soil profile. We measured the 13C
natural abundance of root and shoot biomarkers in samples taken from 15 to 105
cm depth in a C3/C4 chronosequence. After 9 years of maize (C4) cropping, the
distribution of root biomarkers (diacids) significantly changed and their concentration
increased compared to the wheat (CC3) soil. The largest increase was observed at
60-75 cm where diacids reached up to 134 μg/gOC compared to 23 μg/gOC in
the wheat soil. Higher inputs from maize root biomass are also suggested by an
average 13C enrichment of the root markers in the maize compared to the wheat
soil. |
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