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| Titel |
Solid-state 13C NMR experiments reveal effects of aggregate size on the chemical composition of particulate organic matter in grazed steppe soils |
| VerfasserIn |
M. Steffens, A. Kölbl, I. Kögel-Knabner |
| 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 |
250028148
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| Zusammenfassung |
| Grazing is one of the most important factors that may reduce soil organic matter (SOM)
stocks and subsequently deteriorate aggregate stability in grassland topsoils. Land use
management and grazing reduction are assumed to increase the input of OM, improve the soil
aggregation and change species composition of vegetation (changes depth of OM input).
Many studies have evaluated the impact of grazing cessation on SOM quantity. But until
today little is known about the impact of grazing cessation on the chemical quality of
SOM in density fractions, aggregate size classes and different horizons. The central
aim of this study was to analyse the quality of SOM fractions in differently sized
aggregates and horizons as affected by increased inputs of organic matter due to grazing
exclusion.
We applied a combined aggregate size, density and particle size fractionation procedure to
sandy steppe topsoils with different organic matter inputs due to different grazing intensities
(continuously grazed = Cg, winter grazing = Wg, ungrazed since 1999 = Ug99, ungrazed
since 1979 = Ug79). Three different particulate organic matter (POM; free POM, in aggregate
occluded POM and small in aggregate occluded POM) and seven mineral-associated organic
matter fractions were separated for each of three aggregate size classes (coarse =
2000-6300μm, medium = 630-2000μm and fine = |
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