Titlebar

Export bibliographic data
Literature by the same author
plus on the publication server
plus at Google Scholar

 

SOM fractionation methods : Relevance to functional pools and to stabilization mechanisms

Title data

von Lützow, Margit ; Kögel-Knabner, Ingrid ; Ekschmitt, Klemens ; Flessa, Heinz ; Guggenberger, Georg ; Matzner, Egbert ; Marschner, Bernd:
SOM fractionation methods : Relevance to functional pools and to stabilization mechanisms.
In: Soil Biology & Biochemistry. Vol. 39 (2007) . - pp. 2183-2207.
ISSN 0038-0717
DOI: https://doi.org/10.1016/j.soilbio.2007.03.007

Abstract in another language

Soil organic matter (SOM) consists of various functional pools that are stabilized by specific mechanisms and have certain turnover rates. For the development of mechanistic models that predict changes in SOM storage, these pools have to be quantified and characterized. In the past, numerous fractionation schemes have been developed to separate and analyse such SOM fractions. In this review, the SOM fractions obtained with such operational fractionation procedures are described in terms of their pool sizes, chemical properties, and turnover rates. The main objective of this review is to evaluate these operationally defined fractions with respect to their suitability to describe functional SOM pools that could be used to parameterize SOM turnover models. Fractionation procedures include (1) physical separation of SOM into aggregate, particle size, and density fractions and fractions according to their magnetic susceptibility, and (2) various wet chemical procedures that fractionate SOM according to solubility, hydrolysability, and resistance to oxidation or by destruction of the mineral phase. Furthermore, combinations of fractionation methods are evaluated.The active SOM pool with turnover rates <10 years may best be represented by the soil microbial biomass and the light fraction (<1.6–2 g cm−3) obtained by density fractionation (if black carbon contents are considered). Most chemical and physical fractionations as well as combinations of methods yield SOM fractions that are not homogeneous in terms of turnover rates. It has proven to be particularly difficult to isolate functional fractions that represent the passive model pools in which the majority of soil SOM is stabilized. The available fractionation methods do not correspond to specific stabilization mechanisms and hence do not describe functional SOM pools. Another problem is that comprehensive data for turnover rates and data for whole soil profiles are only now becoming available, especially for new fractionation methods. Such information as well as the use of specific markers and compound-specific isotope analysis may be important for future differentiation and evaluation of functional SOM fractions.Keywords: Physical soil fractionation; Wet chemical fractionation; Mean residence time; Turnover time; Recalcitrance; Spatial inaccessibility; Organo–mineral interactions; Conceptual model pools

Further data

Item Type: Article in a journal
Refereed: Yes
Additional notes: BAYCEER37385
Institutions of the University: Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Chair Soil Ecology
Research Institutions > Research Centres > Bayreuth Center of Ecology and Environmental Research- BayCEER
Faculties
Faculties > Faculty of Biology, Chemistry and Earth Sciences
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences
Research Institutions
Research Institutions > Research Centres
Result of work at the UBT: Yes
DDC Subjects: 500 Science
Date Deposited: 11 Sep 2015 06:33
Last Modified: 27 Apr 2016 09:13
URI: https://eref.uni-bayreuth.de/id/eprint/19143