Localization of soil organic matter in soil aggregates using synchrotron-based X-ray microtomography

authored by: Stephan Peth, Claire Chenu, Nelly Leblond, Anneka Mordhorst, Patricia Garnier, Naoise Nunan, Valérie Pot, Malte Ogurreck, Felix Beckmann
Abstract: Modelling carbon mineralisation in natural soils is a major topic in soil and climate research. Current models need to be improved to include soil structure as an influencing factor to better predict C fluxes between pedosphere and atmosphere and to estimate carbon sequestration potentials. Geometry-based mechanistic modelling approaches have recently been developed to systematically study the effect of soil structure on carbon decomposition. Such models require spatially explicit input parameters describing the architecture of the pore space and the heterogeneous distribution of microbes and organic matter as decomposable substrate. The latter is very difficult to determine in situ, resulting in increased uncertainty in the models. To obtain more realistic input data, we have developed a novel approach to locate soil organic matter (SOM) in undisturbed aggregates of soil using a combination of synchrotron-based X-ray microtomography and osmium as a staining agent for SOM. Here, we present the first results using 5mm sized soil aggregate samples with contrasting C-contents in which we obtained maps of organic matter distributions in relation to the pore networks at the aggregate scale.
External Organisation(s): University of Kassel
AgroParisTech - Université Paris-Saclay
Kiel University
Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE)
Helmholtz Zentrum Geesthacht Centre for Materials and Coastal Research
Type: Article
Journal: Soil Biology and Biochemistry
Volume: 78
Pages: 189-194
No. of pages: 6
ISSN: 0038-0717
Publication date: 11.2014
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Microbiology, Soil Science
Sustainable Development Goals: SDG 13 - Climate Action
Electronic version(s): https://doi.org/10.1016/j.soilbio.2014.07.024 (Access: Unknown)