title: Submicron structures provide preferential spots for carbon and nitrogen sequestration in soils.
abstract: The sequestration of carbon and nitrogen by clay-sized particles in soils is well established, and clay content or mineral surface area has been used to estimate the sequestration potential of soils. Here, via incubation of a sieved (<2 mm) topsoil with labelled litter, we find that only some of the clay-sized surfaces bind organic matter (OM). Surprisingly, <19% of the visible mineral areas show an OM attachment. OM is preferentially associated with organo-mineral clusters with rough surfaces. By combining nano-scale secondary ion mass spectrometry and isotopic tracing, we distinguish between new labelled and pre-existing OM and show that new OM is preferentially attached to already present organo-mineral clusters. These results, which provide evidence that only a limited proportion of the clay-sized surfaces contribute to OM sequestration, revolutionize our view of carbon sequestration in soils and the widely used carbon saturation estimates.
authors.affiliation: Lehrstuhl für Bodenkunde, Department Ecology and Ecosystem Management, Center of Life and Food Sciences Weihenstephan, Technische Universität München, D-85350 Freising-Weihenstephan, Germany.
authors.forename: Cordula
authors.initials: C
authors.lastname: Vogel
authors.affiliation: Lehrstuhl für Bodenkunde, Department Ecology and Ecosystem Management, Center of Life and Food Sciences Weihenstephan, Technische Universität München, D-85350 Freising-Weihenstephan, Germany.
authors.forename: Carsten W
authors.initials: CW
authors.lastname: Mueller
authors.affiliation: Lehrstuhl für Bodenkunde, Department Ecology and Ecosystem Management, Center of Life and Food Sciences Weihenstephan, Technische Universität München, D-85350 Freising-Weihenstephan, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Höschen
authors.affiliation: Institute of Soil Ecology, Helmholtz Zentrum München (GmbH), German Research Center for Environmental Health, D-85764 Neuherberg, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Buegger
authors.affiliation: Lehrstuhl für Bodenkunde, Department Ecology and Ecosystem Management, Center of Life and Food Sciences Weihenstephan, Technische Universität München, D-85350 Freising-Weihenstephan, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Heister
authors.affiliation: Research Unit of Environmental Genomics, Helmholtz Zentrum München (GmbH), German Research Center for Environmental Health, D-85764 Neuherberg, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Schulz
authors.affiliation: Research Unit of Environmental Genomics, Helmholtz Zentrum München (GmbH), German Research Center for Environmental Health, D-85764 Neuherberg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schloter
authors.affiliation: 1] Lehrstuhl für Bodenkunde, Department Ecology and Ecosystem Management, Center of Life and Food Sciences Weihenstephan, Technische Universität München, D-85350 Freising-Weihenstephan, Germany [2] Institute for Advanced Study, Technische Universität München, Lichtenbergstrasse 2a, D-85748 Garching, Germany.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Kögel-Knabner