Particulate organic matter as a functional soil component for persistent soil organic carbon

Kristina Witzgall, Alix Vidal, David I Schubert, Carmen Höschen, Steffen A Schweizer, Franz Buegger, Valérie Pouteau, Claire Chenu, Carsten W Mueller

    Research output: Contribution to journalJournal articleResearchpeer-review

    327 Citations (Scopus)
    160 Downloads (Pure)

    Abstract

    The largest terrestrial organic carbon pool, carbon in soils, is regulated by an intricate connection between plant carbon inputs, microbial activity, and the soil matrix. This is manifested by how microorganisms, the key players in transforming plant-derived carbon into soil organic carbon, are controlled by the physical arrangement of organic and inorganic soil particles. Here we conduct an incubation of isotopically labelled litter to study effects of soil structure on the fate of litter-derived organic matter. While microbial activity and fungal growth is enhanced in the coarser-textured soil, we show that occlusion of organic matter into aggregates and formation of organo-mineral associations occur concurrently on fresh litter surfaces regardless of soil structure. These two mechanisms-the two most prominent processes contributing to the persistence of organic matter-occur directly at plant-soil interfaces, where surfaces of litter constitute a nucleus in the build-up of soil carbon persistence. We extend the notion of plant litter, i.e., particulate organic matter, from solely an easily available and labile carbon substrate, to a functional component at which persistence of soil carbon is directly determined.

    Original languageEnglish
    Article number4115
    JournalNature Communications
    Volume12
    Issue number1
    Number of pages10
    ISSN2041-1723
    DOIs
    Publication statusPublished - 5 Jul 2021

    Keywords

    • Faculty of Science
    • soil organic matter
    • soil carbon
    • soil carbon storage
    • mineral-associated organic matter
    • Particulate organic matter
    • NanoSIMS
    • Microaggregates

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