The study was prepared by Martin Wiesmeier, research associate at the TUM's Department of Soil Science, in cooperation with the first author Dr. Gerrit Angst from the German Centre for Integrative Biodiversity Research (iDiv) and other researchers from the Czech Academy of Sciences and the University of Copenhagen.
Maintaining and enhancing soils as carbon reservoirs is a central concern of soil management. In contrast to carbon in partially decomposed plant residues, which is considered unstable and remains in the soil for only a few days to years, carbon bound to soil minerals is often seen as a potential target for action. This stable carbon can remain in the soil for centuries or even millennia. However, focusing solely on this stable carbon is problematic, as different environmental conditions can make measures targeting this carbon inefficient. We gathered current literature and were surprised to see how much stable carbon is emphasised there, although an undifferentiated consideration of this carbon prevents informed and targeted management of soils. Together with our international team of authors from Germany, the USA and Denmark, we have therefore designed a conceptual framework that is based on current scientific knowledge and takes into account the diversity and complexity of soils. This is the only way to effectively manage soils.
The concept particularly emphasises the importance of labile carbon contained in partially degraded plant residues. This can be a useful target for action, depending on environmental conditions. For example, the capacity of some soils to store stable mineral-associated carbon is very limited. Some soils also have conditions that are unfavourable for the build-up of stable carbon but favourable for the build-up of labile carbon. Measures that increase labile carbon and ensure that the levels of this carbon remain constant will have a more lasting impact on carbon storage here than measures that target stable carbon. We cannot emphasise strongly enough how important it is to include the respective environmental conditions in the management of soils as carbon sinks. These determine whether stable, labile or both types of carbon should be the target of measures.
We assume that management strategies designed using the new conceptual framework will maximise soil carbon storage and generate synergies with related management objectives, such as soil health, soil biodiversity and crop yields. Only if we consider soils as a complex and holistic system with specific chemical, biological and physical properties can we manage them successfully and sustainably in a rapidly changing environment.
Link to the original press release of iDIV:
Angst, G., Mueller, K.E., Castellano, M.J., Vogel, C., Wiesmeier, M., Mueller, C.W. (2023): Unlocking complex soil systems as carbon sinks: multi-pool management as the key. Nature Communications. DOI: 10.1038/s41467-023-38700-5