What is a good soil carbon content?

In the context of soil health assessment, possible indicators are being considered at various points. Soil organic matter is central to many soil functions, but is strongly determined by many relatively static site characteristics. Clay content plays a major role, which is why the organic carbon-to-clay ratio has become widespread to provide a comparable assessment of soil carbon content. In this paper, using the German Agricultural Soil Inventory, it is shown that this ratio does not create comparability, but severely disadvantages fine-textured soils by being too strong a denominator. The paper identifies an alternative that could be used to assess carbon content trends in agricultural soils. The limitations of such an approach are also discussed.

https://doi.org/10.1111/sum.12921