New Approach to Experimental Soil Health Definition Using Thermogravimetric Fingerprinting

Degradation and sealing are still frequent in soil management today despite intensive research. An unsatisfactory assessment of soil key components and soil health still limits sustainable land use. For the future evaluation of soil health, soils under productive use have been compared with natural and semi-natural soils using thermogravimetric fingerprinting of air-dried soil samples. This approach has led to a more precise quantification of known relationships and the discovery of several new ones between soil components that have evolved over thousands of years of soil formation without human intervention, each changing in a specific way due to land use. The use-related deviations from the natural soil condition allow a distinction between natural soils, disturbed soils, and soil-like carbon-containing mineral mixtures (e.g., compost, horticultural substrates). Carbon added to soils with fresh organic residues or from anthropogenic (soot, slag) or geological (coal) sources can be distinguished from soil organic matter (humus) accumulated during soil genesis, regardless of extreme chemical heterogeneity. The degree of carbon sequestration in soils is easy to quantify. Using near-natural soils as a reference, considering bound water seems to be a suitable starting point for the experimental definition of soil health. An elucidation of the causal relationships between the soil components used should accompany it.