Soil degradation is a global issue, but how can we actually assess its condition? In Montpellier, researchers are developing and combining biological, chemical and physical indicators to diagnose soil health and guide its restoration. Precision expertise for agro-ecology.
A concept with many dimensions
Talking about “soil health” means asking a complex question: is soil capable of fulfilling its essential ecological functions? This includes its fertility for agriculture, its ability to filter and store water, absorb carbon and host abundant biodiversity.
But unlike a machine, a floor doesn’t have just one “good condition”. Its health depends on context – climate, use, soil type – and evolves over time. That’s why researchers are mobilizing a range of scientific indicators to characterize it in a rigorous and appropriate way.
Three main categories of indicators
In Montpellier, teams from the One Science Foundation are combining several disciplines to analyze the soil at depth, focusing on three main areas:
- Physical indicators: texture, compaction, structure, porosity. These parameters influence water and air circulation, plant rooting and biological activity. Tools such as penetrometry and tomography can be used to quantify these properties.
- Chemical indicators: pH, organic matter, cation exchange capacity, nitrogen or phosphorus content. These data reveal the chemical fertility of the soil and its capacity to nourish crops without excessive use of inputs.
- Biological indicators: microbial biomass, community diversity, microbial respiration, presence of bioindicators such as earthworms. These are the indicators most sensitive to agricultural practices, and often the most revealing of the soil’s ecological condition.
Field and laboratory methods
Scientists from Montpellier combine soil sampling, laboratory analysis and in situ measurements to assess these indicators. They also use long-term databases and agricultural experiments to monitor soil evolution in different climatic and usage contexts.
For example, by observing organic matter dynamics on a decadal scale, we can detect the cumulative effects of agricultural practices on the soil’s capacity to store carbon – a major challenge in the fight against climate change.
Tools for the agro-ecological transition
These indicators are not just for scientific diagnosis. They are also used to design decision-making tools for farmers, local authorities and institutions. At Montpellier, researchers are working to make this data accessible and operational, notably through simplified protocols and digital tools.
The aim: to steer agricultural policies and management practices towards solutions that restore soil quality while maintaining productivity. In this sense, measuring soil health becomes a strategic lever for the success of the agro-ecological transition.