As the world faces the growing consequences of climate change, soil is increasingly recognized as a natural ally in capturing carbon dioxide. Instead of being released into the atmosphere, carbon can be “locked” into the ground — in the form of organic matter. France was among the first countries to realize the importance of this process and developed its own model called AMG, designed to measure how much carbon soil can retain.
The French AMG Model – From Theory to Practice
The AMG model (from Avenir Matière Grasse, meaning “future of organic matter”) was created within the framework of France’s National Low-Carbon Strategy (Stratégie Nationale Bas Carbone). It allows farmers and researchers to calculate how much carbon different types of soil can store depending on farming and tillage methods.
According to data from the INRAE institute, French soils can store 0.2 to 0.5 tons of carbon per hectare per year when good agricultural practices are applied. This corresponds to a reduction of 0.7 to 1.8 tons of CO₂ per hectare per year. If such practices were applied to 10 million hectares, France could store more than 10 million tons of CO₂ annually — roughly equivalent to the yearly emissions of all its tractors and combines combined.
These figures form the basis of the famous “4 per 1000” (4 ‰) initiative, which aims to increase soil organic matter by 0.4% per year. Though modest, that increase would be enough to halt the global rise of atmospheric CO₂ if adopted worldwide.
Practical Examples – Less Plowing, More Life in the Soil
French agronomists have shown that the greatest results come from combining several measures:
-
Reduced tillage (conservation farming) – on plots where plowing was eliminated, soil organic matter rose by 15% in five years, while remaining unchanged under conventional tillage.
-
Cover crops – planting species like white mustard or rye between main crops increased soil carbon by 0.4 tons per hectare per year.
-
Organic fertilizers and composting – adding organic matter instead of mineral fertilizers raised carbon content in deeper soil layers, down to 60 cm.
Professor Delphine Urucard from INRAE emphasizes that “soil must be viewed as a living organism, not as a production surface,” since it is the foundation of drought resilience and biological balance.
Experiences from Other Countries
Similar initiatives exist around the world:
-
United States – in Iowa, a long-term experiment by the University of Michigan found that no-till fields with cover crops store 25% more carbon than conventionally tilled ones.
-
Spain and Italy – in Mediterranean regions, agroforestry systems combine crops and trees planted between rows, cooling the soil, conserving moisture, and increasing deep-soil carbon storage.
-
Australia – the government provides financial incentives to farmers for each hectare where soil carbon content increases, as part of a national carbon credit system.
