Agricultural lands occupy nearly 38% of the land mass of the globe. Often accused of being a source of greenhouse gas emissions, their wise use and the use of virtuous agricultural practices can nevertheless contribute to the fight against climate change through carbon storage. The National Research Institute for Agriculture, Food and the Environment (INRAE), represented by its international vice-president Jean-François Soussana, and the planet A® association, under the leadership of its Chairman of the Scientific Council, Jean-Pierre Rennaud, have entered into a partnership to develop an indicator to measure the evolution of carbon stocks in agricultural soils. Called SOCCROP, it should be made available to the agricultural world in its first version in early 2022.

A partnership in line with the 2019 Planet A forum

Announced at the end of the Planet A forum in 2019, which had as its theme "Earth, matter, planet: soil quality for the health of living organisms", this partnership is a continuation of the work of the initiative " 4 per 1000 ”. The Planet A association, created in 2017 as a true "hub" combining economic, demographic, societal and environmental disciplines and perspectives, places agriculture at the heart of collective solutions. The collaboration with INRAE, whose international vice-president is also a member of the scientific and technical council of "4 per 1000", illustrates the desire of planet A to bring out concrete solutions for the agricultural world, proposed by leading research organizations, experts not only in agricultural and food sciences but also at the forefront of environmental research.

"This project will provide a breakthrough in understanding the international dynamics at work in the management of cultivated soils and their carbon stocks. It prefigures the work that should be carried out from 2022 by the international consortium on soil carbon, which was prepared by the CIRCASA project coordinated by INRAE ​​”, Philippe Mauguin, Chairman and CEO of INRAE.

"The creation of this indicator is the result of a strong commitment made by Planet A during the 2nd International Forum in 2019 in Châlons-en-Champagne. It will be the very first of its kind and will make it possible to provide the agricultural world with a real tool at the service of the quality of their soils. I am convinced, in the long term, it will be a major tool for the protection of our environment, on an international scale ", Benoist Apparu, mayor of Châlons-en-Champagne.

An INRAE ​​team, under the direction of Eric Ceschia (Center d'Études Spatiales de la BIOsphère, CESBIO), has demonstrated a direct link between the annual length of plant cover in cultivated soils and carbon accumulation for major crops in Europe. . It is on the basis of these initial results that the indicator project of the evolution of carbon storage in agricultural soils is based.

"This partnership will make it possible for the first time to achieve an objective indicator, at the plot level and across the globe, of the amount of CO2 that can be absorbed or emitted by agricultural plots depending on the production systems put in place by farmers. SOCCROP ​​will facilitate the estimation of carbon balances on the plot with a view to sustainable soil management and the fight against global warming ”, Jean-François Soussana, Vice-President for International of INRAE ​​and member of the Scientific Council and technique of the "4 per 1000" initiative.

Variations in the vegetation cover of soils directly affect the carbon fixed by vegetation and therefore by the soil. Indeed, the variation in the carbon stock of an agricultural plot depends on the balance of inputs (photosynthesis and organic fertilization) and outputs (harvests, grazing, soil respiration, leaching of carbon in organic form). The soil carbon balance can be modeled as a function of net inputs. This method, which can be used at different scales (plot, farm, region, globe) should make it possible to follow the baseline of soil carbon and any additional storage.

The indicator project has two complementary components. The first, using data from the "4 per 1000" study, aims to analyze and model the relationship between the duration of soil cover and the potential for carbon storage at the level of France. Its results will give rise to a report during the year 2021. The second part will aim to quantify the duration of agricultural soil cover by annual crops or plant cover at the plot level and across all regions. of the world. The study will use "Sentinel" satellite data from the European Space Agency and the first analyzes will be made at the end of 2022.

Thanks to the SOCCROP ​​indicator, it will thus be possible to observe in which regions of the world the increase in the duration of plant cover of cultivated soils is growing or declining. By supplementing this indicator with data on agricultural practices (organic fertilization, management of crop residues, etc.), it will be possible to obtain a global dashboard to monitor the evolution of carbon stocks in agricultural soils and understand further what pace of practices compatible with the “4 per 1000” objective are being deployed around the world.