Soils: a vulnerable shared asset
As we are told by Claire Chenu, a biodiversity expert appointed by the UN as ambassador for the awareness campaign, “We perceive the soil as a mere surface, when it is in fact a living environment.” At present, the Professor in Soil Sciences at AgroParisTech considers that we do not fully appreciate our dependency on this natural resource, whose destruction can be rapid and in some cases irreversible. Soils host 25% of the planet’s biodiversity and provide for almost all of our food production, but their available quantity around the world is falling significantly, along with their essential ability to maintain the biosphere, since they play a major role in carbon absorption, the regulation of water cycles and the decomposition of organic matter, among other things.
Soils host 25% of the planet’s biodiversity and provide for almost all of our food production.
Today, Claire Chenu explains, “As only 22% of the Earth’s land is devoted to farming, this creates tension and food insecurity. Worse still, these few arable areas are themselves threatened by numerous forms of degradation, such as soil compaction by farming and forestry machinery, erosion by ploughing, desertification, contamination by widespread or occasional pollutants, increased salt content, acidification, and more.” But according to this expert, the greatest danger for the Earth is very simply land take: its transformation into a place of human activity. In France, for example, 27 m² of land are turned into commercial space every second, to create traffic circles, train stations, residential subdivisions, and so on. And it is often the natural areas with the richest biodiversity that are destroyed by these large-scale projects.
Fostering natural solutions
Various solutions can be implemented to contain soil degradation and prevent a chain reaction. The natural remedy par excellence, agroecology, should be a preferred solution. Here, the principle is to increase the quantity of living organisms in the earth (plants, worms, insects, etc.) that decompose organic matters, part of which remains in the soil and nourishes it. Nitrate-fixing intermediate crops are another effective option for restoring soils in the long term. These farming methods, which prevent the exposure of bare soil between crops by covering it with plants, also increase photosynthesis and enrich the soil. In the same way, agroforestry plays a remedial role by giving a fresh boost to the earth through the planting of new trees and bushes on farmland and in pastures.
A last solution for adding nutrients to soil that has been deprived of them is the use of composted organic waste, thus involving community action.
Claire Chenu explains that the large-scale implementation of this solution will be furthered by mobilizing action around the International Year of Soils, which provides a unique opportunity for raising public awareness about collective soil restoration. And its thematic similarity with the Paris Climate Conference in December is no accident. As our expert says, “We are facing huge ecological challenges, in which the preservation of soils will be a key factor.”
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