increase soil organic matter

Experts highlight the water retention capacity of healthy soils

Spain faces a serious problem of desertification, increased by increasingly severe droughts and successive heat waves, associated with global warming. To stop this trend, experts consider it essential to revitalize the soil through, for example, increase in its organic matter.

The United Nations program against desertification warned a few years ago that the 75% of the surface of Spain suffers the risk of suffering from this problem, which destroys agricultural production, among many other things.

“The soils [en España] They are highly degraded as a result of a general lack of knowledge about their importance, biodiversity and functions, as well as the factors and time necessary for their regeneration. Although conventional agriculture contributes significantly to soil erosion, there is little awareness of this problem,” says Susana Rodriguez-Echeverría, from the Spanish Association of Terrestrial Ecology (AEET) and member of the Plant-Soil Team.

There is consensus among experts that increasing organic matter in soils is key to their health. The organic component of soil consists of several elements that give life to the land we walk on and depend on: plant residues, small living organisms, decomposing organic matter and stable organic matter (humus).

There are many ways to increase the presence of these elements by adopting sustainable management practicessuch as ensuring that the soil is shaded as much as possible, ensuring minimal soil disturbance, and integrating plant or animal waste into the soil.

The increase in soil organic matter is directly proportional to its ability to retain water, helping to mitigate droughts and forest fires. Drought precisely increases soil evaporation, and the challenge is to reverse this situation. This is where organic matter plays a decisive role.

The organic content Q, with just a 1% increase, can increase the water retention capacity of the soil by up to 75 cubic meters per 4,000 square meters of land.

“Organic matter is essential for soil functioning; would increase the soil’s ability to retain water, decrease erosion and provide the necessary habitat and food for living beings “which are responsible for a large part of the soil’s ecosystem services, such as nutrient recycling and decontamination,” adds Susana Rodríguez-Echeverría.

Tool to ‘sequester’ CO2

“In addition, the increase in organic matter represents an increase in the amount of carbon stored, thus acting as atmospheric carbon sink. If we consider all Spanish agricultural soils, this stock of soil carbon would be a considerable contribution to the removal of carbon from the atmosphere,” says the expert.

For his part, the president of the Spanish Society of Soil Sciences and professor at the Miguel Hernández University of Elche, Jorge Mataix-Solera, points out that “the organic matter of the soil has the capacity to retain water and nutrients, improves the structure and soil porosity is a long-term source of nutrients and is the source of energy for microorganisms. Let us not forget that “A quarter of the planet’s biodiversity is found in the soil.”

“Soil organic matter ensures good soil quality in general, for agricultural production and also as a regulator of the hydrological cycle. Therefore, its maintenance is a win-win between its different ecosystem services,” indicates Rosa M. Poch, president of the FAO Intergovernmental Technical Panel on Soils and Researcher at the University of Lérida.

A global challenge

Leading Spanish soil scientists support Save Soila movement supported by the United Nations and the World Food Programme, which seeks to address the global crisis of soil degradation and support governments in implementing concrete policies for its conservation.

The primary objective of Save Soil is ensure that there is a minimum of 3% to 6% organic matter in agricultural soils around the world. This would make the soil alive and usable sustainably on all agricultural land, notes this platform.

“Policies in this sense are necessary. They arrive a little late, but Europe is moving forward. I think it is very important that society becomes aware of the importance of taking care of the soil and avoiding its degradation and that there are movements like Save Soil that do it a lot more visible for the population and for politicians,” adds Jorge Mataix-Solera.

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