Sunday, December 3, 2023

Recarbonize the soil to fight climate change and hunger

Just as the decarbonization of the economy is being promoted in the world to reduce greenhouse gases, we need to “recarbonize” the soils to restore them and thus combat not only climate change and hunger, an expert from the Organization told Efe. United Nations Food and Agriculture Organization (FAO).

Carbon is the main component of soil organic matter. Its function is crucial for its fertility and the abundant production of nutritious food, according to data from the FAO.

On average, 33% to 40% of the world’s soils are degraded due to unsustainable management practices (they are uncovered, or contaminated by the inappropriate use of fertilizers and agrochemicals) and climatic factors, the expert said in an interview with Efe. senior international soil fertility expert at FAO, Carolina Olivera.

“Everything is measured by organic carbon in the soil, which is like the skin of the soil. It is what allows us to produce food, forests, filter water. Soil degradation is produced simply by the loss of organic carbon,” explained the official.

This degradation translates into a loss of productivity, which is a serious danger for food security, since “95% of food generation comes from the soil.”

Also in a decrease in water retention and, therefore, in the resilience of soils in the face of increasingly prolonged droughts – the number and duration of these have grown by 29% since 2000 -, as well as in their ability to combat climate change.

The world’s soils act as the largest carbon sink on earth, reducing greenhouse gases in the atmosphere.

“We talk about the decarbonization of the economy because we want to stop generating greenhouse gases, but we also talk about the recarbonization of the soil,” said Olivera.

The situation of Mesoamerica and South America

FAO data provided to Efe indicate that about 45% of farmland in South America and 74% in Mesoamerica are degraded, which favors scenarios of food crisis.

“Although they are different causes, sensitivity to degradation is high” in both subregions, Olivera said.

In Mesoamerica “the climate is so hot, so strong at the level of climatic phenomena, droughts followed by hurricanes, that the soil cannot maintain its organic carbon. And in South America it is the topography, very rugged, and the sensitivity to erosion”.

restore soil

Soil is a non-renewable natural resource. One centimeter of this takes 1,000 years to generate, said the FAO expert.

But it is possible to regenerate a soil so that it has a good balance and is capable of hosting sustainable and resilient agriculture, and for this, organic carbon must be restored. One of the main techniques is to protect it by plant cover.

In Mesoamerica, for example, “if we have a plantation of plantain, we recommend that it be planted with another cover crop such as kudzu, or several others that we have that are very effective not only for covering the soil but also for producing food.

We can combine that agrobiodiversity and the diversity of diets and that benefits the soil, the environment and us”, said Olivera.

The longed for black floors

The richest soils in the world are black. Their productivity potential is very high because they maintain a greater carbon capture capacity.

These black soils are found in the Ukraine, Russia, China, the United States, and Canada. “The few that exist in Latin America and the Caribbean are Argentina and Uruguay,” Olivera said.

They exist in areas where there is winter and a layer of ice protects them during a season in which they are not cultivated, which gives them a break.

Quite the contrary than in tropical areas, where the sun falls directly and up to three harvests can be produced in a year: “In Mesoamerica there were not many and there are no more black soils,” he added.

A living floor is the solution to all ills

A “living soil, that works, is the solution to all our ills”, since it allows to reduce production costs due to the lower use of fertilizers and agrochemicals, and produces food with nutritional quality, highlighted the official of the UN entity.

The FAO indicated that in the last 40 years food has lost its nutritional value, and deficiencies in vitamins and nutrients are progressively more pronounced in quantity and quality.

Healthy and sustainably managed soils, with a high content of organic matter, biodiversity, nutrients and moisture, can produce up to 58% more food and retain about 20 times its weight in water, which is essential to maintain production, added the agency. United Nations.


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