Soils: the principal ally for feeding the world

March 9, 2015


Farmers in Chimaltenan​go, Guatemala

M. Fleishman

Some 300 million hectares in Latin America are already affected by erosion and land degradation.

From the recognisable red soils of the tropics to the black volcanic ash of the Andes, Latin America’s fertile soils are encompass the future of millions of people across the world.

But the region’s potential for food production is under threat due to land degradation. According to data from IFAD, around 300 million hectares are already affected by erosion in the region.

And it’s a worldwide phenomenon. According to the WWF, half of the planet’s top soil has been lost in the past 150 years. It’s a loss which puts the planet’s ability to produce food for a growing population into doubt, according to experts.

“Soils sequester carbon, which contributes to climate change mitigation,” explains Mohamed Bakarr, Senior Environmental Specialist for the GEF. “The most valuable part of the soil has a huge organic carbon content, but through erosion it can end up in rivers as silt or released into the atmosphere.”

Soil is the lifeblood of our planet.

But fertile soils are a non-renewable resource and it can take up to a millennium to form just 1cm of topsoil. Furthermore, once formed the health of this thin layer has clear ramifications for the health of the planet.

Today there is a significant disconnect between the soil and daily life. It’s an oversight which is directly affecting 16% of Latin Americans and billions of people worldwide, who depend on the earth for their livelihoods.

In response 2015 has been named the International Year of Soils by the UN, a feat designed to encourage us to look down and connect, once again, with the ground beneath our feet.

" Soils sequester carbon, which contributes to climate change mitigation "

Mohamed Bakarr

Senior Environmental Specialist for the Global Environmental Facility

Latin America: A food superpower

According to estimates from organisations and experts, food production will have to increase by 70% to ensure sufficient supply for more than 9 billion people, the majority of which will come from increased intensification of existing land, according to FAO  estimates.

However, such increases will have a knock-on effect on soil quality. Intensive agriculture practices are one of the primary threats to soil vitality worldwide due in part to:

1) Constant ploughing: Vegetation maintains the soils stability, keeping the layers protected from the elements and preventing the nutrient-rich top layers from washing away through their root network. With each harvest and sowing season, farmers strip away these plants, leaving the soil unprotected.

2) Use of fertilizers: Spraying crops with fertilizers does nothing to address the poor quality of the soil underneath.  If not absorbed by the plants, the chemicals remain on the surface and are flushed away by the rain, often contaminating the local water system.

3) Climate change: Almost a third of global greenhouse gas emissions are generated by the agricultural sector, a major factor in climate change. This in turns speeds up the degradation and desertification process, thus increasing the need for energy, water and fertilizer use in food production.

Agricultural products make up around a quarter of Latin American exports, and a 13% of agricultural trade worldwide. And with 28% of potential new arable land in the region, Latin America is well positioned to increase production.

However, here too, is the threat of soil degradation being felt. For example in:

  • Argentina: For over a century, sheep have been the primary income source in the Argentine Patagonia. Today, 85% of the region is affected by land degradation, the majority caused by over-grazing.
  • Colombia: 148 000 hectares of woodland is lost each year, a large part of which is then dedicated to cattle raising – a sector which already occupies 30% of the national territory

Soil degradation isn’t only a threat to livelihoods, but also to biodiversity and regional ecosystems. As a result, the restoration process is long and complex.

 “One of the challenges of restoring land which has been degraded is that it is very expensive, especially if that land is abandoned,” explains Bakarr. “We encourage farmers to keep using the land, as where livelihoods are tightly embedded with the soil, there is an incentive to invest resources on keeping the soil healthy.”

It is a strategy which is already seeing results in the region.

Instead of felling forests, cattle herders in Colombia, Costa Rica and Nicaragua have received help to raise their herds in the shade. Known as ‘silvopastoral’ agriculture, it helps to restore grazing land and protect biodiversity by raising livestock in the shade.

Dry lands are the most at risk from degradation and desertification. In Argentina, these lands make up three-quarters of the national territory, of which almost half are found in Patagonia. With the help of the GEF, livestock herders in this region have put in place sustainable practices to reduce the pressure on the land and improve the quality of life of the people who live there.