More than half of the world’s soils are in poor condition, threatening global food supplies and biodiversity, while proven measures to improve soil health are not being widely implemented, according to a UN report released on Thursday.
“Globally, we must shift from a mindset of soil exploitation to one of soil stewardship,” the UN’s Food and Agriculture Organization (FAO) warned, reports AFP.
Soils support 95 percent of global food production, host 59 percent of the world’s biodiversity and serve as the planet’s second-largest carbon sink after the oceans, according to the report’s authors.
Yet, they warned, “soil degradation continues to accelerate at an alarming rate”.
The report found that soil management was poor or very poor in 52.5 percent of regions and subregions. In a third, management was rated fair, while only 14 percent had good or very good soil management.
It is the FAO’s second major report assessing soil health worldwide, following its pioneering study in 2015. That report found that most of the world’s soils were in fair, poor or very poor condition.
Since then, the FAO said, the global population has grown by 800 million people, while an additional 80 million hectares – around 200 million acres, or nearly the combined area of France and Germany – had been converted to major crops.
By far the greatest threat to soil is erosion, experts said, with soil being washed or blown away because of unsustainable practices.
Other threats include the loss of organic matter in soil, known as soil organic carbon, nutrient mismanagement, depleted soil biodiversity, salt build-up, pollution and urban expansion.
Climate change threatens to worsen most of these problems, while soil degradation itself can contribute to climate change. However, improving soil health could also strengthen resilience and help combat global warming.
The authors said most techniques for protecting and restoring soils were already well known before 2015, but they were still not being widely implemented.
Soil management had improved in only 10 percent of assessed areas, while it was deteriorating in 58 percent, they said.
One major technique for reducing soil degradation is reducing or abandoning tillage, such as ploughing. Although tillage is as old as agriculture itself, it destroys organic life in the soil and, by breaking up the soil, leaves it more vulnerable to erosion.
Other methods of protecting and improving soil include planting cover crops such as legumes and brassicas.
These crops are grown on fallow fields to hold soils in place and improve their nutrient content. Agroforestry, in which trees are integrated into farming practices, is another approach.
Better use of natural and artificial fertilisers, which can themselves be a source of pollution, is also a key strategy.
The FAO said the problem was not a lack of knowledge but limited access to resources and high upfront costs, which prevent farmers from adopting better soil management practices. It called for greater financial incentives, more localised data and the use of indigenous knowledge, among other measures.
The report was published as diplomats and experts from around the world gathered for the COP17 summit on desertification in Ulaanbaatar, the capital of Mongolia, where they hoped to agree on a global deal to combat drought.
COP16, held in Riyadh two years ago, failed to reach an agreement.
