More than half of the world’s soils are in poor condition, threatening global food supplies and biodiversity, according to a new report by the United Nations Food and Agriculture Organisation (FAO).

The report, released on Thursday, found that soil degradation is continuing to accelerate, with erosion identified as the greatest threat to soil health.

The FAO said soils support 95 per cent of global food production, host 59 per cent of the world’s biodiversity and represent the planet’s second-largest carbon sink after the oceans.

According to the assessment, soil management was rated poor or very poor in 52.5 per cent of regions and subregions worldwide. About a third were assessed as fair, while only 14 per cent were rated good or very good.

The report identified several threats to soil health, including erosion, the loss of soil organic carbon, poor nutrient management, declining soil biodiversity, salt build-up, pollution and urban expansion.

Climate change is expected to worsen many of these problems, while degraded soils can also contribute to climate change. However, the FAO said improving soil health could strengthen resilience and help address global warming.

The latest assessment is the second major global soil report produced by the FAO, following its first study in 2015. Since that assessment, the global population has increased by about 800 million people, while approximately 80 million hectares of additional land have been converted to major crop production.

The FAO said many techniques for protecting and restoring soils have been known for years but have not been widely adopted.

Soil management improved in only 10 per cent of the areas assessed, while it deteriorated in 58 per cent, the report said.

One key method of reducing soil degradation is reducing or abandoning tillage, including ploughing. The FAO said tillage can damage organic life in soil and leave it more vulnerable to erosion.

Other recommended measures include planting cover crops such as legumes and brassicas, as well as agroforestry, which integrates trees into farming systems.

Better management of natural and artificial fertilisers is also considered important, particularly because fertilisers can contribute to pollution when poorly used.

The FAO said the main obstacle was not a lack of knowledge but limited access to resources and the high upfront costs associated with improved soil management.

It called for greater financial incentives, more localised soil data and increased use of indigenous knowledge to help farmers adopt sustainable practices.

The report was released as diplomats and experts gathered for COP17 on desertification in Ulaanbaatar, Mongolia, where participants are seeking a global agreement to address drought.