New research demonstrates unsustainable levels of soil erosion in the UK.
The study examined more than 1,500 existing records and found 16% relating to arable (crop-growing) land showed erosion above “tolerable” levels – meaning rates of soil loss are significantly greater than new soil formation.
This may not reflect the national picture, as the study has highlighted that existing studies are frequently biased towards places which have eroded in the past.
However, the findings still show that erosion can occur at problematic levels under a range of conditions, meaning soil resources are at risk in the medium to long term.
“Unsustainable rates of erosion reduce soil fertility and can have devastating environmental impacts downstream in waterways,” said lead author Dr Pia Benaud, of the University of Exeter. “If we don’t manage it properly in the UK and around the world, it will affect our ability to feed our growing population. Soil run-off also leads to significant extra sediment in waterways, increasing the damage to ecology and risk of flooding downstream.”
Land management affects erosion rates. For example, leaving fields bare, ploughing up and down a hill (instead of across it) or growing arable crops on steep slopes raise the risk of erosion during heavy rain.
Soil types and local geography also affect erosion rates, though erosion is shown to occur on any soil that is intensively farmed, especially when rainfall is extreme.
“Current UK legislation, particularly existing farm subsidies, pay for land to be managed in a way that leads to unsustainable erosion, with public funding,” Dr Benaud said. “We argue that this should be addressed as a matter of urgency by policymakers, with soil protection at the heart of forthcoming environmental land management schemes.”