Over a quarter of global topsoils have lifespans of less than a century, according to a new international study led by researchers at Lancaster University.
The study involved researchers from all over the world who brought together soil erosion data from 38 countries on six continents.
This data was then used to calculate the soil lifespan, meaning how long it would take for the top 30 cm of the soil to erode at each location.
The researchers found that more than 90% of conventionally farmed soils were thinning, and 16% had lifespans of less than a century.
Soil erosion is an increasingly serious threat to global sustainability, endangering food security, contributing to biodiversity loss and driving desertification.
These rapidly thinning soils were found all over the world, including in the UK, and the USA.
Despite this, the researchers have highlighted that through correct conservation strategies the soil can be preserved for future generations.
Converting arable land to forest was found to be the best way to lengthen soil lifespans.
However other approaches that allow farming to continue such as cover cropping, where plants are grown between cropping seasons was also found to be highly effective.
Lead author of the study, Dr Dan Evans of Lancaster University said: ‘Our soils are critically important and we rely on them in many ways, not least to grow our food.
‘Our study shows that soil erosion is a critical threat to global soil sustainability, and we need urgent action to prevent further rapid loss of soils and their delivery of vital ecosystem services.’
Professor Jess Davies, co-author of the study added: ‘Whilst 16% of soils with lifespans shorter than 100 years is a more optimistic estimate than ‘60 harvests left’, the soil is a precious resource and we can’t afford to lose that much over a human lifetime.
‘But importantly what our study also shows is that we have the tools and practices to make a difference – employing the appropriate conservation methods in the right place can really help protect and enhance our soil resource and the future of food and farming.’
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