Cornwall's soils are a hidden climate asset. New research reveals both the risk of carbon loss and the region’s leading role in restoring soil health—offering practical, local solutions for farmers, gardeners, and policy makers alike.
In the quiet rhythms of Cornish farming and gardening lies a powerful, often invisible ally in the battle against climate change: soil organic carbon (SOC). New European and UK-wide research has revealed that agricultural soils across cool, humid regions like Cornwall are among the most vulnerable in Europe to carbon loss. Yet this risk brings opportunity. With new science, local innovation, and a tradition of land stewardship, Cornwall is poised to lead a soil-based climate revolution.
The Soil Carbon Risk Index: A Game-Changer for Europe
A 2025 study led by the European Commission’s Joint Research Centre introduced a groundbreaking soil carbon risk index, mapping 43 to 83 million hectares of farmland at high risk of topsoil organic carbon loss. This study goes beyond simple carbon counts, pairing two critical factors: the hazard (how much carbon is being lost) and the vulnerability (how close a soil is to its storage limit).
Cool, wet regions were identified as hotspots for potential carbon depletion, challenging the long-held assumption that these climates are naturally safe carbon stores. Cornwall, with its rain-soaked pastures, acidic soils, and history of land cultivation, sits right within this zone of heightened risk. These findings are echoed by the 2025 Joint Research Centre (JRC) report (“Soil organic carbon is at risk in a large part of European agricultural land”), published in Nature Communications (March 2025), which maps Cornwall within the top quartile for topsoil carbon loss risk in the UK.
Why This Matters for Cornwall
SOC isn't just about carbon accounting. It underpins soil fertility, water retention, drought resilience, and biodiversity. In Cornwall, where weather patterns are shifting and extreme events are rising, soils with high organic content act as buffers, absorbing rain, retaining nutrients, and resisting erosion.
Yet these benefits are threatened. Intensive tillage, historical drainage, monocultures, and the conversion of pasture to arable land have all contributed to SOC decline. According to national studies, UK agricultural soils have already lost an estimated 0.75% of their carbon reserves between 2009 and 2018.
Local Solutions from the Ground Up
Cornwall is not standing still. Projects like the Cornwall Soil Carbon Project and Farm Net Zero have tested fields on dozens of farms, measuring SOC at various depths and trialling regenerative techniques.
At Lower Sheepscombe Farm near Bodmin, a two-season herbal ley trial saw SOC increase from 4.2% to 4.8% at 0–10 cm depth—well above the national mean. Similar results were recorded at Trewoodloe Farm on the Lizard, where monitoring revealed both improved earthworm counts and a 0.5 tonnes/ha annual carbon gain under reduced tillage and compost incorporation.
These projects, supported by Duchy College and the University of Plymouth, combine field trials with laboratory verification. The Cornwall Soil Carbon Project’s 2023 summary found average topsoil organic carbon at 0–10 cm in Cornish grasslands was 3.8% (range: 2.6–6.1%), compared to the UK mean of 3.2%.
Science Meets Practice: Measuring What Matters
Cornwall is also pioneering ways to measure and verify soil carbon. Alongside traditional lab testing, researchers are using:
These technologies allow for field-scale mapping and long-term monitoring, turning carbon-rich soil from an abstract concept into a quantifiable asset. Since 2021, over 7,500 hectares of Cornish farmland have been baseline-mapped for SOC, with over 65% of demonstration fields showing measurable gains after two years of regenerative practice.
Policy, Payments, and a Greener Future
SOC is now a cornerstone of the UK's future Environmental Land Management Schemes (ELMS). Farmers in Cornwall who baseline and improve their soil carbon could soon receive payments for storing carbon and delivering "public goods."
Cornwall’s work is also directly connected to the European "Mission Soil" initiative, which aims to ensure that 75% of EU soils are healthy by 2030. As a flagship Living Lab, Cornwall’s trials and protocols are feeding into the forthcoming EU Soil Monitoring Law, which will mandate standard soil health tracking across all member states.
Participation in these programs not only advances soil science locally but ensures Cornish farmers are ready to benefit from any future European or UK "carbon farming" payments or compliance requirements as these policies are enacted.
A Call to Gardeners and Growers
SOC isn't just for farmers. In Cornwall’s allotments, back gardens, and community plots, the same principles apply. Composting, mulching, keeping soil covered, and planting perennials all help build carbon underground. Even small plots can store surprising amounts, especially when managed thoughtfully.
From Risk to Resilience
Cornwall's soils tell a story of ancient richness, modern stress, and hopeful renewal. As climate pressures mount, the region's ability to protect and build its soil carbon will determine not just agricultural success, but ecological and economic resilience.
Ongoing research continues to influence national and EU policy development, ensuring that Cornwall's data and practices shape wider carbon farming frameworks. Advances in monitoring, landowner engagement, and field-tested interventions are already helping align Cornwall with global goals for soil health.
With science as a guide and the land as teacher, Cornwall is showing that climate action begins underfoot. Whether in a clifftop garden or across expansive pasture, the future lies in the carbon we keep in the ground.
If every UK grassland increased its SOC by 0.5%—as Cornish pilot farms have achieved—the national soils could sequester an extra 28 million tonnes of CO₂ equivalent per year.
