Late Norfolk farming campaigner’s final briefing paper urges a ‘wider approach’ to soil health

A late Norfolk farming campaigner's final briefing paper has implored the government not to rely on reduced-tillage agriculture as a 'silver bullet' to cut greenhouse gas emissions after Brexit.

Lord Peter Melchett, who farmed at Ringstead near Hunstanton and was well-known for raising the profile of environmental issues and organic agriculture, died in August at the age of 71.

The last briefing paper he wrote as policy director for the Soil Association, published this week, reviews the latest scientific research on conservation tillage, and suggests it is not a guaranteed way of cutting farming's greenhouse gas emissions.

As the government draws up its post-Brexit policies, Defra secretary Michael Gove has voiced support for minimum tillage cultivation and direct drilling as a way to improve soil health. While minimising soil disturbance and erosion, there could be an added benefit as carbon is sequestered over time as organic matter increases – and, with it, soil carbon levels.

But Lord Melchett's paper concludes that levels of soil organic carbon can be over-estimated in no-till or min-till systems, and advises a wider environmental approach to increase soil organic matter, including tree planting and agroforestry, introducing livestock onto arable farms, and longer, more diverse rotations bringing grassland into arable cropping systems.

Lord Melchett said: 'Globally, agricultural soils store an estimated 9.8 billion tonnes of carbon. Managed well, they can reduce greenhouse gas emissions, but managed badly they become a source of emissions.

'There is no question that no or min-till systems can produce positive results in improving soil health and soil quality, but not necessarily in reducing greenhouse gas emissions. On the other hand, despite the use of ploughing on most organic farms, organically-farmed soils have been found to have on average 21pc higher levels of soil organic matter than non-organic soils.

'Conservation tillage should therefore not be relied on as a silver bullet and a much wider environmental approach using proven methods backed by strong scientific evidence, such as agroforestry and organic techniques, is needed if post-Brexit farming policy is to reduce farming emissions.'