Climate change and extinction – the farm that’s showing the way


GUEST POST By Merrick Denton-Thompson

Cholderton, a 1000-hectare estate on the Hampshire/Wiltshire border, participated in DEFRA’s Environmental Land Management Tests and Trials (T&T) to develop a model Land Management Plan based on the exemplary principles adopted by the estate. This plan will assist land managers who are preparing their own management plans for the chalk landscapes of Southern England.

The Cholderton Estate: Sustainable Food Production and Carbon Capture

The estate is run by Henry Edmunds. What sets Cholderton apart is that it is an excellent example of food being produced sustainably. Production targets are set by the disciplines required by the natural carrying capacity of the land.

The estate doesn't apply inorganic nitrogenous fertilizer so there's little nitrate pollution of ground water or greenhouse gas emissions of nitrous oxide a major polluter by the farming industry – 300 times more potent than carbon dioxide as a climate change gas.

Cholderton doesn't use pesticides, and instead focuses efforts on the microbial health of the soil and plant diversity for its biosecurity.

The farm uses a 10-year rotation cycle with a wide variety of pasture-based herb and grass mixes, fixing airborne nitrogen to improve fertility. The combination of a high content of deep rooting herbs and shallow plough for 4 years in 10 has resulted in exceptional levels of residual organic matter averaging out at 9.8 % which equates to 128 tons of carbon per hectare.  This is double the figure achieved by most farms on chalk soils. We have a rich variation in soil types across the country and more research is needed. For many soil types the restrictions created by hard chalk subsoil is not present and potentially the Cholderton approach could generate even higher levels of sequestration across the country. There are many reasons for us to increase soil carbon including increasing the water holding capacity of the land, generating optimum conditions for microbial health, nutrient release, soil creation and natural fertility. Replicating the Cholderton approach across the 5.4 million hectares of arable farmland in England might generate as much as 600 million tons of sequestrated carbon that could be achieved over a number of years. To give some sense of scale it is acknowledged that 468 million tons of carbon dioxide is emitted each year across the whole country.

The results speak for themselves the Wildlife Trust and Plantlife, have declared the farm "one of the richest farmed estates in the country for biodiversity". On top of all this, the farm is resilient, self-sufficient in improving its own fertility - and profitable. These principles have been decades in the making, shaped by Henry Edmund’s scientific analysis of Cholderton's soil, micro-climate, ecosystems and topography.

I believe the principles of farming at Cholderton could, and should, be replicated across the country.

Test and Trials: See for yourself

DEFRA’s T&T programme set out to validate the approach taken by Cholderton by involving Cranfield University on soils, the Wildlife Trust on biodiversity and breaking new ground by valuing the Natural Capital approach.

The test also investigated what advice and guidance was needed to produce these management plans and how the advice should be given. We tested a simple structured document, an IT version of the plan, farm visits and a documentary video.

As part of the T&T 50 farmers spent half a day visiting the estate, just before the harvest earlier this year, and many of them were impressed by what they saw.

Some struggled to believe that the estate achieves such high-quality crops and animals, without using intensive techniques. Some asked about profitability - so Henry Edmunds went out of his way to open his farm accounts to third parties, proving that it's a profitable enterprise.

The Cholderton Test and Trial, in partnership with DEFRA, was submitted for consideration to the Climate Challenge Cup as part of the COP26 Climate Change Conference.  Entrants came from across all industries from the UK and America. Cholderton was one of six award winning finalist announced on the 10th November in the conference.

Cholderton provides a template that thousands of other farms in the UK could copy. The results would be profitable farm systems, delivering secure, sustainably produced food in a countryside teeming with wildlife.