Wiltshire Wildlife Trust's First Biodiversity Gain site at Great Chalfield Farm

Wiltshire Wildlife Trust's First Biodiversity Gain site at Great Chalfield Farm

Big changes are underway across the fields of Great Chalfield Farm. If you’ve walked the footpaths or driven by recently, you may have spotted tractors preparing the ground and hedgerows being shaped—the first visible steps in establishing Wiltshire Wildlife Trust’s very first Biodiversity Net Gain (BNG) site. Set to join the national register this winter, the farm is pioneering how modern agriculture and green finance can join forces, transforming less productive arable land into a thriving wildlife haven while showing landowners practical, nature-friendly ways to diversify their farm businesses.

Tractors, tractors and more tractors…

Anyone driving past or walking around Great Chalfield farm recently may have noticed a lot of activity; tractors hedge cutting, crops being collected in and soils freshly tilled and prepped. There’s a huge amount happening behind the scenes but one of the many exciting changes on the ground is the development of our first Biodiversity Net Gain site, due to go live on the national register this winter. As the farm evolves into a learning hub for farmers and land advisors, it is showcasing how green finance can be woven into a farm business while delivering real gains for nature. At Chalfield we have selected Watgrove and Quarry Field to deliver a range of nature-based solutions and habitat enhancements to generate Biodiversity Units which will be sold to fund the improvements and the long-term management of the habitats. 

Biodiversity Net Gain (BNG) is an approach to building homes, businesses and infrastructure which ensures habitats are left in a measurably better state than they were pre-development. This means that applicable developments in England must restore any biodiversity lost during the building phase and deliver a 10% minimum net gain. BNG became a mandatory requirement for major developments from 12 February 2024, small sites from 2 April 2024 under the Environment Act 2021 and nationally significant infrastructure projects (NSIPs) from 2nd November 2026. 

Martin from C P Awdry preparing the soil for seeding at Quarry Field (Chelsie Fuge, WWT)

Martin from C P Awdry preparing the soil for seeding at Quarry Field (Chelsie Fuge, WWT)

Creating a new species rich grassland mosaic habitat

Quarry Field was an obvious choice to create new permanent habitats instead of continuing with arable production due to its poor yields and difficulty in cultivation – as the name suggests, the soil is largely Cotswold brash and very stoney! This site offers the opportunity to further build-upon the existing corridor of wildlife habitat running east-west across the farm, through the existing woodlands (including county wildlife site Lady’s Coppice), permanent grasslands, dense hedgerows and scrubby margins, surrounding the Chalfield Brook. 

September saw the first steps in reverting this arable field to what will be a species-rich grassland mosaic habitat with scrub roundels, new hedgerow and in the future, a new broadleaved woodland belt along the southern margin of the farm. The final crop of winter wheat came off the field in August, and this was followed by soil preparation (power harrowing) and seeding of the new wild harvested seed mix – huge thanks to Martin of C P Awdry for his support in getting the wildflower seed sown evenly! Over the coming years, we look forward to seeing an abundance of wildflowers such as Field Scabious, Birdsfoot Trefoil, Oxeye Daisy, Common Knapweed, Fairy Flax , Yellow Rattle (and Wild Red Clover established. Fine native meadow grasses will provide the perennial backdrop, including Sweet Vernal-grass, Quaking Grass, Crested Dogstail and Red Fescue . With alkaline soils, we are hoping to create a neutral grassland with many calcareous grassland indicator species. The ambition is for cattle to also be reintroduced to the farm in the coming years to undertake conservation grazing on the site and manage the habitats long term and as part of a grazing strategy more widely.  

Purple, yellow and white wildflowers in tall grass

Wildflowers at Morgan's Hill | Credit: Stephen Davis

If you’d like to know more about Great Chalfield farm or to enquire about our Biodiversity Units, please email naturerecoveryteam@wiltshirewildlife.org