Arable Field Margin - Blackstone Farm - Nigel Jones
What are they?
Between the crop and the field boundary, the ‘field margin’ is not just a wasted edge where nothing really grows; in fact, it provides a vital habitat for some of our much-loved species, from grasses and wildflowers, to the birds and insects that feast on their plentiful seeds and nectar.
Where field edges are less productive, some farmers deliberately leave arable field margins. They can take many forms including uncropped wildlife strips; ‘conservation headlands’ which form the outer margin of the crop, but don’t get so many pesticides; and stubble or grassy margins.
Where are they found?
Field margins can be found throughout the UK’s lowlands in both arable and mixed farmland. Cereals account for around 51% of our arable land, and it’s estimated that there are 400,000 km of cereal field edges in the UK. If all these boundaries included a six-metre field margin, over 210,000 hectares of land could be sensitively managed for farmland wildlife.
Why are they important?
Many farmland species have declined over recent years due to agricultural intensification, so arable field margins provide vital havens for these creatures. In the UK Biodiversity Action Plan (BAP), cereal field margins, in particular, are a priority habitat.
More than 150 plants are characteristic of arable land; wildflowers such as shepherd’s needle, corncockle, broadleaved spurge, cornflower, corn buttercup and pheasant’s-eye were once considered as weeds, but have been almost wiped out in the wild.
In turn, wildflowers are important sources of nectar and pollen for bumblebees, wasps and butterflies. Grasshoppers and beetles take cover in the grasses, along with many beneficial predators, such as spiders and ladybirds, which feed on crop pests like aphids.
Field margins can provide refuges for brown hares and small mammals, such as field voles, which attract barn owls and kestrels on the look-out for a tasty meal. They also offer nesting and feeding sites for birds such as corn bunting, skylark, tree sparrow and grey partridge, all of which are identified as priority species in the UK BAP.
Arable field margins also buffer ditches, rivers and streams from agricultural activity and pollution, and provide valuable wildlife corridors, allowing wildlife to move freely between habitats.
Are they threatened?
Following the Second World War, we became much better at exploiting all of our farmland, producing monoculture crops, and removing field boundaries and margins. Further threats to arable field margins include the use of herbicides and pesticides to intensify crop production; increased winter-cropping causing the loss of winter stubble; a reduction in crop rotation including fallow land; and the removal of field boundaries, such as hedges.
Most recently, changes in agricultural policy have caused the loss of set-aside land (where farmers received government payments for leaving land fallow) which is likely to have a big impact on farmland wildlife in the future.
How are The Wildlife Trusts helping?
Across the UK The Wildlife Trusts provide advice and guidance for farmers and landowners on wildlife-friendly ways to manage their land, including the use of field margins. Many Wildlife Trusts help with advice on government schemes, such as the Entry Level and Higher Level Stewardship schemes in England, which provide payments to farmers to put wildlife-friendly measures into action.
We’re involved in a number of projects to benefit farmland we own or manage ourselves. For example, on the banks of the Thames, the Berks, Bucks and Oxon Wildlife Trust (BBOWT) is managing 250 hectares of floodplain meadow for the benefit of all kinds of wildlife, including reverting arable cropland back to flower-rich fields.
What can I do to help?
- Maintain field margins and take part in conservation measures on your farmland.
- Support the work of your local Wildlife Trust for farmland wildlife and become a member or volunteer.
- Support wildlife-friendly farms by purchasing direct from local farms or checking the label of supermarket products for organic or Soil Association labels.
Buy wildlife gardening products from Vine House Farm – 5% of takings go to your local Wildlife Trust.