Farmers can maintain this funding by making environmental improvements to their land, particularly that surrounding watercourses, for flood defence and particularly to prevent leaching of agrochemicals: fertilisers and pesticides. There is some consideration given to redressing the loss to wildlife of more than 200,000 hectares. One common practice is to leave field margins uncultivated, or even planting wildlife friendly species.
Four types of field margin are defined by the UK Biodiversity Partnership and the UK Government in Action plan for Cereal field margins.
- A ‘Wildlife Strip’ 6m wide adjacent to a cereal crop, together with a.1 m ‘Sterile Strip’ between the wildlife strip and the crop. The wildlife strip is cultivated once a year but not cropped; the Sterile Strip is maintained so as to prevent aggressive arable weeds spreading into the adjacent cereal crop.
- A ‘Conservation Headland’ either 6m or 12m wide forming the outer margin of the crop and separated from an adjacent field boundary or other vegetation by a.1 m Sterile Strip. The Conservation Headland is cropped with cereals but is managed with reduced inputs of pesticides so as to favour wild arable plants and invertebrates.
- A combined wildlife strip and Conservation Headland, separated by a Sterile Strip and managed as described as above.
- Game crops, stubble or grassland fallows lying between annually cropped land and the field boundary.
According to their figures such land could be very significant, more than compensating for the lost set-aside.
The margins of cereal fields could be managed in ways which would benefit wildlife, without having serious detrimental effects on the remaining cropped area. Estimating average national field size to be 12 ha suggests that there are about 400,000 km of cereal field edge in the UK. If all such boundaries included a 6m managed margin, some 200,000 ha of land would be brought into sensitive management (600,000 ha at 12m width).
It seems to me that this approach could be far more useful than its predecessor: a network of margins could link the whole countryside with designated nature reserves and urban spaces. These are exactly the type of ‘green corridors’ that a landscape ecology approach requires.
However, this idilic concept may be limited by the use of non-organic farming methods on the main crops. What about the traditional meadow required for many wildflower species? Find out more about the benefits of this system for birds and small mammals at the RSPB. Buglife, in association with the UK DEFRA, further discuss of the pros and cons, especially for insects.