Set-aside may not have been the perfect natural habitat, because most of it shifted from field to field in rotation, limiting wildlife's chances of getting a hold, but conservation organisations are distressed at the prospect of it disappearing. Set-aside land has also proved good for game.
"The decline of set-aside is a big worry for us," said Andy Evans, a research biologist with the Royal Society for the Protection of Birds. "It looks like going sooner rather than later."
A study in Devon has shown that in winter, the grey partridge, skylark, linnet and yellowhammer all spend far more time on set-aside land than on autumn-sown cereal fields. It is their habitat of choice, and that is almost certainly because they can find more seed, plant and insect food at that hungry time of year. Such birds used to get much of their winter food from the grain spilt in stubble fields during the harvest.
Such fields have largely disappeared; nowadays they are ploughed soon after the harvest for the planting of the more productive autumn-sown cereals.
Numbers of cirl buntings, which have become extremely rare, are rising and it seems that the numbers of skylarks and linnets might have begun recovering after years of decline.
The advent of mass set-aside is thought to be a cause, perhaps the main one.
Set-aside land sown with grass seems to be particularly good for ground- nesting birds raising their young.
Research by Oxford University and the British Trust for Ornithology has shown that skylarks can raise 40 chicks on 100 hectares of set-aside, and just four on the same area of autumn-sown cereal fields.