Arable weeds and set-aside: a cause for conservation or a cause for concern?

Abstract

Set-aside continues to provoke strong feelings. Responses to a survey of farmers in the summer of 1993 included, 'It's heartbreaking' and 'We shouldn't have to do it' (King 1993). The criticisms reflect outrage at leaving land unproductive for economic motives at a time of perceived world food shortages. However, the economic and political situation which led to the introduction of set-aside is real enough (e.g. Floyd 1992), and set-aside will remain for several years at least. The more positive reactions to set-aside from King's (1993) survey accept this situation and look for benefits; 'Great scheme!', 'Outlaw natural regeneration', 'Natural regeneration seems to provide more scope for wildlife'. Here the attractions were economic, agronomic and environmental respectively.
Despite the feelings of some farmers, agriculture is not solely the business of producing food. There is an increasing market, in terms of grants and support measures, for high quality countryside. The quality can be assessed in terms of amenity, conservation value or environmental benefit such as reductions in nitrate leaching. Experience of the experimental Countryside Premium Scheme shows that high quality countryside can be delivered by longer-term set-aside; some areas have been used to provide feeding areas for geese, while others have been converted to much-appreciated grasslands for public access and enjoyment (Ewins & Roberts 1992). Set-aside can be used for the benefit of both people and wildlife, and farmers' standing in the local community can improve as a result (A. Rutherford, pers. comm.). However, under the present regulations, much set-aside land is now managed on a rotational basis following cereals. Natural regeneration is commonly allowed, giving rise to a flora consisting of a mixture of arable weeds and volunteers (e.g Clarke 1992). Unless cultivated or frequently mown, it is often regarded as being poor quality countryside because of its derelict appearance.
However, untidy stands rich in broad-leaved plants can provide valuable habitats and feeding areas for a wide range of animals, and rare plant species can sometimes thrive on first year set-aside land (Wilson 1992; Firbank et al., 1993). If managed appropriately, rotational set-aside can bring about considerable benefits to wildlife, albeit with potential risks of increasing weed problems for the rest of the cropping rotation. The weedy floras of early set-aside can be regarded as both causes for concern and causes for conservation, and conflicts of interest can arise between good agronomic practice and effective management for wildlife. In this paper, we address the potential benefits of rotational set-aside for conservation, with particular reference to scarce plants. We will then briefly address the fears about increasing weed infestations, before suggesting how the conflicts of interest between conservation and control can be minimised.