The impact of the selective use of pesticides at the edges of cereal crops on wild gamebird stocks in Britain.

Abstract

An experimental reduction of the use of pesticides (herbicides, fungicides and insecticides) on cereal fields was carried out between 1983 and 1987 on an arable farm in Hampshire, southern England and between 1984 and 1987 on farms elsewhere in eastern England. The aim was to establish the extent of the impact of pesticide use on grey partridge chick survival (and to study the effects on subsequent breeding populations) and to develop, by experimentation, a method of enhancing the conservation value of farmland at minimum cost to the farmer.
In each year, the average brood size of the grey partridge was significantly higher on blocks of cereal fields where the crop margin (or headland) was only selectively sprayed with certain pesticides than on fully sprayed blocks of fields. Since the introduction of selectively sprayed headlands on part of the Hampshire study farm, breeding density has increased from 3.7 pairs km² to 11.7 pairs km², a statistically significant increase when compared to previous changes in breeding density on the farm and to changes in breeding density of fully sprayed farmland on neighbouring farms.
These results are discussed in the light of the widespread and dramatic decline of the grey partridge and the benefits of such selectively sprayed or 'conservation headlands' already observed to other forms of farmland wildlife.