The economics of establishing field margins and buffer zones of different widths in cereal fields.

Abstract

The yield of winter wheat (Triticum aestivum) was assessed from the edge of the crop to the centre of the field on sixteen fields in 1994 and twenty-four fields in 1995, which were located in Shropshire, Leicestershire and Hampshire. The mean yield at the crop edge (0-1 m) was 5.5 t/ha compared with 9.4 t/ha, showing a yield reduction of 44%. An inverse polynomial regression model provided a good approximation of the relationship between grain yield and distance from the crop edge.
Integration of the area under the curves allowed average yield to be calculated for various distances from the crop edge. Using these values and prices of wheat grain of £50, £70 and £90 per tonne gross margins for the winter wheat crop were calculated. Comparison of these figures with the payments offered for grass margins under the Countryside Stewardship scheme and the Pilot Arable Stewardship scheme, shows that when wheat is below £70/t the payment offered for grass margins that are 2-12 m is greater than the gross margin lost by taking land out of wheat production. When payments for 2-12 m wide grass margins are compared with the loss of income from yield foregone and set-aside payments on a 10 ha field, the farmer's overall income is positive, ranging from £124-£22 respectively.
Strategic use of set-aside adjacent to field boundaries should be considered because of the potential benefits when this area is managed for wildlife, even though the loss of income from having 20m wide set-aside has been calculated as £1220 on a 10 ha field.