The spatial aggregation of organic farming in England and its underlying environmental correlates

Given the current debate on the global food crisis, conservation in Europe is expected to shift from maximizing biodiversity at the expense of yield to conserving biodiversity under food production constraints. Organic farming is potentially of great importance for environmentally sustainable farming. Understanding the distribution of organic farms and the environmental, social and cultural correlates is necessary to predict the way in which this may change over time. We collated data from 30 variables describing the topography, climate, soils, farm size/type, human population characteristics and farm business in the English agricultural landscape. Factor analysis reduced these variables to six orthogonal axes, which describe the suitability of land for arable farming, the degree of ruralization (distance to urban centres and population density), the farm size and type, the soil hydrology and texture, and the amount of woodland (forestry). An analysis of the distribution of organic farms showed that they are spatially aggregated at the regional and neighbourhood scales and that their presence in a 10 x 10-km grid square can be predicted from the farm size/type. Analysis of the concentration of organic farms showed that about a third of the variance in their occurrence across the country can be predicted by a statistical model including the six landscape axes and a term to account for spatial aggregation. Synthesis and applications. Our results show that a combination of environmental variables associated with a lower agricultural potential predisposes farmers to convert to organic farming, which further promotes conversion of farmers in the neighbourhood. Organic farming as a 'wildlife friendly' method is more likely to occur in agriculturally less-favoured areas where economic incentives for conversion to organic farming do not need to be high and the loss of production due to conversion will be comparatively small. This suggests that an efficient conservation strategy, which takes the global demand for food into account, would be to promote organic farming as an agri-environment scheme in landscapes that are already rich in organic farms at the expense of those existing high-production landscapes that are not.