Nutrient Management in Support of Environmental and Agricultural Sustainability

Given that we must farm land in order to eat, the total environmental burden imposed by farming a crop such as winter wheat in the UK appears to as close to the minimum as is possible when production is at its most efficient. The value of the services other than food production, such as flood water buffering, pollination, carbon storage and so on, that land can provide is relatively large compared with the value in reducing environmental burdens from pesticide use, nutrient pollution and greenhouse gas emissions by farming less intensively. More land will need to be brought into cultivation in order to provide the same amount of food if the intensity of farming is reduced but the loss of ecosystem services outweighs the reduction in. Nevertheless, losses of nutrients, especially nitrogen (N), from agriculture are a serious concern and the current cost of the environmental footprint of agriculture is significant compared with the value of the food it produces. This article examines nutrient burdens and analyses the means by which the total environmental burden might be reduced relative to productivity. These include increasing the efficiency of farming, removing constraints to yield, and establishing multiple uses for land at the same time as farming. It concludes that agronomic measures which improve nutrient capture and which obtain more yield per unit area are valuable means to avoid degradation of environmental quality because both nutrient pollution and land consumption can be avoided. Means that appear to offer a reduction of 5-10% in each are suggested.