Energy usage in British agriculture—A review of future prospects

Abstract

The sudden increase in the price of oil in 1973/1974 drew attention to the fact that energy resources are not inexhaustible. Since then fossil fuel consumption has risen and is currently close to the 1973 peak level. While agriculture has become technologically more efficient, it has become less efficient in its use of energy during the last few decades. Agricultural production up to the farm gate utilises less than 4% of national power energy consumption while it provides over 55% of the nation's unprocessed food. However, when the total food processing part of this cycle is taken into account nearly 16% of total national energy consumption is used in the overall production and preparation of food. When the biological and industrial energetics are considered, it is apparent that intensive agricultural production has both a low biological efficiency and a comparatively high usage of energy, apart from ruminant meat production under natural grazing conditions. What is needed is a planned use of resources coupled with a reduction in energy inputs without significantly depressing the high current levels of agricultural productivity. The possibility of achieving this objective is discussed. Reference is made to an earlier review by the same authors in which three potentially different sources of energy—straw, livestock wastes for use as fertilisers and livestock wastes for the production of methane—were examined. This paper discusses in detail glasshouse heating, power station waste heat utilisation and the possible exploitation of wind power. The paper concludes that the future for energy usage in agriculture is full of interesting possibilities requiring continuing R&D inputs. Nevertheless, investment in new energy forms must come from government sources, because of the high capital costs and attendant risks.