Land as a constraint on food production.

The purpose of this paper is to consider the extent to which the area and quality of land limit the level of food production in the UK. As the population and its disposable income have increased so has the land area devoted to non-agricultural activities. In addition, the area of tree planting has been enlarged to replace the depleted reserves of forest. Simultaneously a great deal of research, development, investment and hard work have been devoted to increasing the productivity of the smaller land area available for food production. The outcome has been a substantial success. Though land area for food production has decreased by 831 ooo hectares (or 3.4% of the total UK area) between 1955 and 1975, output per unit area has increased by approximately 3% linear over the same period. Even taking into account the increase in population and the changes in food demands towards commodities which require more land per unit product, the level of selfsufficiency, for all foods, has increased from about 50% in 1955 to 54% in 1975. For foods which can be produced in the UK the figures are 64% and 68% respectively. There are many indications that the changes which have taken place in the past 30 years in the balance between land and food production in the UK should not be extrapolated into the next 25 years as an indication of the likely balance at the end of the century. On the assumption that land area will continue to be essential as a means of converting solar radiation, through photosynthesis, for food production, an attempt has been made to indicate the constraint which land imposes on the ability of the UK to feed its own population.