ABSTRACT
The social, economic and political factors affecting agriculture should be under the control of man, but whether they are under sensible control is a matter of opinion, leading at times to heated and acrimonious debate. As food is essential for life to survive, it might be thought that the need for the major agricultural products of a given population could be calculated with some confidence. Even a small increase in the amount of money available for expenditure on food can have a similar effect, increasing the demand for out-of-season items which hitherto were only eaten during their season of local production. The threat of starvation in two world wars, when food imports were severely restricted, made governments of countries such as Britain realise that it was imprudent and improvident to allow market forces to jeopardise home food production. The increasing importance of the energy factor has led to attempts to formulate energy balances for food products.
