FOSSIL ENERGY USE IN AGRICULTURE - AN INTERNATIONAL COMPARISON

This paper is aimed at assessing the comparative importance bf constra ints in land and labour endowment for energy balance in agriculture, w hen assessed at the level of national crop production systems. The rel ation between output/input energy ratio of agriculture (output: food e nergy in crops; input: commercial energy embodied in technical inputs) , average labour productivity (food energy (in Joules) produced per ho ur of labour allocated to agriculture) and land productivity (food ene rgy (in J) produced per hectare of cropped land) has been studied on a 75-country sample using a cluster analysis procedure. A cross-section equation has been developed, explaining output/input ratio in terms o f intensity of land and labour-food-energy throughputs. The results su ggest that land constraints, with respect to the total population size , rather than labour constraints, tend to be associated with comparati vely higher energy requirements in agricultural production. Therefore, the 'emancipation' of agricultural production from land shortages imp lies two 'biophysical costs.' That is, for the production of the same amount of food, a consistent increase in demographic density implies b oth a larger consumption of fossil energy input and a larger environme ntal impact. (C) 1997 Elsevier Science B.V.