FIGURE 17.1 Economically active population in agriculture in selected regions of the world 1965–2010 (projected) TABLE 17.4 Arable area per capita, actual and projected in hectares (and in acres)

The greatest single reason why agricultural production has increased so much since the 1940s, in spite of only a limited increase in the cultivated area, has been through the big increase in resource-augmenting inputs, particularly fertilisers. In The Global 2000, Barney (1982) estimates that fertiliser use in the world in tonnes per year was as follows: 18 million between 1951 and 1955,38 million between 1961 and 1965, 80 million between 1971 and 1975, and would be 220 million for the year 2000. In the period 19515 the developed countries used almost 75 per cent of that total, while in the year 2000 they could still be using two-thirds of the much larger total.