Cereals, nitrogen and population: an assessment of the global trends.

In the lecture following the award of his Nobel Prize for Peace in 1970 the eminent agronomist Norman Borlaug remarked: 'If you desire peace, cultivate justice but at the same time cultivate the fields to produce more bread'. This is as true now as it was then. This article analyses trends in the relationship between cereal production and nitrogen fertilizer consumption up to the year 2030. It concludes that a doubling of chemical nitrogen consumption over this period is necessary to maintain world cereal production per capita at its present level.