Monday, August 31, 2009

The Oil Intensity of Food

Lester R. Brown has posted a guest blog entry to The Oil Drum on The Oil Intensity of Food. The author of Plan B 3.0 provides us a perspective on the American food system which rests on an unstable foundation of massive fossil fuel inputs.

Today we are an oil-based civilization, one that is totally dependent on a resource whose production will soon be falling. Since 1981, the quantity of oil extracted has exceeded new discoveries by an ever-widening margin. In 2008, the world pumped 31 billion barrels of oil but discovered fewer than 9 billion barrels of new oil. World reserves of conventional oil are in a free fall, dropping every year.

This prospect of peaking oil production has direct consequences for world food security, as modern agriculture depends heavily on the use of fossil fuels. Most tractors use gasoline or diesel fuel. Irrigation pumps use diesel fuel, natural gas, or coal-fired electricity. Fertilizer production is also energy-intensive. Natural gas is used to synthesize the basic ammonia building block in nitrogen fertilizers. The mining, manufacture, and international transport of phosphates and potash all depend on oil.

The Energy use and economical analysis of wheat production in Iran: A case study from Ardabil province has details about the energy efficiency of food production. In terms of total energy equivalents the following table summarizes the production of wheat in the study:

Inputs (MJ/ha) - 47,078
  • Human Labour - 317
  • Machinery - 4,574
  • Diesel fuel - 12,267
  • Chemical fertilizers - 14,654
  • Farmyard manure - 4,575
  • Chemicals - 260
  • Water for irrigation - 4,230
  • Seeds - 6,201
Outputs (MJ/ha) - 92,786
  • Grain - 66,368 (4,515 kg)
  • Straw - 26,418 (2,113 kg)

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