Energy Use in Agriculture

Abstract

Production of food in the United States today has become an energy-intensive industry. All aspects of farming in the United States now involve use of machinery, all of which, of course, require energy for operation. A much higher percentage of the land under cultivation today for production of food is irrigated than was the case early in the twentieth century. Most of farm irrigation today involves pumping of water, an energy-intensive operation, as opposed to gravity-feed systems used a few decades ago. Until the early to mid-twentieth century, plant nutrient requirements were provided by animal manure, combined with careful crop rotation. Today, the great majority of crop fertilizer requirements are supplied by chemical fertilizers. Production of most chemical fertilizers is very energy intensive. This is particularly true for nitrogen fertilizers containing ammonia. The plant nutrient in which soils are most often deficient, thereby requiring fertilizer application, is nitrogen, and by far the most often-used form of nitrogen is anhydrous ammonia. Production of ammonia is extremely energy intensive.