Energy use in agriculture: An overview

Abstract

Humans have found ways to secure their food from the Earth's land, beginning more than a million years ago with the hunter-gatherers. Much of the world's agriculture was-- and still is-- carried out by hand (Pimentel and Pimentel, 1996). Once fossil energy supplies became available about 200 years ago, intensive agricultural production developed. Although contemporary, energy-intensive agricultural systems are highly productive, their sustainability is questionable because: (1) rapid population growth necessitates continued increases in the use of cropland and water resources; (2) fossil energy resources that are essential for supplying fertilizers, pesticides, irrigation, and mechanization are non-renewable; and (3) the agricultural environment is being degraded by both soil erosion of cropland and pasture land and by the pollution of fresh water resources. Now, at the turn of the century, we are faced with meeting the food needs of a rapidly expanding human population. Currently, more than 3 billion people in the world are malnourished due to outright food shortages and poor distribution of some foods (WHO, 1996). In addition, shortages of cropland, fresh water, fossil energy (fertilizers