the energy requirements for the production of irrigated crops in the southwestern u. s. are presented and discussed. energy requirements for tilling, planting, fertilization, cultivation, pest control and harvesting are presented for cotton, alfalfa, lettuce and barley. the irrigation energy requirement is given for both surface and groundwater supplies using surface and sprinkler irrigation systems. energy requirements are discussed in terms of average crop energy yield per unit of energy input and average crop value per unit of energy. it was concluded that irrigation required most of the energy with groundwater sources, and it was the largest input with surface water supplies and sprinkler irrigation. fertilizer was the second largest input with crops requiring nitrogen. except for hand harvested lettuce, harvesting and hauling required more energy than crop establishment. reduced fertilizer usage, minimum tillage and more efficient harvesting and transport can reduce total energy inputs. however, with groundwater, efficient pumping and water use are the most important energy conservation concerns. 16 refs