(“History” 60). In 1954, for the first time in history, there were more tractors on farms than horses or mules to do the work (“Historical” 62). By the mid-1950s, most farms had a tractor, a truck, a self-propelled combine, a 14-foot drill, a 10-foot plow, and a 12-foot cultivator; therefore, with this amount of technology, it took approximately 6 1/2 hours of labor to produce 100 bushels of wheat, or 4 acres (“History” 63). Anhydrous ammonia was becoming an increasingly popular source of nitrogen to increase corn yields in the late 1950s (“History” 64). In 1960, one farmer supplied 25.8 people in the United States (“historical”67). To produce 100 bushels or 3 acres of wheat in 1965 required about 5 hours of labor, a tractor, a 14-foot self-propelled combine, a truck, a 12-foot plow, and a 14-foot seeder ("historical" 68). By the 1970s, no-till agriculture had emerged and was widely used (“History” 71). In the United States, one farmer supported 47.7 people in 1970 (“historical” 72). In 1975, a tractor, truck, 30-foot sweeper, 27-foot seeder, and 22-foot self-propelled combine could produce 3 acres or 100 bushels of wheat with 3 ¾ hours of work. To make 100 bushels of corn, 1 ⅛ acres, with a few trucks, a 12 foot self-propelled combine, a tractor with a 5 btm plow, a 20 foot tandem disc, a seeder and a 20 foot sprayer, it required 3 ⅓ hours of work (“History” 74). In the 1980s, more and more farmers practiced direct seeding or