One of the most persistent agricultural myths is that larger mechanized farms are more efficient and profitable than smaller traditional farms. But larger farms spend more per unit of production because they buy expensive equipment, fertilizer, and pesticides. unlike industrial enterprises in which economies of scale characterize manufacturing, smaller farms can be more efficient--even before accounting for health, environmental, and social costs. A 1989 National Research Council study flatly contradicted the bigger is more efficient myth of American agriculture. "Well-managed alternative farming systems nearly always use less synthetic chemical pesticides, fertilizers, and antibiotics per unit of production than conventional farms. Reduced use of these inputs lowers production costs and lessens agriculture's potential for adverse environmental and health effects without decreasing--and in some cases increasing--per acre crop yields."
Bill McKibben made a similar point in Deep Economy.