TY - JOUR T1 - The natural resource limits of U.S. agriculture JF - Journal of Soil and Water Conservation SP - 289 LP - 294 VL - 48 IS - 4 AU - Lawrence W. Libby Y1 - 1993/07/01 UR - http://www.jswconline.org/content/48/4/289.abstract N2 - BY any measure, the U.S. has the world's most productive, most successful agricultural system. The specifics are spelled out ad nauseam in every experiment station annual report, in the introduction to every major address by the Secretary of Agriculture. Productivity increases have come through massive substitutions of physical, Biological, and intellectual capital for land and people in the food production processes. Fewer people produce more food on less land than ever before. And there is little compelling evidence that we are running out of productive innovations. Those macro trends obscure year to year or four-year to four-year output fluctuations associated with U. S. food policy, international competition, trade policies, etc. And while land goes out of agriculture, that which remains is farmed more intensively. National Inter Regional Agricultural Projection model anticipates reduction in pasture and less productive fragile lands in agriculagriculture with continued increases in irrigatied cropland up from 19 million acres in 1945 to 47 million acres in 1987, capturing about 30 percent of profits in food production (6). Fewer farmers does not mean fewer people working in agriculture as the food system … ER -