Agricultural sustainability requires that the individual farm firm be competitive and profitable while simultaneously enhancing environmental quality and the natural resource base upon which the farm firm and agricultural economy depends. The reliance of conventional agriculture systems on purchased inputs external to the firm presents possible challenges to the long-term sustainability of the system. Crop rotation systems are one cropping system alternative that can reduce agriculture's dependence on external inputs through internal nutrient recycling, maintenance of the long-term productivity of the land, and breaking weed and disease cycles. Decision criteria to choose among competing crop rotation systems can include impact on soil quality and...