Soil tilth is defined as the "physical condition of soil as related to its ease of tillage, fitness as a seedbed, and its impedance to seedling emergence and root penetration." Sustainable agriculture has been defined in Iowa as "the appropriate use of crop and livestock systems and agricultural inputs supporting those activities which maintain economic and social viability while preserving the high productivity and quality of Iowa's land." Thus, it is not possible to discuss sustainable agriculture without considering soil tilth. Development of a sustainable agricultural system requires a viable and stable soil resource, so we will explore linkages between the two concepts.