a1 Research Associate, Department of Agronomy and Soils, Washington State University, Pullman, WA 99164-6420.
The positive role of biological diversity in enhancing agricultural sustainability is presented in the context of crop rotation. Once common in virtually all farming systems, crop rotations have been simplified or eliminated during the past two decades from farming systems in most industrialized countries. Specialization, production intensification, government commodity programs, and the resulting short-term economic decisions have all had an influence in reducing crop rotation and diversity. Economic and environmental concerns have raised the question of agricultural sustainability in the public arena. We discuss here the role of diversity and crop rotation in relation to the sustainability issue, including matters of agronomic, economic, and environmental benefits, as well as increased efficiency in the use of fossil fuels. Constraints and future directions in the use of crop rotation in modern agriculture are described.