"Sustainable agriculture" has emerged as the most agreed-upon term to synthesize a variety of concepts and perspectives associated with agricultural practices that differ from those of conventional production. Sustainable agriculture requires increased knowledge about and management of ecological processes. In conventional US agricultural practices, ecological processes viewed as necessary for sustainability may be disrupted or altered by large inputs of agricultural chemicals. The sustainable agriculture contains three equally important components: environmental quality and ecological soundness, plant and animal productivity, and socioeconomic viability. The Agroecosystem component of the environmental monitoring and assessment program is developing a systems-Ievel approach to the long-term monitoring of agroecosystem sustainability. Measurements will be made for a suite of indicators at sites selected from a probability sampling frame. A system must be ecologically sustainable or it cannot persist over the long run, and thus cannot be productive and profitable.