Agricultural management systems function in an environmental, social, and economic context. The future context of agriculture in the United States will differ from the present in ways that cannot be predicted with certainty, but will likely challenge the sustainability of current systems. Research on sustainable agricultural systems must consider this uncertainty, and policy decisions must take uncertainty into account. Approaches for dealing with uncertainty include planning for extreme events, adopting policies with multiple benefits, improving predictive capabilities, and educating decision makers and citizens on the implications of future uncertainties. (Copyright (c) 1992, Haworth Press, Inc.)