One of the greatest challenges facing agriculture for the foreseeable future is to resolve conflicts caused by a growing competition for the services of the soil, water, and other natural resources on which agriculture depends-driven by growing demands for food, fiber, and for nonagricultural services these resources provide. To meet this challenge, research is needed which is integrated across the relevant sciences to better understand and predict the properties of agricultural production systems in all of the dimensions that have come to be represented by the concept of sustainability. If we were to achieve this capability to analyze agriculture as a managed ecosystem, it would be possible to move beyond the current regime of agricultural policies, driven largely by interest-group politics, toward science-based policies that recognize the tradeoffs associated with competing uses of natural resources.