The development of sustainable agroecosystems requires bridging traditional disciplinary divisions between human and biophysical sciences. Despite impressive gains in scientific understanding about agroecosystems in recent decades, this ecological knowledge is rarely reflected in local, regional, or global policies and land management decisions. With a global food crisis underway, and soaring costs of the non-renewable resources that support current industrial agricultural production, we are at a critical juncture for managing agricultural landscapes. If agroecological approaches are to be incorporated into policy interventions, research must integrate across ecological, socioeconomic, and political systems. Defining the relevant system boundaries is a central component of ecosystem-based research. Which environmental quality and social factors are considered in interdisciplinary research questions on agricultural sustainability? What geopolitical boundaries do studies span? And, how does agroecological research affect the global policy environment (and vice versa)? One challenge to cross-disciplinary research is that the boundaries of interest for studying ecological systems and social systems can differ. Presenters will share examples of cross-disciplinary agroecological research and policy development from community to landscape scales, and will discuss how the process of defining, or bounding, research problems impacts agricultural sustainability.