This introduction situates key themesfound in papers given at a recent workshop on thechanging material practices, meanings, and regulationof US organic food production. The context is theemergence of an international bio-politics ofagriculture and food and, more particularly in the US,the contradictions of sustainable agriculturemovements catalyzed by the rapid scaling up of organicagriculture from a niche activity to nascentindustry.