I argue in this dissertation, that alternative agriculture offers an epistemological challenge to the conventional approach to food production. To put it succinctly: alternative agriculture is not just about another way to grow; it's about another way to know. I test this hypothesis through an examination of the discourses of three of the more organized networks in U.S. alternative agriculture: biodynamics, organics and ecoagriculture. These networks have supported research, education and outreach activities around alternative agriculture for decades. I focus on people and institutions of the U.S. Midwest. Bruno Latour's actor-networks and his "circulatory" model of the process of "science-making" provide me with a method for analyzing the creation of alternative knowledge by these groups, from their founders to the present. This research relies on writing by Foucault and Latour as well as by agricultural geographers to inform an investigation into the alternative knowledge networks, with a focus on the discourse of soil fertility. The definition and use of science in core texts provides a central thread for the analysis, which sheds light on how different groups claim and defend territories of agricultural knowledge, and construct their arguments about soil in alternative production. I analyze the identification and labeling of material nature, as well as specific technologies developed to do this work. I also examine criteria for, and evaluation of, experts as well as how people build alliances with other scientists and with a larger public, and how they argue for the importance of their scientific contributions. Although these networks all produce arguments for "following nature," they offer radically different perspectives on what nature consists of, and different frameworks and technologies for working with it. I also juxtapose this discourse analysis with an analysis of the public discourse and regulatory language of the federal standard regulating organic production---the Organic Farm Production Act of 1990, controversy around which prevented it from being implemented until 2002. This comparison sheds light on some of the specific challenges presented to mainstream production and conventional agricultural science by alternative agriculture, and on the process by which some alternative ideas become mainstream
