Understanding the substance of farmer knowledge serves as a first step to conserve this essential knowledge base in practice; however, it is equally critical to document the particularities of farmer expertise in local contexts to provide essential knowledge for other contemporaneous and future generations of farmers, scientists, and policymakers alike. Moving forward, there is therefore a need to elevate the importance and value of farmer knowledge across multiple disciplines such that farmer knowledge is considered “expert” knowledge throughout alternative agriculture . While other studies attempt to integrate the artificial binary between “formal” and “informal,” or “expert” and “non-expert” knowledge and view the two forms of knowledge as complementary , in this paper we maintain that farmer knowledge is scientifically valid, expert knowledge and therefore warrants formal, standalone documentation within the scientific literature . While it is true that the terms “traditional,” “folk,” and/or “indigenous” knowledge are applied in certain contexts, in this paper, the term “local knowledge” is most appropriate , as farmer participants were all white and all either first- or second generation settlers on unceded Patwin-speaking Wintun Nation tribal lands in Yolo County, CA. To frame this paper, we apply Agrawal’s definition of local knowledge as knowledge that is “integrally linked with the lives of people, always produced in dynamic interactions among humans and between humans and nature, and constantly changing.” This definition of local knowledge recognizes the key elements of local knowledge: 1) It is produced by people and among people; 2) It is always produced in relationship with nature; and 3) It is a dynamic process. More broadly defined, local knowledge involves dynamic processes and complex systems of experiences, practices, and skills developed and sustained by people in their environmental and socioeconomic realties . Further, plant growing rack local knowledge may develop even within one or two generations of place-based experience . In the US, there exists a handful of studies documenting rural local knowledge and rancher local knowledge .

Very few studies explicitly examine local knowledge in the context of alternative agricultural or organic systems, referred to as “farmer knowledge” in the literature. This type of knowledge is a subset of local knowledge that enables knowledge holders to farm alternatively in their specifical local contexts. To date, most formal studies on farmer knowledge tend to focus on farmer decision making as it relates to the adoption of new practices . Few studies exist at the intersection of local knowledge, alternative agriculture, and soil management. To consider this gap, we focus this study on a significant epicenter for alternative agriculture in the United States: Yolo County, California, which represents unceded Patwin-speaking Wintun Nation tribal lands. This region in northern California is unique in that it is among the handful of places in the country that emerged as a catalyst and knowledge hub for the organic agriculture movement and where a large concentration of high value, innovative organic production farms continue to thrive today. Due to a unique set of historical and ecological circumstances, the region experienced an influx of organic farmers beginning in the 1970s . During this decade, Yolo County—in combination with Santa Cruz, CA—became a significant node in the organic movement. Its emergence as a significant node was in part due to Yolo County’s proximity to the San Francisco Bay Area and the University of California, Davis—which provided key institutional support—and also partially due to the existence of largely prime agricultural lands combined with a temperate climate ideal for growing year-round. As a result, Yolo County became one of a few of places where regulations for organic production first evolved and experimentation with organic farming first emerged . Following the farm financial crisis of the 1980s, land prices in the County sharply dropped ; this economic window provided an opportunity for a new generation of farmers to insert a more ecologically-minded approach to farming.

Many of these farmers arrived to Yolo County relatively new to farming —often young, educated white urbanites with a desire to farm alternatively to the industrial agribusinesses that had historically dominated the landscape of Yolo County since the early 1900s . When these so-called “back-to-the-land” farmers arrived, many were particularly interested in soil fertility—a conscious effort to avoid “mining the soil” and address ongoing issues with soil degradation in agriculture . While initially these back-to-the-landers lacked historically- and ecologically specific knowledge of the lands they cultivated , over the last three decades or more, it is highly probable that they have individually amassed a wealth of local, place-based knowledge of their specific management contexts and soil landscapes . In this sense, farmer knowledge of soil management presents a particularly salient entry point for further examination in the context of Yolo County specifically. How did these particular farmers address the challenge of soil management in their region? What have they individually and collectively learned about soil management, in theory and in practice? Such questions are particularly important to consider given that—from a pedological and agricultural perspective—soils are heterogenous across landscapes. For example, even at the scale of a single field, differences in micro-environments, management histories, inherent soil characteristics, and time of year can all dramatically influence how a particular field can be most effectively managed. Addressing this challenge in soil management and understanding the nuances of soil management are fundamental to organic systems—where deep place-based knowledge of soil landscapes is the basis for building and sustaining healthy soils on-farm—and more broadly, resilient agriculture. Yet, farmer knowledge of soil management is still generally under-researched, particularly in the United States and particularly among organic farmers.

Though documentation of farmer knowledge of soil management in alternative agriculture exists, most studies focus within the “development” context . Similarly, research on indigenous knowledge of soil is frequently approached from an ethnopedological or traditional ecological knowledge perspective , and lacks focus on production and/or organic agriculture. To date, farmer knowledge of local soil landscapes and related soil management practices remains entirely undocumented in Yolo County. Yet, the unique historical and ecological context makes farmer knowledge of soil health and soil management in this region especially important to document; this knowledge is potentially foundational as organic farmers adapt their farming approaches and management in the face of increasing social, economic, and environmental uncertainties. This research is informed by a Farmer First approach, which recognizes farmers as experts and crucial partners in researching and innovating solutions for resilient, alternative agriculture . The Farmer First approach recognizes multiple knowledge forms and challenges the standard “information transfer” pipeline model that is often applied in research and extension contexts . We used an open-ended, qualitative approach that relied on in-depth and in-person interviews to study farmer knowledge. Such methods are complementary to surveys that use quantitative methods for capturing a large sample of responses . Because they are more open-ended, qualitative approaches allow for more unanticipated directions ; however, indoor vertical garden system as Scoones and Thompson point out, removing local knowledge from its local context and attempting to fit it into the constrictive framework of Western scientific rationality is likely to lead to significant errors in interpretation, assimilation, and application. While interviews are not able to capture the quantity of farmer input that surveys do, in-depth interviews allow researchers to access a deeper knowledge base that has inherent value—despite limitations in scalability and/or transferability—as participants respond in their own words, using their own categorization, and perceived associations . Such in-depth interviews are therefore essential to research on farmer knowledge and local knowledge .In-person interviews were conducted in the winter, between December 2019 – February 2020; three interviews were conducted in December 2020. We used a two-tiered interview process, where we scheduled an initial field visit and then returned for an in-depth, semi-structured interview. The purpose of the preliminary field visit was to help establish rapport and increase the amount and depth of knowledge farmers shared during the semi-structured interviews. Farmers were asked to walk through their farm and talk more generally about their fields, their management practices, and their understanding of the term “soil health.” The field interview also provided an opportunity for open dialogue with farmers regarding management practices and local knowledge . Because local knowledge is often tacit, the field component was beneficial to connect knowledge shared to specific fields and specific practices.

After the initial field visits, all 13 farmers were contacted to participate in a follow up visit to their farm that consisted of a semi-structured interview followed by a brief survey. The semistructured interview is the most standard technique for gathering local knowledge . These in-depth interviews allowed us to ask the same questions of each farmer so that comparisons between interviews could be made. To develop interview questions for the semistructured interviews , we established initial topics such as the farmer’s background, farm history, general farm management and soil management approaches. We consulted with two organic farmers to develop final interview questions. The final format of the semi-structured interviews was designed to encourage deep knowledge sharing. For example, the interview questions were structured such that questions revisited topics to allow interviewees to expand on and deepen their answer with each subsequent version of the question. Certain questions attempted to understand farmer perspectives from multiple angles and avoided scientific jargon or frameworks whenever possible. Most questions promoted open-ended responses to elicit the full range of possible responses from farmers. In the interviews, we posed questions about the history and background of the participant and their farm operation, how participants learned to farm, and to describe this process of learning in their own words, as well as details about their general management approaches. Farmers were encouraged to share specific stories and observations that related to specific questions. Next, we asked a detailed set of questions about their soil management practices, including specific questions about soil quality and soil fertility on their farm. In this context, soil quality focused on ecological aspects of their soil’s ability to perform key functions for their farm operation ; while soil fertility centered on agronomic aspects of their soils’ ability to sustain nutrients necessary for production agriculture . A brief in-person survey that asked a few demographic questions was administered at the end of the semi-structured interviews. Interviews were conducted in person on farms to ensure consistency and to help put farmers at ease. The interviews typically lasted two hours and were recorded with permission from the interviewee. Interviews were transcribed, reviewed for accuracy, and uploaded to NVivo 12, a software tool used to categorize and organize themes systematically based on research questions . Coding is a commonly used qualitative analysis technique that allows researchers to explore, understand, and compare interviews by tracking specific themes . Through structured analysis of the interview transcripts, we identified key themes and constructed a codebook to delineate categories of knowledge. Once initial coding was complete, we reviewed quotations related to each code to assess whether the code was accurate. The final analysis included both quantitative and qualitative assessments of the coded entries. For the quantitative measure, we tallied both the number of coded passages regarding different themes or topics, and the number of farmers who addressed each theme. In addition, we examined the content of the individual coded entries to understand the nature of farmer knowledge and consensus or divergence among farmer responses for each theme. All farmers interviewed mentioned direct experience as being one of the most important modes for understanding their landscape, their farming system, and management practices essential to their farm operation. Farmers described this accumulation of experience as “learning by doing,” being “self-taught,” or learning by “trial and error” . These farmers added that in learning by experience, they made “a lot of mistakes” and/or faced “many failures” but also learned from these mistakes and failures—and importantly, that this cycle was crucial to their chosen learning process. More than half of the farmers interviewed maintained that no guidebook or manual for farming exists; while reading books was viewed as valuable and worked to enhance learning for individual farmers, to farm required knowledge that could only be gained through experience. Moreover, nearly all farmers also explicitly commented on the fact that they have never stopped learning to farm . Overall, farmers learned primarily through personal experience and over time, making connections and larger conclusions from these experiences.