Protein availability has shaped human settlement across the globe for millennia

Knowing how many wage and salary workers are employed sometime during the year gives a more accurate portrait of worker earnings and mobility. In 2014, agricultural employers hired over 829,000 unique workers, which suggests that two workers filled the average year-round equivalent job, meaning that the total farm workforce was twice average farm employment. Although the unemployment insurance data do not include the characteristics of farm workers, they do show that most farm workers have only one farm employer during the year, which indicates that California has a very stable agricultural workforce. An earlier study reported almost three workers for each year-round farm job in the 1990s, and a higher share of workers with more than one farm job . Analysis of data for 2007 and 2012 finds that the ratio had dropped to two unique workers for each average agricultural job . The 2014 analysis presented here shows that this two-to-one worker-to-job ratio has remained constant.Agricultural systems are ecosystems that are managed under economic and logistic constraints to meet social needs and interests related to food and fiber production. As such, they are critical to a broad range of issues and interests, from environmental concerns related to conservation and ecosystem services to social concerns related to poverty and justice. While the interested parties vary widely, they agree that agricultural systems throughout that world are under performing in important ways and need to be adapted to better meet a range of goals,square plastic pot such as increased yield and input efficiency, or decrease reliance on inputs and unwanted externalities.

Such a statement would be a suitable introduction for a dissertation that focused on anything from the use efficiency of nitrogenous inputs to the legal details of international trade policies. The implication with such transitions is that the specific focus would be particularly appropriate response to the more general problem, and this is often directly stated. There is nothing necessarily wrong with this approach and it is important to both focus on specific problems and contextualize them within larger issues. However, this habit of quickly jumping from a general concern to a specific response can distract from the fact that there are numerous equally valid but radically different specific responses, and a whole series of response at intermediate scales linking the research specifics with the general context. This dissertation takes a different approach, and the following chapters are not linked by a specific geographic focus or a single highly focused research question, but by a larger epistemological problem facing efforts to bring about change within agricultural systems. Agricultural systems are inherently complex, which means that that they behave in surprising or non-linear ways that are difficult or impossible to predict in the way that an engineered system might be predictable. This is a result of both inherent features, such as emergent processes and transient dynamics, as well as incomplete and uncertain knowledge of these systems. As such, they cannot be treated like engineered systems or reconstituted from reductionist or piecemeal analysis. This complexity in agricultural systems can be investigated as a purely theoretical problem, but—like it or not—the results are often applied to practical concerns, such as management strategies and alternative policies.

This problem then is how to balance complexity and pragmatism to drive adaptation in agricultural systems. This problem is not pursued directly—whatever that might look like—but through three more focused interdisciplinary studies that are practical and pertinent engagements with this philosophical issue. These studies address this epistemological problem within three different study systems and with three different target audiences in mind. The first looks at the interdisciplinary field of development studies and seeks to help academics better understand the semantics of these conversations so that they can better participate in them. The second summarizes the scientific literature on soil organic carbon storage within diverse Mediterranean landscapes to help land managers make carbon-informed decisions. The third investigates alternative management options within a complex and heterogeneous agricultural landscape in semi-arid West Africa to help farmers and rural organizations make more adaptive decisions. The first chapter, which will be published in the Sociology section of Cogent Social Sciences in June 2017, is a study of the semantics of the term “development” within the field of development studies. This emerging field has far-reaching interests related to international relations, social and institutional change, rural poverty, poverty alleviation efforts, and many other interrelated topics. Agricultural systems and adaptive change are dominant themes in this literature, which addresses many perspectives and issues not normally appreciated in the agricultural sciences. The field of development studies explicitly appreciates the complex nature of the relevant questions, and emerged as an academic subject through the recognition that no single discipline to properly tackle the necessary issues alone.

The field also has high practical engagement with these issues, and the participants are often trying to inform policy decisions, influence non-government organizations, or find some other way to effect change. Unfortunately, these efforts to balance complexity and pragmatism are limited by some avoidable semantic confusion. The term “development” is central to this interdisciplinary conversation, but it is used in diverse and highly specific ways among the participating disciplines. Economists are likely to use it to refer to economic growth, politicians might assume it refers to specific policies and deliberate interventions, and anthropologists often relate it to externalities of colonization and globalization. These meanings are well understood within each discipline but there is little shared understanding between them. Careful semantic analysis is not necessary in the former, and perhaps as a result it is not common in the latter. Instead, influential authors in the field are willing to conclude that the term “development” cannot be defined, even though it is used to define the field itself. Most authors have been willing to leave this situation there, perhaps in their hurry to tackle the complexity of the issues and get on with more normative efforts. This chapter applies Confucius’ insight that the “rectification of names” is a necessary first step in an intellectual investigation,25 liter pot and directly investigates this semantic question directly. Using insights from Socrates and Wittgenstein, I survey the development studies literature to produce a descriptive typology of the variety of distinct but related ways the word is used in the field. I then demonstrate the benefit of this typology for interpreting complicated discussions of “development” by conducting a textual analysis of influential texts that propose provocative alternative understandings of “development.” I then do the same for articles from the prominent journal World Development to examine shifts in patterns of use over the last 40 years. In doing so, I am able to document evidence of the maturation of development studies from a conglomerate of multiple distinct disciplines to an increasingly unified field that in the future may be considered a coherent discipline in its own right. The second chapter, which was published in Agroecology and Sustainable Food Systems in 2015, is a literature review of how soil organic carbon levels are affected by changes in land use and land cover, and how these changes can be mitigated by alternative agricultural management practices. These related questions reflect a growing shift towards investigating and responding to climate change and other environmental issues at ecosystem or landscape scales, and to do so by balancing multiple interacting forces. Such systems approaches are in contrast to more reductionist investigations that target specific processes but do not attempt to bring them to bear on each other. For example, the possibility of carbon sequestration through alternative management practices has often been investigated at the field scale and without any historical context. Such analysis can be interesting, but it is not sufficient to understand overall landscape carbon storage patterns or opportunities, or to direct efficient management practices within diverse settings. Such interpretations requires additional analysis, such as comparing the potential effect of alternative practices against the amount of carbon that was originally lost through the conversion of the land into agriculture, or could be recovered through alternative land uses, rather than alternative agricultural management practices.

This particular study was conducted at the request of The Nature Conservancy of California to inform their activities within agricultural landscapes, so is a clear example of the need to balance the complexity of the relevant processes with the pragmatic need to inform management activities. Given the geographic context, The Nature Conservancy was particularly interested in questions of carbon management within Mediterranean landscapes and commercial vineyards. Their request was simply to summarize the relevant literature and develop carbon budget estimates to inform spatial models. Unfortunately, this was not simply a case of insufficient knowledge reaching management practitioners, but also of a research gap within the scientific literature. Despite the substantial interest in carbon storage within managed landscapes, I found a serious dearth in relevant studies on both change in land use/cover and the effects of alternative vineyard practices. There was also a tendency to rely on inappropriate methods, such as shallow sampling depths. This question was therefore not simply a case of the ecological processes being complicated and dynamic, but also dramatically incomplete knowledge of those processes. The initial hope was to perform a meta-analysis to draw quantitative conclusions, but due to the limited availability and often low-quality of relevant published research, I had to settle for a literature review. The general pattern that I found was of dramatic declines in soil carbon with conversion of native Mediterranean land cover types into agriculture, with vineyards often containing the least soil carbon of any land use. Alternative management practices with vineyards could increase the soil organic carbon levels, but it was clear that even the best practices could recover only a fraction of the lost carbon. I concluded this literature review with a critical analysis of certain methodological practices and assumptions, recommendations for research priorities and alternative strategies, and a discussion of the risk of making strong quantitative conclusions or predictions from insufficient and highly variable information. The third and final chapter focuses on the balancing of complexity and pragmatism to inform independent farmer management decisions within rainfed cropping systems in Senegal and The Gambia. These countries form the western edge of the African Sahel, which is the region south of the Sahara desert that gets just enough rainfall to support agriculture. “Sahel” is the Arabic word for “shore,” a reflection of the marginal nature of this region, and it is prone to periodic droughts and famines and often considered ground zero for how climate change is affecting agricultural livelihoods. Accordingly, the Sahel and adjacent semi-arid regions are a major target of international development efforts, which often focus on improving the rainfed cropping systems that are the primary source of food and income for the rural population. The pragmatic need for agricultural adaptation in this region is clear, but the complexity of the local agricultural systems is often overlooked, and as a result these efforts have been far less effective than expected. At first glance, Senegal and The Gambia appear to be relatively homogeneous countries. They are flat, consist largely of sandy and low organic matter soil, and contain a continuous rainfall gradient from around 200 mm/year in the north—just enough for pasture and marginal crop growth—to over 1000 mm/year in the south— enough for thick monsoonal forests. By global standards, the rainfed cropping systems are also fairly homogeneous, with little fertilization or mechanization and low productivity. They look nothing like the highly productive systems of more industrialized countries but, the thinking goes, they should. Most agricultural recommendations in the region, and even the way in which research is done and recommendations are made, are primarily derived not from the local systems but from some more industrial example. Agricultural adaptation is often assumed to be analogous to the adoption of practices from these more productive systems. On second glance, however, there is a high level of spatial and social heterogeneity that is relevant to rural livelihoods and greatly influence the ways in which these systems can change. A great adaptive opportunity for one farmer might be impossible or even maladaptive for their neighbor due to subtle differences that might easily go unnoticed by the most careful researcher. This heterogeneity is due to factors that are known but often overlooked, such as political insecurity, factors that are known but difficult to quantify, such as household purchasing power, and factors that may simply be unknown to researchers, such as farmer preferences.