Of the five initial variables, the fraction of land in cropland, the soil Storie index, and the land fraction converted to urban had high positive loading values on PC1. The close relationship between these variables is consistent with other studies that show high rates of urbanization on some of the highest quality cropland in the state . Soil salinity and the fraction of land in the 100‐yr floodplain had high positive loadings on PC2. Figure 2.4 shows the spatial distribution of land use vulnerability throughout California as measured by the sub‐ index. While relatively high land use vulnerability occurs throughout the Central Valley, areas of particular concern are the Sacramento‐San Joaquin Delta, and the corridor between the Sacramento and Fresno. In these areas of rapid change from agricultural to urban land uses, sub‐index values were frequently > 2.5 standard deviations above the mean. In the Delta region, the high vulnerability was largely due to the risks posed by both urbanization and flooding on highly productive agricultural soils. In contrast, a combination of increasing urbanization and high soil salinity were the important drivers of vulnerability further south in the San Joaquin Valley. Conversion of prime farmland to urban uses is essentially a permanent loss of agricultural potential, with many consequences for agricultural livelihoods and society at large. When urban development fragments agricultural land, farmers often lose the benefits associated with being part of an integrated farming economy; for example, sources for inputs, information sources, and processing facilities . Farming activities occurring along the urban edge can raise concerns about noise, odor, dust, and spray drift among new suburban residents, while vandalism of farm fields can cause problems for farmers . Regional and local strategies to preserve farmland and manage urban growth include strengthening agricultural zoning policies,hydroponic gutter acquisition of conservation easements on farmland, establishment of urban growth boundaries, and prioritizing infill development .

Given that greenhouse gas emissions from urban land can be more than 70 times greater per unit area than cropland , policies that preserve agricultural land will also help achieve the mitigation targets set by California’s recent suite of climate policies, namely AB 322 and SB 375.3 While the risks of flooding and soil salinization are not new to California farmers, they are likely to be exacerbated by climate change. Declining snow water storage in the Sierra Nevada is expected to increase the frequency and severity of flooding in the Central Valley . As such, efforts to help regional and district water resource managers develop accurate flood forecasts and flexible reservoir operations will further improve adaptive capacity .More than 3 million acres of irrigated farmland in California have soils with an electrical conductivity above 4 dS m‐1, a standard threshold for the occurrence of agricultural impacts . Of the acreage affected, more than two‐thirds is located in the San Joaquin Valley. In these areas, various irrigation methods can be used to leach salts out of the crop’s rooting zone . But since salts can still accumulate along the margins of the wetted area, growers must often apply water in excess of crop needs to ensure that salts are sufficiently leached . The installation of systems to drain, reuse, and dispose of saline effluent are also options, though high costs and a lack of suitable disposal sites remain important barriers .Results of the PCA for the socioeconomic vulnerability sub‐index indicate that 70.3 percent of the cumulative variance among grid cells is accounted for by retaining three principal components . Seasonal and migrant farm workers, loss of farms, and farm disaster payments all had high positive loadings on PC1, while loss of farm jobs and the social vulnerability index loaded highly on PC2. The commodity concentration was largely independent of these other factors, as indicated by its high positive loading on PC3. Three counties along California’s Central Coast all had socioeconomic sub‐index values greater than 1.5 standard deviations above the mean . The high vulnerability of these counties was due to two main factors: the high rate of disaster payments per unit of cropland; and the large number of seasonal and migrant farm workers per unit of cropland. A closer look at the agriculture in these counties reveals that while each have only a small amount of cropland, the mild coastal climate allows them to devote a large fraction to vegetable and berry crops. Since these tend to be high‐value crops that require more labor, it follows that disaster payments and the number farm workers per unit of cropland area are also higher.

Larger counties such as Monterey, San Joaquin, Imperial, and San Bernardino had moderately high socioeconomic vulnerability due to some of the same factors. In Yuba, Sutter, and Madera counties vulnerability was driven by a combination of high disaster payments and a loss of farm jobs. The main factor influencing the high vulnerability in Mendocino County and the moderately high vulnerability in Napa and Sonoma counties was their high Herfindahl index values, which captured the heavy concentration of wine grape production in this region. While disaster payments are used here as an indicator of vulnerability, the federal programs that provide these payments are generally seen as a way to help farmers cope with risk and strengthen their adaptive capacity. Since many fruit and vegetable crops receive no federal subsidies, disaster payments and crop insurance are among the few remaining options for specialty crop producers . However, as agricultural support programs receive greater scrutiny under tightening state and federal budgets, studies that examine the impact of potential reforms and their effects on vulnerability are needed. In contrast to government programs, the advantage of diversification to new crops, products, markets, or income sources is that farmers have more control over the outcome. But while diversification can help spread risk and facilitate a shift toward new crops should the need arise, concerted efforts to improve knowledge‐sharing among stakeholders will be needed to overcome the risks and trade offs associated with unfamiliar cropping systems and market opportunities .Figure 2.6 provides an illustration of total agricultural vulnerability statewide by integrating the four sub‐indices into one total AVI index. Based on this analysis, moderate vulnerability exists in most of California’s agricultural lands, which suggests that there is a need for all agricultural communities to begin to develop adaptation plans that address the potential impact of changing climate, land use and economic factors. Many local and regional governments are now developing climate action plans that accompany updates to their general plans . To date, these climate action plans have mostly focused on greenhouse gas mitigation, but the results presented here suggest that adaptation should hold an equally important place in local planning activities. The total AVI also suggests that there are several regions of concern that merit careful consideration.

These include the Sacramento‐San Joaquin Delta, the Salinas Valley, the corridor between Merced and Fresno, and the Imperial Valley, which all had a mix of high and very vulnerability. While the sub‐indices discussed above help to highlight the location‐specific factors contributing to these regions’ overall vulnerability, the indexing method used in this study is inherently coarse. Given this limitation, future studies that follow a “place‐based” approach will be needed in order to understand the unique local characteristics, both biophysical and socioeconomic, that may contribute to improved resilience within agricultural communities. The recently completed case study of agricultural adaptation to climate change in Yolo County, summarized in Section 3 below, is an early example of how to integrate these elements .While the AVI presented above represents an early a proof of concept, significant gaps remain in the set of potential variables that could be included in the index. In particular,u planting gutter future iterations of the AVI will need to consider additional variables that more fully assess the vulnerabilities to California’s water resources and livestock systems in a spatially explicit manner. For livestock, studies that evaluate statewide spatial variation in the season length of adequate forage and its links with winter precipitation may be a useful addition . These are but a few of the many types of spatial datasets that might be integrated in to the California AVI. In its current form, the AVI is designed to assess “present” agricultural vulnerability. However, going forward there is potential to modify the AVI so that it can accommodate future projections of climate, land use, and socioeconomic variables. For example, integrating down scaled climate projections into the climate vulnerability sub‐index, or integrating statewide UPlan runs into the land use vulnerability sub‐index, are very feasible next steps . Yet, since many of the biophysical and socioeconomic factors included in the sub‐indices can vary unpredictably over time, and in some cases have not been accurately modeled into future, use of the AVI to examine future scenarios may have inherent limitations. To overcome the potential limits, contributions of expertise and data from a broad range of stakeholders, government agencies, and academic disciplines will no doubt be required.Preservation of agricultural land is a priority in Yolo County, and planning is focused on regional land use guidelines that maintain land in agricultural production and concentrate new development into urban areas. Regions within Yolo County are distinguished by their land forms , proximity to the Sacramento River and Delta , water availability , and the influence of small towns and cities . There is greater prevalence of wine grapes along the river, processing tomatoes in the alluvial plains, and organic fruits and vegetables in an isolated, narrow valley to the north. Flooding along the Sacramento River poses the most significant regional hazard from climate change; water flows will increase by at least 25 percent by 2050 due to a decrease in snow pack in the Sierra Nevada . As for most of California during the past few decades, there has been a trajectory toward less crop diversity, larger farm sizes, but fairly stable markets for commodities . Most commodities are managed with high intensification of agricultural inputs . The number of organic farms, however, is growing. A recent survey showed that many riparian corridors have low scores for soil quality and riparian health , and there is concern about transport of pesticides to the San Francisco Bay delta .

Environmental quality is now receiving more attention with active grower participation in programs from several agencies.Phase I of this case study examined possible effects of increased temperature and decreased precipitation on Yolo County crops . The horticultural “warm‐season” crops in the county will experience more stress than field crops, due to greater environmental sensitivity of their reproductive biology, water content, visual appearance, and flavor quality. New horticultural crops may include “hot‐season’ crops in summer, and “cool‐ season” crops that prefer warmer winters. Expansion of citrus and of heat and drought‐tolerant trees are likely partly because fewer winter chill hours will be difficult for some stone fruits and nuts . Forage production for livestock in upland grasslands may increase with warmer temperatures during the winter rainy season, but field experiments with elevated carbon dioxide do not corroborate this expectation . More nitrogen limitation will likely occur under eCO2 , unless N‐fixing legumes become more abundant. During the past 25 years, crop diversity has decreased across Yolo County , but resilience to extreme events, such as heat waves, may be enhanced in the future by a more diverse crop mix that varies in stress tolerance. Water supply has been considered the most uncertain aspect of climate change for farmers in Yolo County, who rely on groundwater for about 30 to 40 percent of their supply in a normal water year .Discussions with the Yolo County UC Cooperative Extension farm advisors indicate special concern for stripe rust on wheat , insectpests on nuts, medfly, corn earworm on tomato, tomato spotted wilt virus, stem nematode on alfalfa, and earlier activity of perennial weeds such as bindweed . Crop management is subject to change to improve production and environmental quality. Phase I evaluated a set of practices and found that most practices either benefitted GHG mitigation or benefitted adaptation to a changing climate. More comprehensive analysis of these complex relationships is needed.

While this choice can be painted as paying the class in question not to work and thus may face push back from the public or even within government, it avoids the myriad complications that stem from subsidizing production, including surplus crises, fights over price adjustments, and conflicts with international trade agreements. In short, leaving production to the most efficient, while supporting the less competitive via income payments allows policymakers to open up more market share for the most efficient while protecting the uncompetitive from impoverishment. A second critical juncture concerns rules structuring benefits, specifically the imposition of benefit limits. A decision to forego benefit limits is arguably more inclusive as it does not discriminate based on some measure of success or size of operation but is also more expensive. Alternatively, the decision to restrict benefits can be seen as discriminatory, splintering the target group into the privileged and unprivileged while saving costs in the long run. This decision has important consequences for the scope and type of future reform. Despite repeated attempts, a reform that the CAP has never been able to impose due to ardent opposition from a few member states is a benefit limit. As a result, some farmers receive hundreds of thousands of Euros in CAP income payments every year. Policymakers wishing to minimize the costs of support to extent possible will want to impose benefit limits, whether they be yearly or lifetime, at the time the policy is created. Benefit levels can always be extended and expanded, but it is much harder to retrench these policies. By imposing limits early, policymakers can better contain overall costs. In addition, these choices position politicians to make popular reforms rather than unpopular,nft hydroponic and likely unsuccessful reforms . However, it may be quite difficult to get the target’s representative groups and unions to agree to a policy that essentially imposes a two-tier system.

The third critical decision concerns qualification and/or behavior standards and requirements. On the one hand, avoiding or limiting standards and rules increases the odds of compliance and support from the target population. On the other hand, imposing standards and rules early controls costs and makes future reform easier. The CAP has struggled to evolve over time, largely failing to impose even the most basic of standards on payment recipients. Policymakers who decide to manage class decline through a CAP-style income support system must think carefully about what types of standards and requirements make sense and impose them early. For example, two reforms CAP officials have struggled to impose are environmental standards and eligibility rules . Neither of these ideas, that farmers should have to meet basic environmental standards or that one’s primary profession must be agricultural in order to receive aid for those employed in agriculture, is particularly radical, but since no real rules or standards for good environmental practices or eligibility existed when the CAP was created, it has been nearly impossible to impose them in a meaningful way in subsequent reforms. Taken together, these three junctures identify moments when policymakers must think carefully about their decisions for how to manage a declining class because these decisions are sticky, proving hard to reverse, and carry important long-term implications. My dissertation and its core findings speak to a broader question of what happens to declining social classes. By investigating the current status of farmer power, I cast light on how and when the political power of a social class is affected by a decline in numbers. Farmers are not the only class to have experienced a dramatic reduction in its share of the population; the blue-collar industrial working class has shrunk dramatically with the shift to a service sector oriented economy. European governments have buffered workers against the effects of deindustrialization with generous disability and early retirement benefits. In addition, in many countries, unemployment programs for workers were structured to ensure that benefits would not run out. As this brief example illustrates, the framework I have used to examine the decline of Europe’s farmers can also be deployed to examine and explain the decline of other social classes. For both blue-collar workers and farmers, policy took the same path. It started with an effort to preserve the class by subsidizing employment and ultimately ended up with a policy that paid individuals not to work.

The path to this final policy outcome in both cases was long and expensive. The lesson, then, for reformers is move to an income support policy as quickly as possible. While these policies are expensive and often unpopular, costs can be contained and crises avoided if these types of programs are adopted first, and reasonable benefit restrictions are imposed early. In sum, my project is not only about the intricacies of CAP reform, but also about the conditions that permit or forestall EU and welfare state policy reform, the techniques for overcoming resistance to policy change, and ultimately the politics of and strategies for managing social class decline. This body of research beginning with my study of farmers and expanding to other threatened social classes will further clarify the important puzzle of why some groups are able, against all odds, to exercise strength without numbers.The rising prevalence of drought conditions in California and elsewhere has dramatically increased demands on groundwater for irrigation and human consumption.Organic and inorganic contaminants in the water supply are prevalent in many human impacted sites such as agricultural, industrial, and municipal. However, simply measuring known sources of contamination has the potential to miss the complex effects of microbial communities in the soil and groundwater. Diverse microbial communities in subsurface environments including groundwater systems exhibit extraordinary phylogenetic diversity and metabolic complexity that has only recently become apparent using culture-independent sequencing-based analytics. The impact of changes in water chemistry on these aquifer microbial communities, and ultimately on groundwater quality, is unknown. Nitrogen as ammonia and nitrate are among the most ubiquitous groundwater contaminants due to widespread use in agriculture as fertilizers, as unintentional discharge in septage and effluent. While crops absorb much of the applied fertilizers, significant amounts leach to groundwater. In certain regions of California’s Central Valley, over 40% of drinking water aquifers have elevated levels of nitrates. The impact of these nitrogen compounds on environmental and groundwater microbial communities is not well understood, including the secondary effects on human, livestock, and wildlife health, and the potential for naturally occurring microbial populations to mineralize ammonia and nitrate to non-toxic forms. There thus exists an urgent need to understand these processes and how they may interact with remediation strategies to protect the quality of groundwater supplies.

To explore these important issues, we sampled groundwater from three adjacent wells completed at different depths that are part of a long term study on agricultural groundwater. The wells are affected to different degrees by manure, a common source of aqueous agricultural contamination. We subjected these samples to chemical analytics as well as next-generation sequencing, assembly,nft system and genomic analysis. Our genomic analysis revealed a highly diverse microbial community dominated by many new lineages of the Candidate Phyla Radiation and the Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota,Nanohaloarchaea superphyla and new lineages of the Planctomycete phylum with metabolic potential for both bio-remediation of the contamination as well as production of potentially hazardous secondary metabolites.We collected individual samples from each of four sites , the contamination source water as well as three wells. The domestic well water sample was clear and colorless in appearance with no odor. This water is pumped from ~100 m depth and used for human and cow consumption. Cow waste is pumped into the effluent lagoon , which was cloudy and brown in appearance with an apparent odor of ammonia and feces. After settlement of particulates, the lagoon water is used as a fertilizer source for the surrounding corn fields. Monitoring well 5 and monitoring well 6 are located immediately down gradient and upgradient respectively from a corn field receiving lagoon water . These wells are screened from 3 m to 10 m below ground surface . Monitoring well samples were clear and yellowish-green in appearance with a slight organic odor. Depth to the water table for the monitoring wells was 3.4 m bgs, and the wells were sampled at a depth of 4.3 m bgs. A previous hydrologic analysis indicated that MW5 is primarily recharged from the manured corn field, MW6 receives partial recharge from the manured corn field and partial recharge from an adjacent unmanured orchard, and DOM is primarily recharged from the adjacent orchard with slight impact from the manured field.Each water sample was tested for the presence of USDA pathogenic bacteria by inoculating liquid enrichment media and plating on selective nutrient media. The specific pathogens tested for were Salmonella, Enterococcus, Escherichia coli, and E. coli O157. Of these, Enterococcus, Escherichia coli, and E. coli O157 were detected in the LAG sample, but no pathogens were detected in any of the groundwater samples. Previous samplings from these and other similar monitoring wells on dairies did reveal the presence of USDA pathogens. However, it is not known how long these pathogens remain viable in the groundwater, and lagoon water had not recently been applied to the field where the monitoring wells are located. Our failure to detect these pathogens in groundwater suggests that they have a limited residence time.We asked whether the microbial composition of the water samples matched the chemical and culture-based observations. We analyzed the water microbial communities for DOM, LAG, MW5, and MW6 by constructing a whole metagenome library for each water sample and shotgun sequencing to a depth of ~50 million paired end 101 bp reads. We analyzed taxonomic makeup of the samples both by 16S rRNA gene profiling and whole metagenome assembly. First, we used EMIRGE to do reference-guided assembly of 16S ribosomal subunit genes and abundance estimation for each of our shotgun sequencing libraries.

We then assigned taxonomy to the 16S assemblies using the RDP web interface. Second, we assembled all of our reads and binned genomes from the assembled contigs and then assigned taxonomy to the genomic bins using RAPSEARCH to the UniProt UniRef100 database. The two metagenomic approaches we took are in good agreement with each other and with the water chemistry, however, we did not detect any of the cultured pathogens from the surface water by sequencing, suggesting they are rare. The shallow groundwater communities of MW5 and MW6 have similar species composition and are similar to the activated sludge bioreactor communities recently reported by Speth et al , a community sampled from the nitrogen removal stage of sewage wastewater treatment. However, in addition to observing 10 of the 12 phylogenetic groups reported by Speth, we additionally see 13 more in the groundwater. Specifically enriched are prokaryotes from the recently described nano-bacterial Parcubacteria and Microgenomates , nano-archaeal DPANN and ThaumarchaeotaAigarchaeota-Crenarchaeota-Korarchaeota superphyla as well as two distinct clades of Planctomycetes: the OM190 group, and the anammox Brocadiaceae group. Examining the EMIRGE data at abundances over 5%, the Archaea dominate, with the Crenarchaeote, Thermocladium , Woesearchaeota , and Methanomassiliicoccus . The Bacteria include anammox Planctomycetes from the Brocadia group , Acanthopleuribacter , Microgenomates genera , Dehalogenimonas , Parcubacteria genera , and Opitutus . The other major lineages in these samples include many known as nitrifiers, denitrifiers and methylotrophs as well as the heterotrophic eukaryote, Chlorella , at 7.4% and 5.4% respectively. In contrast to the similarities seen between the two shallow groundwater samples, the DOM and LAG samples each have their own distinct communities. The DOM sample is dominated by Domibacillusfollowed by Sphingomonasand Nitrospira . Anammox genomes are more rare in the deep groundwater, matching the trend seen in nitrate concentrations. The surface water is dominated by Rikenella ,which is known from animal feces. Several other likely animal-associated genera are abundant, including Anaerorhabdusand Acholeplasma , as well as a photosynthetic bacterium, Halochromatium . Overall, the taxonomic representation in the water samples matches well with expectations based on the chemical data. We note that several taxa appear unexpectedly in both the DOM and LAG samples, and we suspect these are contaminants in DOM from airborne dust. Specifically, Rikenella, the most dominant member of LAG, is present at 2.9% abundance in DOM. Likewise Anaerorhabdus, Coprobacillus, Halochromatium, and Acholeplasma are abundant at >5% in LAG and ~1% in DOM.