Month: March 2024

The rapid expansion of perennial crop acreage in the past two decades raises concerns about increasing and hardening water demand . As perennial crops have a sizeable initial investment cost, fallowing perennial crops during drought results in greater economic losses than fallowing annual crops. Therefore, GSAs with a high percentage of water use by perennials will likely experience challenges in implementing sustainability management during drought. To minimize economic loss during a severe multiyear drought, a large buffer between the sustainability threshold and actual water level should be maintained for those GSAs, that is, to prepare for a 5-year drought with conditions like 2014s, a groundwater buffer should be aimed with an approximate depth at least five times the values shown in Figure 13c, after accounting for surface water availability and total porosity of the aquifer. The NASA ECOSTRESS mission has an ongoing partnership with USDA, states of California, Florida, and Iowa, and many water districts on using remote sensing evapotranspiration to better inform water resources management . Anderson et al. also find that the improved temporal frequency of ECOSTRESS resulted in improved evapotranspiration estimates and captured peak growing season during which there were no Landsat acquisitions. The mission adopted both PT-JPL and DisALEXI to map evapotranspiration ,growing berries in containers which serves as the basis for the derive L4 products, such as Water Use Efficiency and Evaporative Stress Index . ECOSTRESS also operationally provides the Priestley-Taylor potential evapotranspiration product, which has been demonstrated to be useful for water management agencies for spatial estimates of reference evapotranspiration .

Our model evaluation work suggests that PT-JPL’s evapotranspiration estimates could potentially be further improved over irrigated croplands in agricultural regions with ample evapotranspiration measures over diverse crop types. On the other hand, our spatial estimates show that EToF, which is analogous to ECOSTRESS’s Evaporative Stress Index, varies by crop types and within the Central Valley for the same crop types. Users of the Evaporative Stress Index product over Central Valley should also account for the threshold of water stress dependencies and variability by crop types and other factors such as orchard age and salinity.Although overall our refined evapotranspiration estimation approach here has similar performance to that in more complex models such as DisALEXI , there are still a few factors that can cause errors in our estimates. PT-UCD is a single-source approach. We noticed an overestimation of rice net radiation when the field was flooded, probably due to the challenges posed by heat storage in the water column and the effect of a wet surface, and an underestimation of net radiation over the two AmeriFlux corn sites between every April and July. We also found a larger uncertainty in estimating actual Priestley-Taylor coefficients for corn during the dormant season between January and April. Although evapotranspiration during the nongrowing season accounts for a small fraction of total annual water use, explicit consideration of soil, and plant components of energy balance is expected to improve the accuracy of evapotranspiration estimates. The energy balance closure issue, for example, has been well recognized for the eddy covariance measurements . Baldocchi et al. and Eichelmann et al. , for examplee.g., conducted several analyses at AmeriFlux sites in the Sacramento-San Joaquin Delta and found a closure of 79.3% in an alfalfa site, that is, the ratio of the sum of sensible and latent heat flux over the residual between net radiation and ground heat flux and storage, and 71% in a rice site.

Their study suggests that incomplete storage calculation, rather than underestimation of eddy covariance measurements of fluxes, plays a major role in the lack of energy balance closure for their sites in the Sacramento-San Joaquin Delta. Therefore, we did not perform the correction for eddy covariance measurement sites from our data set. Additional uncertainties can be introduced due to the varying footprint size of the flux towers and the scale mismatch between 30 m ET and tower measurements. We compared the annual evapotranspiration value extracted from a single Landsat pixel collocated with measurement sites and the mean of the values within the surrounding larger areas . The differences in estimates between a 90 × 90 m window and the single pixel were small, with the largest difference of −3.2% occurred at site 18 in 2016. The differences generally increased with a larger footprint, depending on the heterogeneity of the areas, e.g., over a 510 × 510 m window at site 16 in 2016 had the largest mean relative difference of −10.3% from the corresponding center pixel value. Other studies also suggested that a rigorous footprint approximation is needed in future studies to make a fair comparison with field measurements . For example, Kljun et al. ‘s flux footprint model could be implemented at flux tower sites to determine the weight and extent of the pixel window. Compared to those driven by MODIS with daily revisiting , the evapotranspiration estimates derived from Landsat have the benefit of capturing finer spatial details, which is critical for water use assessment over a heterogeneous landscape. Landsat’s 16-days repeating cycle, however, can potentially lead to uncertainty in water use monitoring, especially during the rainy season or during the rapid plant growth and senescence stages. In this study, the uncertainty due to the temporal interpolation of the missing days was found minimal overall, likely because the rainy season coincides with dormancy or the very beginning or ending of the crop growth for the majority of crops in Central Valley due to its Mediterranean climate .

There were situations, for example, right after irrigation or right after harvesting for crops that undergo multiple harvests , when a relatively large error was introduced from the estimates interpolated from observations a few days apart. Future work is also needed to increase the temporal resolution of water use estimate by fuzing Sentinel 2 A&B satellite observations every 5 days with Landsat data. A sophisticated data fusion technique will also improve the accuracy of evapotranspiration monitoring and assessment, by taking advantage of complementary observations from multiple sensors . The robustness of our optimization approach partly relies on the availability of multiple field measurements for diverse crop types across the Central Valley. The automatic workflow developed here allows for a continuous improvement of the optimization accuracy, by taking advantages of the increasingly available crop evapotranspiration measurements with the increased deployment of both research-grade and commercialized surface renewal stations in the state . Although the Priestley-Taylor parameters in this study were tailored for California’s cropland, our data-model integration framework is generalizable to other regions. Once recalibrated and tested with local field data,blueberry container the PT-UCD approach can be applied to monitor daily evapotranspiration and assess water use at various scales over regions besides the Central Valley.Organophosphate pesticides are commonly used insecticides that inhibit acetylcholinesterase enzyme function and have been associated with poorer neurodevelopment in children . Children are particularly susceptible to the adverse impacts of pesticides and those living in agricultural areas may be exposed via multiple pathways, including diet, drinking water, residential use, drift from agricultural applications, and take-home exposures . Assessing exposure to OP pesticides is difficult due to their short biologic half lives and rapid excretion from the body . Dialkylphosphate metabolites, the most commonly used biomarker to characterize OP exposure in epidemiologic studies , have biological half-lives of less than 30 min to >24 h, depending on the parent OP and route of exposure . Measurements of metabolites or parent chemicals in 24-hr urine samples are considered the “gold standard” for assessing daily exposure to pesticides and other environmental chemicals that are excreted in urine . However, factors such as cost and participant burden make it difficult to collect 24-hr samples . While collection of spot urine samples is a convenient alternative, research suggests that analysis of biomarkers with short half-lives, including DAPs, in spot samples may result in exposure misclassification due to higher inter- and intra-individual variability . First morning void urine samples may reduce exposure misclassification, as they are more concentrated and reflect a longer period of accumulation . Few studies have assessed how well either random spot or FMV urine samples approximate internal pesticide dose estimated from 24-hr samples, information that is critical for risk assessment and pesticide regulation.

Estimating dose based on metabolite concentrations from spot samples also requires an accurate measure of urinary dilution and total daily urinary output volume . In adults, 24-hr urinary metabolite excretion has been estimated from spot urine samples by adjusting for creatinine excretion as an index of total daily urinary output volume . However, few studies have evaluated the validity of this approach in children. Due to likely differences in children’s urinary creatinine excretion from factors including age, sex, muscle mass, body mass index , diet, and fluid intake , adjusting for creatinine to estimate toxicant doses in children may introduce unknown sources of variability . Although not used as widely as creatinine correction, some evidence suggests that adjusting for specific gravity may be a more robust method to account for urinary output among children . The US Environmental Protection Agency is mandated by the 1996 Food Quality Protection Act to review and establish health-based standards for pesticide residues in foods and examine the cumulative health effects of exposure to mixtures of pesticides that share a common mechanism of toxicity, with prioritization of pesticides that may pose the greatest risk, such as OPs . The U.S. EPA has selected the Relative Potency Factor method to conduct hazard and dose-response assessments. RPFs are calculated as the ratio of the toxic potency of a given chemical, determined by the oral benchmark dose10 value based on a 10% brain cholinesterase inhibition, to that of an index chemical. Individual OP doses derived from index chemical toxicity equivalent doses can be summed to create cumulative OP dose equivalents . In this study, we measured DAP metabolites in spot and 24-hr void urine samples collected from 25 preschool-aged children over 7 consecutive days. The objective of this analysis was to evaluate the validity of using volume- and creatinine-adjusted FMV and non-FMV spot urine samples to estimate total 24-hr OP dose in children according to the 2006 US EPA Organophosphorus Cumulative Risk Assessment guidelines. The results of these analyses have implications for policy and risk assessments and could serve as a case study for other non-persistent toxicants measured in urine. Subject recruitment and procedures have been described previously . Briefly, we enrolled a convenience sample of 25 children recruited from clinics serving low-income families in the Salinas Valley, California. Eligible children were 3–6 years old, in good health with no history of diabetes or renal disease, toilet trained, and free of enuresis, and had English- or Spanish-speaking mothers who were ≥ 18 years old. Sampling occurred in March and April 2004. The University of California at Berkeley Committee for the Protection of Human Subjects approved all study procedures and parents provided written informed consent. Each family participated in the study over 7 consecutive days. On the first day, study staff measured the participating child’s height and weight, provided the supplies needed to collect urine samples, including specimen trays and jars, gloves, collection jars with blank labels, a small refrigerator, and two 24-hr sampling record forms, and instructed the parents and child on how to collect, record, and store samples. Urine voids were collected either directly into a collection jar or into a sterile pre-cleaned specimen tray placed over the toilet, which was then transferred by parents into the collection jar. Fig. 1 shows the timing of study activities. On spot-sampling days , families collected a single void at their convenience, recording the time of collection on the jar labels and identifying the sample as an FMV or non-FMV spot sample. On 24-hr sampling days , families were instructed to collect all urine voids from the 24-hr period as separate specimens, including the child’s FMV, all daytime and evening spot voids, and the FMV of the following day , if it occurred within the 24-hr sampling period. Participants were instructed to record the timing of all voids, including missed voids, on the 24-hr sampling record form. We limited the current analyses to samples collected on 24-hr sampling days .

Accurate and high resolution albedo data is important for modeling surface melt water runoff on the ice sheet. Contributors to the project include UCLA doctoral students Matthew Cooper and Lincoln Pitcher, UCLA postdoctoral researcher Kang Yang, Rutgers University doctoral student Sasha Leidman and Aberystwyth University doctoral student Johnny Ryan .Researchers at UC Berkeley, including professor Sally Thompson’s group in the Department of Civil and Environmental Engineering, are using UAS as a novel thermal sensing platform. Working with robotics experts at the University of Nebraska, Lincoln, the team tested an unmanned system capable of lowering a temperature sensor into a water body to record temperature measurements throughout the column of water — which is useful in, for instance, identifying habitat zones for aquatic species. Initial field experiments that compared in situ temperature measurements with those made from the UAS platform indicate that UAS may support improved high-resolution 3-D thermal mapping of water bodies in a manageable time frame sufficient to resolve diurnal variations . More recent work has confirmed the viability of mapping thermal refugia for cold-water fish species from this platform.UC Berkeley professor Todd Dawson and his redwood science group are using UAS-mounted multi-spectral cameras to create 3-D maps of giant sequoias — trunks, branches and foliage — at higher resolution and with far less labor than was previously possible. The maps were developed through a partnership with Parrot Inc. The company builds the cameras and UAS used in the research,raspberries for containers and partners to manage the software, Pix4D, that was specially designed to analyze the images.

Knowing the total leaf area and above ground biomass of a tree and the structure of its canopy, for instance, allows researchers to calculate daily carbon dioxide and water uptake — important variables in assessing the interactions between trees, soil and atmosphere as the climate changes. A high-resolution map also yields information about a tree’s influences on its immediate environment — how much leaf litter falls to the forest floor, for instance, and to what degree shade from the canopy influences the microclimate around the tree, or the habitats in it. Another application: A precise map of a tree also provides a good estimate of how much carbon is stored in it as woody biomass. This information, in turn, can be combined with information from coarser methods of forest mapping, such as LIDAR, to improve estimates of the carbon stored in a large forested area. Mapping every tree in a forest at a high level of detail isn’t practical. But such maps of a sample of trees can provide good correlations between carbon mass and a variable like tree height, which LIDAR can measure to a high degree of accuracy — yielding a better estimate of the total amount of carbon in the forest.The forests of California are threatened by drought and disturbance. Bark beetle infestations in the state’s coniferous forests are a particularly large concern considering recent drought conditions, the threat of potential forest fires, and climate change. There is a need for both better methods for early detection of beetle infestation, and for visualization tools to help make the case for investments in suppression . High spatial resolution multi-spectral UAS imagery and 3-D data products have proven to be effective for monitoring spectral and structural dynamics of beetle-infested conifers across a variety of ecosystems . Sean Hogan of the UC ANR IGIS program is testing the use of machine learning algorithms applied to UAS imagery to efficiently classify early beetle infestations of ponderosa pines in California’s Sierra Nevada foothills.

Preliminary results indicate that even imagery from a basic GoPro RGB camera can be used to accurately detect bark beetle–induced stress in these trees. Over 34.1 million of California’s 101 million acres are classified as grazed rangelands . The cattle industry contributes significantly to the state’s economy, and the proper management of these rangelands is important for many reasons, including forage production, preservation of natural habitats and the maintenance of downstream water quality. High-quality, timely information on rangeland conditions can guide management decisions, such as when, where and how intensively to graze livestock. UAS enable high-resolution aerial imagery of rangelands to be collected at much greater speed and lower cost than was previously possible. Translating that imagery into information that is useful to range managers, however, remains a challenge. A UC ANR team — including GIS and remote sensing academic coordinator Sean Hogan, UC Davis–based rangeland and restoration specialists Leslie Roche, Elise Gornish and Kenneth Tate, assistant specialist Danny Eastburn and Yolo County livestock and natural resources advisor Morgan Doran — is working on this problem from several angles at research sites in Napa County’s Vaca Mountains, and in Lassen and Modoc counties. Every year, the U.S. government authorizes the U.S. Department of Agriculture to spend tens of billions of taxpayer dollars to support various agricultural and nutrition programs. Two in particular provoke both ire and unqualified support among elected representatives and other observers: the Food Stamp Program , which is operated by the Food and Nutrition Service , and the commodity support program, which is operated by the Farm Services Agency . This is partly due to the fact that the amounts spent are significant, but also because the potential impacts of these programs are questionable and extremely difficult to evaluate.

The Food Stamp Program is designed to augment the food budgets of qualified recipients, allowing them to purchase more food; the commodity support program ensures that commodity growers receive no less than a certain minimum price for their crops,even though market prices often fall significantly below that “price floor.” U.S. citizens and some permanent resident aliens are qualified to participate in the FSP if they meet the following criteria: a gross monthly income below 130% of the federal poverty level, and a net monthly income below 100% of the federal poverty level ; less than $2,000 in “countable resources,” such as a bank account; the ability to meet work requirements for able-bodied adults; and the ability to provide a Social Security number for all household members. In 2003, the USDA distributed a total of $21.4 billion in food stamp benefits to a monthly average of 9.2 million low-income households; each received an average of $195 per month . Although the food stamp program has been shown to marginally increase the quantity of food consumed by participants, a review of the dietary impacts of U.S. food assistance programs found that “there is no convincing body of evidence that [the FSP] improves the overall quality of the recipients’ diet, although there is some indication that it has increased the intake of some nutrients” . While the correlation between income level and fruit and vegetable intake has not been examined,blueberries in pots the proportion of consumers who eat at least five servings of fruits and vegetables daily is lower among black than white Americans; likewise, those with less than a high school education consume fewer servings than college graduates . Essentially all Americans, and not just food stamp recipients, would benefit from purchasing and consuming more healthful food products. Increasing the purchasing power of low-income Americans, however, is of particular importance due to the fact that calories are most cheaply available in the form of added fats and sugars, while nutrient dense foods are often significantly more expensive by comparison . Besides not improving participants’ dietary quality, the food stamp program also doesn’t serve those eligible to receive benefits particularly well: in 2003, only 61% of those eligible nationwide participated in the program, and in California only 39% of those eligible participated . Low participation rates represent, in the case of California alone, between $650 million and $1.49 billion in lost federal dollars annually . There are several explanations for these participation rates. Potential food stamp recipients often lack knowledge about eligibility criteria. In addition, the application process is notoriously difficult and dehumanizing, and the benefits are often perceived as not being worth the hassle. There is also persistent, and often well-founded, fear among immigrant communities that undocumented family members will be exposed to the U.S. Immigration and Naturalization Service by the application process for eligible individuals, such as U.S.- born children. California’s large immigrant community is an important factor contributing to the state’s low food stamp participation rate.Direct commodity support payments are subsidies paid directly by the USDA-FSA to growers of crops such as corn, wheat, cotton, soybeans and rice to offset low prices in the marketplace. These price supports do not in all likelihood significantly affect the retail price of food products, because only a small portion of that price is attributable to the cost of subsidized ingredients.

For example, the cost of high-fructose corn syrup in Coca-Cola or of corn in a box of Corn Chex represents only about 1% or less of the retail price. However, subsidies depress commodity market prices by raising production levels above demand. By keeping commodity prices artificially low, price supports also encourage the use of commodities in processed foods and as animal feed. Because subsidy payments are directly linked to farm production levels and total farm revenues, the program also encourages overproduction . The program is popular among large-scale commodity growers, who can receive millions of dollars each year, and legislators eager to show support for American farmers. It was therefore surprising to many that in early 2005 President Bush proposed placing a cap on commodity support payments of $250,000 per grower. With the recent defeat of the Grassley-Dorgan amendment in the Senate, which would have established a $250,000 cap on payments, whether that cap will be established will have to wait until the debate on the 2007 Farm Bill begins in earnest . Direct commodity payments are enormous and highly concentrated among the largest and most profitable growers. For example, $107.3 billion was paid out between 1995 and 2003, with 87% of the $11.5 billion spent in 2003 going to the top 20% of recipients . Agricultural production in California is skewed heavily toward specialty crops such as fruits, vegetables and nuts, which do not qualify to receive direct payments. As a result, fewer California growers are eligible to receive commodity subsidies. In 2003, close to 20% did — mostly growers of rice, cotton and wheat; they received roughly 6%, or $672 million, of the U.S. total commodity payments in a similarly concentrated fashion .The food stamp and commodity support programs illustrate that U.S. agricultural and nutrition policies are not specifically designed to promote health or good eating habits. A considerable proportion of commodity payments, for example, is directed to crops that are used primarily to produce calories in the form of added fats or sugars or as feed for livestock. What’s more, the bulk of these payments goes to very large growers of commodities that are overproduced to such an extent that subsidies are necessary to offset low market prices. Similarly, the food stamp program supplements the incomes of millions of low-income Americans so that they can afford to purchase an adequate amount of calories, but does very little to influence the nutritional quality of their diets. Unhealthful diets and inadequate fruit and vegetable intakes are the norm among most Americans, and diet-related chronic diseases such as diabetes, heart disease and obesity disproportionately affect low-income Americans. Making healthful foods more widely available and less expensive to consumers would help bring agriculture and nutrition policies into accord with public health goals, and would be good public policy . USDA Economic Research Service researchers recently highlighted the potential “unintended consequences” of policies to combat obesity — such as listing the number of calories on menus at fast-food restaurants or levying taxes on snack foods — and concluded that such policies would in all likelihood not cause consumers to choose healthier foods . These researchers also examined the relative importance of economic and behavioral factors in influencing fruit and vegetable choices . Research has demonstrated that cost significantly influences consumer food choices, especially among low-income consumers, and that retail price reductions are an effective method to increase the purchase of more healthful foods .There is no question that the food stamp and commodity support programs would distribute payments quite differently if the goals of both were explicitly to promote better eating habits among U.S. consumers. Increasing the level of benefits or expanding food stamp eligibility criteria is always a contentious and politically difficult issue.

The confluence of higher amounts of C and NO3 – moving into a reduced zone could be the reason that the matrix surrounding the preferential flow channel has higher denitrification rates, while the regions further away from the preferential flow channel have lower amounts of microbially available C and NO3 – . In contrast, residence times are too short in the channel to allow for reducing conditions to develop. The ability of the entire vadose zone to denitrify would depend on the overall surface area of preferential flow paths to the rest of the surrounding matrix in the zone of flooding. Overall, we find that low permeability zones alone or embedded within high flow zones demonstrate highest denitrification rates across all soil profiles.Because the ERT column more closely approximates the heterogenity of our agricultural field site, we use this column to demonstrate the impact of hydraulic loading and application frequency on nitrogen fate and dynamics. Simulated profiles of liquid saturation, NO3 – , NO3 – :Cland acetate for the simplified ERT stratigraphy for scenarios S2 and S3 are shown in Figure 9 and A3. It is interesting to note that AgMAR ponding under scenarios S2 and S3 resulted in fully saturated conditions to persist within the root zone only. In comparison, the 68 cm all-at-once application for scenario S1 resulted in fully saturated conditions to occur at even greater depths of 235 cm-bgs . This resulted in the NO3 – front moving deeper into the subsurface to depths of 450 cm-bgs under S1 compared to 150 cm-bgs for scenarios S2 and S3 . Much lower concentrations of NO3 – were found at 450 cm-bgs in scenarios S2 and S3 compared to S1 .

Thus,large pots plastic larger amounts of water applied all-at-once led to NO3 – being transported faster and deeper into the profile. Surprisingly, model results indicate 37% of NO3 – was denitrified with scenario S1, while 34% and 32% of NO3 – was denitrified in scenarios S2 and S3, respectively. For scenarios S2 and S3, denitrification was estimated to occur only within the root zone. This was confirmed by NO3 – :Clratio that did not show any reduction with depth for these scenarios. A reason for this could be that acetate was not estimated to occur below the root zone, preventing electron donors from reaching greater depths for denitrification to occur. In contrast, model results for S1 indicate that acetate was leached down to 235 cm-bgs below the limiting layer. Overall, model results indicate that NO3 – did not move as fast or as deep in scenarios S2 or S3; however, the ability of the vadose zone to denitrify was reduced when the hydraulic loading was decreased. The main reason for this was that breaking the application into smaller hydraulic loadings resulted in O2concentrations to recover to background atmospheric conditions faster than the larger all at-once application in scenario S1. In fact, the O2 concentration differed slightly between S2 and S3. Because O2 inhibits denitrification, we conclude that these conditions resulted in the different denitrification capacity across application frequency and duration. In summary, we find that larger amounts of water applied all-at-once increased the denitrification capacity of the vadose zone while incremental application of water did not. However, NO3 – movement to deeper depths was slower under S2 and S3.Because initial saturation conditions impact nitrogen leaching, we also simulated the impact of wetter antecedent moisture with 15% higher saturation levels than the base case simulation for the ERT profile. Simulated profiles of liquid saturation, NO3 – , NO3 – :Cland acetate for the simplified ERT stratigraphy under wetter conditions are shown in Figure 10. Model results demonstrate that the water front moved faster and deeper into the soil profile under initially wetter conditions for all three scenarios.

Within the shallow vadose zone , across AgMAR scenarios, O2 concentrations were similar initially, but began differing at early simulated times, with lower O2 under wetter antecedent moisture conditions than with the base-case simulation. In addition, both oxygen and nitrate concentrations showed significant spatial variation across the modeled column. Notably, nitrate concentrations were 166% higher in the preferential flow channel compared to the sandy loam matrix under wetter conditions, while only 161% difference was observed under the base case simulation . Nitrate movement followed a pattern similar to water flow, with NO3 – reaching greater depths with the wetter antecedent moisture conditions. Under S1, however, at 150 cm-bgs, NO3 – decreased more quickly under the wetter antecedent moisture conditions due to biochemical reduction of NO3 – , as evidenced by the decrease in NO3 – :Clratio, as well as by dilution of the incoming floodwater. In the wetter antecedent moisture conditions, 39%, 31%, and 30% of NO3 – was denitrified under S1, S2, and S3, respectively. For S1, where water was applied all at once, more denitrification occurred in the wetter antecedent moisture conditions, however, the same was not true of S2 and S3 where water applications were broken up over time. This could be due to the hysteresis effect of subsequent applications of water occurring at higher initial moisture contents, allowing the NO3 – to move faster and deeper into the profile without the longer residence times needed for denitrification to occur. Thus, wetter antecedent moisture conditions prime the system for increased denitrification capacity when water is applied all at once and sufficient reducing conditions are reached, however, this is counteracted by faster movement of NO3 – into the vadose zone. Simluations from our study demonstrate that low-permeability zones such as silt loams allow for reducing conditions to develop, thereby leading to higher denitrification in these sediments as compared to high permeability zones such as sandy loams. In fact, the homogenous silt loam profile reported the maximum amount of denitrification occurring across all five stratigraphic configurations .

Furthermore, the presence of a silt loam channel in a dominant sandy loam column increased the capacity of the column to denitrify by 2%. Conversely, adding a sandy loam channel into a silt loam matrix decreased the capacity of the column to denitrify by 2%. These relatively simple heterogeneities exemplify how hot spots in the vadose zone can have a small but accumulating effect on denitrification capacity . Note that differences in denitrification capacity maybe much greater than reported here because of increased complexity and heterogeneity of actual field sites when compared to our simplified modeling domains. Another observation of interest for silty loams is the prominence of chemolithoautotrophic reactions and Fe cycling observed in these sediments. In comparison, sandy loam sediments showed persistence and transport of NO3 – to greater depths. A reason for this is that oxygen concentration was much more dynamic in sandy loams, rebounding to oxic conditions more readily than in silt loams, even deep into the vadose zone . Dutta et al. found similar re-aeration patterns in a 1 m column experiment in a sand dominated soil,square planter pots with re-aeration occurring quickly once drying commenced. Even with the presence of a limiting layer, defined by lower pore gas velocities and higher carbon concentration, a sandy loam channel acted as a conduit of O2 into the deep vadose zone maintaining a relatively oxic state and thus decreasing the ability of the vadose zone to denitrify. In systems with higher DOC loadings to the subsurface, oxygen consumption may proceed at higher rates creating sub-oxic conditions in the recharge water and more readily create reducing conditions favorable to denitrification in the subsurface . We note here that microbial growth, which was not modeled in this study, could also affect the rates of O2 consumption and re-aeration, which could lead to underestimation of O2 consumption . Overall, denitrification capacity across different lithologies was shown to depend on the tight coupling between transport, biotic reactions as well as the cycling of Fe and S through chemolithoautotrophic pathways. Under large hydraulic loadings , overall denitrification was estimated to be the greatest as compared to the lower hydraulic loading scenarios . The main reason for the higher denitrification capacity was the significant decline in O2 concentration estimated for this scenario, whereas such conditions could not be maintained below one meter with lower hydraulic loadings under scenarios S2 and S3. However, nitrate was also transported deeper into the column under S1 as compared to S2 or S3. Tomasek et al. found the reverse in a floodplain setting, where intermittent indundation with flood water, comparable to our S2 and S3 contexts, resulted in higher rates of denitrification in the zone that was always inundated, due to priming of the microbial community and pulse releases of substrates and electron donors. Future studies examining the impact of AgMAR on denitrification should include processes such as mineralization to see if the same behavior would be observed. It seems that there may exist a threshold hydraulic loading and frequency of application that could result in anoxic conditions and therefore promote denitrification within the vadose zone for different stratigraphic configurations, although this was not further explored in this study.

In another study, Schmidt et al. found a threshold infiltration rate of 0.7 m d-1 for a three hectare recharge pond located in the Pajaro Valley of central coastal California, such that no denitrification occurred when this threshold was reached. For our simulations, we used a fixed, average infiltration rate of 0.17 cm hr-1 for our all-at-once and incremental AgMAR scenarios, however, application rates can be expected to be more varied under natural field settings. Our results further indicate that the all-at-once higher hydraulic loading, in addition to causing increased levels of saturation and decrease in O2, resulted in leaching of DOC to greater depths in comparison to lower, incremental hydraulic loading scenarios . Akhavan et al. 2013 found similar results for an infiltration basin wherein 1.4% higher DOC levels were reported at depths down to 4 m when hydraulic loading was increased. Because organic carbon is typically limited to top 1 m in soils , leached DOC that has not been microbially processed could be an important source of electron donors for denitrification at depth. Systems that are already rich in DOC within the subsurface are likely to be more effective in denitrifying, and thus attenuating, NO3 – , such as floodplains, reactive barriers in MAR settings, or potentially, organically managed agroecosystems .. This finding can also be exploited in agricultural soils by using cover crop and other management practices that increase soluble carbon at depth and therefore remove residual N from the vadose zone . While lower denitrification capacity was estimated for scenarios S2 and S3, an advantage of incremental application was that NO3 – concentration was not transported to greater depths. Thus, higher NO3 – concentration was confined to the root zone. If NO3 – under these scenarios stays closer to the surface, where microbial biomass is higher, and where roots, especially in deep rooted perennial systems such as almonds, can access it, it could ultimately lead to less NO3 – lost to groundwater. While there is potential for redistribution of this NO3 – via wetting and drying cycles, future modeling studies should explore multi-year AgMAR management strategies combined with root dynamics to understand N cycling and loading to groundwater under long-term AgMAR. Simulation results indicate that wetter antecedent moisture conditions promote water and NO3 – to move deeper into the domain compared to the drier base case simulation. This finding has been noted previously in the literature, however, disagreement exists on the magnitude and extent to which antecedent moisture conditions affect water and solute movement and is highly dependent on vadose zone characteristics. For example, in systems dominated by macropore flow, higher antecedent soil moisture increased the depth to which water and solutes were transported . In a soil with textural contrast, where hydraulic conductivity between the topsoil and subsoil decreases sharply, drier antecedent moisture conditions caused water to move faster and deeper into the profile compared to wetter antecedent moisture conditions . In our system, where a low-permeability layer lies above a high permeability layer , the reverse trend was observed. Thus, a tight coupling of stratigraphic heterogeneity and antecedent moisture conditions interact to affect both NO3 – transport and cycling in the vadose zone, which should be considered while designing AgMAR management strategies to reduce NO3 – contamination of groundwater. Furthermore, dry and wet cycles affect other aspects of the N cycle that were not included in this study .

The heart of new agricultural paradigms for a hotter and more populous world must be systems that close the loop of nutrient flows from microorganisms and plants to animals and back, powered and irrigated as much as possible by sunlight and seawater. This has the potential to decrease the land, energy, and freshwater demands of agriculture, while at the same time ameliorating the pollution currently associated with agricultural chemicals and animal waste. The design and large scale implementation of farms based on nontraditional species in arid places will undoubtedly pose new research, engineering, monitoring, and regulatory challenges, with respect to food safety and ecological impacts as well as control of pests and pathogens. But if we are to resume progress toward eliminating hunger, we must scale up and further build on the innovative approaches already under development, and we must do so immediately.The Colorado potato beetle, Leptinotarsa decemlineata Say 1824 , is widely considered one of the world’s most successful globally-invasive insect herbivores, with costs of ongoing management reaching tens of millions of dollars annually and projected costs if unmanaged reaching billions of dollars. This beetle was first identified as a pest in 1859 in the Midwestern United States, after it expanded from its native host plant, Solanum rostratum , onto potato . As testimony to the difficulty in controlling L. decemlineata, the species has the dubious honor of starting the pesticide industry, when Paris Green acetoarsenite was first applied to control it in the United States in 1864 . Leptinotarsa decemlineata is now widely recognized for its ability to rapidly evolve resistance to insecticides, as well as a wide range of abiotic and biotic stresses ,plastic gutter and for its global expansion across 16 million km2 to cover the entire Northern Hemisphere within the 20th century .

Over the course of 150 years of research, L. decemlineata has been the subject in more than 9,700 publications ranging from molecular to organismal biology from the fields of agriculture, entomology, molecular biology, ecology, and evolution. In order to be successful, L. decemlineata evolved to exploit novel host plants, to inhabit colder climates at higher latitudes , and to cope with a wide range of novel environmental conditions in agricultural landscapes. Genetic data suggest the potato-feeding pest lineage directly descended from populations that feed on S. rostratum in the U.S. Great Plains. This beetle subsequently expanded its range northwards, shifing its life history strategies to exploit even colder climates, and steadily colonized potato crops despite substantial geographical barriers. Leptinotarsa decemlineata is an excellent model for understanding pest evolution in agroecosystems because, despite its global spread, individuals disperse over short distances and populations often exhibit strong genetic diferentiation, providing an opportunity to track the spread of populations and the emergence of novel phenotypes. The development of genomic resources in L. decemlineata will provide an unparalleled opportunity to investigate the molecular basis of traits such as climate adaptation, herbivory, host expansion, and chemical detoxifcation. Perhaps most significantly, understanding its ability to evolve rapidly would be a major step towards developing sustainable methods to control this widely successful pest in agricultural settings. Given that climate is thought to be the major factor in structuring the range limits of species, the latitudinal expansion of L. decemlineata, spanning more than 40° latitude from Mexico to northern potato-producing countries such as Canada and Russia, warrants further investigation.

Harsh winter climates are thought to present a major barrier for insect range expansions, especially near the limits of a species’ range. To successfully overwinter in temperate climates, beetles need to build up body mass, develop greater amounts of lipid storage, have a low resting metabolism, and respond to photoperiodic keys by initiating diapause. Although the beetle has been in Europe for less than 100 years, local populations have demonstrating remarkably rapid evolution in life history traits linked to growth, diapause and metabolism. Understanding the genetic basis of these traits, particularly the role of specific genes associated with metabolism, fatty acid synthesis, and diapause induction, could provide important information about the mechanism of climate adaptation. Although Leptinotarsa decemlineata has long-served as a model for the study of host expansion and herbivory due to its rapid ability to host switch, a major outstanding question is what genes and biological pathways are associated with herbivory in this species? While >35,000 species of Chrysomelidae are well-known herbivores, most species feed on one or a few host species within the same plant family. Within Leptinotarsa, the majority of species feed on plants within Solanaceae and Asteraceae, while L. decemlineata feeds exclusively on solanaceous species. It has achieved the broadest host range amongst its congeners , potato , eggplant , silverleaf nightshade , horsenettle , bittersweet nightshade , tomato , and tobacco, and exhibits geographical variation in the use of locally abundant Solanum species. Another major question is what are the genes that underlie the beetle’s remarkable capacity to detoxify plant secondary compounds and are these the same biological pathways used to detoxify insecticidal compounds? Solanaceous plants are considered highly toxic to a wide range of insect herbivore species, because they contain steroidal alkaloids and glycoalkaloids, nitrogen-containing compounds that are toxic to a wide range of organisms, including bacteria, fungi, humans, and insects, as well as glandular trichomes that contain additional toxic compounds.

In response to beetle feeding, potato plants upregulate pathways associated with terpenoid, alkaloid, and phenylpropanoid biosynthesis, as well as a range of protease inhibitors. A complex of digestive cysteine proteases is known to underlie L. decemlineata’s ability to respond to potato-induced defenses. There is evidence that larvae excrete and perhaps even sequester toxic plant-based compounds in the hemolymph. Physiological mechanisms involved in detoxifying plant compounds, as well as other xenobiotics, have been proposed to underlie pesticide resistance. To date, while cornerstone of L. decemlineata management has been the use of insecticides, the beetle has evolved resistance to over 50 compounds and all of the major classes of insecticides. Some of these chemicals have even failed to control L. decemlineata within the first year of release, and notably, regional populations of L. decemlineata have demonstrated the ability to independently evolve resistance to pesticides and to do so at different rates. Previous studies have identified target site mutations in resistance phenotypes and a wide range of genes involved in metabolic detoxifcation, including carboxylesterase genes, cytochrome P450s,blueberry container and glutathione S-transferase genes. To examine evidence of rapid evolutionary change underlying L. decemlineata’s extraordinary success utilizing novel host plants, climates, and detoxifying insecticides, we evaluated structural and functional genomic changes relative to other beetle species, using whole-genome sequencing, transcriptome sequencing, and a large community-driven bio-curation effort to improve predicted gene annotations. We compared the size of gene families associated with particular traits against existing available genomes from related species, particularly those sequenced by the i5k project , an initiative to sequence 5,000 species of Arthropods. While efforts have been made to understand the genetic basis of phenotypes in L. decemlineata , previous work has been limited to candidate gene approaches rather than comparative genomics. Genomic data can not only illuminate the genetic architecture of a number of phenotypic traits that enable L. decemlineata to continue to be an agricultural pest, but can also be used to identify new gene targets for control measures. For example, recent efforts have been made to develop RNAi-based pesticides targeting critical metabolic pathways in L. decemlineata. With the extensive wealth of biological knowledge and a newly-released genome, this beetle is well-positioned to be a model system for agricultural pest genomics and the study of rapid evolution.A single female L. decemlineata from Long Island, NY, USA, a population known to be resistant to a wide range of insecticides, was sequenced to a depth of ~140x coverage and assembled with ALLPATHS followed by assembly improvement with ATLAS . The average coleopteran genome size is 760 Mb , while most of the beetle genome assemblies have been smaller . The draf genome assembly of L. decemlineata is 1.17 Gb and consists of 24,393 scafolds, with a N50 of 414 kb and a contig N50 of 4.9 kb. This assembly is more than twice the estimated genome size of 460 Mb, with the presence of gaps comprising 492 Mb, or 42%, of the assembly.

As this size might be driven by underlying heterozygosity, we also performed scafolding with REDUNDANS, which reduced the assembly size to 642 Mb, with gaps reduced to 1.3% of the assembly. However, the REDUNDANS assembly increased the contig N50 to 47.4 kb, the number of scafolds increased to 90,205 and the N50 declined to 139 kb. By counting unique 19 bp kmers and adjusting for ploidy, we estimate the genome size as 816.9 Mb. Using just the small-insert 100 bp PE reads, average coverage was 24X for the ALLPATHS assembly and 26X for the REDUNDANS assembly. For all downstream analyses, the ALLPATHS assembly was used due to its increased scafold length and reduced number of scafolds. The number of genes in the L. decemlineata genome predicted based on automated annotation using MAKER was 24,671 gene transcripts, with 93,782 predicted exons, which surpasses the 13,526–22,253 gene models reported in other beetle genome projects. This may be in part due to fragmentation of the genome, which is known to infate gene number estimates. To improve our gene models, we manually annotated genes using expert opinion and additional mRNA resources . A total of 1,364 genes were manually curated and merged with the unedited MAKER annotations to produce an official gene set of 24,850 transcripts, comprised of 94,859 exons. A total of 12 models were curated as pseudogenes.The predicted number of TFs is similar to some beetles, such as Anoplophora glabripennisand Hypothenemus hampei , but substantially greater than others, such as Tribolium castaneum , Nicrophorus vespilloides , and Dendroctonus ponderosae. We assessed the completeness of both the ALLPATHS and REDUNDANS assemblies, and the OGS separately, using bench marking sets of universal single-copy orthologs based on 35 holometabolous insect genomes, as well as manually assessing the completeness and co-localization of the homeodomain transcription factor gene clusters in the ALLPATHS assembly. Using the reference set of 2,442 BUSCOs, the ALLPATHS genome assembly, REDUNDANS genome assembly, and OGS were 93.0%, 91.9%, and 71.8% complete, respectively. We found an additional 4.1%, 5.4%, and 17.9% of the BUSCOs present but fragmented in each dataset, respectively. For the highly conserved Hox and Iroquois Complex clusters, we located and annotatedcomplete gene models in the ALLPATHS genome assembly for all 12 expected orthologs, but these were split across six different scafolds . All linked Hox genes occurred in the expected order and with the expected, shared transcriptional orientation, suggesting that the current draf assembly was correct but incomplete . Assuming direct concatenation of scafolds, the Hox cluster would span a region of 3.7 Mb, similar to the estimated 3.5 Mb Hox cluster of A. glabripennis. While otherwise highly conserved with A. glabripennis, we found a tandem duplication for Hox3/zen and an Antennapedia-class homeobox gene with no clear ortholog in other arthropods. We also assessed the ALLPATHS genome assembly for evidence of contamination using a Blobplot , which identified a small proportion of the reads as putative contaminants .We estimated a phylogeny among six coleopteran genomes using a conserved set of single copy orthologs and compared the official gene set of each species to understand how gene families evolved the branch representing Chysomelidae. Leptinotarsa decemlineata and A. glabripennisare sister taxa , as expected for members of the same superfamily Chrysomeloidea. We found 166 rapidly evolving gene families along the L. decemlineata lineage , 142 of which are rapid expansions and the remaining 24 rapid contractions . Among all branches of our coleopteran phylogeny, L. decemlineata has the highest average expansion rate , the highest number of genes gained, and the greatest number of rapidly evolving gene families. Examination of the functional classification of rapidly evolving families in L. decemlineata indicates that a subset of families are clearly associated with herbivory. Te peptidases, comprising several gene families that play a major role in plant digestion, displayed a significant expansion in genes . While olfactory receptor gene families have rapidly contracted , subfamilies of odorant binding proteins and gustatory receptors have grown . The expansion of gustatory receptor subfamilies are associated with bitter receptors, likely reflecting host plant detection of nightshades .

The movement actors that have been most engaged in the policy processes described in this chapter are those that do not reject but instead embrace state power as an essential tool in creating change and in holding municipalities accountable for providing public goods. Through persistent advocacy, gardeners have won concrete concessions in all three municipalities. Still, the results of these engagements have led me to question how urban agriculturalists have accepted a limited politics of the possible dominated by perceptions of neoliberal urbanism. This chapter explores how municipalities and activists have changed the legal and political landscape for gardeners over the last five years. Since the 1970s, urban spaces in industrial nations have undergone radical transformation through processes of neoliberalization. In the United States, the phase of “roll-back neoliberalism” beginning in the 1970s saw a loose coalition of actors engaged in the neoliberal project of dismantling social programs and defunding the welfare state . More recently, “the processes of roll-out neoliberalization” created new modes of governance that both empower the market asauthority and assert the power of the state in differing ways. While neoliberalization processes have been heterogeneous in their development, embedded in specific historical and regulatory contexts, and produced geographically uneven results, critical scholars have noted the strategic role that cities have played in neoliberalization . In what the authors termed “the urbanization of neoliberalism”, cities have become both the targets and the experimental terrains of neoliberal policies such as place-marketing, enterprise zones, urban development corporations,greenhouse ABS snap clamp market-oriented restructuring projects, public-private partnerships, entrepreneurial project promotion, and new strategies for social control .

Creative destruction and the urban built environment are highlighted as key components to neoliberal processes. Surplus value is no longer primarily generated through industrial production as described by Marx in Capital, but by spatial production instead . Financial and government institutions promote the rational use of space through land markets . When landowners constantly strive to put land to its “best and highest use” in order to obtain the highest rents, they impact how land will be used and determine future capital and labor investment. Because this work is speculative, their decisions can force allocations that might not otherwise occur . In this sense, the circulation of capital in rent coordinates the organization of land use that produces surplus value and accumulation. Individual investment decisions, in addition to furthering the process of surplus value extraction, can lead to urban disorganization. In the long run, “strategies to commodify urban space often faildismally, producing devalorized, crisis riven urban and regional landscapes in which labor and capital cannot be combined productively to satisfy social needs” . It is in these spaces, in vacant lots, reclaimed brown fields, and liminal spaces along roadsides and abandoned buildings that urban agriculture has frequently thrived. But in the Bay Area, gardening is thriving in both devalorized landscapes, such as the flat land of West Oakland, and the competitive land markets of places like downtown San Francisco. Gardening has become a key tool in entrepreneurial and cost-saving policies that encourage urban development throughout the uneven economic geographies of the region in both devalorized landscapes and highly competitive land markets.San Francisco, Oakland, and San Jose each have actively grown possibilities for urban agriculture in their municipal policy and programming over the last five years. Each city, situated in its own economic and social history, has taken its own path.

While there is much commonality between their stories, I observe significant differences, much of which is due to each city’s relationship to a primary driver of economic and social change – the Silicon Valley tech industry. In the sections that follow, I describe and analyze the municipal changes in zoning codes, community garden and parks programming, general plans, and municipal funding for gardening initiatives, as they are situated in the demographic and political economic realities of each municipality. The new wave of tech industries is less capital intensive both in cost and physical capital, which has meant more start-ups are able to seek out small commercial spaces in San Francisco and other regional cities with socially dense, creative centers . To continue attracting large companies of the new tech wave in a region with competing municipalities with much lower tax rates, San Francisco in 2011 passed a exemption on its 1.5 percent payroll tax to entice companies to move into a set of very specific buildings in Mid-Market. This tax break, nicknamed the “Twitter tax break”, will be phased out by 2018 due to the passage of the 2012 Prop. E. Using the rationale that taxing payroll de-incentivizes job creation, Prop E replaces the payroll tax and over a 5 year-period creates a gross receipts tax, taxing total business revenue depending on industry . Still, the region continues to attract venture capital-backed high tech industry at a higher rate then any other location in the world, with more than $13.5 billion invested in 2011 alone . Bridging tech and real estate development, commercial real estate technology startup firms based in the region brought in $74 million of capital investment between 2012- 2014 . The Silicon Valley is the national leader in these investments and with New York Represents 36% of real estate technology startups worldwide. San Francisco’s popularity for tech development and real estate has contributed to the recent housing crisis and resistance to further development.

In this context of high rents and struggles over availability of urban space, gardeners and the City of San Francisco have developed forms of urban agriculture that are compatible with the prioritization of land for real estate development both in the practical allocation of particular lands and in the cultivating an entrepreneurial, creative image of urban gardening. Since former Mayor Newsom’s Executive Directive on Healthy and Sustainable Food in San Francisco was announced in July 2009, the city has made major changes impacting urban gardeners. These changes have included making a prominent place for urban agriculture in the San Francisco General Plan, developing a municipal Urban Agriculture Program, updating zoning codes, and becoming the first California city to implement AB 551, legislation which allows landowners to pay lower property taxes by agreeing to use land for urban farming for at least five years. All of these initiatives have been championed by various actors in the urban gardening communities of the city, in particular the San Francisco Urban Agriculture Alliance . After Newsom’s directive, which committed the city to providing land for increased production of healthy food, various advocates of urban agriculture joined together to form the SFUAA in late 2009 . The executive directive created the San Francisco Food Policy Council , which was tasked with ensuring the goals of the directive were implemented into law. The SFFPC, formed in September 2010 and led by Project Manager Paula Jones, played a significant role in the development of the SFUAA. Suzi Palladino, SFFPC member, former staff member at the Garden for the Environment, and founding member of the SFUAA, described the genesis of the alliance, “San Francisco’s urban agriculture community has long existed as an energetic, but uncoordinated,snap clamps ABS pvc pipe clip network of grass-roots organizations… Catalyzed by Mayor Gavin Newsom’s Executive Directive on Healthy and Sustainable Food and the work of the San Francisco Food Policy Council, the urban agriculture sector has come together to form the SFUAA, whose members include practitioners and stakeholders working in the sector” . At the request of the SFFPC, SFUAA formed a Policy Working Group to review the goals of the directive and provide recommendations for on goal implementation including increasing the use of public lands for gardens, making resources like compost available to gardeners through distribution centers, and establishing a city entity to coordinate public support of gardening . In December 2010 with the continued advocacy from the SFUAA Policy Working Group and the efforts of members like Eli Zigas, Caitlin Galloway and Brooke Budner of Little City Gardens, Newsom and the San Francisco Planning Department announced a proposed change to planning code. Proponents of the code change said this change would allow for the growth of urban gardening throughout more of the city. The zoning proposal eliminated the need to apply for a Conditional Use Permit to be able to sell produce from urban gardens . In addition it permitted the operation of small scale urban farm, market gardens, or community and home gardens for personal consumption, donation or commercial purposes, allowed in all zoning districts and regulating the sale of urban garden produce . The new zoning language distinguished between three types of urban agriculture: community agriculture, any garden or urban farm on less than one acre used primarily for the production of food or crops for sale, and large scale urban agriculture for parcels over one acre in size .

On April 20, 2011 the Urban Agriculture Ordinance 66-11 was signed into law after the Board of Supervisors unanimously voted in favor of it. Surrounded by freshly harvested produce, Mayor Edwin Lee signed the ordinance at Little City Garden’s urban farm and celebrated a victory for gardeners and the city with the SFUAA . The ordinance quickly gained national attention as one of the most comprehensive pieces of recent legislation on urban agriculture . Supervisor David Chui who co-sponsored the law stated, “This bill puts San Francisco on the map as a national leader in urban agriculture, and is a tangible example of how government can create more sustainable communities.”. Community activists in both Oakland and San Jose drew inspiration or at least political momentum from this decision. During the process of the zoning code changes, the Recreation and Open Space Element of the General Plan was also being edited to include strong support for urban gardens . The General Plan had last been updated in 1986, when SLUG had successfully advocated for increased support of community gardens in the plan . In Policy 2.12, the 1986 General Plan advocated for the expansion of community gardening opportunities throughout the city, with the goal of developing one hundred community gardens by 1996 through partnerships with SLUG and other organizations. When ROSE was adopted in April of 2014, it included several objectives highlighting the importance of urban agriculture. Policy 1.8 most directly supported urban agriculture with the following objective, “to support urban agriculture and local food security through development of policies and programs that encourage food production throughout San Francisco” . Furthermore, the policy described how urban agriculture should be expanded on both public and private land with the support of the city. As elaborated in the policy, this would include providing public land including but not limited to public housing land, providing support to organizations engaged in urban agriculture, incentivizing the creation of gardens on private land, and permitting distribution mechanisms for produce on public land. Policies 1.1, 3.1, and 5.3 encourage the use of open space from medians to larger parks to develop community gardens. Policy 5.3 explicitly directs City departments to look for opportunities to expand green space on both public and private property, encouraging the development of temporary use agreements with property owners who may be interested in building in the near future. The plan cites the Street Parks Program as an innovative approach to increasing resident management and engagement in public space. The Program is a partnership between the Department of Public Works and the San Francisco Parks Alliance to encourage neighborhood groups to create community-managed gardens for three or more years on public right of ways owned by DPW . Most gardens in the program thus far have been ornamental, but whether ornamental or vegetable gardens, Realtor Ron Wong noted street parks increase the curb appeal of neighborhoods and can boost property values . In San Francisco, the appeal of these programs is apparent for a municipality that is trying to cut maintenance costs and gain additional value from property taxes when properties change ownership. Overall community gardening and urban agriculture maintain a significant presence in the new ROSE seen in the policy objectives above, the inclusion of community gardens as one of the defining types of ‘recreation and open space’ use, and the use of a Tenderloin People’s Garden photograph in the plan. SFUAA’s work was essential in making these changes to the ROSE possible. Another consequence of the 2010 recommendations of the SFUAA was that in July 2012 San Francisco Supervisors approved legislation, which added to the Administrative Code.

Land inventories document open spaces within cities where gardening could occur. Inventories were used during the Potato Patch and Depression Relief periods and recently been readopted as an urban planning tool useful for gardening advocates . Land inventories or audits have been used in several bay area cities, including San Francisco, Oakland, Richmond, and San Jose, to assess available space for urban gardens in addition to mapping existing projects. These inventories have been authored by and inspired from a variety of sources including municipal offices, local non-profits, and academic researchers with connections to local food movements . Each has used spatial data to create maps with which particular criteria can be used to identify potential land for gardening. Criteria vary between the inventories but each analysis generally seeks vacant lands with appropriate environmental conditions for cultivation . The targeted land of these inventories can be categorized as either all vacant or public vacant land. The difference is important. Mapping can be used as a tool of future making as well as making legible the importance of contemporary spatial practices. Maps facilitate discourses of possibility, hope, and politics. These land inventories are just that. For McClintock and Cooper their inventory “is one of many new steps in an ongoing movement to develop a more resilient, sustainable,drainage planter pot and just food system in Oakland” and “a crucial first step in developing policy and action related to developing a robust food system for low-income food deserts in the flat lands” . Two of the more prominent inventory authors focused on public land with an explicit commitment expressed in that choice. In “Cultivating the Commons”, a nationally recognized report and assessment, McClintock and Cooper claimed that land owned by public agencies in Oakland is a public resource and a part of the “commons” .

The authors intended the assessment to be used as a tool to increase use and management of public spaces by local residents. SPUR researcher, Eli Zigas concurred with the recommendation to deploy land inventories of public land . Through identifying vacant public land and working with policy makers, he hoped more residents could engage in urban gardening in San Francisco public spaces. For Zigas, private land, while a good option in some cases, did not have the same potential as the use of public lands. In their 2012 report, SPUR argued “even with a lease, land tenure for gardeners and farmers is often tenuous. Privately owned vacant land has a very high value because of its development potential. Urban agriculture projects, which can rarely pay much rent, have difficulty securing the long-term leases that are often essential to their success“ . When asked about SPUR’s focus on public land, Zigas stated “Personally I think I’m more interested in putting time into something so it can stick around for a long time” . Gardening on public land is understood to have greater tenure security as well as the benefit of community members managing a public resource or commons. Other inventory authors stress the opportunities on both public and private land. In his urban planning masters thesis, Lewis noted that while it may seem practical to use city-owned vacant land in San Jose, due to budget shortfalls, the city’s interest in selling land for revenue generation and a relative lack of open public spaces, secure public land might not be easy to come by . Lewis, now the executive director of an urban gardening non-profit called Garden to Table, suggests assessing private land for potential urban agriculture projects that have defined time limits can create win-win situations for gardeners and owners interested in future development. For Kevin Bayuk, a long-time San Francisco permaculturalist and author of a 2010 inventory later used by the SPUR 2012 inventory, has indicated that public and private categories do not necessarily get gardeners sufficient information on “available and appropriate” spaces .

While Bayuk, cofounder of the Urban Permaculture Institute, advocates for the use of both public and private land, he sees backyards as an important area to prioritize for urban agriculture advocates interested in maximizing food production because of their environmental, energy and water saving potentials . The inventories take a variety of approaches to addressing the question of appropriate land for gardening. Questions of use history, environmental quality, travel time to site, and importance of ownership are considered. Two reports that have received significant attention in the local and nation urban agriculture communities and publications, the SPUR and Cultivating the Commons reports, clearly advocate for the use and revitalization of public land. The authors contend that the state is responsible for providing access to public lands for community purposes. They argue that through policy change and the support of local public officials, the new garden spaces can be tenure secure in the long run. For others, like Bayuk, the insecurity of land tenure in the competitive land markets of the Bay Area means assessing both public and private land will lead to a greater number of beneficial land arrangements. Across the Bay Area gardeners have partnered with public agencies to gain access to land for gardening. Traditional plot community gardens have been popular in the region over the last several decades. In addition to these community gardens, urban agriculturalists are increasingly partnering with city agencies to develop partnerships for projects outside of the plot model. In an era of shifting neoliberal governance, some gardeners have expressed concerns that these partnerships can result in uneven allocation of resources. Traditional community garden programs run by municipal parks and recreation departments continue to exist throughout the Bay.

The San Jose and Oakland programs began in the 1970s during the last wave of popularization of urban gardening. The San Francisco program, while initially started in the 1970s, experienced a significant pause in operations in the 1980s and 1990s but is functioning again today. Many of today’s community gardens have long waiting lists due to both popularity and infrequent turn-over of gardeners. For example, San Jose’s Wallenberg Community Garden has over 120 individuals on their waitlist. In San Francisco, when a resident inquired about getting a plot in the Dearborn Community Garden in 2012 she was told there was a 22-year waitlist . While not all gardens have extensive waitlists, most do. New urban agriculture projects frequently run on a model based on education, community building, or job training that uses a collective growing model rather than individual plots. This model is not new, nor is the attempt to secure public land for these projects. The Farm, developed in the 1970s in San Francisco, is a prominent example of an early community-led urban agriculture project that eventually obtained city approval, was externally funded, and collectively operated on public land. SLUG, in San Francisco, operated collective garden projects on city land, such as the Saint Mary’s Farm and obtained contracts for tens of thousands of dollars with the city for many years. Today in Oakland, these public-private partnerships are flourishing and urban agriculture on public land is not coordinated by one larger private agency,plant pot with drainage unlike the partnership between San Francisco and SLUG from the 1980s to early 2000s. Various non-profits are partnering with the City of Oakland Office of Parks and Recreation to use and manage currently existing park space . In 2011, community members began organizing the Edible Parks Taskforce, a coalition of organizations including Phat Beets, PUEBLO, City Slicker Farms, Acta Non Verba, the Victory Gardens Foundation, Planting Justice, and many others. They joined together to propose an Edible Parks Community Stewardship Program, which would promote the use of public space for edible landscaping for community self determination. The program is inspired by Oakland’s Adopt-a-Spot program, where individuals, groups, and businesses can volunteer to manage pieces of public land and help reduce city costs. The Taskforce wants the city to standardize and clarify the process for use of public land. Some feel the process for accessing parkland for gardening has varied based on the political support of different organizations . Despite conversations for over a year and the presentation of a concrete proposal with support from three city council members, the city has been slow to engage with the task force and has yet to offer support. In an East Bay Express article published June 2014, Stephanie Benavidez of the Office of Parks and Recreation disagreed the city had been slow to respond and that said, “We have different goals and objectives. It’s about finding common ground” . The city has received many requests for expansion of gardening in parks and on other public land and claims the need to balance the needs of the community at large with those of the growing urban agriculture movements.

Both city officials and some neighbors worry this interest in urban gardening is only held by a small subsector of the population, questioning the amount of space that should be managed by these private sector organizations. There is concern that they may intentionally or unintentionally exclude certain people or practices from the area they garden or the projects may be adopted then discarded creating more work for city employees. In February 2013, City Slickers Farms broke ground on a new park and farm project in Oakland, the West Oakland Farm and Park, which has received significant public support. The area is being built to include vegetable beds, a fruit orchard, and urban livestock, a large lawn area for recreation and a dog run. Barbara Finnin, a former City Slicker Farms Executive Director, wants to create a “space for people tohang out and meet and recreate and have fun… It’s about community gathering spaces that people feel safe in” . The plans were developed through a three-month planning process, engaging neighbors to identify what they would like to see in a community park. The process was similar to the process that the Alameda Parks and Recreation Department recently facilitated to determine the future of a large swath of recently acquired land to become the Jean Sweeny Open Space Park. The difference being that West Oakland Farm and Park will not be a public park in management or ownership. In 2010, the organization received a $4 million grant from funding from Proposition 84 to buy the land and build the Farm and Park on a vacant lot; the organization will have to raise funds for operating costs. Proposition 84, The Safe Drinking Water, Water Quality and Supply, Flood Control, River and Coastal Protection Bond Act of 2006, fund a variety of environmental improvement projects, the vast majority of which run through municipal and state departments. To improve sustainability and livability of California communities, the state allocated $580,000,000 to urban greening and the development and support of parks . The City Slickers grant, one of the largest funded, was chosen in part because of the organization’s 10-year history in the community and community engagement in the envisioning process . Many welcome the development of the new Farm and Park. Yet for some others, the project calls into question the significant public funding of a project that will ultimately not be owned or operated as a public park. Occupations and squatting have been used by gardens as a strategy to gain access to space, engage neighbors in considering urban land use priorities, and gain public attention for the work of their organizations or groups. Squatting, or using land without the permission of the landlord, has been a popular strategy for politically motivated gardeners since the 1970s. The term “guerilla gardening” was coined in the early seventies by Liz Christy of New York’s Green Guerillas, a non-profit still supporting community gardening today. The Green Guerillas “threw ‘seed greenaids’ over the fences of vacant lots. They planted sunflower seeds in the center meridians of busy New York City streets. They put flower boxes on the window ledges of abandoned buildings” . Soon they turned to reclaiming urban lots and creating community gardens in these vacant spaces. Today, many activists and gardeners are inspired by these strategies. The relationship between urban garden activism and the use of vacant land without permission has shifted since the rise of the Occupy Movement in fall of 2013.

While there are significant concerns over the implications of and ideologies implicit in garden projects, urban agriculturists situate gardening in contemporary food movements and their quest for critical self-reflection and change. This wave of urban agriculture has arisen in a time of unprecedented national attention to the politics and potentials of social transformation through food. The next chapter will address the development, commitments, and key debates of contemporary urban food movements in more detail. What is notable in characterizing urban agriculture today is the proliferation of new alternative food institutions, which bring together food movement actors with governmental and broader civil society audiences. In the last two decades food policy councils and collaborations have been a key location for the development and support of garden projects, local policy to support the improvement of food systems, and the enrollment of support of more powerful community actors. FPCs frequently involved public-private partnerships or within local government . The first FPC was formed in 1980 in Knoxville, Tennessee after a local organization partnered with the Metropolitan Planning Commission to lobby the city to form a body to enact change in the local food system . By 2004, there were fifteen FPCs in the US and Canada . A 2012 Community Food Security census of FPCs in the US and Canada reported one hundred fifty-five FPCs in operation,drainage pot one hundred eleven of which were independent organizations and forty were housed in government offices .

In the Bay Area several food policy organizations have been active in mobilizing and shaping work in urban gardening communities including the Berkeley Food Policy Council, Oakland Food Policy Council, Richmond Food Policy Council, San Francisco Food Policy Council, San Mateo Food System Alliance, and Santa Clara Food System Alliance. In addition to food policy organizations, garden networks and policy oriented gardener groups have been active bodies shaping movement priorities and actions. These include the San Francisco Urban Agriculture Alliance and the East Bay Urban Agriculture Alliance. Urban agriculture has also been embraced as a strategy by large regional non-profits with foci broader than food including health based organizations such as the Health Trust and the HOPE collaborative, and urban planning organizations such as San Francisco Planning and Urban Research . New agrifood institutions have in many areas sought to bring together alliances across racial, ethnic, and class differences. This work of collaboration and alliance building has also occurred outside and beyond the reach of alternative food initiatives . McClintock identifies cross-racial organizing and alliance development as key characteristics to urban agriculture in Oakland, stemming from coalitional work of black liberation, environmental and environmental justice, and community empowerment organizing. Urban agriculture has the capacity to be a means of connecting differing urban movements oriented towards justice including interests in healthy food, immigrant’s rights, racial discrimination and institutionalized racism, etc. In alignment with the calls for the right to the city, as discussed in the introduction, gardeners have used cross cultural alliances to marshal material and political resources, as well as used privileged access to resources to support the work of movements led by low income people and people of color.

Phat Beets’ resistance against gentrification, La Mesa Verde’s work to build cross-cultural networks of backyard gardeners for food security support, and Growing Home’s work to advocate for the unhoused population in San Francisco’s need for spaces of refuge and creativity through gardening are all examples that will be discussed in Chapter 4. These examples point to key moments of cross difference work and movement alliance building that represent one side of advocacy for change within predominately white, middle class food movements, a tension that is explored in Chapter 3. One thread of food organizing that has attempted to engage cross-difference organizing and environmental sustainability, is the holistic, interconnectedness approach of permaculture and agroecology. Most municipal community gardening programs require gardeners to use organic methods. Nearly all non-profit garden organizations promote sustainable and low-input gardening. In the Bay Area both argoecology and permaculture, specific forms of sustainable agriculture, have played significant roles in urban gardening as it defines its commitments to land access strategies and movement building. Permaculture originated in Australia in the mid 1970s as a collaboration between professor Bill Mollison and his graduate student David Holmgren. A movement soon began to promote “permanent agriculture” and “permanent culture” as ecological design. As such, permaculture is not just a gardening method but a philosophy and form of environmental and social design that promotes “harmonious integration of landscape and people providing their food, energy, shelter, and other material and non- material needs in a sustainable way bounded by the ethics of care of people, care of earth and reinvestment of surplus” .

In California, permaculture gatherings began in Orleans in 1994 and the San Francisco Permaculture Guild was founded in the late 1990s . Today guilds and several informal permaculture groups exist in San Francisco, the East Bay, and Santa Cruz. Courses are taught at Merritt College and by local trainers. In 2010 Movement Generation Justice and Ecology Project and the Occidental Arts and Ecology Center held the first Liberation Permaculture course that brought together leaders from social justice and urban agriculture organizations in the Bay Area to learn and build a “permaculture for the people” with a focus on justice. Agroecology has also had a strong influence in the work of urban gardeners in the Bay Area. Many leaders have been trained at the UC Santa Cruz Center for Agroecology and Sustainable Food Systems Apprenticeship Program. CASFS dates back to 1967 when Alan Chadwick first developed a student garden and began teaching students about sustainable gardening. This effort would later be transformed into a formal apprenticeship program. In 1980 Dr. Steve Gliessman was hired to start the Agroecology program at UCSC and in 1993 the program was renamed the Center for Agroecology and Sustainable Food Systems in order demonstrate agroecology’s duel focus on social and ecological change. Many nonprofit garden project staff graduated from UCSC and studied agroecology in some capacity while at the University. At UC Berkeley, another founder of agroecology,Miguel Altieri, has taught agroecology to thousands of students since 1981. In addition to the influence of agroecology through the University of California system, Food First: The Institute for Food and Development Policy, founded in 1975 and based in Oakland, has long been committed to agroecology and sustainable agriculture as a pillar of international movements addressing the root causes of hunger and farmer insecurity. As an organizational leader of political food movements in the Bay, Food First’s publications, events,large pot with drainage and commitment to agroecology have influenced many gardeners. The effect of agroecology and permaculture in Bay Area gardens is evident in the ecologically sustainable practices deployed in the urban gardens and in the movement’s approaches to land tenure and property. Gardeners debate if long term tenure is necessary for developing sustainable and resilient agroecosystems, which in turn shapes both ideological and practical approaches to accessing land. As gardener, former planning professor, and citizen scholar, Sam Bass Warner stated in 1987, “Control of land has always been the rock that smashed American urban garden projects”. In this chapter we have explored the history of gardening in the US and in the Bay Area. Urban agriculture has had a rich history with period of massive expansion and support from municipal, federal, and urban planning institutions. It has, however, largely remained in the realm of “interim use”. Although gardens provide many social and ecological services, municipal agencies and private landowners have held other priorities for long-term use of land. This historical approach to urban agriculture limits gardeners today who wish to develop long lasting projects. Gardeners today are working with planners, local officials, universities, and others to advocate for gardening as a more legitimated land use. The movement is mainly led by coalitions of non-profits and puts significant emphasis on agroecological approaches. These characteristics facilitate particular approaches towards and debates over land access. The next chapter explores the strategies, tools, and politics of gardeners’ approaches to land access, which demonstrate complex engagements with tenure and property and conflict within gardening communities over these engagements.

A new wave of urban agriculture is coming at a time of an explosion of food activism in the United States. Popular culture, the First Lady, and new media are abuzz with discussions of sustainable food, local food, growing your own food, and food as a means towards improved lives and an improved world. Urban gardening and local food are trendy. Many are drawn to food-based social action as a means to create change at more than the individual level. People are drawn to food as a space for organizing for social change. Urban food projects of many varieties have focused on food as a mechanism towards justice. This chapter traces the growth and development of concerns for social, economic, and racial justice in food movements. In California, many older alternative food initiatives have their roots in the 1960s and 70s movements for social justice and environmental protection . Rural organizing for racial and economic justice manifested through the interethnic coalition that become the United Farm Workers union. In cities, the War on Poverty provided resources for communities organizing to address hunger, community disempowerment and racial injustice. Nationally, the environmental movement won victories for the greater regulation of pesticides. Concerned about the environmental impacts of industrial agriculture, as well as expressing resistance to the Vietnam War and consumer culture, many youth turned to the ‘back-to-the-land’ movement, helping to initiate the organic food movement. Environmentalists and natural foods advocates found a place of solidarity with people looking for social and economic justice through the creation of alternative food initiatives . By the 1990s alternative food initiatives focused on rural issues had shifted their attention away from the needs of farm workers . The social justice commitments of alternative food organizing in California turned towards the urban centers. Since the 1990s, urban efforts have focused on increasing food access, empowering marginalized communities, strengthening producer-consumer connections, challenging historic inequities, and building more democratic food systems. Through self-critique, external critique, and learning through experience, food activists have shifted, refined, and recommitted to practices in pursuit of justice. This chapter will explore how justice has been constructed and sought as a practical frame with which to change society through three iterations of the alternative food movement in the last three decades: the community food security movement, food justice movement, and food sovereignty movement. This chapter does not suggest nor seek to represent the entire food movement as principally concerned with justice, but instead delves into a deeper understanding of those how subgroups of this broader movement have understood and sought justice through their work. The alternative food movement has evolved in response to internal and external pressures over the last several decades. Many scholars argue that since the early 2000s there has been an increasing focus on justice within alternative food organizing . At the same time many have noted the increasingly dominant role of neoliberal ideologies and policy strategies in food movement work . Critiques from within and outside of the food movement have made activists consider or reconsider their organizing strategies and trajectories. How activists engage in framing, or the tactics of defining and bounding their work for social change, has important material and symbolic consequences. This chapter will explore three ideological points of tensions that create debate and internal change within these movements: approaches to centralized and decentralized power, approaches to racialized histories and identity, and justice as a question of socionatural relations. Contrary to the arguments of many food scholars, I claim that food movements are both conflicted with and drawn to a tendency in contemporary social movements, a trend that is less neoliberal and more radical leftist: a move away from reliance on the democratic socialist state ideal that reinforces the notion that the appropriate site of political action is that of government institutions. While many in food movements still believe that food injustices can be successfully addressed through state reform and bolstering welfare programs, others take a more nuanced approach. While they may still support movement actions on the farm bill or national policy initiatives, many activists are turning towards notions of self-determination and sovereignty that decenter and question the capabilities of nation state systems in the pursuit of justice.

Urban political ecology contains a political program “to enhance the democratic content of socio-ecological construction by identifying the strategies through which a more equitable distribution of social power and a more inclusive mode of environmental production can be achieved” . As a result, urban politics play a key role in this emancipatory political project. At the forefront of any radical action must be considerations of how social actors can take control of the production of urban space “in line with the aspirations, needs and desires of those inhabiting these spaces” and questions of “whose nature is or becomes urbanised” . While gardening may present revolutionary or transformative approaches to urban spatial production, blind enthusiasm for the potential of these projects does not engage the essential questions of where, how, and with whom the gardeners’ work is developed. Gardens reflect and reproduce different boundaries of enclosure, inclusion and exclusion – both with participants and material, spatial land tenure relationships – within neighborhoods and within movements. Decisions on the construction of these boundaries shape the character of a garden and the role it will play in social change. Recognizing the multiple meanings and representations of ‘community’ in urban agriculture, Pudup calls for the adoption of the term ‘organized garden project’ instead of community garden. Organized garden projects refer to specific places,vertical farming in shipping containers geographical spaces not typically used for growing agricultural products that are cultivated by organized groups of people with collectively defined goals.

One such goal is securing tenure arrangements that allow gardeners to continue their projects in the manner they desire, whether that be through roving gardens moving from vacant lot to vacant lot, acquiring the use of public parks and public programing to support urban agriculture, or using gardens as a political tool in resisting development and gentrification. Gardeners recognize that their tenure strategies are bounded or to some degree shaped by contemporary property relations. Their assessment that property relations are a determining dynamic for the future of their gardens is acute. Many gardeners also contend that they are active participants in shaping the property relations that may determine the fates of their projects. Gardeners stress their projects are making a real impact on how local municipalities are embracing urban gardening as land use, how residents view the use of land for food production, and how gardening can challenge the priority of land value for development. I term the process of decision making gardeners that take in manifesting a land access strategy landing. Landing is a process of creating closure, when utopian desires are enacted on the land and preexisting property relations. Through landing gardeners recreate old or develop new socio-spatial relations, setting direction, and foreclosing on other possibilities if only for the moment. In analyzing organized garden projects in the San Francisco Bay Area, this dissertation explores two central themes: the political project to gain secure land tenure for the future of urban agriculture and the production of practices and narratives of property and urban space through garden projects. The first theme stems from the argument by gardeners and garden advocates that contemporary urban agriculture projects should become a permanent part of US cities. Gardeners are acutely aware of the lack of land tenure security on both public and private land due to the politics of ownership. A 1996 survey conducted by the American Community Gardening Association found that of urban gardens in thirty eight cities in the US, only 5.3% were owned by the gardeners or in permanent land trust .

The desire and commitment amongst garden advocates, spurs the questions: what form of garden are being promoted as the ideal for permanent urban agriculture, and what are the potential material and discursive consequences of these forms? The second theme explores how gardeners are engaged in reimagining the production of urban space and property as a dominant capitalist institution. In doing so, it also examines the tensions among differing cultures within urban agriculture that participate in utopian projects of recreating contemporary cities in more just and sustainable ways. These projects exist within conditions of possibility produced by urban development politics and also shape, through rhetoric and practice, a terrain of political possibility for change. Analyzing the ideologies, institutions, and practices of property promoted by differing garden projects can shed light on the potential contributions of these projects to transformative urban and food politics.Urban agriculture has had a presence in US cities since the 1880s, with several periods of popularization and growth . However, with the reemergence of gardening as a strategy in the community food security, food justice and food sovereignty movements, scholars debate how and if this new wave of urban agriculture can contribute to radical urban transformation. Historically, gardens served as a tool to improve urban conditions, especially during times of economic or social crisis when small patches of cultivation expanded to city or nation-wide projects . Urban agriculture has served as a social safety-net by feeding low-wage workers and subsidizing the social reproduction of workers during these times of crisis . Today’s social movements engaged in urban agriculture focus on lack of physical access to healthy food, racism in US food systems, and gaining popular control of the food system.

Self-provisioning through urban food production has been embraced as a means to address these social problems. In addition to improving food resources, scholars assert that urban agriculture contests dominant logics about the best use of urban space. McClintock argues that urban agriculture exists in tension with capital simply by putting underutilized land to use in the production of food . Mares and Peña agree that urban agriculture projects are forms of resistance to commodification of space, asserting that the use of spaces for agriculture that would gain higher rents for other uses . In highlighting that use-value is prioritized over exchange value, scholars are reviving Lefebvre’s arguments about the resistance potentials of urban social movements. Urban agriculture can raise questions about who deserves access to urban land and urban development processes. For Lefebvre, abstract space, like Marx’s abstract labor, contains the seeds for differential space, the seeds for resistance. In describing exchange-value coming to overpower the mode of production in the processes of urbanization, he saw the potential for urban revolution in the struggle for the ‘right to the city’ . To Lefebvre, the entire world was becoming the urban as the production of space became a more dominant force than industry. ‘Urban’ carried the prioritization of use-value as space became “an inscription of time promoted to the rank of a supreme resource” . Yet, within his critique of growing urban hegemony, Lefebvre proposed the concept of the right to the city, a right that is not bound to the city,hydroponic vertical farming systems but is better described as a right to “a place in an urban society in which the hierarchical distinction between the city and the country has disappeared . This can be read in the increasing financial investment in farmland nationally and abroad; for example in 2010 the pension fund TIAA-CREF invested $2 billion in farmland in the US . In the face of growing inequity in cities dominated by neoliberal practices, critical urban theorists and community activists have once again returned to the framework of ‘right to the city’ proposed by Lefebvre in 1968 . The concept of right to the city connects both the just distribution of material resources and the democratization of the processes of urbanization. Urban gardening that prioritizes the use of city land for food production, cultural engagement and community building can both challenge the dominant logics of development and also provide the seeds for coalition building under the banner of ‘right to the city’. Gardeners in the Bay region argue that their work does this by demanding a say in urban governance. At the same time gardeners also question if their work contributes to urbanization that continues to benefit capital’s interests and does little to empower marginalized communities. Gardening led by non-profits can be read as part of the contemporary trend where third sector organizations have proliferated and become institutionalized as the appropriate site space for the formation of citizen subjects . Social change enacted through volunteerism and non-profit groups, as opposed to state agencies, can have undemocratic consequences of limiting who is invited or able to participate in decision-making processes, such as those of governance and production of urban space. Furthermore, gardeners are also aware that their work may be and is, as illustrated in several examples in this study, aiding in the processes of gentrification, a significant issue in the region. Urban gardening has become increasingly popular at the same time that discourses of sustainability have gained increasing political influence within US cities. Sustainability policies and discourses have opened possibilities for urban improvement projects such as gardening under the umbrella of larger plans for continued urban development and capitalist accumulation .

Such reasoning has given scholars and activists hesitancy in their desire to view urban agriculture projects as materially or discursively transformative land use practices. The potentials of radical land use through gardening must be contextualized in the actually existing practices of the social movements in which gardeners participate, i.e. contemporary food movements. Some scholars have argued food politics has largely been de-politicized and individualized as neoliberalism impacts food and agricultural activism . Other scholars have cited gardens as a site of “against and beyond”3 politics both challenging contemporary capitalism and building new forms of social relations . This dissertation engages the question of how gardeners frame the politics of possibility. Although all the gardeners interviewed in this study were committed to food movements as discussed in Chapter 3, the politics and urban utopian imaginaries of the gardeners vary. One thread of politics that has a strong presence in organized garden projects is what Dixon calls “the anti-authoritarian current” articulating the work of “against and beyond”. Anti-authoritarian politics, the politics of “another world is possible”, seek to create political spaces beyond party building used by liberals, social democrats, and Leninists alike, as well as beyond non-profit dominated spaces or isolated affinity group organizing . Activists work against domination, exploitation, and oppression through bottom-up organizing strategies to create new social relations and forms of social organization beyond contemporary models, thus ‘prefiguring’ more desirable practices . “Against and beyond” resists a dichotomy of oppositional or alternative politics that emphasizes either changing contemporary systems or creating new ones, seeing the potential in prefigurative politics in spaces like the land politics of urban gardens. Hegemonic power structures, like the dichotomy of private and public property, while dominant are not singular, complete, or without internal contradiction . The power of hegemony must be continually renewed and defended through multiple cultural and material processes . Thus, I read gardens as an essential site to understand contestations of the institution of property. Althusser described the process of subjection as part of the processes of securing hegemonic power . Through practices ideology is made material; when these practices are repeated, ritualized and institutionalized, we can observe the form of ideological state apparatuses. Ideology functions to constitute individuals as subjects through a process of interpellation. Simply put, the individual is hailed, recognizes the call, and freely submits to her subjection. The subject not only recognizes herself in the interpellation, but also recognizes that this is an accurate representation of reality, seeing others as subject. Gardeners, within and beyond food movements, seek to create subjectivities of possibility, thus creating conditions of possibility for intersubjective change. Althusser recognized that the processes of interpellation and the development of ideology are simultaneous processes or “things that happen without any succession” . This mechanism permits the reproduction of the relations of production and resulting social relations of oppression, resistance, or multiple forms in and outside of hegemonic social relations depending on your reading . Thus when one gardener calls for the need for more ‘vandals’ as subjects called to create more food through guerilla tree grafting, they recognize subject formation as part of a broader process of engendering ideology challenging the dominance of private property’s boundaries and production urban environments that favor possibility, both oppositional and alternative, through gardening. Political projects, like the one of the vandal, are also not singular, complete or without internal contradiction. Analyzing the internal contradiction of political projects within particular spatiotemporal contexts can open possibilities for alternatives .

Following Mutharika’s departure from the UDF in 2005, the president engaged in an aggressive campaign to attract support across ethnic and regional divisions, an effort that was highly successful as indicated by the broad-based electoral support he received in the 2009 election in which he defeated the second-place candidate, John Tembo, by a margin of 66% to 31%. The shifting political landscape, however, meant that traditional ethnoregional alignments were temporarily upended.8 Second, Malawian parties lack the local level networks that allow machine-based parties in other parts of the world to identify core and swing voters at the village or neighborhood level. Political parties in Malawi function primarily at the national level with weak or nonexistent formal structures at the local level . This was particularly true of Mutharika’s DPP, which, having been formed in the aftermath of the president’s 2005 departure from UDF, initially lacked even basic local-level infrastructure. While individual politicians, such as parliamentarians, no doubt maintained their own informal networks at the local level, the challenge of distinguishing partisans from non-partisans based on observable markers would have been formidable. Given these informational limitations we expect the subsidy program to be largely untargeted with respect to ethnicity and party support at the individual level within villages . The analysis of subsidy targeting and its political effects employs data from two waves of a panel survey of rural Malawians in 122 villages clustered in three districts: Rumphi, Mchinji, and Balaka. Each administrative region of Malawi is represented in the study, as are the three major ethnolinguistic groups .

The surveys are part of the Malawi Longitudinal Study of Families and Health ,danish trolley which began in 1998 and aims to understand how villagers cope with health challenges like HIV/AIDS. In each district, the MLSFH used a cluster sampling strategy across selected census enumeration areas. A random one-in-four sample of women of reproductive age and their husbands was drawn from villages to yield a target sample in 1998 of 1,500 women and their husbands . The resulting sample in 1998 included 1,532 evermarried women aged 15-49 and 1,065 of their spouses. In 2004, the MLSFH added a sample of 984 adolescents aged 15-24, and during the 2008 round a sample of 549 parents of respondents in earlier MLSFH rounds was added . New spouses of MLSFH respondents were also added in each wave. Though the original sampling strategy in 1998 was not designed to be representative of the rural population in Malawi, the sample’s characteristics are very similar to those of the rural population interviewed by the Malawi Demographic and Health Surveys that covered nationally representative samples . Between the two rounds studied here, 1,016 respondents were lost to follow-up;9 thus, though the 2008 round included a sample of 3,909 respondents and the 2010 sample included 3,786 respondents, our analysis includes only those 2,851 respondents who were interviewed in both 2008 and 2010. The analytical sample in this paper drops to 1,846 when we remove study participants whose responses on standard questions are inconsistent between the 2008 and 2010 waves and when responses are dropped because of missing information on key variables.We augment the individual-level panel data with village-level data collected through a survey of village headmen in the 122 research villages conducted in 2008.The first step in the analysis is to test for evidence of targeting.

While the results from this analysis are interesting in their own right, the primary goal is to identify factors that might confound the analysis in the next section of the subsidy’s effects on voters’ political preferences. To examine targeting in our survey area, we draw on a question on the 2010 survey that asked respondents whether they had received a voucher for fertilizer or seeds in each of the previous two years. We focus on those who received the subsidy in the 2009/10 growing season, which immediately preceded the second wave of the survey. The data show that 73.7% of respondents received the agriculture subsidy in 2009/10. Respondents in the three district clusters were about as likely to receive the subsidy, with 74.6% receiving it in Rumphi, 78% in Mchinji, and 68.2% in Balaka. The independent variables for the targeting analysis come from the 2008 survey unless otherwise specified. Our key independent variable measures party support according to responses to a question that asked, “Do you feel close to any particular political party?” Those who answered affirmatively were then asked which party. In total, 53.2% of the sample registered support for a party, with the largest share expressing support for the incumbent party, DPP, and smaller shares indicating support for one of the opposition parties . The distribution of party support in our survey area mirrors national-level trends found in the 2008 Afrobarometer survey.We also include a measure of whether respondents are “minority partisans” in their villages, supporting a party other than the party thought to be supported by most people in the village. We test for targeting along ethnic lines, given the centrality of ethnic divisions and ethnoregional favoritism in Malawi’s political history . We include a dummy variable for Lomwe respondents and also include dummies for Malawi’s other major ethnic communities, the Tumbuka, Chewa, and Yao. In our survey area, these four groups make up 93.9% of the sample. We also include an indicator of whether respondents come from minority groups within their villages, using data from the headmen survey on the majority ethnic group at the village-level.

Following Pan and Christiaensen , who found that local elites in Tanzania tended to capture the benefits of a similar subsidy program, the analysis includes several measures of social stature to test whether those in leadership positions within their communities may have been more likely to benefit. We include indicator variables measuring whether respondents were members of the Village Development Committee, the Chief’s Council, or the District Development Committee in 2008. To test whether the program benefitted the most needy, we include multiple measures of socio-economic status. First, we include a measure of wealth constructed as an index of household asset ownership.We include three measures of whether respondents experienced negative economic shocks in the year prior to the 2009/10 growing season. These relate to: 1) loss of income, 2) poor crop yields, or 3) the death or serious illness of an adult member of the household. Though only the second measure explicitly references an agriculturally related loss, all three measures capture severe shocks that make households particularly vulnerable to food insecurity. We also include a measure of farm size and standard demographic measures: age, education, and whether the household was headed by a female. We use logistic regression to examine individual-level subsidy targeting,vertical aeroponic tower garden and include village fixed effects to account for village-level differences that might affect access to coupons, including politically-motivated targeting across villages. We cluster standard errors by household because in some cases multiple respondents were interviewed in the same household. Table 1 shows the results and Figure 1 plots the marginal effects of each variable holding other covariates at their mean values. Figure 1 indicates that, conditional on village, the subsidy was not targeted with respect to party preferences or ethnicity in our survey area. Supporters of the incumbent party in 2008 were no more or less likely to benefit from the subsidy program in 2009/10 . Likewise, opposition party supporters were no less likely to receive the benefit, nor were individuals who were minority partisans in their villages. The results also show that, relative to members of smaller ethnic groups , respondents from Malawi’s major ethnic communities were no more or less likely to receive the subsidy during the 2009/10 season. We also entered each ethnic dummy variable individually in additional tests and found no evidence of ethnic targeting in these specifications. Likewise, we find no evidence of discrimination against individuals from minority groups at the village level. Consistent with findings by other scholars , we fail to find evidence that Malawi’s AISP effectively targeted those with greatest need, despite the program’s stated goal of reaching those most at risk for food insecurity. Our results show that neither poorer respondents, nor those with smaller land holdings were more likely to receive the subsidy. Moreover, respondents who experienced an economic shock related to loss of crops, livestock or income in the previous year were no more likely to benefit from the AISP than those unaffected by such income shocks.

Further, households that suffered the death or serious illness of an adult in the previous year were actually less likely to receive the input subsidy. Together, these results suggest the program did not successfully target those with greatest need – poor, smallholder farmers threatened by food insecurity. The results on demographic factors show that age and education were unrelated to receiving the subsidy. We find negative and significant gender effects. In our survey area, female headed households were 10.4% less likely to receive the subsidy. Given that the models control for a wide range of factors that might affect levels of need, social stature, and economic shocks, the finding reported here suggests that female heads of households were less likely to benefit from the program as a result of gender discrimination rather than other factors that might be correlated with gender.Finally, the results indicate that members of district and village development committees or chief’s councils were not statistically significantly more likely to benefit from the program. To answer this question we examine trends in party support among recipients and non-recipients across the two survey rounds. Our measure of political preferences – taken from questions on the 2008 and 2010 surveys that asked respondents whether they “feel close” to any party – sets a high threshold for finding a positive effect. Similar studies typically use measures of vote choice , which are likely to be more fluid and potentially subject to influence by anti-poverty programs. Our measure probes deeper connections between voters and parties, and is therefore less likely to be influenced by short term changes in government policy.Moreover, Zucco’s study of the political effects of a conditional cash transfer program in Brazil found evidence of an effect only on vote choice and not on partisanship. Thus, the measure of party support available in our survey data in all likelihood biases against finding a positive effect of the subsidy on political preferences. A second challenge relates to the nature of the treatment effect we seek to estimate. Sociotropic theories of economic voting have found that voters may punish and reward incumbents based on the overall performance of the economy . If voters in Malawi base assessments of the incumbent on aggregate outcomes – rather then their own personal welfare – the subsidy program may represent a treatment that was received by all Malawians. Studies have shown that the AISP contributed to reduced food prices in Malawi, indicating that Malawians may have benefited indirectly even if they did not receive subsidy coupons . These factors also bias the analysis against finding a connection between individual measures of subsidy reception and party support. Despite these challenges, the data suggest that the subsidy did affect political preferences. Table 2 compares the increase in support for the DPP between 2008 and 2010 among those who did and did not receive the 2009/10 subsidy. Among non-recipients, the percent expressing support for the DPP rose by 3.4%, from 34.8% to 38.2%, while for those who did receive the subsidy, the increase was approximately three times larger: 9%, from 35.3% to 44.3%. Thus, receiving the subsidy in 2009/10 is associated with a 5.6% increase in DPP support. While these results are suggestive of a treatment effect, there is, of course, the possibility that subsidy recipients differed from non-recipients in some important ways, and these underlying differences – not the subsidy – account for the greater increase in DPP support among recipients, relative to non-recipients. We are reassured by the results from the previous section, which showed that the 2009/10 subsidy was largely untargeted in our survey area, particularly with regard to prior party support and the primary demographic factor – ethnicity – that has traditionally been associated with party support in Malawi. Nonetheless, differences might remain that could confound the treatment estimation.

The range of average landholdings across household groups is larger in Nicaragua and El Salvador than in Honduras and Guatemala . 5 In part, these differences reflect the criteria that were used to classify rural households; however, both the average landholdings and the criteria used to construct our household groups also reflect differences in access to land in the four countries. What constitutes a large holder household in Nicaragua is not the same as in Guatemala, for example.In addition to being heterogeneous, rural households exhibit diversified income sources, technologies, and demands. The same rural household commonly participates in multiple activities and receives income from various sources. Policy shocks that directly affect one activity are transmitted to others within the household as well as to other households in the rural economy. In most household groups, the share of household income from agricultural and livestock production is less than 50% and for some groups it does not reach 25%. Nearly all groups obtain around 50% of their income from wages, the majority of which are non-agricultural. Even commercial households depend heavily on wage labor for their income. Agricultural and livestock production in each household group is also diverse. For example, in Nicaragua, medium commercial households acquire a little less than one third of their total value-added from the production of basic grains, and the other four producing groups obtain between 16% and 24% from this activity. Livestock accounts for between 27% and 52%,raspberry cultivation pot depending on the household group. The shares of traditional export crops are less than 10% of total value added in all groups except large commercial households.

Production of non-traditional crops represents more than 10% of total value added in all household groups, and non-agricultural production accounts for more than 10% in all but low-education landless households and large commercial producers . Similar levels of diversification are found in the other three countries. In all groups, the average household participates in multiple income activities, including production, wage labor, and migration. There is evidence of technological diversification, reflected in differences in factor value-added shares in the same activity but across households. In general, family value added shares are smaller in the same activities for large commercial households than for subsistence producers, while market-input shares are larger for commercial producers. Technological heterogeneity across households, like differences in market access, is generally absent from aggregate economy-wide models.To construct the rural economy-wide models, we first used data from the surveys to construct a Social Accounting Matrix for each rural household group. Each of these SAMs could be viewed as generated by a single agricultural household model. The SAMs were then joined together into a rural sector-wide SAM for each country. Nearly all of the information needed to calibrate the corresponding household models and the rural economy-wide models are contained within these SAMs, as explained below. The four rural SAMs are interesting in and of themselves, because they offer a snapshot of individual groups of rural households as well as the linkages that transmit influences of policy shocks among households. The framework of the SAMs is described in appendix B. Each household SAM consists of a set of 44 production activities, 5 factors, government, 9 investment accounts, and three “rest-of world” accounts, including the rest of the rural sector of which the household is part, the rest of the country, and the rest of the world outside the country.

Unfortunately, no single data source provides all of the information necessary to estimate the SAMs. Because of this, data from diverse sources were used to construct a SAM for each rural household group in each of the four countries. The SAMs, together with econometric estimates of remittance elasticities and family value-added shares, were used to calibrate the household models that constitute each DREM. The key data sources for each country include the rural components of the El Salvador Multi-purpose Household Survey of 2003, the Guatemala National Living Standards Survey of 2000, and the Nicaragua Living Standards Survey of 2000. All three of these are nationally representative and provide information on socio-demographic variables, production and inputs, wages, migrant remittances and income from other sources, and expenditures. Anationally representative survey was not available to construct the Honduras DREM; thus, the six rural household SAMs were constructed from two data sources: a survey of rural households conducted by IFPRI-WUR-PRONADERS in 2001-2002 , and a rural household survey conducted by the University of Wisconsin and The World Bank in 2000-2001 . The IFPRI survey covered 376 households and 1066 parcels in 19 cantons, and the University of Wisconsin survey covered 850 households in 26 cantons, mostly in the northern part of the country. We primarily used the IFPRI survey to construct the Honduras household SAMs, because of its greater detail on production costs and consumption expenditures and because it is more nationally representative, as hillside zones constitute 80% of the nation’s land area. The Wisconsin data were used primarily to disaggregate family value added.

The form of each household-specific factor and consumption demand depends on technology and preferences. On the technology side, we assume Cobb-Douglas production functions for each household group and good, in which the exponents are set equal to factor shares in value added, as implied by profit maximization and available from the household SAMs. Consumption demands were modeled using a linear expenditure system with no minimum required quantities , implying that preferences of individual groups are described by a Cobb-Douglas utility function. Budget shares, like factor value-added shares, were calculated from the household expenditure columns in the SAMs. The elasticities of remittance income with respect to migration were estimated by regressing household remittances on the number of family migrants in each household. The solution to the base model for each country determines labor demands in each activity, production, full income and consumption demands for each rural household group, the agricultural wage, migration, and shadow prices of grain in subsistence household groups.This base model is the starting point for carrying out simulations to explore the impacts of CAFTA’s agricultural provisions on rural welfare.Simulations were conducted under three different scenarios designed to explore the impacts of trade policy adjustments, which are depicted in appendix A, on the rural economy of each of the four countries in the short, medium, and long run. The simulation experiments are summarized in table 4. Our simulations are founded on two propositions. The first is that domestic prices of agricultural commodities would decrease by percentage amounts equivalent to the changes in tariffs prevailing prior to CAFTA. The second is that the changes in agricultural prices would directly affect only the producers that market the good in question. That is, subsistence households would not be affected directly by trade reforms,low round pots although they may be affected indirectly, via other rural markets.The extreme or long-run scenario, in which an immediate elimination of tariffs for all agricultural goods is simulated . This scenario illustrates what might occur without transition policies, including gradual removal of tariffs, and with no change in Central American countries’ agricultural exports to the United States. Unlike NAFTA, CAFTA does not call for a reduction in tariffs for white maize. Nevertheless, we include the removal of tariffs on white maize imports in this simulation because it is intended to represent the extreme case and also because there may be some substitutability between white and yellow maize in production and consumption. The intermediate or medium run scenario simulates a case in which there is immediate elimination of tariffs for sensitive agricultural goods whose tariff-free quotasexceeded imports from the United States in recent years, and/or for which the tariff phase-out period initiates during CAFTA’s first year. How to treat maize in this scenario is complicated for various reasons. Although CAFTA differentiates between white and yellow maize, there is some degree of substitutability between the two. However, in our simulations it is not possible to differentiate between yellow and white maize. Most household production in Central America is of the white varieties, but the available data do not distinguish maize by color. Additionally, the decision of whether to include or exclude maize based on the difference between CAFTA quotas and imports depend on the period during which one measures maize imports. This intermediate scenario includes maize liberalization in El Salvador, Guatemala, and Nicaragua.

In these three countries, tariff-free quotas established for the first year of CAFTA significantly exceed maize imports from the Untied States; thus, one would expect a decrease in domestic prices in the medium but not the short run. Maize liberalization is excluded from the intermediate scenario for Honduras, where tariff-free quotas are equal or inferior to pre-CAFTA imports and are small compared with total supply . This scenario also includes the elimination of tariffs for beans and meats in each of the four countries, because a grace period was not negotiated for these products. Finally, rice was included for Honduras, where the negotiated quota exceeds current imports. Finally, the low or short-run scenario simulates a situation in which sensitive products with special safeguards and/or grace periods of 10 years or more are excluded. This scenario excludes liberalization of rice, maize, small livestock, and milk products in each of the four countries. It eliminates tariffs on large livestock and beans in Guatemala, Nicaragua, and Honduras. There are special safeguards and a 15-year phase-out of tariffs on these products in El Salvador. The phase-out period of included products initiates in year 1 and that of excluded products begins after year 5 of CAFTA’s implementation. The exception is low-quality meats in El Salvador, for which the grace period is only three years. The results of these scenarios depend on the design of the scenarios, which reflect pre-reform protection levels and the details of the agreement’s implementation in each country, the linkages among rural households and markets, which transmit the effects of the reforms through the rural economy, the mix of pre-reform production and income activities in each household group and country , and , the model parameters, which shape the responses of rural household production, consumption and migration.The extreme scenario represents a significant shock for the rural economies of all four countries. Its immediate effect is felt in the producer households that sell the affected goods prior to CAFTA. Market linkages transmit the effect from these to the other rural household groups, including landless and subsistence households. Basic grain production falls sharply in almost all cases; however, there are striking differences between countries as well as among household groups within countries . Grain production decreases by 26-30% in Guatemala, 14% in Honduras, and 8-50% in Nicaragua. Supply elasticities for each household group, which can be calculated from the simulations, reflect general-equilibrium adjustments in each country’s rural sector. For maize, these range from 0.26 to 1.15 in Nicaragua, 0.70 to 0.90 in Honduras, and 1.65 to 1.69 in Guatemala. In most cases, the largest decreases in supply are for the grains that were most heavily protected prior to the CAFTA reform: rice in Nicaragua, El Salvador and Honduras and maize in Honduras. Nevertheless, in some cases general-equilibrium effects mitigate the effects of prices changes implied by the elimination of tariffs. This is the case in El Salvador, where the price of maize decreases by 20% under the extreme scenario but maize production falls by 1.4 and 12.2 percent in small and medium commercial households, respectively. This seemingly paradoxical result is explained by the importance of livestock products in this group’s production mix and an even steeper decline in livestock products under this scenario. The changes in basic grain prices do not have a direct effect on subsistence households. However, its impact is transmitted to these households via rural markets, particularly for labor. Implicit or shadow prices of specific basic grains are almost unchanged in El Salvador, but they decrease 0.9-2.8% in Guatemala, 0.5-1.3% in Honduras and 2.1-6.7% in Nicaragua, compared to decreases in commercial prices that range from 15% to 62%. Lower shadow prices of grains accompany decreases in subsistence household incomes. Labor demands on large farms contract, causing a reduction in rural wages in all scenarios.