Tag: hydroponic channel

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Increased growth in response to CO2 fertilization is-well documented for many plant species

Sustainable land use is identified by most stakeholders as a priority for California, i.e., that trade offs between agricultural productivity, environmental quality, and human livelihoods and well-being be assessed for the greatest long-term benefits to society as a whole. A major risk is that sustainability may be lost when climate change and urbanization increase the pressure for short-term financial gain from current agricultural lands, especially given a range of potential scenarios for climate change range between positive to problematic. For this reason, alternate coping strategies must be assessed for their short- and long-term feasibility and sustainability. The immense breadth of commodities produced in California requires that the government expand its focus on policies or programs that support the many aspects of Californian agriculture that may be affected by these changes . Crop insurance premiums will undoubtedly rise for farmers if the insurance industry perceives a threat from climate change in the form of extreme events, such as Hurricane Katrina in New Orleans, 2005. At present, practical implications for agriculture are lagging behind the science that is predicting climate change. As pointed out by the World Meteorological Organization , neither farmers nor policy makers have good access to information for decision-making, beyond that offered by general climate forecasts. This is particularly important for repercussions of land use change that will result from the combined effects of urbanization and climate change. Although technological advances have great potential for adaptation , they should be more clearly specified by joint efforts between agriculturalists and economists, so that land use changes are planned rather than reactionary to surprise events. The practicality of moving crops from one area to another area is not simple . Shifts in land-use are not considered a market impact and therefore, are not included in most global models , but they potentially have large economic and environmental effects on people and the resource base in agricultural landscapes. For this reason,hydroponic nft a cautiously optimistic approach would emphasize agricultural research and land use planning that would examine novel scenarios for agriculture to minimize risks, facilitate coping strategies for extreme events, and ensure long-term productivity, perhaps at the expense of short-term financial gains by agricultural producers or urban developers.

The potential impacts of climate change are varied, multifarious and occur across a range of temporal and spatial scales. California is a highly populated state, rapidly growing, with dwindling resources already subject to extensive competition. In the previous sections, though we organized our discussion of climate change impacts into specific categories, it was already evident that many issues crossed over the different categories. In this section, we synthesize some of the issues identified above to demonstrate the interdependence and chain effects associated with different aspects of climate change. by developing several targeted examples of climate change impacts on California agricultural landscapes, as identified in the preceding sections of this report. There are and will be other such interactions, many of which are not yet apparent.Users of agricultural water in the Central Valley are among those most vulnerable to climate change and could be devastated by severely dry forms of climate warming . The allocation of water resources across the state is in part based upon estimates of crop water use efficiency from a limited number of crop species . Urbanization of the Central Valley will place increasing pressure on water resources and reduce their availability to agriculture. Farmers are more likely to be impacted than urban and industrial users, who can pay more for water. Farmers may benefit, however, if climate change results in an increase in water availability at critical times . At present, agriculture represents approximately 7.4% of total Californian employment; however, in the Central Valley it accounts for 25% . Farming is already a precarious occupation for some and challenging resource limitations may be all it takes for some to give into urbanization pressures and sell to developers. The confluence of changing availability of water resources, increasing urbanization, and the high dependence upon agriculture as a source of employment, may lead to disproportionately large effects of climate change upon the Central Valley of California.Increased photo assimilation of C can lead to decreased concentrations of leaf N, soluble protein, and of the carboxylating enzyme, Rubisco, and nitrate reduction may be inhibited at high CO2 concentrations, such that growth is reduced. A reduction in protein and nutrient content of plant tissue may decrease the nutritive value of food for all consumers, including herbivorous pest invertebrate species .

While warming accelerates the life cycles of many invertebrates, and thus negative impacts associated with invertebrate pests , herbivorous invertebrates may actually grow more slowly because their food source is nutrient- and protein-poor. In response, these pests may increase their feeding rates to satisfy their nutritional requirements. Furthermore, decreased plant nutritional status actually decreases resistance of some plants to pathogenic organisms. These examples highlight the importance of exploring multiple effects of elevated atmospheric CO2 concentrations on crop growth and pest communities.Temperature influences key developmental stages of many important tree crops , for which California is the country’s sole producer . Decreased chilling can result in late or straggled bloom, decreased fruit set and poor fruit quality . Heat waves may also cause early bolting, or reduce pollination success. Climate warming may lead to faster developmental rates, decreased generation times, and range expansion of some pest invertebrate species . Thus, climate change may have implications for integrated pest management and control of such pests, their natural enemies, control measure and the future climate. In a warmer climate, whereas development of some tree crop species may be slowed, that of their pests may be increased, making these crops highly vulnerable to pest damage. Rapid rates of adaptation to climate change by invertebrates may exceed the slow rate of development of resistant germplasm available to growers, thus further exacerbating this situation.Soil organic matter is an important source of nutrients, especially in organically managed agroecosystems. Under a warming climate the rate of soil organic matter decomposition is predicted to increase . This may lead to enhanced nutrient availability to plants, provided nutrient release and plant demand are temporally synchronous, but may also reduce the efficacy of soil C sequestration . Soil moisture is another key driver of soil organic matter decomposition , whose availability with climate change remains hard to predict. If carbon trading markets develop in California, trade offs between enhanced nutrient supply and decreased carbon sequestration may become significant, especially given the high energy requirements for producing inorganic fertilizers.Beneficial organisms and their processes, e.g., N fixation by symbiotic and free-living rhizobia, are stimulated by elevated CO2. Conversely, ozone exposure reduces plant growth and crop yields, hinders nitrogen-fixation, compromises disease resistance, and increases susceptibility to invertebrate damage. Although ozone is phytotoxic, elevated atmospheric concentrations of CO2 can ameliorate damage caused by O3 in some circumstances. The interacting effect of different climate factors on multi-trophic interactions are uncertain, making species-specific predictions based on single-factor analyses tenuous at best. Ecosystem-context, especially on-farm or in situ studies, and experiments in changing climate scenarios are required.While by no means exhaustive,hydroponic channel the examples developed above are intended to act as stimuli for future research to identify linkages both within and beyond agriculture to understand climate change impacts and plan adaptive strategies.Impacts of climate change, irrespective of scale, land use and sector, will be wide ranging and varied.

Climate change will impact California differently than it will other parts of the United States. National policies may not always be entirely appropriate, easily implemented, or in the best interests of the state. Consequently, impacts and our response must be assessed in the context of climate change impacts and responses both within the US and globally. Furthermore, climate change and its impacts need to be taken in the context of a world that is rapidly changing in many ways. Population growth, urbanization, and shifting patterns of agricultural production, decreased water resource supply and increased competition for those resources are areas of high priority. Recognition of the fact that actions taken now and in the near future will play a critical role in mitigating and minimizing impacts, as well as maintaining flexibility and adaptive capacity, is essential. California agriculture faces serous challenges in the coming century and beyond. Be that as it may, it has shown considerable adaptive capacity in the past, and with the right information and a suitable policy environment and infrastructure, it can continue to do so into the future. California agriculture’s potential as a net mitigator of climate change is substantial, and as such is an avenue worthy of detailed investigation. Impacts of action and inaction in limiting and/or responding to climate change will be felt well into the future. The climate is changing. California agriculture stands to be impacted substantially. The time to act, with well informed, flexible and sustainable approaches, is now.Technological innovation has been identified as one of the important engines for economic development and growth . It is driven through producing knowledge by firms and individuals, which allows them to stay competitive in the market . Since the seminal paper by Griliches , the concept of the knowledge production function has been further developed in theory and applied at national , regional , sectoral , levels, and even using a meta analysis of 15 individual studies . Agriculture is one of the sectors in which innovation has become extremely important due to scarcity of natural resources, such as land and water, and increased demand for food driven by population growth. According to Food and Agricultural Organization of the United Nations estimates,global population is expected to grow by more than a third, or 2.3 billion people, between 2009 and 2050. Agricultural productivity would have to increase by about 70% to feed the global population of 9.1 billion people over this period. Arable land would need to increase by 70 million ha, with considerable pressure on renewable water resources for irrigation. Efficiency in agricultural practices and resource usage are among the suggested prescriptions to ensure sustainable agricultural production. Sands et al. also predicted net positive improvements in global agricultural production in the year 2050, in a simulated scenario of rising population and low agricultural productivity growth. While such studies are reassuring, it becomes imperative to guarantee continuous research and development in agriculture to sustain the current rate of productivity growth, and to increase it to counter both population growth and natural resource scarcity in the future. Such objectives can be met by proper investment in agricultural R&D and its dissemination to the agricultural producers. A first step is the identification of the process of converting research and dissemination inputs into knowledge used for improvement of food production. Much of the literature reviewed in Section 2 below focuses on knowledge production functions in industrial firms and sectors. Fewer works apply the concept of knowledge production function to agricultural research , and we are not aware of estimation of such function for agricultural extension. Agricultural extension is a public based research and dissemination of knowledge to farmers by universities and/or government agencies. In this paper, we apply the concept of knowledge production function to an agricultural extension system by focusing on research-based agricultural knowledge generated by the University of California Cooperative Extension . This publicly-funded research and extension system has offices across counties within the state of California. We analyze the nature of the input-output relationship between the research inputs invested by UCCE in R&D and outreach, and the knowledge produced and disseminated by UCCE. This paper contributes to the literature in several ways that set it apart from similar endeavors. To our knowledge, this paper is the first to develop a knowledge production function for an agricultural extension system that creates and disseminates knowledge, which is in itself an innovation. Second, it develops a weighted average value of knowledge, including a number of different components of knowledge produced. Third, the paper uses academic publications to measure knowledge produced by extension, as opposed to patents used in measuring knowledge in private sector. Finally, it distinguishes knowledge production across California counties and over time, suggesting relative advantages in knowledge creation by counties with potential implications for public budget allocation.

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Consolidation occurring at the food manufacturing level has progressed rapidly for some time

The farm share for fruits and vegetables tends to be much lower and does not differ much between fresh and processed fruits and vegetables.The second major measure of food marketing costs in the U.S. is the marketing bill, which is calculated as the difference between what consumers spend for domestically produced farm foods and what farmers receive. In 2001 the farm share of the food marketing bill was 19 percent. This measure of the farm share has also been declining steadily over time, falling from 41 percent in 1950 to 31 percent in 1980 and then to 24 percent in 1990. The marketing bill takes account of food expenditures both at home and in restaurants. The proportion of the U.S. food dollar spent outside the home has been rising rapidly. In 2002, such expenditures accounted for 46 percent of the food budget compared to 37 percent in 1990 and 32 percent in 1980.While the overall U.S. food market is characterized by slow growth, eating habits are becoming more diverse. Demographic and psychographic trends, such as ethnic diversity and new attitudes about food consumption as it relates to self-identity and well-being, have contributed to a much more segmented market. Food marketers must increasingly target specific consumer segments rather than employing mass marketing strategies. More retailers are looking to their suppliers to assist them in understanding and better serving different types of consumer segments. In response, many suppliers are becoming involved in new types of marketing services, including consumer research and category management. The latter is designed to help retailers improve net profitability for a category of products through efficient assortment, pricing, promotion and shelf-space management. For suppliers the aim is to focus on identifying and servicing the evolving needs of specific accounts as a preferred supplier,nft channel rather than marketing more homogeneous products with fewer support services on a spot market basis. The U.S. retail industry is dominated by chain stores. In 2002, retail chains accounted for 83 percent of supermarket industry sales vs. 58 percent in 1954 .

The remainder of sales is by independent stores, although the vast majority of these stores are affiliated to buying groups, either voluntary chains such as Supervalu or to a lesser extent retailer cooperatives such as Associated Wholesale Grocers. In 2002 there were 32,981 supermarkets including all format types. Firms in the U.S. food-marketing sector often view a large market share, including, if possible, the position of market leader, as a key requisite to success. Pursuit of market share has led to a dramatic consolidation in the U.S. food chain at all levels, ranging from the farm through food retailing. Due to the difficulty of capturing sizable market share from rival firms, many U.S. food marketers have pursued share growth through mergers and acquisition of rivals. Mergers and acquisitions in the food sector occurred at a rapid pace in the 1980s, temporarily peaked in 1988 at 573 mergers, declined and then reached an all-time high of 813 in 1998, since declining to 415 in 2003 . Although the growth in merger activity has temporarily abated, cumulative activity in recent decades has likely had important implications for the structure of competition in the U.S. food sector.About 16,000 food and tobacco processing companies operate in the U.S., but in 1997 about 75 percent of sales were by the 100 largest of these firms. The largest sales growth, fueled mostly by mergers and acquisitions, has been recorded by the top 20 of these 100 firms, which in 1997 were estimated to account for about 50 percent of value added in food manufacturing . Most of the 53 food and tobacco industries surveyed in the U.S. Census of Manufacturing have experienced increasing concentration over time. The average market share held by the four largest firms in these industries has risen from 43.9 percent in 1967 to 53.3 percent in 1992, the most recent year for which data are available. In contrast to the food manufacturing sector, over the decade 1987-97 retail concentration ratios were quite stable with the share of U.S. food sales accounted for by the top 4, 8 and 20 retailers at about 20, 30, and 40 percent, respectively. During this decade new players were emerging in the U.S. food system, including value oriented retailers such as Wal-Mart with its fast expanding super center and club store formats, specialty food retailers like Trader Joe’s, European entrants into U.S. food retailing, and other mass and drug store merchandisers entering the food business.

This phenomenon is called channel blurring and continues with the recent emergence of “Dollar Stores,” on-line food shopping and the on-going competition from the food service sector for the consumer food dollar. This challenging marketplace motivated many conventional retailers to become larger in hopes of improving their competitiveness. From 1997-1999, in particular, mergers occurred between several already large retail chains, beginning to induce important and still unfolding changes in relationships between buyers and suppliers. By 2002 the estimated share of U.S. food sales accounted for by the top 4, 8 and 20 retailers had reached 31, 45, and 57 percent, respectively. This means that in 2002 suppliers faced a market where only 20 retail firms sold at least $276 billion in food. Despite the mergers, the United States has no truly national supermarket chains. In 2002 only eight chains had over 1,000 stores, and only one of these has over 2,000 outlets. Given the large geographic size of the United States, chains tend to be regional in focus. However, the recent high merger activity has contributed to much larger chains than ever before, with five surpassing $25 billion in sales in 2002, and four with stores in over half of the country. Still, many local and regional chains remain quite competitive by staying in close contact with their customers and implementing highly targeted marketing strategies. The regional,hydroponic nft ethnic and demographic diversity of U.S. consumers leads some to predict that small to mid-size chains may have an important role to play for some time to come. Within the retail channel the super center concept has emerged as a major industry force, which further concentrates buying power in the hands of a few very large new players. Super centers are a type of mass merchandising format combining a full-line supermarket with a full-line discount department store and range up to 24,400 square meters in size , compared to 4,900 square meters for the average supermarket. Total 2002 grocery-equivalent sales of super centers were estimated at $45.5 to $50.3 billion with total super center sales reaching $116.7 billion . The largest entrant to this format is Wal-Mart, with an estimated $29.3 billion in U.S. grocery-equivalent 2002 food sales, a 75 percent share of national super center sales and 1,333 super centers as of mid-2003. Already the largest retailer in the world, operating in ten countries, Wal-Mart is opening over 200 new super centers per year in the U.S. alone, and is fast becoming the dominant global player in grocery retailing with $244.5 billion in 2002 global sales among all its store formats, including large discount stores and warehouse club stores .

Wal-Mart has also entered the conventional grocery-retailing sector in the U.S. with 52 neighborhood markets in 2002, and growing. Wal-Mart’s immense buying power combined with its approach of driving non value-adding costs out of the food system appears to have raised the competitive benchmark for conventional retailers. It emphasizes supply chain management via covendor managed automatic inventory replenishment procurement systems. Vendors have shared responsibility for growing the category and have real-time access to data on sales of their products via Wal-Mart stores. In exchange, they provide special services, packs and support, such as category management, tailored to the needs of the Wal-Mart account. Even for volatile fresh produce items Wal-Mart tends to operate on a seasonal or annual contract basis with a small number of preferred suppliers per product or category. Other retailers are also developing closer linkages with preferred suppliers, gradually causing a shift away from the spot market, the traditional modus operandi in fresh produce procurement. Another factor contributing to greater food retailer market power is the intensifying battle for their limited shelf-space by food marketing firms. During 2003, food-marketing firms introduced 11,574 new food products . Since the average supermarket carries about 30,000 product codes, competition among firms introducing new products has led to the common practice of retailers charging fees known as “slotting allowances” for allocating shelf space to new products. Supermarket space allocations and the competition for display areas are critically important to California marketing firms. Until recently, fresh produce was exempt from slotting allowances, but these fees entered the produce department in the latter half of the 1990s with the introduction of branded fresh-cut produce. These items, like other consumer packaged goods commonly subject to slotting allowances, require dedicated shelf-space year-round. While bulk produce items are still not usually subject to slotting allowances, payment of other types of fees has increased marketing costs for growers and shippers . Increased retail buying power is influencing supplier strategies and inducing marketing alliances and joint ventures at the shipper level. Shippers have increasingly sought to come closer to matching the scale of the fewer, larger buyers. Marketing alliances between shippers appear to be the mechanism of choice as they allow each party to maintain its own growing, packing and cooling operations. This seems important for fresh produce shippers, most of which are family-owned and not publicly traded even if their businesses are structured as corporations. The larger scale obtained from marketing alliances helps firms to make greater investments in marketing systems and services, since they can be spread over a higher sales volume. Each year more suppliers are offering category management services, broadening their product lines, and becoming year-round, either via domestic or international diversification of supply sources. This greater vertical coordination can enable both suppliers and retailers to plan more effectively and reduce transaction costs, thereby improving the horizontal competitiveness of each party.U.S. food demand trends reflect the preferences of an older, wealthier, more ethnically diverse and more educated population today than 20 years ago. The entrance of more women into the workforce, in conjunction with higher incomes, has led to an increased demand for convenience in food preparation and consumption. In general, lifestyle and demographic trends have stimulated demand for eating out as well as for more value added, higher-quality, specialty and convenient food products sold in retail establishments. In response to decades of market share erosion to food service, food retailers increasingly seek to compete by providing ready-to-eat home meal replacement offerings. This implies greater retail recognition that their offerings have traditionally been “ingredients to prepare” while consumers have increasingly sought“meals to eat.” Food suppliers are actively assisting retailers in launching these more convenient new products. More and more, differentiated, specialty food products may also be organically grown, as both growers and marketers seek points of difference to compete in a saturated food marketing system. Organic foods are estimated to account for around 2 percent of U.S. retail food sales, about $9-9.5 billion in 2001 . As the nation’s largest producer of organically grown commodities California producers are major participants in the growth of this sector . Fruits and vegetables have benefited from many demographic and lifestyle trends occurring over the last 25 years, a plus for California’s horticultural-reliant agriculture. For example, higher-income households on average consume more fresh produce than do lower-income households; in 2000 households earning more than $70,000 per year on average spent $496 dollars on fresh produce annually, compared to $302 for households in the $15,000 to $29,999 range . Hispanic households, the most rapidly growing segment of the population, consume more fresh produce than do non-Hispanic Whites or African Americans . Hispanics currently represent around 13 percent of the population and are projected to reach 18 percent by 2020. However, despite the forces favoring healthful diets, U.S. consumers have become more overweight, with two-thirds of adults estimated by USDA to be overweight in 2000, including one-third obese. According to ERS’s loss-adjusted annual per capita food supply series, average daily calorie consumption was 12 percent, or roughly 300 calories, above the 1985 level .

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Costs added along the marketing chain to the final consumer often add as much or more than farm costs

That means crops Flexibility and resourcefulness by California farmers have minimized drought-induced supply reductions for tree, vine and vegetable crops, for which California has large market shares and for which retail prices would be sensitive to California disruptions. Water is being shifted away from field crops that enter the food supply indirectly and for which California is not a dominant producer. These facts mean that even a severe drought is having only slight impacts on supplies to consumers and thus only slight impacts on consumer food prices. Of course, the longer the drought lasts, the larger the impacts. grown in the Central Valley have been more subject to government mandated water cuts than crops grown in regions with a higher reliance on groundwater or local deliveries. Crops such as fresh vegetables, berries, avocados, and high-priced wine grapes are grown mostly in regions that have faced fewer mandated cuts in water supplies. Crops such as tree nuts and tree fruit, lower-priced wine grapes, and field crops tend to be grown in the Central Valley where they have been subject to more surface water cutbacks . Second, when droughts occur, farmers have strong incentives to shift water to crops with higher net revenue per acre-foot of water in order to minimize economic losses. Forage crops such as hay, corn silage, irrigated pasture, grain crops, and other field crops have much lower revenue per acre and require more acre-feet of water than tree and vine crops or vegetables . During a drought year, multi-crop farms have strong incentives to reallocate their water to crops that generate more potential profit or at least minimize losses—including losses of capital invested in orchards and vineyards. A farm growing say, grapes and wheat, will naturally leave the wheat field unirrigated to save water and keep vines alive and productive. And, farms that have the physical and legal ability to shift water to others, hydroponic grow systems will naturally be more willing to transfer water away from low revenue per acre field crops and toward other farms, either nearby or, often, much further south, that use water for tree nuts, fruits, or vegetables.

Geography and irrigation infrastructure reinforces the tendency for concentrating supply reductions on field crops. The primary regions for growing fresh vegetables and berries in California include the central and southern coastal valleys and Imperial County. Imperial County receives irrigation water from the All American Canal and the Colorado River system, thus insulating the region from this California drought. The coastal valleys have had low precipitation but rely primarily on local groundwater aquifers that have not been under as much pressure during this drought as those in the Central Valley. Table 1 lists lettuce as the representative fresh vegetable crop, but the Central Coast is also home to most production of crops such as celery, broccoli, and spinach. The Central Coast, from Santa Cruz County down the coast to Ventura County, also produces most of the strawberries and raspberries. The high revenue per acre and per acre-foot of water for crops such as strawberries and lettuce also provide great incentives to apply the irrigation water needed to sustain production. Irrigation water per acre varies widely by crop and region, from around one acre-foot per acre for winter and spring vegetables grown in cool coastal regions with ample humidity, up to perhaps five acre-feet per acre for some trees and alfalfa in the hot and dry southern San Joaquin Valley. Of course, crop yields are also high where irrigation use is high. Water costs per acre-foot also vary widely from lows of $20 to $50 per acre-foot for surface water in the north, in places where water has been plentiful or where groundwater tables are near the surface. Regular pumping costs or delivery costs can exceed $1,000 per acre-foot in some regions and during drought periods. In general, however, it is clear that where physically feasible and allowed by regulation, farms will tend to use available water on tree, vine, and a few other crops while shifting water away from field crops. The drought affects California production of livestock commodities mainly through impacts on forage crop output. Poultry, egg, dairy, and finished beef production relies mostly on grains shipped in from other states. But, California-produced hay, silage, and irrigated pasture are important for cattle. Hay and silage, mostly produced in California, comprise about 20% of California milk production costs.

Therefore, a 50% increase in costs of hay and silage due to the drought would increase milk production costs at the farm by a bit less than 10%. Many observers point to the large share of California produce in the nation’s supply. Table 2 indicates California’s large share of U.S. production for tree, vine, and vegetable crops. These are the crops for which the current drought is not causing large supply cuts. California has smaller market shares for livestock and field crops where California supply reductions are large. These facts mean that even when California supply falls significantly, say for wheat, rice or hay, the amount in the U.S. or relevant global market falls by a much smaller percentage. Two caveats affect the interpretation of these production shares. First, for some important crops, the relevant markets are global. For example, Table 2 indicates that about two thirds of California almonds and about half of California rice are exported. Global market share is crucial. For almonds, California also has a large share of the global market so if supply were to fall , price would indeed rise. Exports are also important for dairy products, processing tomatoes, and rice. Markets for each of these commodities faces particular conditions. In the case of milk and tomatoes, California ships processed products into competitive national and global markets. For rice, California is a tiny part of global markets, but produces a specialized style of rice for which California production shortfalls do affect price somewhat. Finally, in the case of wine, imports matter as well as exports. While California dominates U.S. wine production, the market is quite competitive— especially in the case of wine from Central Valley grapes that are most likely to be affected by drought.Of course, farm price changes are not the only driver of retail prices.For example, the farm share of retail cost for strawberries or lettuce is 30% but only about 7% for bread. These relationships mean that even if prices rise at the farm, the percentage impact for retail consumers is generally muted—and more muted for processed products and those subject to costly and specialized marketing and transport. Flexibility by retailers and consumers also moderates price impacts.

Given that drought has slowly evolving impacts with substantial warning, wholesale and retail buyers have ample time to plan ahead and source products from where they are most available. Finally, many consumers are willing to substitute across products such as types of melons or lettuce, or from table grapes to some other fruit if relative prices change. California produces about 20% of the U.S. milk supply,hydroponic channel which can be processed into cheese. The farm share of the retail price for cheese is about 30%. That is, the price of milk before it has been processed into cheese makes up 30% of the cheese retail price. The own-price elasticity of demand for milk, a measure of the responsiveness of quantity demanded to a given change in price, is -0.3. Given the reduced hay and forage supplies to the dairy industry and associated higher prices, we estimate that California milk production may decrease by 5% due to the drought. Plugging these parameters into the equation tells us that the retail price of cheese would increase by 1%. California is the dominant supplier of fresh produce in the U.S. during much of the year, and its share of the U.S. lettuce market is about 80%. Given a 3% decrease in the quantity of lettuce supplied by California farms, retail price would increase by about 1.5%. California produces japonica rice for the U.S. and international markets. California rice accounts for about half of the relevant U.S. market, some of which uses specialized California rice and some of which uses medium grain rice produced elsewhere. The market share and demand elasticity reflect that California rice is unique for certain uses in some markets and has close substitutes for other uses. Because of severe reductions in surface water availability, California quantity of rice will likely fall by about 33%, and is therefore likely to cause a 10% increase in retail price. As a highly processed farm product, grapes account for only about 10% of the retail price of wine. We use an average elasticity of demand for wine grapes of about -0.5. We estimate that California makes up about half of the relevant market for U.S. wine sales, with imports comprising much of the rest. The reduction in grape quantity of only 1% due to the drought reflects the relatively low share of water costs in grape production costs and the limited supply flexibility for a perennial crop. These parameters imply the drought is likely to cause an increase in the retail price of California wine of about 0.10%.A convenience sample of 300 field workers was recruited from 15 farms in agricultural regions of California’s Central Valley during the summer of 2014. To gain access to the work sites, we invited employers to participate in the study through outreach at local meetings and events, flyers, and word of mouth. About 30% of the farms we approached agreed to participate in the study. Bilingual, bicultural field staff recruited employees of the farms by explaining the purpose and protocol of the study in Spanish and obtained consent. Eligible participants were 18 years of age or older, worked in the fields for at least 6 hours per day, understood Spanish and were neither pregnant nor had any impediment to swallowing the ingestible sensor .

All eligible participants who volunteered were enrolled in the study for a single day of data collection and were given a small monetary gift of appreciation. Preshift measures—A brief, preshift questionnaire was administered orally in Spanish to assess participant eligibility and to collect demographic information. A capillary blood sample was taken and analysed using the handheld i-STAT point of care test to measure serum creatinine . The i-STAT measurements are traceable to isotope dilution mass spectrometry through the standard reference material SRM967.Weight was measured in a base layer of clothing using a Seca 874 medical scale, and height was measured without shoes using a Seca model 213 stadiometer . Field staff recorded base layer clothing to ensure that the participant wore the same garments for weighing after the shift. Participants swallowed a CorTemp HT15002 ingestible wireless temperature transmitter probe . The probe transmitted core temperature at 1 min intervals.Participants were fitted with a Polar T31 ECG heart rate transmitter around the thorax which transmitted heart rate measurements at 1 min intervals. Signals from the probe and the heart rate strap were recorded using a CorTemp HT150016 Data Recorder attached to their belts. All staff involved in data collection were trained and supervised, and all equipment was regularly calibrated to ensure accuracy. Post shift measures—Following the work shift, ~7–12 hours after ingestion of the CorTemp, workers returned to the data collection station and unloaded all external equipment. They were then reweighed in the same clothing as they wore during the preshift weight, prior to ingesting any water or refreshments. A post shift questionnaire was orally administered in Spanish to obtain information on health history and possible social and behavioural risk factors, such as a personal or family history of kidney disease and work history. A second capillary blood sample was obtained to document serum creatinine, and glycated haemoglobin was measured using a Siemens DCA Vantage Analyzer . A single blood pressure was obtained in the seated position using an automated blood pressure cuff . Participants’ BMI, blood pressure, diabetes risk status and blood creatinine level were shared with them at the conclusion of the day, and participants who had abnormal results were referred to local health clinics for follow-up care.