Tomatoes are likely a better proxy for other vegetable crops , though each will have its unique requirements . As we imagine a shift towards dry farm agriculture in California, it is also important to consider how land that is suitable for dry farming is currently being used. Combining areas that are suitable for tomato dry farming with and without irrigation, we compiled a list of the top ten crops by area that are currently grown on these lands . Some of them are currently being dry farmed with some regularity in the state and could signal particularly easy targets for a shift to low-water practices. Others are dry farmed in other Mediterranean climates and suggest an important opportunity for management exploration in lands that might be particularly forgiving to experimentation. The remaining crops are some of the most water intensive in the state and would therefore lead to substantial water savings if the land could be repurposed. While unrealistic in the near future, calculating potential water savings from a complete conversion of suitable lands to dry farming allows for comparison with other water saving strategies. Even assuming that an acre-foot of irrigation is added to each acre of dry farm crops every year , if all the land listed in Table 3 were converted to dry farming and irrigated to the statewide averages listed in the table , California would save 700 billion gallons of water per year, vertical grow system or nearly half the volume of Shasta Lake, the largest reservoir in the state.
Given the overlap between suitable dry farm areas and high priority groundwater basins, these potential water savings are especially valuable as water districts scramble to balance their water budgets in light of SGMA. Perhaps the largest caveat to these potential water savings–and any analysis of dry farm suitability that relies solely on environmental constraints–is the economic reality in which conversions to dry farming currently occur. As discussed above, while a dramatic reduction in irrigation inputs might be feasible from a crop physiological perspective, whether farms can remain profitable through such a transition is an entirely different question. Given a dramatically increased supply of dry farm tomatoes, the profits that current dry farmers rely on could easily crumble. When considering other, less charismatic crops that could be good candidates for dry farming , customers’ likely hesitance to pay as steep a premium for high quality produce as they do for tomatoes also casts doubt on the viability of a large-scale dry farm transition given current profit structures for farmers.Our suitability map shows potential for vegetable dry farming to be practiced on California croplands that are currently irrigated, though its expansion is inherently limited. Even if markets could be adapted to support an influx of dry farmed vegetables, our map indicates that climatic constraints will largely require dry farming to be practiced in coastal regions or other microclimates that can provide cool temperatures and sufficient rainfall. However, the Central Coast’s tomato dry farming offers principles–but not a blueprint–for low water agriculture in other regions.
Based on themes from our interviews, these principles show a cycle of water savings that connect reduced inputs, management diversification, and market development . The cycle begins with lower irrigation , which can be accomplished in concert with soil health practices that build soil water holding capacity and increase long-term fertility. Reduced weed pressure and lower biomass production can then lead to reducing other inputs, such as labor and fertilizers, while also allowing for further water savings. The combination of reduced inputs and soil health practices then gives rise to a product that is unique in its water saving potential, and may also be of unusually high quality. By encouraging consumers to appreciate the products, or through novel policy support, farmers can develop markets that will provide a premium for these low-water products–or payment for the practice itself–which in turn creates an opportunity to expand the practice, further lowering inputs.As we ask how policies may impact dry farm production systems, we find a forking path in what types of expansion may result from different policies. An increase in production can be accomplished through both scaling size and scaling number . Both options can tap into the water saving cycle to decrease water usage; however, the search for just, agroecological transitions has pointed time and again to the need for scaling number . On the Central Coast, small, diversified farms have used this water saving cycle to both cut water use and develop a specialty product that allows growers to farm in areas with high land values by increasing their land access, profits, and resilience to local water shortages. Through these principles, small-scale operations have differentiated their management from both industrial farms and even other small farms in the region by creating a system based in localized knowledge, soil health practices, and thought-intensive management.
However, it cannot be taken as a given that this water saving cycle will continue to uplift the small scale operations on which it started. Recent work highlights the potential for biophysical and sociopolitical conditions to combine to shrink–rather than grow–the use and viability of agroecological systems . In the case of dry farm tomatoes, socio-political attention is already beginning to target the biophysical need to decrease water consumption. If well-intentioned policy interventions designed to decrease irrigation water use build markets that value the fact of dry farming, rather than the high quality fruits it produces , growers will be able to scale the size of dry farm operations without needing to rely on the highly localized knowledge required to produce high quality fruits. As large grocers scale up dry farm produce sales without worrying about quality-based markets that may quickly saturate at industrial scales, the agroecological systems that originally produced dry farm tomatoes may be edged out of the market. On the other hand, if policies build guaranteed markets for small farms growing dry farm produce, dry farming may grow by scaling out to more small-scale operations. Policies focused on water savings may then favor industrial or small-scale farms, depending on how interventions shape the “Market Development” aspect of the cycle. We therefore examine this cycle not only as a means to save water, but ask if and how it can enhance the viability of nonindustrial farming operations as the food system adapts to restricted water availability. We consider the relevant policy recommendations outlined in Blesh et al.’s analysis of how institutional pathways can act synergistically with farmer networks to enable agricultural diversification , asking which have the potential to point future dry farming towards scaling size vs scope.To better situate these policy options in the local context, we first look to the outcomes of institutional intervention in organic strawberry production in a very similar region on the Central Coast, and consider the analogous options for dry farm tomatoes. Similar to dry farm tomatoes, organic strawberry production was launched into the spotlight by government-mandated input curtailments . For strawberries, the development of an organic strawberry production system also coincided with the adoption of an organic certification process by the US Department of Agriculture. Growing public interest in organic strawberries and the methyl bromide ban led to the rapid expansion of industrial-scale organic strawberry production– blatantly scaling size of production . As production increased, organic strawberry markets saturated and prices crashed, pipp racking leaving an economic landscape where only the largest operations could remain viable selling strawberries at market prices . At this point, agroecological growers had to redouble their efforts to target local consumers with direct marketing strategies, as the organic label no longer added the necessary value to profitably sell their product.In an analogous case for dry farm tomatoes, it is easy to see the immediate appeal of establishing a “dry farm” label that can incorporate the social value added to dry farm tomatoes into the price of the product without relying on consumers trusting and paying a premium based solely on higher qualities. However, by divorcing dry farm practices from quality premiums and trusting relationships with customers, a dry farm label would make it much easier for large-scale growers to enter the dry farm market. These larger operations–which may struggle to produce high quality fruits or maintain direct relationships with customers but can still decrease water usage enough to produce a certified dry farm tomato–could easily grow dry farm produce at large enough scales to edge smaller growers out of the label. As has been seen in the organic program, industrial growers could also lobby for an official relaxation–a literal watering down–of label standards . This sidestep of the dry farm practices described in the above interviews would not only further advantage large scale farmers, but would also undermine the very water savings that they are meant to encourage. Administrative costs involved in enrolling in payment-for-practice programs can be a cumbersome barrier to entry, while low payouts at small scales dissuade small farmers who implement the practice from enrolling .
These patterns are currently seen in programs offering cost shares for cover cropping, where farm size is significantly larger for participants than non-participants .Given farmers’ interest and current experimentation with dry farming non-tomato vegetables, expanding the set of crops that can be dry farmed and adapted to local conditions is a clear target for future policies. Support for research and participatory breeding programs/variety evaluation could spur development of locally-adapted dry farm varietals. By compensating farmers for experimentation with diversified dry farm rotations and development of locally adapted varietals, policymakers can also absorb some of the risk inherent to on-farm experimentation and encourage innovation on the farms that are most familiar with the practice, while simultaneously lowering barriers for farmers new to the practice. To create a policy environment where experimentation feels more accessible to farmers, minimum lease terms could be set for farmland, allowing farmers to feel more secure in investing in localized practices . Priority could also be given to creating programs that connect farmers–particularly new farmers and those who hold underrepresented identities–to available farmland. Without the burden of securing water access, lands that would otherwise be impossible to farm with summer crops could become arable, particularly in conjunction with the concurrent support of the other policies discussed here. Though many areas will still require some access to water to successfully dry farm , crops’ need for water coincides with points in the season when surface water is most available , making areas with inconsistent water access over the course of the season likely candidates for dry farm success. Priority might initially be given to areas shown as suitable on the map, but as new and locally adapted crop varieties emerge, access may also extend.As water shortages are exacerbated by changing climates in California and across the globe, there is an increasingly urgent need to adapt agricultural systems to use less water. By nearly or entirely cutting irrigation to tomato crops grown in the summer season, dry farming has particular appeal as a low-water alternative to irrigation-intensive agricultural systems. While tomato dry farming is an inherently localized farming practice, suitable only for implementation in a specific region, it also offers a global model for how farming systems might shift towards low-water agriculture. Beyond decreasing water use, with the right policy support, dry farming also presents an opportunity to support innovation on small, diversified farms, transitioning the food system towards an agroecological future.Joya de Cerén offers a unique and exciting opportunity to study the daily lives of Mesoamerican rural residents and their household contexts during the Late Classic period in what is now El Salvador. The village was rapidly abandoned and experienced a sudden burial below several meters of fine volcanic ash and coarse cinders deposited from the eruption of Loma Caldera circa 592–660 CE . This eruption was relatively small in that its ash deposits only covered a few square kilometers . The ancient village of Cerén was unlucky enough to be located only 600 m southeast of Loma Caldera, falling victim to several hours of tephra falls and lava bombs that buried the settlement. Along with the rapid burial from tephra deposits, thatch roofs of the domestic structures caught on fire, subsequently preserving much of the village even further. The conditions that resulted from this eruption led to exceptional archaeological preservation and allows for the recovery of earthen architecture as well as materials left in situ that related to daily activities such as intact ceramic vessels, finely crafted lithic tools, and organic material that was utilized in a wide range of ways.