Month: October 2022

To decipher the molecular defect in d53, we isolated D53 by a map-based cloning approach. Using an F2 population of ~ 12,000 plants generated from the cross between Ketan Nangka and the mutant, we further delimited the D53 locus to a 34-kb DNA region on the BAC clone OSJNBa0032J07, which contains three putative genes . Sequence analysis revealed a single-nucleotide substitution and 15 nucleotides deletion in the third exon of LOC_Os11g01330 in d53, which resulted in an amino acid substitution and deletion of five amino acids . To verify that this mutation caused the tillering dwarf phenotype, we generated transgenic plants expressing the wild type or mutant D53 gene under the control of rice Actin1 promoter, in a wild-type background. Strikingly, all transgenic plants expressing the mutant d53 gene showed a more exaggerated tillering phenotype than those expressing the wild-type D53 gene. The severity of tillering phenotype in these transgenic plants was correlated with the expression level of the transgene. Notably, overexpression of the wild-type D53 gene also caused a moderate increase in tillering, compared to the vector control plants . These observations suggested that the D53 protein acts as a repressor in the SL-mediated branching-inhibition pathway and that the dominant tillering phenotype of the d53 mutant was most likely caused by a gain-of-function mutation in d53. To further confirm this, we generated D53 knockdown transgenic plants using a RNA interference approach. As expected, reducing D53 expression in d53 background drastically reduced the tiller number . Taken together, these data support the proposition that d53 mutation enhanced D53 activity in repressing SL signaling. D53 is predicted to encode a protein of 1131 amino acids. A BLAST search identified a closely related homolog of D53 with 96.6% amino acid sequence identity in the rice genome. In addition, D53 homologs were found in other monocots and dicots, but not in lower plants, animals or microbes, indicating that D53- like proteins are specific in higher plants . Sequence analysis by the HHpred structure prediction server revealed that D53 shares a similar secondary structure composition, despite low primary sequence homology, to proteins of the class I Clp ATPases family, hydroponic channel which are characterized by an N-terminal domain, a D1 ATPase domain, an M domain, and a D2 ATPase domain36.

Notably, the D2 domain of D53 contains a highly conserved linear sequence, FDLNL, which closely matches the ETHYLENE RESPONSE FACTOR-associated amphiphilic repression motif , which is known to interact with the TOPLESS family of proteins and involved in transcriptional repression37 . Real-time PCR analysis revealed that D53 was widely expressed in the examined rice tissues . D53 promoter driven GUS reporter gene assay showed that GUS staining was observed in vasculature in roots, shoots, leaves, leaf sheaths, nodes, internodes and young panicles, preferentially in the parenchyma cells surrounding the xylem . Moreover, D53 expression was up-regulated by GR24 treatment in wild-type plants, but down-regulated in six d mutants, suggesting that expression of D53 is regulated by SLs signaling . The D53-GFP fusion protein is exclusively localized to the nucleus in rice protoplasts and the pActin::D53-GFP transgenic root cells . Previous studies have identified the F-box protein D3 and the α/β hydrolase D14 as two key components of SL signaling in rice10,12, of which D14 and its orthologues in Arabidopsis and Petunia have been proposed to directly participate in SL perception 19,27,28. Yeast two-hybrid assay showed that both D53 and d53 could physically interact with D14 in the presence of GR24 . Domain deletion analysis indicated that the D1 domain of D53 was essential for the GR24-dependent D53-D14 interaction. Interestingly, its binding activity was inhibited by the M and D2 domains, although their negative effect can be overcome by the N domain . We verified the D53-D14 interaction in N. benthamiana leaf cell nucleus both in the presence or absence of exogenously applied GR24 using a bimolecular fluorescence complementation assay . The observed interaction between D53 and D14 in the absence of exogenously applied GR24 might be due to the effect of endogenous SLs present in the tobacco leaf cells. Consistent with the previously reported GR24-depedent interaction between DAD2 and PhMAX2A in yeast19, our in vitro pull down assay also revealed a direct physical interaction between D14 and D3 in a GR24- dependent manner . Furthermore, using recombinant GST-D3-OSK1 fusion protein as the bait, our in vitro pull-down assay showed that D14 could be more efficiently coimmuno precipitated from d3 plant extracts in the presence of exogenously applied GR24 . Together, these results suggest that SLs may act to promote complex formation among D14, D3 and D53, linking D53 to the hormone-perception components of the SL signaling pathway. To investigate how SL regulates D53, we performed a set of additional experiments. Both western blot analysis and fluorescence microscopy examination showed that GR24 treatment induced rapid degradation of the D53 protein in wild-type cells, but not in d3 and d14 mutant cells . We further showed that D53 was degraded by the proteasome, as a proteasome inhibitor, MG132, but not other protease inhibitors, effectively blocked GR24-induced D53-GFP degradation . Notably, unlike the wild-type D53-GFP fusion protein, the mutant d53-GFP fusion protein appeared to be stable in the presence of GR24 . Interestingly, we noted that D53-GFP and D53-LUC were still degraded in the d53 mutant cells, but not in d3 or d14 mutant cells , indicating that the D53 degradation pathway was still operational in the d53 mutant.

Together, these results suggest that SL triggers proteasome-mediated degradation of D53 in a D14- and D3-dependent manner. Importantly, the insensitivity of d53 protein to SL-triggered turnover is consistent with the observed dominant gain-of-function mutant phenotype of d53. To provide genetic support for the functional relationship between D53, D3 and D14, we generated d3 d53 and d14 d53 double mutants. The d3 mutant had more tillers and it was shorter than the d14 and d53 single mutants . The d14 d53 double mutants exhibited a dwarf tillering phenotype resembling the d14 and d53 parental plants, whereas the d3 d53 double mutant exhibited a dwarf tillering phenotype resembling d3 . The lack of obvious additive effects among these mutants suggests that D3, D14 and D53 act in the same signaling pathway. To further test their epistasis relationship, we knocked down D53 gene expression in the d3 and d14 backgrounds. As shown in Fig. 4g and Extended Data Fig. 9b–d, the mutant phenotype of d3 and d14 was restored to nearly wild type levels, demonstrating that D53 acts downstream of D3 and D14, and that accumulation of D53 protein is responsible for blocking SL signaling and conferring the dwarf tillering phenotype in these mutants. It has been speculated that perception of SLs triggers the degradation of putative repressors by the SCFMAX2 ubiquitin ligase complex to suppress shoot branching21,29,30. In this study, we established that D53 acts as a repressor of SL signaling in rice. Consistent with the previous observation of GR24-dependent interaction between DAD2 and PhMAX2 , we found that GR24 also promotes the interaction between D14 with D53 and D3 . Further, we showed that D53 is targeted for degradation by the proteasome in a D14- and D3-dependent manner . Together, these data collectively support the notion that SL perception by D14 acts to promote ubiquitination of D53 by the D14-SCFD3 ubiquitin ligase, and subsequent degradation of D53 by the proteasome, leading to the propagation of SL signal and downstream physiological responses . Our findings revealed a remarkable similarity between the hormonal perception and signaling mechanism of SL and several other classes of plant hormones, including auxin, jasmonate and gibberellin25,38–40 . Interestingly, a recent study reported that a D53 homologue in Arabidopsis, SMAX1, acts downstream of MAX2 in repressing the seed germination and seedling photomorphogenesis phenotypes of max2, but not the lateral root formation, axillary shoot growth, or senescence phenotypes of max2 . Further, as observed for D53, three closest homologs of D53 in Arabidopsis were also induced by GR24 treatment41, suggesting that D53 and its homologues play a broad role in regulating different developmental processes and that the D3/D53 functional module is conserved between monocots and dicots. Consistent with this notion, the SL-analogous compounds karrikins also employ a MAX2 and KAI2 – dependent pathway to regulate seed germination and seedling growth29,42. The identification and characterization of D53 in SL signaling now set the stage for further dissection of the mechanisms by which SLs regulate plant form and its complex interactions with parasitic weeds and symbiotic arbusular mycorrhizal fungi3 .According to the United Nations, the population of the world is expected to grow in the next century, which in turn encourages the development of innovative techniques to ensure agricultural sustainability. Agriculture on productive land is threatened not only by high levels of urbanization, uneven water distribution, hydroponic dutch buckets and inclement weather, but also is threats to biodiversity that have unfavorable environmental impacts.

Due to the anticipated drastic population growth and constraints on resources in the upcoming decades, only 10% of the demand for food is estimated to be met by expansion of productive lands, with the remainder relying on new techniques that can achieve higher yields. Therefore, developing novel methods to augment the ratio of crop production over used land is a vital issue. In recent years, the indoor vertical farming systems with artificial light are found to be a viable solution to resolve the in-creasing demands of future agricultural products. The IVFS are promising alternatives to open field or greenhouse agriculture because they have precisely monitoring environmental parameters and are insensitive to outdoor climates, which can boost annual sales volume per unit area up to 100 times compared to that of open lands. Furthermore, employment of light emitting diodes as light sources can initiate and sustain photosynthesis reactions and the optical wavelength, light intensity, and radiation intervals can further enhance growth quality. Recently, many studies have been carried out to investigate how environmental parameters, such as closed-loop control, ultrasound, and electro-degradation, affect hydroponic cultivation of leafy vegetables in these systems. One of the most influential factors affecting growth in IVFS is to maintain a uniform air flow at an optimal air current speed over plants canopy surfaces.It has been found that inducing a horizontal air speed of 0.3–0.5 m s−1 boosts photosynthesis through more efficiently exchanging species between the stomatal cavities in plants and the flow of air. Lee et al. studied the effects of air temperature and flow rate on the occurrence of lettuce leaf tip burn in a closed plant factory system. Furthermore, it was observed that the relative humidity of the air flow can significantly influence calcium transportation in lisian thus cultivars. According to Vanhassel et al., higher levels of relative humidity can significantly decrease the occurrence of tip burn. Therefore, it is vital to maintain relative humidity in the desired range to ensure even distribution of calcium in lettuce leaves. Over the past few years, researchers have been trying to develop techniques for improving uniformity over cultivation zones. Regardless of the recent progress, the control and automation systems of IVFS bring additional costs, which makes systematic experimental investigation and optimization a challenge. Computational fluid dynamics has been utilized as a reliable tool to numerically simulate complex physical phenomena. Markatos et al. developed a CFD procedure to study velocity and temperature distribution in enclosures using buoyancy-induced physics. Stavrakakis et al. investigated the capability of three Reynolds Averaged Navier-Stokes models to simulate natural ventilation in buildings. Papakonstantinou et al. presented a mathematical model for turbulent flow and accordingly developed a 3- D numerical code to compute velocity and temperature fields in buildings. A novel gas-liquid mass transfer CFD model was developed by Li et al. to simulate the absorption of CO2 in a micro-porous micro-channel reactor. Yuan et al. visualized the air paths and thermal leakages near a complex geometry using a transient thermal model with buoyancy-driven convection, conduction and thermal radiation heat transfer and flow field near a vehicle structure. In the context of agriculture, researchers have extensively employed CFD analysis for study of ventilation, air flow, and microclimate in indoor systems. Zhang et al. developed a CFD simulation to assess single-phase turbulent air stream in an indoor plant factory system and achieved the highest level of flow uniformity with two perforated tubes.

The Pajaro Valley Water Management Agency formed in 1984 to manage existing and supplemental water supplies within the basin. PVWMA has implemented policies and an assortment of strategies to address groundwater overdraft while maintaining agricultural productivity and meeting water demands in the area, which have risen steadily in the past 50 years along with population, agricultural acreage, and groundwater extraction, with pump age rising from 7.5 million m3 in 1964 to 13.5 million m3 in 2009 . Agricultural land predominates in the valley and was estimated at 10,000 ha in 2006, compared to 5,000 ha for urban and rural municipalities . Crops include berries, vegetable row crops, grapes, apples, and cut flowers, and production has developed into a multi-million dollar agricultural sector with crop yields valued at over $800 million in 2011, and the region ranks fifth for total agricultural production in California . Large corporations, such as Driscoll’s, California Giant, and Martinelli’s & Company helped the area to become one of the top ranked farming cities in the country, and this agroindustrial pressure creates a unique economic environment worth studying, which includes high-value crops, a recycled water system, and an aquifer recharge basin.Although crops shift yearly due to numerous factors such as traditions, preference, economic profit, etc., the total area of agricultural land has remained consistent since 1989 . Agricultural demand for Pajaro Valley was divided into inland and coastal regions. Given the extent of the historic seawater intrusion and coastal access, agricultural demand for Pajaro Valley was divided into inland and coastal regions that are delineated by the CDS and Highway 1 . This study defined inland crops as strawberries, vegetables , bush berries , vine grapes, artichokes, apple trees, cut flowers, and other crops and coastal crops as strawberries,ebb and flow trays vegetables, artichokes, cut flowers, and a small number of other crops. These crop assignments were adapted from the 2012 PVWMA data in the Basin Management Plan Update .

Overdraft of the Pajaro Valley groundwater basin has depleted the aquifer storage and led to saltwater intrusion from Monterey Bay into freshwater aquifers, causing water quality degradation and unsustainable storage levels. Seawater intrusion has been observed up to 4.8 km inland and could potentially reach farther if over extractions continue . PVWMA is executing several measures as part of a Basin Management Plan to address the imbalance of water demands and supplies. The CDS was implemented in 2009 to supply irrigation water to farms in coastal areas with compromised groundwater supplies. Water from the CDS serves in lieu of local groundwater and helps to reduce coastal seawater intrusion by reducing groundwater pumping near the coast through the delivery of a mixture of groundwater from farther inland in the basin, water recovered from a locally managed recharge system, and wastewater from the Watsonville Area Water Recycling Project. This facility and its conveyance system can produce ∼4.934 million m3=year , which includes recycled water, Harkin Slough recovery wells, and blend wells. PVWMA also increased groundwater supplies through the Harkins Slough Project, a managed aquifer recharge and recovery basin. The project aims to replenish a shallow aquifer by infiltrating water diverted from the Harkins Slough in the winter to provide an alternative solution to the overuse of groundwater. Water demand and supply challenges of this area provide a unique opportunity to develop strategies for improved water allocation and conservation. This study uses the coupling of a simulation and optimization model to provide a unique approach to sustainable groundwater management and could be integrated into future decision-making processes and groundwater sustainability plans.A GBM was built and calibrated to represent the water supply, water use, and groundwater storage of Pajaro Valley groundwater basin. An optimization model was built to determine crop acreages that maximize agricultural profit given water availability constraints. The models were coupled to estimate the aquifer storage and assess the sustainable carrying capacity of Pajaro Valley groundwater basin by using the outputs from the optimization model as inputs into the groundwater box model.Data sources for inflows included land use data and Harkin Slough recharge inflows obtained from PVWMA and precipitation and reference evapotranspiration obtained from the California Irrigation Management Information System. An estimate of evapotranspiration was developed based on data from the National Solar Radiation Database and the Hargreaves-Samani equation whenever ETo data was unavailable . Monthly crop coefficients values were obtained from Hanson et al. . In this study, the agriculture water demand was estimated using potential evapotranspiration, which can differ from the actual evapotranspiration. The application efficiency was assumed to be spatially uniform throughout the valley.

The percentage of irrigation use for gravity, sprinkler, drip, and other methods were obtained from the California Department of Water Resources and average application efficiencies were obtained from Sandoval-Solis et al. . Data sources for outflows include population data for the City of Watsonville, and rural municipalities that were retrieved from the US Census Bureau , and water use per capita for indoor and outdoor consumer water use from 1999 to 2015 was obtained from Cahill et al. . WUPC from 1966 to 1999, was assumed as the fixed value of the 1999 WUPC. Similarly, WUPC from 2016 to 2040 was assumed to be the same value as in the year 2015. Rural WUPC was estimated to be 29% of the City of Watsonville, based on the urban-rural population ratio. The acreage factors and acreage share percentage were obtained from Lin et al. . Well production data for the City of Watsonville, agricultural wells and recycled water was provided by PVWMA. Linear regression models were used to fill gaps when input data for specific periods were missing. Table S1 shows the model equations.Based on Eq. , at a given time, a groundwater basin has a certain amount of water that might increase or decrease based on the change of storage. If the total inflows are greater than the total outflows, the positive change will increase the groundwater storage. Conversely, if the outflows exceed the inflows, then the negative change will result in the decrease in groundwater storage. In this study, net groundwater storage is defined as the average change of storage for a determined period, and the change of storage is calculated every year by subtracting the inflows minus the outflows. GBM inflows ranged from 24.6 to 96.6 million m3=year, and outflows ranged from 40.7 to 98.6 million m3=year. In contrast, PVHM inflows ranged from 16 to 103 million m3=year, and outflows ranged from 30.8 to 90 million m3=year. Groundwater pumpage is dominated by agricultural use and was 13.5 times greater than urban and rural water demands. Recharge to the aquifer from precipitation is 6.2 times greater than recharge due to excess irrigation. Fig. 2 shows the net change in groundwater storage of the GBM and PVHM.The optimization model was built to estimate a series of optimal acreages that maximize economic profits. Profits were estimated as yearly benefits , which were the difference between crop revenue and the costs of production for that crop. All prices were adjusted using the consumer price index for 2015. Crop revenues were calculated based on crop incomes from crop reports and economic contributions of Monterey County from 1966 to 2014 and the annual crop and livestock reports of Santa Cruz County base.

COP components of the model were obtained from budgets published through current cost and return studies from the University of California Cooperative Extension . These budgets were used to determine annual costs per acre for each crop including operational, cultural, and overhead costs that covered land preparation, plant establishment, fertilization, pest management, harvest, labor, equipment costs, property taxes, irrigation, sanitation, and management salaries. The price of water was removed from each budget because it was included separately in the optimization equation for specific circumstances in Pajaro Valley. COP budgets for crops grown in the California central coast region were used for strawberries, vegetables, bush berries, artichokes, and apple trees, while the COP budget for grapes grown in the upper San Joaquin Valley was used for vine grapes. The UCCE has not published a COP budget for cut flowers in California; therefore estimates were made based on COP budgets developed by the Cooperative Extension at Penn State University. Based on budget availability, each crop was treated slightly differently. The COP for strawberries was found by taking the average of two budgets, one for each year of production . The COP for vegetables was determined based on budgets for various types of lettuce grown in this region because lettuce is commonly used in rotation with strawberries . The COP for bush berries was calculated through consideration of the budgets for raspberries and blackberries,4×8 flood tray including an establishment year, the first year of reduced production, and four subsequent years of steady production . The COP for artichokes was based on a single production year . The COPs for apples and vine grapes were based on a 25-year life of an apple orchard and vineyard, respectively . The first year of establishment for vineyards is the most expensive, with subsequent years costing one-third of the initial price. The COP of the other crop group was based on the budgets of alfalfa, wheat, and beans . Table 2 shows the COP budgets and revenue figures. All crops show economic benefit except for vine grapes, for which revenue remains below the break-even point. From the year 2000 to 2010 vine grapes had economic benefits, but not from 2010 to 2015 where COP exceeded revenues. Vine grapes have become less economically viable in recent years because of inexpensive imports from Australia, competition from corporate farms in other regions of California, and the fact that harvest standards often change in harvest time, hang time, and Brix standards .

The cost of water in Pajaro Valley was defined by the price of water and the energetic cost for pumping. Annual rates published by the City of Watsonville and PVWMA set water prices, which differ based on user location and water source . Water prices ranged from $101 to $338 per acre-ft and increased with an average yearly rate from 3% to 9.5% . The energetic cost of pumping was estimated to range from $0.18 to $0.20 kWh for an average well depth of ∼90 m for domestic wells, and ∼131 m for municipal wells .The coupled model determined the optimal crop pattern by maximizing net economic benefits while constraining agricultural water and land use, which decreased groundwater overdraft. Both scenarios began in the year 2000 with approximately ∼8,000 ha and 62.5 million m3=year of water use. For the next 15 years, the trend increased to ∼8,500 ha and 64.1 million m3=year for the baseline scenario and these values were maintained until 2040. The optimized scenario decreased water use to 49.3 million m3=year for ∼6,315 ha . The crop acreages that gained the most economic revenue and water use were bush berries, cut flowers, strawberries, and vegetables. These crops were allocated within their maximum allowable acres. The lowest crop revenues were for apple trees, vine grapes, artichokes, and others, reflecting their minimized acreages. The optimal land use had a total acreage reduction of 15%. The objective function was to maximize the net revenue from agricultural production while determining the optimal crop pattern for the available water. A similar objective function is observed in other studies. Mainuddin et al. determined the irrigation plan by optimal crop area allocation and groundwater requirement by maximizing the net economic benefit in Thailand. Benli and Kodal developed a linear model that allocates optimally available resources, rearranges crop patterns, and maximize economic crop revenue. These studies showed a decrease in available water corresponded to the upper limits of acreages of higher values crops, which is consistent with the finding from this study that crop acreages increase or decrease relative to the change in their economic profit. Regarding economic benefit, the baseline scenario showed total revenue of $274 million, which increased to $289 million in the optimized scenario using the same allotment of water . The net difference between the optimized and baseline scenario is shown in Table 4, where the pattern of higher revenue for the optimized scenario is observed even when the available water was reduced to 60 million m3. However, if available water is reduced to 50 million m3, revenue is reduced to ∼$239 million. In general, annual revenue decreased by 2.4% on average, which translates to ∼$5 million loss per reduction of 1.2 million m3 of available water.

Moreover, despite clearly being a developing country, China’s de minimis exemption for product-specific support is equivalent to only 8.5% of the total value of production of a basic agricultural product . Moreover, some measures, such as investment subsidies for all farmers and input subsidies for the poor and other resource-scarce farmers, that are generally available for policy makers to use in developing countries, are not allowed in China . Because of its Socialist background and the difficulty that the world has had in assessing the scope of the government’s intervention into business dealings of all types, China agreed to a series of measure governing the way that they will deal with the rest of the world in cases of anti-dumping and countervailing duties. Most simply, special anti-dumping provisions will remain for 15 years. According to these provisions, in cases of anti-dumping China will subject to a different set of rules that countries can use to prove their dumping allegations. In addition, the methods that countries can use against China to enforce anti-dumping claims when they have won will differ from most of the world. In essence, this set of measures makes it easier for countries to bring, prove and enforce dumping cases against China. It should be noted, however, that that although the rules differ from those governing trade among other countries, China will get the same rights in their dealings with other countries, a element that could help them in some cases with their dealings with dumping matters when they concern their partners’ exporting behavior. China’s WTO commitments and privileges associated with the measures in other parts of the agreement also will directly or indirectly affect its agriculture. For example, on agricultural chemicals, China has committed to replace quantitative import restrictions on three types of fertilizers by TRQs. Tariffs will be cut on accession and further cuts will be phased in by 2005 in almost all industrial products, . Furthermore, China will reduce significantly its non-tariff measures and eliminate all quotas, tendering and import licensing on non-farm merchandise by no later than 2005. For textiles and clothing, however, the current ‘voluntary’ export restraints will not be completely phased out until end of 2008, meaning that the expansion of exports may not expand as fast as they would under a less restrictive regime.

Substantial commitments to open up services markets in China also have been made. While substantial institutional and marketing reforms implemented in agriculture since the late 1970s will help facilitate the response of households to the changes that will arise with the implementation of WTO and, flood table more generally in China’s overall transition to the post accession WTO regime, China still requires considerable reform to meet its WTO membership commitments . In fact, the government has realized for a considerable time that it faces a real challenge. In fact, in many instances, officials are taking this challenge as an opportunity to stimulate and accelerate its on-going reforms in both international and domestic policies. Policy responses as a result of WTO accession are expected take one of two forms. One is a policy response that is required of China in order for it to be able to keep the nation’s commitments and to adjust its domestic policies to be consistent with those promulgated by the WTO’s rules. The other is a response that will consist of introducing some new set of measures that are allowed under the new framework that could help to boost China’s economy and minimize adverse shocks that arise as part of the accession. Identifying the two kinds of policy changes is essential to study how China’s WTO accession will affect the ways that policy makers respond after accession.Many of the most important changes that will occur because of WTO will be in the area of legal and legislation changes. China reserves the right to use a transitional period of one year from the date of accession to amend or repeal any institution, regulation, law or legal stipulation in its current economic policies in order to make them consistent with the spirits of nondiscrimination and transparency. The government recognizes this and has already started to make a concentrated effort to rectify existing legal rules and legislation in the late 1990s. To provide a general guidance for ministerial and local government authorities to amend or repeal the relevant regulations, laws and policies, the State Council decreed two important Regulations in January 2002: the Regulations on Formulation Process of Laws; and the Regulations on Formulation Process of Administrative Laws. Essentially, a guide for local governments and ministries, these new regulations were issued with the aim of transferring many government functions toward the market and directing the government to take a more regulatory, indirect role in commerce and trade. It tries to limit the role of government and emphasizes that the role of government is primarily one to provide social and public services. The regulations also seek to simplify administrative processes and increasing the transparency of regulations and policies.

For example, during the last stage of WTO negotiation, each ministry formed its leading group or committee to work on all of the laws and regulations under its jurisdiction. These committees typically were comprised of decision makers and experts who had the mandate of cleaning up all existing regulations and preparing a proposal for amending or repealing those laws and regulations that are not consistent with the WTO rules and China’s commitments to its WTO accession. Local governments also had similar committees. Ministries and provincial government are also working closely with its corresponding law and regulation committee under the Standing Committee of the National People’s Congress for those laws and regulations to be amended or repealed by the People’s Congress. Several recent experiences involving amending laws and regulations and creating new institutions related to agriculture demonstrate the effectiveness of these committees and China’s overall commitment to its WTO obligations. For example, China’s Patent Law was re-amended on July 1, 2001. Many of the associated regulations also were redone. Moreover, a new set of regulations on Plant Variety Protection was put into effect in 1999 when China became the 39th member country of UPOV. Soon after passage, government agencies quickly proposed and implemented detailed regulations facilitating the implementation of PVP. The MOA and State Forest Bureau also created a new set of institutions, a series of Plant New Variety Protection Offices. Finally, China’s Seed Law was issued in 2000. Hence, the rights of new plant varieties are now protected by both the PVP and Seed Law. To assist in the initial implementation of these laws the government has set up an IPR Affairs Center under the Ministry of Science and Technology. In order to fulfill its legal obligations related to agriculture, MOA also has repealed several regulations since 2000 that sought to subsidize certain types of enterprises and apply different rules in agricultural input industries to different economic actors. Officials have eliminated the Regulations on the Development of Integrated Agricultural, Industrial and Commercial Enterprises under State Farms and the Regulations on the Development of Rural Township and Village Owned Enterprises . Seed Management Regulations that gave monopoly powers to local seed companies and Pesticide Field Trial Rules that discriminated against foreign companies were abolished. Despite the above substantial efforts, China still requires considerable institutional reform. There are still a number of laws and rules that treat domestic and foreign companies and individuals differently. These changes still need to be changed to allow China to fulfill the legal obligations that they are committed in its Protocol of Accession to WTO. It may be even a greater challenge to build up the nation’s capacity for effective implementation of the amended and new laws.

Reforms and liberalization in China’s trade laws and regulations are perhaps the most advanced, in part, because of its strategic role in the economy . Through nearly 20 years reform, China’s foreign trade regime has gradually changed from a highly centralized, planned and import substitution regime to a more decentralized, market-oriented and export promotion one . These changes in trade and other policies have significantly affected the total and composition of China’s trade in favor of the products in which China has a comparative advantage. On the other hand, as argued by Martin , while China’s trade policies in most areas have been transformed in the reform era, trade in many agricultural goods remains under relatively non-transparent state trading arrangements. Accession to the WTO will be a critical time for China to push its trade reform in agricultural sector, including both tariff and non-tariff measures. Changes in tariff policy are more straightforward and simpler than non-tariff policy reforms. China followed its tariff reduction schedule specified in the Protocol on the first day of 2002. Average tariff rate was reduced from 15.3% in 2001 to 12%. For agricultural products the tariff reduction was from 21% to 15.8%. China has also started to implement its three years of transition of progressively liberalize the scope and availability of trading rights for agricultural products as discussed in the last section. Export subsidies have been ordered to be completely phased out on the first day of 2002. Compared to the trend of tariff reduction in the past decade, the tariff changes due to China’s WTO accession should present relatively few problems. Significant reforms will,however,rolling benches be required in the area of non-tariff measures. Among various aspects of non-tariff barriers, state trading could be a particular important area to consider when reforming China’s agricultural trade policy. China has agreed to phase out restrictions on trading rights for all products except those under TRQ trade regime that will implement a more gradual approach in phasing out the state-trading regime . After three years of WTO accession, the private sector is supposed to dominate the trade of almost all agricultural products. There are provisions to keep the state involved in three commodities, however: wheat, maize and tobacco. The measures for Technical barriers to trade and sanitary and phy-sanitary as well as institutional arrangements to fulfill the agreement on Trade-Related Intellectual Property Rights are the other important issues which China has to deal with. The Agreements on TBT and SPS focus on using internationally accepted standards to discipline the use of standards as protectionist devices. This rules-based approach can be valuable in improving policy formulation, but is likely to require investment in strengthening standards related institutions. Comprehensive adoption of these measures should lead to improved policies and, by basing policies on a scientific approach, move away from the time-consuming and inefficient approach of resolving these issues on a political basis. China will undoubtedly struggle in its effort to create a fully transparent and open trade regime with respect to non-tariff barriers. The case of labeling requirements for GMO imports, most conspicuously soybeans, shows how frustrating and protracted the creation of any set of regulations and institutions can be. In June 2001, the government suddenly announced that in response to concerns about the presences of GMO foods in the nation’s import basket, it would require that all goods contained GMOs from there on out would require labeling. Unfortunately, no one in the world who was shipping to China had a system in place to do so. China did not tell any one what was the process to apply for a permit for importing labeled commodities or the place to learn about the process. Initially, trade in soybeans was thrown into disarray. China’s traders lost money, soybean users faced tremendous losses, and prices threatened to rise sharply. Even when facing such a crisis, there was no way that any agency could clarify the matter or announce a plan. Instead, the government postponed any decision to an unspecified future date and trade has since continued.2 The point of this is, however, that even when there is a crisis facing the external sector is often is difficult to rapidly come up with effective and transparent regulations and implementing processes. After 20 years of reform, China’s agriculture has become much more market-oriented . Traders moved products around the country with increasingly regularity and factors adjusted more rapidly. By the late 1990s, only grain, cotton, and to some extent silkworm cocoon and tobacco, were subjected to price interventions. But even in these cases, their markets, especially those for grain, have been shown to have become increasingly competitive, integrated and efficient overtime .

We can look at the effects from only two recessions, 2001 and the Great Recession, because the CPS does include certain key variables prior to 1994. It also lacks a variable on bonus payments. In contrast to the NAWS, the CPS data does not record whether an immigrant is undocumented. Therefore, we focus on immigrants in general and form interaction terms between immigrant status and the recession dummies. Otherwise, we use as similar a set of demographic variables as possible. Table 4 presents the regression results for the ln wage and weekly hours in the three sectors. In none of these three sectors did either recession affect the wages of non-immigrants or of immigrants. Presumably, wages are sticky in these sectors, partially due to union and other contracts and minimum wage laws. The unemployment rate had a statistically significant effect only in the construction sector, and that positive effect is small, as in the agricultural sector. The 2001 recession did not affect the weekly hours in these sectors. The Great Recession reduced weekly hours by 1.3 hours in the hotel sector but not in the other sectors. Thus, for most employed workers in these three sectors, weekly hours remained constant during recessions. This result contrasts with that in the agricultural sector where weekly hours rose substantially during recessions.But they most often use traditional technologies, despite the existence of more modern alternatives. This puzzle has sparked extensive research to understand which barriers constrain technology adoption. Researchers have focused most particularly on credit and insurance markets failures and on information frictions . Focusing on the latter, decades of research show that knowledge indeed plays an important role for adoption . Recognizing this, governments have invested heavily in dispatching agricultural extension workers throughout rural areas to transmit information from scientists to selected farmers — with the hope that information will then flow to others via social networks. But these public-sector efforts are widely recognized as having had limited impact . In advanced economies, by contrast,berry pots private businesses have become the main source of information about technological innovations for potential clients. Farmers rely on commercial input dealers not only to purchase inputs but also to be informed about available technological options.

These dealers are in turn informed by the companies whose products they sell and by public agricultural agencies and research institutions . In developing countries, could there similarly be a greater role for private business-motivated entrepreneurs in the public agricultural extension system? The optimal boundary between government and private entities in the provision of public services is an extensively studied topic in economics . Empirical research has found that outsourcing public service delivery to private firms can improve provision in many sectors such as potable water, health, food distribution, and education . Unlike these sectors, developing country agriculture has yet to see a large role for private business in delivering public services. Agriculture thus offers an opportunity to study whether private input suppliers can internalize benefits from the spread of information and become agents in the delivery of public services. Our experiment provides information on new technologies to local input suppliers , rather than to selected farmers as in the business-as-usual approach. Specifically, we give agrodealers access to a new seed variety for their own learning. Taking this business-oriented approach to agricultural extension could influence farm-level adoption in different ways. On the one hand, input suppliers — unlike contact farmers — have economic incentives to spread information. They stand to reap profits when suggesting the use of new inputs to farmers. Repeated interactions with farmers over time may discipline them into providing high-quality recommendations benefiting their clients.1 On the other hand, agrodealers might purposefully under-provide quality . Or they may recommend products that maximize their own profits instead of customer welfare, as has been observed in numerous other sectors . These concerns about securing through agrodealers adoption of the right technologies by the right farmers are akin to concerns about the quality of public services provided by the private sector . Therefore, our analysis seeks to answer both whether informed agrodealers increase adoption and whether they do so for the farmers that stand to benefit the most from the innovation. We study these questions with an experiment where information services are provided to local seed dealers. Our sample consists of 72 blocks, spread across 10 districts in the Indian state of Odisha.

We consider the dissemination of Swarna-Sub1, a new and profitable flood-tolerant rice variety that reduces the damage caused by flash flooding.We partnered with the government extension service to support their conventional activities in 36 control blocks. This included providing seed minikits to the contact farmers on whom they rely to use the new technologies and spread information about them in their social networks. It also involved carrying out large-scale “cluster” demonstrations where many farmers grow the new variety on contiguous pieces of land, and organizing farmer field days to share results from demonstrations. These are all activities the government extension service would do with adequate resources, but we supported them as part of the experiment to make sure that they were carried out and that our control group reflects business-as-usual activities at their best. We provided the exact same quantity of seeds and the same information to input dealers in the 36 treatment blocks. We did not support any conventional extension activities as was done in the control blocks. These dealers are highly local, small-scale businesses, selling seeds and sometimes other inputs such as agro-chemicals. They were free to choose how to use the demonstration seeds. The key distinction between this treatment and the standard mode of agricultural extension is that information constraints are being relaxed on the supply side, rather than on the demand side for new technology. The treatment tries to leverage the natural incentives created by the marketplace for private businesses to transmit information to their clients. Turning to the results one year later, we find that the dealer-based approach to the diffusion of information increases adoption of Swarna-Sub1 — the variety being introduced — by over 56 percent, i.e. from 6.3 to 9.8 percent of farmers. We further find that the average farmer in the treatment blocks is cultivating 69 percent more land with the variety, and the cultivated area of adopters increases on the intensive margin by about 9 percent. Consistent with these results on farm-level adoption, we find that the treatment triggered a supply-side response.

The magnitude of this response is similar to the increase in adoption. By the 2018 season, two years after the new seeds had been introduced, dealers in treatment blocks were about 59 percent more likely to have Swarna-Sub1 in stock. There is also some evidence that informing agrodealers causes a change in local input production. Treatment blocks were producing 40-50 percent more Swarna-Sub1 seeds during the three years after the intervention. An immediate next question is whether farmers induced to adopt in the dealer treatment are those with relatively higher expected returns. Dealers may invest little in promoting a particular input to the right farmers if something else provides them higher profit margins. Dealers in our setting principally sell seeds that are produced by the state-run seed corporation — that fixes both wholesale and retail prices equally for all seed varieties. This aspect of our setting eliminates a differential price motivation for dealers promoting the new technology. We consider a different possibility where dealers might encourage adoption by farmers with the greatest potential benefits if they want to maintain a good reputation as providers of high-quality advice. To consider this, we test for treatment-effect heterogeneity according to past flood exposure — an important determinant of returns.We find that the treatment effects of dealer-based extension are largest for households that are expected to have the highest returns. We would not expect this type of heterogeneity if dealers were sharing information indiscriminately or without considering the possible benefits for farmers. This offers a first piece of evidence that dealers are concerned with their reputation when sharing information. We then explore whether dealers proactively promote the new variety and what might explain their behavior. For this, we sent “secret shoppers” to around 300 dealers to inquire about new rice varieties in the third season of the study — two years after the seeds were introduced. We find direct evidence that the treatment changes what dealers say to farmers coming into their shops. Dealers in treatment blocks are about 25 percent more likely to mention Swarna-Sub1 when listing the new varieties to consider. When specifically asked for a recommendation,hydroponic grow system we find that dealers are less likely to recommend older types of seeds and in some cases more likely to recommend trying SwarnaSub1. These findings suggest that relaxing information constraints on dealers leads them to share this information with farmers. As a final piece of evidence, we ran an experiment to test whether business incentives and reputational concerns motivate dealers to spread information. In partnership with a local NGO, we revisited dealers during the fourth season to further solicit recommendations. Each dealer was randomized into one of two treatments. In the first treatment, someone visited the dealer and asked which farmers, locations, and varieties would be best for a demonstration where farmers would cultivate a new variety and then the NGO would organize a meeting with other villagers to explain its attributes. Importantly, the name of the dealer giving the recommendation would be advertised during the meeting. We refer to this treatment as the reputation treatment because the dealer’s identity would be publicly displayed as part of the demonstration. In the second treatment, the program was presented as one where the NGO would not name the dealer and would collect the harvest after the demonstration and redistribute it as seeds to other farmers. This treatment reduces the salience of reputation for the dealer and lowers their business motivation by reducing the demand that would be created by the demonstration.

We find that priming dealers to consider their reputation and business motivation changes the advice they give. In particular, it causes them to suggest different locations, types of farmers, and seed varieties. Starting with location, when presented with a candidate list of villages for the program, dealers in the reputation treatment are more likely to suggest a village not on that list. Most of this is explained by treatment dealers being more likely to suggest their own villages. Dealers in the reputation treatment also spend more time thinking of which farmers to recommend. They are more likely to suggest neighbors or other people in their own village. Finally, the reputation treatment causes dealers to recommend less common seed varieties. Taken together, these findings suggest that business interests and reputational concerns play a role in the information sharing process for dealers.These results help interpret the findings in our main experiment. Concerns over market share and reputation could be factors causing dealers to promote an improved seed — even if it does not provide them with higher profit margins. In sum, we present the first evidence on how leveraging private agents on the supply side of input markets can help disseminate agricultural technology more effectively than the conventional methods used by the public sector. An important channel through which this happens is that dealers, when they gain information, spread it actively to farmers. Importantly, the gains from leveraging agrodealers are largest in areas where the technology delivers the highest benefits to farmers. Reputational concerns may be one of the factors that motivates dealers to match the technology to farmers with the highest expected returns. These results contribute to the literature on public-private partnerships by showing how using private-sector input suppliers to spread knowledge can improve the delivery of public services.Moreover, it does so at a lower cost compared to expanding the current practices used in the public sector. It is cheaper to visit a small handful of dealers compared to carrying out large-scale demonstrations and training. Our findings contribute to the literature on agricultural technology adoption in the developing world.Several studies consider different methods to improve the provision of extension services. For instance, cell-phone-based monitoring of extension workers can help solve agency problems and increase the number of farmers reached . Alternatively, researchers have considered efforts to better select, incentivize, and train the farmers that the extension service partners with . Finally, field days to share information from demonstrations is a commonly used technique . This literature has focused on ways of reaching more farmers via the traditional channels — either through direct outreach or by learning from the contact farmers that were trained by extension workers.

The settlers participated in organized, communal holiday events such as Hanukkah, Purim and the annual Passover Seder. There were bar and bat mitzvahs that celebrated the coming of age of Jewish boys and girls, as well as funerals that honored those who passed. Indeed, settlers had “established a religious burial society and created a small Jewish cemetery” that served the colony.The 1950 figures, again culled from the Rosenzweig Report in Bruman’s Field Book III, divulge that DORSA allocated monies totaling $7,900.00 to subsidize various functions and administrative arms at the colony. This included $400.00 for ‘Religious Purposes,’ but also $3, 500.00 for the school and $1,000.00 for the Hospital. The Sosúa Council had responsibility for administrative oversight at the colony, and the settlers made monthly contributions to the Council that were from 1% to 3% of their income. Bruman noted that the Loan Cooperative filled the basic banking needs of the Sosúa settlers. The cooperative functioned as a bank and clearing house for all financial transactions at the settlement. Indeed, all “money transactions of the Sosúa Cooperative were made through the Loan Cooperative.”Sosúa also had its entrepreneurs who began private enterprises at the colony. One of Rosenberg’s key goals for Sosúa was the establishment of small crafts and niche businesses to create revenue streams aside from a farm-based income. They included a turtle-shell business that made arts and crafts goods, which were then sold throughout the country, a haberdashery which made shirts and pants, a cobbler who also made slippers, several restaurants, and a cinema which had its own ‘Cine bar’ selling refreshments. Also included among the fledgling businesses were a plumber and a dentist whose services were not paid for by DORSA. The colony’s reliance on agriculture as its primary source of income did not pan out, and showed that a shift to dairy products was necessary if the colony was to become self-sustaining and profitable. That change came with the addition of cattle, dairy cows,ebb flow and pigs. In about four years since its first refugees arrived in May 1940, Sosúa’s dairy industry had grown into a thriving business with national importance.

The new emphasis on dairy and meat products, made it clear that Sosúa’s initial focus on agriculture had been a failure. Sondheimer wrote that “It was soon seen that the best source of cash income was from milk production. The original plan was revised,” and the economic focus shifted to dairy products and meat processing. Each settler who joined the Cooperativa Industrial Lechera, C. por A. or CILCA by its initials, founded in late 1941, and the Ganadera meat cooperative founded in 1945, became shareholders with one share in each of the enterprises. The Ganadera “slaughtered meat, tenderized beef and ham, and produced bologna, frankfurters, and sausages.”Both CILCA and Ganadera became award-winning anchor businesses that drove the economy of Sosúa. Indeed, their products were sold throughout the island with CILCA butter “in constant demand [because] it is considered the best butter produced in the Republic.” Rosenzweig noted that “out of the 27,000 total acres of the settlement, 18,000 were judged suitable for grazing. Sondheimer’s report of 1944 noted that the improvement in the breeds of animals was done through “the judicious introduction of [imported and superior] breeding stock.” The inferior, native breed of cattle was cross-bred with imported Holstein, Zebu and Senegal bulls, which translated into heartier and heavier calves, and increased yields of milk and meat.The CILCA C. por A. is, at the time of this writing in 2016, still in business, although no longer wholly owned by Jewish settlers/stockholders. It remains a visible reminder of Sosúa’s success as an agricultural colony founded by Jewish refugees fleeing the violence of war torn Europe more than half a century earlier. The Ganadera, Compania Industrial Ganadera C. por A. also enjoyed phenomenal success, with their meat products sold throughout the island and elsewhere. Indeed, from its inception as a small, local Jewish co-op, it experienced increased sales and profits throughout its life. By 1950 it had an annual turnover of an impressive $200,000, whereas in the preceding year, 1949, its receipts were $164,000.The turnover at CILCA C. por A. was equally impressive. In 1949 the receipts totaled $198,000, and by 1950 they jumped to over $245,000. The hapless Jewish refugees who arrived in Sosúa in 1940, built a business empire that is today valued at over millions of dollars, this in spite of the tremendous odds that were stacked against them.

People without a country and land to call their own, a people who had their personal possessions and wealth confiscated, and who were involuntarily pushed out of their homeland, were the success of an experiment happening leagues away from the madness then infecting most of the world.The end of the colony paralleled that of World War II. Many refugees had arrived at Sosúa with no intention of staying on as farmers or ranchers. Some did not want to remain in the Dominican Republic at all, and were among the first to flee the colony when they had the chance. Some who had connections and/or family in the United States, moved there directly after the war. A few chose to return to their European homeland, still reeling from the effects of more than six years of conflict. Then again, some migrated into other Latin American countries such as Brazil, Argentina and Chile. Some remained at Sosúa, yet moved from the homestead farm to the administrative hub at El Batey to be closer to ‘downtown’ and its attractions. Today only a small museum resides at the site of the original colony, reminding those who now come in search of tropical dreams, that this was once a Promised Land for some ‘hapless’ Jewish refugees who had escaped the Nazi terror.Rosen had developed a successful agricultural settlement model in Crimea based on the three-point plan discussed earlier. However, what worked so well in the Crimea failed miserably at Sosúa. It must be noted that the Bolivian haven for Jewish refugees at Buena Tierra in the Yungas region was, according to the historian Leo Spitzer, also an abject failure. Such failures, on the other hand, can be considered as successes given that they had achieved their original objective: saving lives. Buena Tierra was cobbled together from three formerly profitable but now derelict haciendas: Charobamba, Santa Rosa, and Polo Polo in the semitropical Yungas region to the northeast of the capital city of La Paz. As with Sosúa, Buena Tierra included a professional agronomist who did detailed surveys of available tracts of land on which to settle the Jewish refugees. Bolivia also had, as in the Dominican Republic, a president, Germán Busch Becerra , who came from the ranks of the military. After a military coup, Busch seized the presidency in July of 1937. Busch was born in the Beni Province to a physician father who had emigrated from Germany at the beginning of the twentieth century and a Bolivian mother of Italian heritage.98 Busch also wanted to establish agricultural settlements in Bolivia, some years before the conference at Évian took place. Busch’s chief reason for supporting agricultural settlements was that Bolivia was held hostage by fluctuations within the international commodities markets where it had to purchase essentials.

Bolivia, under Germán Busch, struggled to become self-reliant and feed itself. Busch’s strategy was to avoid any of the pitfalls inherent in the international commodities markets.99 The Bolivian president’s ally, Mauricio Hochschild was a billionaire mining magnate and naturalized Bolivian. Both men saw the wisdom of having “European immigrants as agriculturalist colonists to cultivate and exploit the vast, potentially rich, but largely undeveloped semitropical and tropical areas of the country.” The recruitment took place through Bolivian Consular officials stationed in Europe, who “were instructed to attract prospective agricultural immigrants with an offer of free land, free transportation within the country, and a one-year maintenance allowance.” This experiment resulted in the founding of the Colonia Busch. The colony failed from the start,greenhouse benches yet it also provided a model for future colonization of the Yungas by Jews who had fled war-torn Europe in droves.100 In early 1940 Hochschild and officials from the Joint founded the Sociedad Colonizadora de Bolivia, or SOCOBO, which oversaw the development of Jewish agricultural settlements, including the training of the would-be settlers. SOCOBO functioned much like its Dominican twin DORSA. It was a legal corporation that entered into agreements and contract negotiations with government officials. It also handled, along with officials from the Joint, the logistics involved in getting Jewish refugees into Bolivia, and then supplying them with the necessary funds, housing, seeds and farming equipment to begin life anew as Bolivian farmers. Much faith was put in the word of Felipe Bonoli, the Italian agronomist and naturalized Argentine who had past success in Argentina establishing a settlement of Italians on the land. Bonoli had gone to the Yungas region to report on the state of the land and the feasibility of purchasing the properties. The plan was to combine the three derelict haciendas into one large settlement and rename it Buena Tierra. The Yungas region is in the lush semitropical Andean lowlands, an area with plenty of rivers for irrigation. The three haciendas were once thriving farming concerns “on which coffee, cocoa, mangoes, oranges, tangerines, bananas and coca had once been cultivated,” yet had been abandoned by their former owners.Bonoli had deemed the properties suitable for settlement as their fertile soil could be recycled and put into cultivation and pasturage. Bonoli was also taken by the physical beauty of the semitropical, lush Yungas, as were investigators for the REC. Echoing the sentiments of Rosenberg and Rosen about the natural beauty of Sosúa, REC investigator Walter Weiss gushed with praise for the Yungas site; “Not only is the soil long-rested and fertile with mountain streams running in sufficient quantities [but] nowhere in our far West have I seen more wonderful panoramas.”

Members of the REC and the Joint believed that Buena Tierra would be attractive to the refugees as a sight for settlement. The pioneers would have land, low-cost housing and opportunities not available elsewhere on the continent. Recall that most Latin American countries closed their doors to Jewish refugees who came in search of a safe haven, so the list of places in which to immigrate was very short indeed. In addition to the difficulties one encountered fleeing Europe, were the difficulties of getting to the extremely isolated colony. The trip from the capital of La Paz was a ‘terrifying one.’ One left La Paz, altitude 11,000 plus feet, ascended an additional 3,000 feet to La Cumbre, and then began the hair-raising descent into the Yungas and its ‘green, lushly vegetated valleys.’In a masterful bit of understatement, Spitzer noted that “travel on this road is not an easy journey to undertake.” This was aptly illustrated by the numerous crosses that dotted the narrow road, put there to mark the spot of the frequent, fatal crashes that happened to careless travelers. The lack of a network of passable roads accessible by automobile or truck further enhanced the colony’s isolation. It was essential to build a network of roads that would connect the colony with the outside world, one which would facilitate access to domestic markets and ports. Bolivia was in the main dependent on imported goods and foodstuffs for clothing and food. Bolivians consumed rice from India, drank coffee grown and processed in neighboring Colombia and Brazil, and used wheat grown in Canada and Argentina to bake their bread and pastries.It was hoped that agricultural colonies such as Buena Tierra could put Bolivia on the path to feeding itself and, in the process, become self-sustaining. The money saved by reducing costly imports would be invested in settlement schemes such as Buena Tierra. Money would also come from the Jewish philanthropies such as the Joint, and the recently founded protection society known as the Sociedad de Protección a los Imigrantes Israelitas, or by its acronym SOPRO. The SOPRO had offices in several large Bolivian cities, including one in the famous silver mining center of Potosí, that provided aid to Jewish refugees, many of whom had arrived with just the clothes on their backs. It may be recalled that the Nazis had imposed the onerous Flight Tax on Jews emigrating from Third Reich lands beginning in the 1930s, causing the financial ruin of many. So, as in the Dominican Republic, the majority of the Jewish refugees who made it to the safety of Bolivia were penniless.

Our empirical analyses of grower attitudes and behaviors demonstrate that local diffusion networks enhanced the effectiveness of the SVWQC. The more producers interacted with diffusion networks, the more likely they were to be satisfied with watershed management policies, participate in policy activities and adopt environmentally sound management practices, as long as they were cost effective. To further validate our results, we conducted on-farm, personal interviews with more than 20 Sacramento River Valley producers involved with water quality management. We feel that these findings are strong enough to emphasize to policymakers the importance of recognizing how government decisions can weaken or strengthen these local diffusion networks. Any dismantling of diffusion networks represents a loss of human and social capital, and capacity for cultural change, which severely degrades the ability to integrate sustainability principles into agricultural policy and decision-making. A variety of evidence suggests that recent policies have decreased the investment in such networks. For example, California agricultural commissioners are local agencies that perform a variety of programs and duties in each county. Historically, their core programs have included pesticide-use enforcement, quarantine, pest detection, pest exclusion, weights and measures programs, and outreach. In recent years, some non-core programs of the agricultural commissioners’ offices have extended into land-use planning and natural resources management. In our survey, the agricultural commissioners were identified as the most trusted and most frequently contacted source for information about water quality. However, while their non-core programs and duties have expanded, funding sources have generally failed to keep pace with new programs and responsibilities, including water quality . Another example is that the two main federal funding sources for land grant university agricultural outreach programs — Agriculture Experiment Stations and the Cooperative Extension system — increased by only 4.8% and 1.6%, respectively, 25 liter pot from 1996 to 2006, whereas costs inflated at a much higher rate.

Although the full impact of these flat budgets depends on state and local decisions, they have contributed to significant decreases in local diffusion networks in California and several important agricultural states. Likewise, from 2002 to 2004, California lost 152 county Cooperative Extension positions in 20 different counties. A final example is federal Farm Bill policies that influence local funding for the Environmental Quality Improvement Program , which is administered throughout the United States by the Natural Resources Conservation Service and in conjunction with local resource conservation districts. This analysis has limits as a case study in sustainability. The Conditional Waiver program in California is still too new to have achieved long-term success, has a relatively limited geographic scope and focuses mostly on the environmental aspects of sustainability. However, local diffusion networks will continue to be important to the future of these programs in California; they will also play a central role wherever sustainability involves policies that require innovation, collective action and cultural change. Agricultural production is increasingly strained by changing climate and population growth. With the global population expected to reach 9.8 billion by 2050, farmers will have to grow about 70% more food than current production.Meeting this challenge will require scientific advances that bridge the gap between conventional techniques and new technologies in plant breeding. Selective breeding has been used for thousands of years in the domestication of crops to artificially select desired traits in foods. More recent breeding techniques have used chemicals to induce random DNA mutations, hoping that one of these mutations is involved in a trait of interest and spending decades attempting to remove unwanted random mutations through breeding. Because these techniques do not introduce foreign DNA into a plant, they are not considered to be genetically engineered.In the past decade, efforts to select for desirable plant traits have drastically increased with new biotechnology to more quickly and precisely introduce changes at the genetic level.New gene editing techniques like CRISPR-Cas9 have revolutionized the field, allowing plant breeders to target traits of value with greater speed and precision. This revolution has also allowed smaller, non-traditional groups to enter the market.

While the creation of GE crops was previously done by research universities and industrial agriculture companies, it is increasingly undertaken by small to mid-sized innovators. As a net exporter of agricultural products, particularly to developing countries, the US could see significant economic benefits from growth in the agricultural sector.Despite the fact that the US plants the largest acreage of GE crops in the world , the development of GE crops in the US has not been able to reach its full potential.4 This is primarily due to costs associated with the complicated regulatory process. It is expensive to bring a GE crop from the laboratory bench to commercial distribution, averaging $130 million and 7 years for a single crop in the US.5 For this reason, GE research has focused on staple crops like corn and wheat. However, the US exports a much larger variety of crops–in California alone, the grape, almond, and pistachio markets are significant contributors to the state’s multi-billion-dollar agriculture economy.The proliferation of new, cheaper gene-editing techniques that can be applied to these crops and the rapid growth in developers have therefore raised issues around the regulation of genetically modified plants.GE plant regulatory policy is primarily created and implemented by three federal agencies: the Environmental Protection Agency , the Food and Drug Administration , and the United States Department of Agriculture . These agencies regulate different types and features of GE crops, depending on the specific use of the crop and how it was produced. Their responsibilities regarding GE crops are outlined by the 2017 Update to the Coordinated Framework for the Regulation of Biotechnology7 and the 2019 Executive Order 13874 .Here, we focus on the role of the USDA in biotechnology regulation as it is the agency with the most recent updated regulations in response to EO13874. Within the USDA, the Animal and Plant Health Inspection Service is the main agency responsible for regulating GE crops and other biotechnology products that may pose a risk to agricultural plant and animal health. For example, in November 2018, APHIS decided that a Pichia kudriavzevii mutant manufactured by Lygos, Inc. should be regulated.This was in accordance with APHIS’ mission to regulate potential plant pests; P. kudriavzevii is a fungus known to cause disease in citrus and grapes. APHIS proposed an updated regulatory policy in June 2019: the Movement of Certain Genetically Engineered Organisms.While still in review ,this rule aims to reduce “regulatory burden for developers of organisms that are unlikely to pose plant pest risks”. One key element is allowing developers to self-determine exemption for their GE plant by comparing it to all plants with completed regulatory reviews, with the option to request written confirmation from APHIS.

To support accurate self-determinations, APHIS proposes creating a publicly-accessible database containing the results of all completed regulatory status reviews, including each reviewed combination of plant, trait, and mechanism of action . While recent federal actions have sought to clarify and modernize regulation, significant barriers to scaling up the production of GE products still exist. Together, the 2017 Coordinated Framework Update and EO13874 outline the need for a unified and straightforward process for the approval of new bio-technologies, but the specifics of such a process are weakly defined at present. While EO13874 calls for the creation of a Unified Biotechnology Web-based Platform, the current iteration is a website with internal redundancies and links to a confusing web of regulations, leaving the user frustrated and with limited additional information. Updated regulation is in flux, with the relevant agencies still developing their updated approach. We recommend several measures that can be taken by the USDA to address the above shortcomings and provide a clear path to safely and efficiently bring GE crops to market. First, the USDA must update federal regulations to clarify and consolidate communication regarding the GE plant approval process. The current APHIS proposal, albeit improved, fails to simplify the regulatory process in a way that makes it accessible to small to medium sized innovators who have no previous experience with regulation. Federal agencies should coordinate their response to inquiries in addition to improvement of the aforementioned unified web platform. Since the USDA is currently the designated funder of the consolidated web-based platform , raspberry cultivation pot we propose assigning coordination to the USDA. This agency is best poised to oversee regulations by using its EO13874-mandated appropriations to develop and manage a clearinghouse for all GE-related inquiries. The USDA would thereby serve as a liaison between all three federal regulators and innovators, benefitting innovators and the agencies alike. Second, while we support APHIS’ creation of a database of all completed regulatory reviews to help developers make self determinations, we argue that the proposed use does not go far enough. APHIS states that developers whose GE plant has the same plant-trait-MOA combination as a previously-reviewed organism could easily self determine non-regulation by APHIS.Developers must request a review or permit if their GE plant has not been previously reviewed and does not fit into another exempted category. We argue that this exemption for previously-reviewed plant-trait-MOA combinations applies to few GE plants and provides no significant relief of regulatory burden. Instead, we propose that APHIS extend this exemption to GE plants with a previously-reviewed trait-MOA combination that is combined with a new plant. If a trait-MOA combination is reviewed in one plant and determined to cause no plant pest risk, then it is unlikely to cause a plant pest risk in a different plant. This is consistent with APHIS’ attempt to create more risk-based regulation and reduce regulatory burden. Third, the federal government, led by the USDA, should push an agenda that supports implementation of clarifying web-based platforms. EO13874’s recommended Unified Biotechnology Web-Based Platform provides the foundation for improvement, but does not go far enough.

The platform should contain more than just descriptions for the regulatory roles of the USDA, FDA, and EPA as it does now.While the site also allows users to contact the agencies with questions regarding regulation, a far better use of the platform would be an avenue to submit an application for commercial approval of a biotechnology product. The web platform currently states that “[each] regulatory agency has its own specific application procedures” but does little more than offer links to each website.If the goal of the current regulatory modernization is to streamline and clarify the process of GE plant approval, then the unified web platform should serve as a tool to help small and midsize producers begin the process of product approval.By simplifying the GE regulatory requirements, the process of taking a GE crop to market will be more transparent and navigable for small to medium sized companies. However, a policy that extends exemptions will also benefit established companies with proprietary traits that have already undergone federal inspection and are better poised to scale up those traits into new crops. This may make it harder for small innovators to succeed in the market. If new proposals are implemented, the USDA will absorb new roles for the overall efficiency of the regulatory process. However, the agency will also have a greatly decreased regulatory burden since many new gene-edited crops will be exempt from USDA regulation. Still, the USDA may not have sufficient capacity to handle requests without a corresponding increase in funding to hire personnel to manage these new roles.We recommend the regulatory exemption of GE plants with a previously-reviewed trait-MOA combination, a unified and detailed web platform for applications for commercial approval, and the consolidation of federal regulatory communication to the USDA. If implemented, our proposals will reduce regulatory burdens on companies and researchers seeking to bring new products to market without eliminating meaningful safety and consumer protection standards. An extension of the regulatory exemption to more GE plant products will likely bring the greatest benefit to large firms, since it will be easier for them to adjust their techniques to bring the same trait to different plants. It will also allow the USDA more time to focus on regulation of novel GE crops, which have completely new traits or mechanisms of action.

We used NLCD land cover to classify natural habitat types, which were not identified in the SCAG layer. Lands in classes which were essentially open space with substantial human activity and which had less than 10% impervious surface were classified as ‘disturbed’. When land-cover layers from the different sources were inconsistent, we verified classifications with ground visits or visual inspection of air photos .We used motion-activated digital cameras at 38 sites to detect carnivore species from April 2007 to June 2008, resulting in 1,130 trap nights. Cameras were placed in and around 6 orchards and 2 continuous wild lands , with distance to nearest camera between 30– 900 meters . At all sites, cameras were placed along similar-sized dirt roads, near signs of carnivore activity or at trail junctions when possible. We placed scent lure in front of the camera to encourage animals to approach the camera and to stop long enough to be photographed. For each carnivore species at each camera site, we tallied the number of nights in which the species was detected at least once. We considered each 24-hour trap night to begin at 6:30 am, and cameras were active continuously between 12 and 76 nights at a particular site.We began the modeling process by selecting the best detection model for each species while holding occupancy rate constant, as in Negro˜es et al. and Duggan et al.. We expected that season and land cover at the camera site could affect detection rate so we included both as covariates in detection models. Detection covariates, as well as predictors of occupancy described below, were standardized by z-score as described in Donovan and Hines. Next, to determine if spatial clustering affected occupancy, and at what scale, we compared models including site , meta-site , or county as predictors of occupancy while including any detection variables selected in the previous step. We then included the covariate from the top-ranked model of spatial scale as a predictor in the candidate model set for occupancy of that species. Finally, for each species we modeled occupancy while including detection covariates from the top-ranked detection model for that species. Potential predictors of occupancy included land cover at the camera site,vertical farming distance from each camera to the perimeter of continuous wild lands , and season .

We also evaluated the degree to which area of orchards and other landscape variables in the neighborhood of a camera influenced carnivore occupancy. To do so, we used the land-cover map to quantify the extent of orchards and covariates within a 1,935 m-diameter circle centered on each camera, approximately the average size of a bobcat home range in this region and intermediate between range sizes of foxes and coyotes. We had 38 sites, and therefore examined only single- and double-factor occupancy models to avoid over parameterization.We report results for the average model, but also include summaries of the top ranked model and all models within 2 AICc points of this model, indicating substantial support. To compare the selection support for each predictor variable, we also calculated variable importance weights, which are the sum of the model weights of all models that contain a given variable. Averaged models include only models within 2 AICc points of the best model. Variable importance rates are assessed across all models and therefore each variable has equal representation.Cameras were active for a total of 667 trap nights in orchards, 201 in natural vegetation near orchards, and 262 in wild lands. We detected 8 of the 11 native carnivore species in the study region. Seven native species were detected in orchards: coyote , striped skunk , bobcat , gray fox , mountain lion , black bear , and raccoon . Eight native species were detected in natural vegetation: coyote , bobcat , mountain lion , gray fox , raccoon , badger , black bear , and striped skunk . The 3 native carnivore species not detected included ring tail, spotted skunk, and long-tailed weasel.On average, the number of native species detected per site differed among land-cover classes , but differences between individual classes were not statistically significant . The number of native species detected was greatest in orchards , intermediate in sites with natural vegetation adjacent to orchards , and lowest in wild land sites . The top-ranked detection rate models for coyote and gray fox included land cover at the camera station location , with higher detections in avocado orchards or near avocado orchard relative to wild lands. Season was also included in the top-ranked models; for fox, the direction of the effect could not be distinguished from 0 , while for coyote, detection rate was lower in the dry season than in the wet season . These detection covariates were included in all subsequent models. For bobcat, the intercept-only model was the top model, so subsequent bobcat models did not include detection covariates.

For all three species, the intercept-only occupancy model was the top-ranked model for spatial variation, thus we did not include spatial variables as predictors of occupancy in our final set of candidate models. Avocado orchards, either at the camera site or in the neighborhood of the camera, were included in at least one competitive occupancy model for all three carnivore species . The area of avocado orchard in the neighborhood of a camera was the most important predictor of bobcat occupancy and was included in all top four models for bobcat occupancy . The area of avocado orchards in the neighborhood of a camera was the third most important predictor for gray fox occupancy . For coyote, the area of orchard in the neighborhood had a weak negative effect , but both avocado orchard and ‘near orchard’ at the camera site had a positive effect . Land cover at the camera site was not included in any competitive bobcat or gray fox occupancy models. Distance to continuous wild land was the most important variable for predicting gray fox occupancy and third most important variable for bobcats , with occupancy increasing closer to or within wild land habitat. Distance to continuous wild land was not, however, included in any competitive coyote models. The area of disturbed land in the neighborhood of the camera was included in competitive models for both coyote and gray fox occupancy , but large standard error values for fox occupancy suggested a weak influence. Disturbed land was not included in models for bobcat occupancy . Woodland, shrub, and grassland/herbaceous vegetation in the neighborhood of a camera had a positive effect on occupancy in all models for all species, except that woodland had a negative effect on gray fox occupancy.Carnivores were detected with surprising frequency in avocado orchards. We detected most carnivore species native to coastal southern California in avocado orchards, and these orchards were used frequently by bobcats, coyotes and gray foxes. Further, we detected more carnivore species in orchards than in wild land sites. Although orchards are often adjacent to wild lands, the presence of carnivores in orchards does not appear to be simply an artifact of landscape context. If this were the case, we would expect to find more carnivores in wild lands than in orchards, which we did not. We would also expect to find that distance to continuous wild land was a more consistently important predictor in our models; although it was the strongest predictor of occupancy for gray fox, it was present in only one competitive model for bobcat occupancy and no competitive models for coyote.The food subsidy value of avocados may explain why omnivores such as bears, coyotes, and raccoons were present in orchards. Indeed, remote cameras have recorded these species eating avocados in southern California , but why obligate carnivores like mountain lions and bobcats would be present in orchards is less clear. Orchards may provide good cover for carnivores; many of these species are habitat generalists, and orchards often replace oak woodlands with structurally similar vegetation.

In our study, we did not find an effect of wet versus dry season on occupancy, as might be expected if carnivores were attracted by water sources. However, irrigation lines, combined with abundant avocados, might simulate year-round wet-season conditions for small mammals, perhaps leading to bottom-up effects in these agricultural systems. Future research could assess whether orchards are providing more food and water for small mammals than native vegetation,vertical garden hydroponic and whether a relative increase in prey might help explain the use of these lands by carnivores. Finally, further study could evaluate whether the presence of infrequently-used dirt roads in orchards might appeal to animals moving across densely vegetated landscapes.There is growing interest in managing for movement of wild animals through agricultural areas. Knowing the value of different land-cover types for habitat or movement can inform conservation decisions regarding which lands should be purchased or put under easements, or which areas are most suitable for the placement of highway crossings. Avocado orchards appear to serve as both foraging and movement habitat for most carnivore species in California, and conservation easements or other incentives to keep land in orchards could offer a cost-effective conservation strategy. Such alternative conservation strategies are particularly important when considering agriculture in Mediterranean-type ecosystems, which are highly threatened.Research is increasingly showing that agricultural crop yields will be susceptible to future changes in temperature, precipitation, length of growing seasons, and carbon dioxide concentrations. While future climate is uncertain, the potential for important effects on major agricultural crop producers such as the U.S. is clear. The quantity and composition of U.S. agricultural crop production, where crops are grown, trade, and economic value of U.S. crop production could be affected. An important challenge in understanding these implications is that agricultural products are traded across the globe. The U.S. is both a major agricultural importer and exporter of agricultural crops, meaning that U.S. agriculture may be affected not only by future climate in the U.S., but also future climate outside of the U.S. via international trade. These international linkages raise questions about the relative importance of the direct and indirect effects on U.S. agriculture; that is, is the potential for changes in temperature and precipitation in the U.S. more or less important than the potential for changes outside of the U.S. to U.S. agricultural crop producers?

Many studies have looked at the global response of agricultural systems to changes in climate, as well as the relative importance of where the agricultural impacts occur. In recent years, attention has begun to turn toward the implications of international trade on the U.S. agricultural sector in particular, finding that international trade effects for the U.S. agricultural sector are comparable in importance to direct, domestic impact. Zhang et al found that considering full, global climate impacts causes significant changes in the projections of U.S. production and exports of crops. Costinot et al and later Gouel and Laborde examined the aggregate impact of widespread local yield changes on global agricultural markets, again finding that the full picture is necessary to understand the future, as comparative advantages among regions shift with particular attention paid to domestic adjustments in land allocation. Finally, Baker et al. extended these findings to a new modeling application, determining that not only does considering global markets cause significant changes in the projections of U.S. agricultural crop production relative to a U.S. only focused study, but also that freer trade may help buffer local productivity shocks. These results suggest the potential for meaningful effects on the financial revenue of the U.S, agricultural sector through changes in both domestic production and international prices. In this paper, we systematically explore the implications of changes to domestic and international temperature and precipitation for U.S. agricultural crop production using a regionally-resolved, global scale model of energy, land, economic, and climate systems: the Global Change Assessment Model . This paper adds to the literature by providing a complementary quantification and replication of the production effects explored in Baker et al. and other modeling efforts with a different model. The analysis in this study is conducted using a modified version of GCAM 5.2. GCAM is a global model that couples representations of the energy system, the economy, agriculture and land-use, water, and the global climate in a single computational platform.

The county tax assessor’s office and the local city hall are important sources of tax records and permits that have been obtained for the property, which can help uncover past uses. Examples of prior uses of sites that may have caused soil contamination are parking lots, junkyards, auto repair or painting, carpentry, machine shops, dry cleaners, gas stations, railroad yards, and illegal dumping. The history of a site will help to determine what kind and how much soil testing is necessary. A site that has been primarily residential or used as green space is generally lower risk. A site that has had past industrial or commercial uses should be more carefully analyzed.The U.S. Environmental Protection Agency finding recommends that for urban areas, “at a minimum, the soil test should include pH, percent organic matter, nutrients, micro-nutrients, and metals, including lead” finding. This level of testing is adequate for a site that has been residential or green space. Most commercial soil labs can test for the most important heavy metals, including lead, arsenic, cadmium, chromium, and nickel. More testing may be appropriate for a site with a history of industrial or commercial use, which might include CAM-17 testing. finding An EPA-recognized laboratory is the best choice for this level of testing.It is possible that other types of tests may be necessary, such as testing for PAHs finding, a class of potentially toxic byproducts of incompletely burned garbage, oil, wood, coal and other organic materials. They can accumulate in soils and become a concern on a site that has been used previously as a car wash, parking lot, road and maintenance depot, or vehicle service station. Staff members at soils labs can be great sources of information. They are generally willing to talk on the phone about appropriate testing based on site history. However, there are instances where additional support may be necessary.According to the California Department of Toxic Substance Control finding, “brown fields are properties that are contaminated, or thought to be contaminated, and are under-utilized due to perceived remediation costs and liability concerns” finding. In cases involving brown fields that were formerly industrial or manufacturing sites, old gas station sites, and other situations, expert assistance may be necessary: these sites may have cleanup issues beyond what a community project can accomplish without technical expertise and a significant budget. These sites may be too expensive to test and remediate; help may be available, though, through state and local brownfield programs.

California DTSC oversees a voluntary cleanup program for brownfield sites. Some cities have brownfield programs that may be able to provide guidance, resources, and perhaps even help in securing funding for cleanup. Although urban agriculture is not yet a common reuse for brownfield sites,vertical tower for strawberries it is an area for further exploration. Local offices of the USDA Natural Resources Conservation Service finding may also be able to provide technical assistance and guidance on a case-by-case basis.Laboratories generally provide an online instruction sheet on how to sample the soils, prepare the samples, and mail them to the lab. Once you have selected a lab, review its website for instructions or speak to a staff member by phone. Detailed instructions on collecting soil samples are also available in several of the resources listed in the section “Sources of More Information.” Review these instructions carefully, since poorly collected or unrepresentative soil samples may not provide accurate information. Generally, it is essential to approach soil testing with a plan in mind. Making a simple map of a proposed site and noting areas with different characteristics helps you decide how many samples to collect.Most labs are receptive to questions regarding interpretation of test results. Soil testing will indicate whether plant nutrients are low and need to be raised for best plant growth and whether the soil pH needs to be adjusted. The soil test can also indicate whether there are higher than acceptable levels of heavy metals or other contaminants, depending on what tests were requested.Heavy metals are the contaminants most commonly tested for, and there is more guidance available about heavy metals, especially lead, than for many other contaminants. Even so, there is no one standard as to what constitutes safe levels of heavy metals in urban agriculture. Most guidelines that exist are created for residential use scenarios and contact with soil through skin exposure or accidental ingestion, rather than being formulated for gardening or farming. Still, they provide some guidance about what is acceptable. One standard to consider is the California Human Health Screening Level finding, which is used by the City and County of San Francisco and the City of San Jose in their guidance on lead hazard assessment for urban gardens and farms.

For lead, the HHSL is 80 parts per million finding. Anything lower is considered below the level of concern for human health. Another standard is U.S. EPA’s Soil Screening Levels finding for residential use, which consider lead to be a hazard at levels of 400 ppm or more. In 2013, the U.S. EPA Technical Review Work group finding for Lead provided a bit of clarification specifically for gardening and deemed soil lead at less than 100 ppm to be low risk for home-grown produce.The U.S. EPA TRW chart with specific, tiered soil lead recommendations for gardening is available in table 2. These standards are advisory only; check with local municipalities finding to find out whether more specific requirements have been established. Two related products can be considered for use in improving existing garden soil. Biochar is a charcoal product that when mixed with soil adsorbs heavy metals and binds them tightly, making them less available in the soil. It has other potential benefits, including holding water and releasing plant nutrients. The second product, activated charcoal, is sometimes mixed with soil to adsorb contaminants including certain pesticides, herbicides, and petroleum products. Both can raise soil pH, which could pose a problem if soil is already alkaline. See the section “Sources of More Information” to learn more about these materials before applying them.The most cautious strategy, perhaps most likely to be considered when dealing with a brownfield site, is to remove existing soil from the growing area and replace it with soil that is certified safe. However, this expensive procedure is out of the range of what most community groups or individuals can afford. Contaminated soil must be disposed of according to law, which can be expensive, in addition to the costs involved with soil excavation, removal, and replacement. A more common approach is to build raised beds and fill them with clean soil. A study of backyard, school, and community garden soils in San Francisco showed that raised bed gardens had significantly lower levels of arsenic, cadmium, and lead than in-ground gardens finding. Another study, conducted in Chicago, measured significantly less lead in raised bed gardens than in-ground gardens finding.To create raised beds, urban farmers can build frames of redwood or other lumber, brick, concrete, rocks, or any other sturdy material that won’t leach contaminants into the soil. Treated lumber should be avoided since lumber treatments may cause copper or other metals to leach into the soil. Water-permeable fabrics can be applied as a barrier between the on-site soil and the imported soil used to fill raised beds. Landscape fabric is permeable to liquids and air, unlike black plastic. Landscape fabrics are made from various materials, including non-woven polypropylene, woven fabric, biodegradable paper mulch, or flexible geotextile fabric. Once the frame has been lined with landscape fabric it should be filled with “clean” soil.

One way of ensuring that soil is clean is to purchase topsoil or planting mix certified by the Organic Materials Review Institute finding. OMRI performs an independent review of products intended for use in certified organic production, handling, and processing. OMRI reviews producer-submitted products against the National Organic Standards and generates a list of acceptable products.Local urban farmers or gardeners may have recommendations on potential sources of quality soil. Some vendors may be able to provide documentation that soil has been tested, and if not, a sample of the soil could be sent to a lab for testing to be sure that it is not contaminated.Other types of containers besides raised beds can be used in urban agriculture. For example, some commercially available growing systems are self-watering, for smaller-scale projects. Others are mesh “socks” that are filled with growing medium and placed on top of the soil. These types of “instant gardens” may be especially appropriate for short-term projects. Although tires are sometimes used as planters, this practice is not recommended, since tires can contaminate soil with leached metals as they degrade over time.Many sites have created successful urban agriculture projects through depaving. For example, in 2006, volunteers removed 5,000 square feet of asphalt from the grounds of Carthay Center Elementary School in Los Angeles and created a thriving garden for the entire community. To improve the hardened clay soil, tons of soil, mulch, and compost were donated and tilled into the soil by volunteers. The garden consists of raised beds and in-ground beds, as well as a stone fruit orchard, citrus orchard, tropical garden, butterfly garden, and poetry garden. If a site plan calls for depaving, test for heavy metals and other contaminants prior to asphalt removal. To test soil beneath asphalt, cut triangular holes in the asphalt with a hand-held concrete saw to expose the soil. Then remove the asphalt triangles, along with any sub-grade debris or stones, and obtain the samples. Replace the pavement triangles and add sand or pea gravel afterward to eliminate a tripping hazard. If soil tests show heavy metals above recommended levels, consider raised beds or large containers rather than removing the asphalt.As urban farming in all its forms becomes more popular, municipalities are beginning to consider a variety of policies related to land use for this purpose, including requirements for soil testing and remediation. Generally,vertical growing the decision faced by municipalities is whether to require soil testing and a remediation plan where appropriate, or to make recommendations and provide educational materials on best practices. Requiring soil testing can create challenges for municipalities if they do not have staff available and qualified to review and evaluate soil test results and remediation plans. Some municipalities require soil testing for contaminants finding for community gardens. Anyone contemplating establishment of such a garden or farm should check with the local city or county environmental health department, parks and recreation department, or other appropriate agency. Municipal decision makers should ensure that policies do not create insurmountable barriers for urban agriculture.

Many community groups pursuing community gardens or other urban agriculture projects have limited funds to conduct extensive site analysis for contaminants and perform any needed remediation. At the same time, contamination of urban soil is an important environmental health consideration, yet it is possible to have urban agriculture that is both safe and cost-effective. Soil testing is extremely important and should be facilitated and encouraged by municipalities. Ideally, this would include subsidizing the cost of soil testing and providing assistance with interpretation of soil tests and development of simple remediation plans. Minimally, it would involve having a list of best practices that urban farmers would agree to implement at their site. Education is important in every case. Many best management practices, such as adding organic matter and managing soil pH, are important strategies for ensuring safe soils but are not practical to handle via policy. Cities and counties should explore forming partnerships with the local UC Cooperative Extension office to provide educational resources and training on soil management for urban agriculture. UC Cooperative Extension has trained Master Gardener volunteers available who may be able to help provide education at the local level. Cities should also foster a connection between their own brownfield program, if one exists, and urban farmers. Municipal brownfield programs should be encouraged to work with urban farmers to identify potential sites and support testing and remediation for urban agriculture projects. This strategy is being used successfully in several U.S. cities, including Milwaukee, Wisconsin, and Kansas City, Missouri.Cround water is a critical resource for California water management. Stored in aquifers, water from rainy seasons can be used during dry and hot summers and supports water users through droughts if it is replenished in wet years.