Tag: horticulture

From a mechanistic perspective, tillage directly changes the mixing of soil and crop residue as well as soil structure, which then affect soil biogeochemistry and crop performance through various mechanistic pathways . As such, all other impacts on water, energy, carbon and nutrient cycles from tillage are then simulated as an emergent outcome in a coherent way. In contrast, some models represent the effect of tillage as direct modification of evaporation flux and decomposition rates based on multiplication factors derived from empirical data , which introduces excessive parametric uncertainty and strong context dependence on the empirical data used for model parameterization. Simulate as many measurable variables as we can, such that the model simulation can be thoroughly validated, and measurable constraints can be easily incorporated to further improve the model simulation. For example, as discussed in Section 2.3, GPP largely determines the carbon input to the soil , and crop yield are major carbon outputs from cropland, thus models with observational constraints from ground or satellite measured GPP and/or crop yield will unsurprisingly outperform models without such constraints. From a mass-balance perspective.GPP could serve as a particularly strong constraint for quantifying litter and root exudates, two critical carbon cycle components that have significant spatial heterogeneity but are hard to measure . Another example is the recent paradigm shift from using conceptual and non-measurable SOC pools to using measurable SOC fractions for SOC simulation in process-based models . SOM is a complex mixture of materials with heterogeneous origins, chemical compounds, microbial accessibility, and turnover rates . Physical fractionation of SOM differentiate particulate organic matter and mineral-associated organic matter ,danish trolley which all are measurable in the laboratory and have different characteristic residence times .

Beyond the change in total SOC, quantifying the changes and distributions of POM and MAOM may help address the permanence issue of soil carbon credit. However, most previous soil carbon models simulate SOM dynamics as non-measurable fluxes between conceptually defined and non-measurable soil carbon pools . Only if POM and MAOM are properly conceptualized and represented in the models can they be used to simulate the changes of those SOM fractions and can measured SOM fractionation data be used as direct constraints for models . Model-data fusion here refers to a set of techniques that reduce the uncertainty of states and parameters of process-based models or data-driven models using local information to obtain improved estimation of carbon outcomes . MDF also has the ability to evolve by incorporating new sensors/sensing data or new model developments to this framework. MDF is the core part of the “System-of-Systems” solution, with the basic rationale that available observations can only see part of a system, but a model that has the necessary processes can leverage available observations to help constrain the overall system and thus improve prediction accuracy for the processes that observations do not see. The most successful example of MDF is weather forecast – the integration of weather models with satellite observation – leading to its everyday use by different industries . MDF is not a new concept in earth science and ecological studies , as methods such as Bayesian Inference, Data Assimilation, and Emergent Constraint have been extensively used to improve various predictions at some sites, watersheds, or relatively coarse spatial grids ; however, the use of MDF for field-level carbon outcome quantification has many new requirements. We propose a new MDF approach to enable MDF being conducted at every individual field level, while also quantifying critical components of the carbon cycle to inform both science and management practices.

Essentially, for every field in a targeted region, cross-scale sensing provides high-resolution and spatially-explicit E, M, C observations, which are then used as either inputs or constraints for a model with necessary processes represented , and a set of location-specific parameters will be constrained for every field. By doing so, carbon outcome quantification allows the uncertainty quantification at every field, and model verification at every field is also made possible when extra carbon-related observations can be used as independent validation data. This MDF approach to enable high resolution and spatially-explicit model constraining represents a major advance over any of the existing quantification protocols that only require validation at the regional scale. This new MDF approach fulfills the model validation needed to test whether a model or a solution has true scalability, which was defined earlier as the ability of a model to perform robustly with accepted accuracy on all targeted fields. Only models that can reproduce the accepted ‘accuracy’ at any random fields can be used as an accepted MRV tool for agricultural carbon outcome quantification. Meanwhile, such a new MDF calls for new computational techniques, as the conventional implementation of MDF techniques would be too computationally expensive to handle the field-level MDF. Take Champaign county in Illinois alone as an example, it has ~12,000 fields in active cultivation; and the state of Illinois has ~1,000,000 fields in active cultivation; conducting intensive MDF using traditional implementation for each of these fields is infeasible. Moving to AI-based solutions and fully leveraging GPU computing to facilitate efficient and effective scale-up of the field-scale MDF over a broad region is the only path forward, which will be discussed further in Section 3.4. Scaling a System-of-Systems solution to all the individual fields with similar accuracy and at a low cost is a twofold problem: cross-scale sensing to generate rich E, M, C information for constraining various aspects of agricultural carbon cycles ; and scalable application of MDF over millions of individual fields .

To reduce the computation cost to scale up, both problems require the inclusion of AI and a transition from CPU-heavy to GPU-heavy models on super computing or cloud-computing platforms for massive deployment. Below we will specifically discuss three pathways to help realize the upscaling of MDF, spanning across a spectrum of different levels of integrating process based models with AI. Pathway 1: The most straightforward path to reduce model uncertainty is to use MDF to constrain model parameters. However, the high computational cost of parameter optimization limits the scaling of MDF. A feasible bypass without massive re-coding is to leverage deep learning algorithms and develop GPU-based surrogate models. Forward inference of deep neural network-based surrogates can be orders of magnitude faster than CPU-based process-based models, making them particularly suitable for parameter calibration . Successful applications have been reported in hydrologic and Earth system models , this strategy is also practiced in other complex systems such as agroecosystem and climate models . Traditional parameter optimization algorithms work by iteratively searching for the optimal parameter combination to minimize an objective function , but may get stuck at random local optima where multiple parameter combinations correspond to identical model outputs. If parameters are calibrated for individual pixels, this illposed issue may lead to a discrete spatial distribution of the target parameters. Recently, neural network-based parameter learning methods have demonstrated promising possibilities to address this issue without a searching procedure . For example,vertical aeroponic tower garden the differentiable parameter learning framework developed by Tsai et al. enables the inference of model parameters by an unsupervised parameter learning network, which was automatically constrained by the surrogate network to produce reasonable parameter combinations in the training phase. Compared to the traditional SCE-UA method in calibrating the Variable Infiltration Capacity model, the parameter learning network estimates physically more sensible parameter sets with continuous spatial patterns because the inputs of the parameter network are themselves spatially coherent. Although AI-based surrogate models provide a pathway for the MDF upscaling, the objectives of further research should not be limited to speeding up the parameter calibration procedure but to exploring generalized pathways for estimating interpretable and reasonable model parameters. Pathway 2: The second pathway is a hybrid modeling approach to integrate machine learning and mechanistic modeling in one integrated modeling system to achieve computational efficiency, prediction accuracy and model transferability. Knowledge Guided machine learning is one such approach that learns complex patterns from data while incorporating domain-specific knowledge, such as physical rules , causality and nature of variables , informed by process-based models .

Preliminary success has been achieved in many topics including stream flow prediction , lake phosphorus and temperature estimation , and GHG emission modeling . In particular, the KGML-ag model developed by Liu et al. incorporated knowledge from the ecosys model into a GRU model and outperformed both the ecosys model and pure GRU model in predicting the complex temporal dynamics of N2O fluxes . The expanded KGML-ag method for quantifying carbon budgets exhibited strong agreement with the NEE measurements obtained from 11 eddycovariance sites . Combining KGML with Meta-learning may increase model transferability by accelerating hyperparameter learnings that account for spatial heterogeneity . Despite this early success, efforts to develop hybrid models are still in its nascent stage. Scaling field-level KGML for carbon accounting across millions of fields would require innovative approaches to assimilate multimodal remote and insitu sensing data, possibly by assimilating these data via low dimensional embeddings to constrain neural networks. Future research should also address multi-objective learnings, because existing KGML models are mostly mono-objective and lack synergistic considerations for the coupling of soil biogeochemistry. Pathway 3: Fully upgrading existing agroecosystem models to GPUaccelerated systems necessitates intensive code redesign and rewrite, thus requiring longer coordinated efforts with dedicated funding support . Based on previous explorations for Earth System Models  and specific challenges in agricultural carbon outcome quantification , the ideal GPU-accelerated agroecosystem models should have the following characteristics: having the same or higher level of performance and interpretability as in the original model; working freely in the GPU environment and be flexible enough to adapt to hardware improvements; and enabling the assimilation of generic data ensemble from multiple sources with different scales for efficient training/validating/fine tuning and on-time correcting. Progress is faster in upgrading modules with relatively known physical rules, such as in the areas of climate and hydrology than in biogeochemistry or human disturbance . For example, previous efforts on rewriting domain-specific language to adapt the GPU-accelerated systems succeeded in weather modeling  and climate modeling . An extensive effort is currently underway to adapt DOE ESMD/E3SM with modern machine learning techniques to next-generation architectures that are capable of GPU computing and generic data assimilation . The recently proposed concept of neural earth system modeling , aiming for a deep and interpretable integration of AI into ESMs, might be the closest solution for upgrading agroecosystem models as well. One profound step for such upgrading is to replace every submodule of the process-based model with a ML surrogate, and to train those surrogates jointly with real world observations. However, proceeding in this direction needs to conquer the challenge of mapping highly non-linear processes involving partial differential equations with different coefficients at different spatial and temporal resolutions. One solution that has shown some early success in predicting global atmospheric circulations is Fourier Neural Operator , a neural network specifically designed for solving an entire family of PDEs by learning mappings between functions in infinite-dimensional spaces . However, FNO is only one kind of “black box” neutral solver for PDEs. To be adopted in agroecosystem simulations, FNO needs to combine with other machine learning models to consider the connections and heterogeneity in space and time, and needs knowledge-guided constraints to provide predictions following physical/biogeochemical rules. Model validation, a procedure to benchmark model simulation with independent, high-quality observational data, is the only way to build model fidelity. The new MDF approach of high resolution and spatially-explicit model constraining essentially proposes a more strict way to test model scalability, defined as the ability of a model to perform robustly with accepted accuracy on all targeted fields. “Scalability” of a model or a solution should not only be demonstrated by model performance at a limited number of sites with rich data, where extensive parameter calibration is allowed; a true test of model “scalability” should be also demonstrated at many random sites, where only limited measurements are available. The latter is what a real world application entails – we are required to quantify the carbon outcomes at any given field. To achieve the above goal to fully validate the model scalability, a three-tier validation approach is needed, and results from these three tiers should be reported to the community for fair and transparent comparison.

State land reform efforts also encouraged the deepening of monoculture in the Peloponnese. Two land reform laws, one in 1835 and another in 1871, were passed at moments of swelling demand for currants and enabled investors to plant new vineyards. After the revolution, land that was owned by the Ottoman state—which was most land—was transferred to ownership by the Greek government. The intention was to sell this land quickly, but the assassination of Kapodistrias put these plans on hold. Called the “national estates,” this land remained the property of the Greek state. Private cultivators were permitted to live on the national estates and work the land as their own, and instead of paying rent, they paid a tax to the Treasury called the “right of usufruct,” which amounted to 15% of the total output of the land worked.In the last quarter of the nineteenth century, a crisis in Western Europe caused a sudden spike in demand for Greek currants. Around 1863, the North American insect phylloxera vastatrix arrived in France aboard a steam ship. American vines had evolved an immunity to the aphid over centuries of coexistence, but phylloxera proved fatal to European vines, which had never been exposed to it. In addition to the rise of greenhouses and amateur entomologists in France and the UK, the main cause that enabled phylloxera to travel from America to Europe was the advent of new steam ships. By 1860, steam ships had improved dramatically from earlier models and could now cross the Atlantic in ten days, which was a short enough time for the phylloxera aphid to survive the journey.As a result of uncertainty and misinformation,aeroponic tower garden system phylloxera was allowed to spread slowly but widely throughout France.After the aphid was first positively identified in France in 1868, it spread throughout that country in the 1870s, devastating vineyards.

Even though the aphid had been identified, there was no known treatment. Despite the efforts to stop the spread of phylloxera through the use of flooding and the application of carbon bisulphide, the aphid continued to spread and to cause destruction in France and beyond.Phylloxera destroyed vineyards in sixty out of the seventy-five of the wine-growing provinces in France, and from 1869 to 1883, French wine production decreased by forty percent.By 1881, phylloxera had also been identified in the wine regions of Germany, Italy, Spain, Portugal, and Algeria.Phylloxera did not make it to the vineyards of southern Greece, and Greek cultivation rose to fill the vacuum created by vineyard collapse in Europe—in addition to the foreign demand for Greek currants for British puddings, there was now a demand for Greek currants for the raisin wine they could be used to make. Phylloxera had reduced French wine production by more than half, putting it well below the requirements of domestic demand, not to mention the requirements of the foreign demand for French wines. As a result, French consumers turned to making wine out of Greek currants, importing them cheaply from London since prices had fallen so low and making them into wine in the South of France.The Société Corinthienne in Marseilles was established to import currants from Greece to be processed into raisin wines.French currant imports continued to rise every year, and by 1889/1890, France imported more than 70,000 tons or about half of all of Greek currant production to convert into raisin wine for domestic consumption.Despite accounting for a minority of total land use, currants did account for the majority of the overall exports of Greece . Due to the increased relative profitability of currants, monoculture progressed and currant exports grew at the expense of other commodities. One scholar has called this period, from the 1860s to 1893, the “golden age” of the currant in Greece.During this time, currants were the majority of the overall exports of Greece. From 1850 on, they accounted for around half of the overall value of Greek exports, and in some years over 75%.

In the last quarter of the century, currant exports soared from 50,000 tons to 170,000 tons by 1900.While the rest of Europe was suffering the Great Depression of 1873–96, the Greek economy thrived.Despite the outsize role of currants in the Greek national economy, the state was not heavily involved in the currant industry. The state’s role was limited to imposing a tax on currants, and it occasionally intervened to negotiate a lower tariff in importing countries. Currant taxes remained the same from year to year—a 10% land tax and a 6% export duty, both collected at the customs office. In 1858, these taxes were fixed. For every 1,000 Venetian liters, the land tax was 10.50 drachmas, and the export duty was 5 drachmas.In Patras, the currant tax funded a wide array of projects, including public education, public welfare, public insurance, and university scholarships. Infrastructure in Patras, however, was not funded through taxes on currants, but through taxes on imports. Patras lacked a pier and a quay until 1840. These were constructed through a 0.5% tax on imports imposed in 1836, and from 1840–1869, these funds were used for repairs to the quay and to build wooden storage sheds.Toward the end of the century, big projects like the Athens to Patras railway and the Isthmus Canal were underwritten by the future revenue to be collected through the currant tax. Over the course of the nineteenth century, from the end of the Greek Revolution until 1893, currant cultivation spread through Greece in three distinct phases, punctuated by dips at “crisis” moments . In the first phase of expansion, from 1828 until 1852, the currant vineyards recovered from their destruction during the war, fueled by the continuing strength of the demand for currants from Britain. It took ten to twelve years for a currant vine to reach full productive maturity, and five to seven years before it started bearing any fruit at all.As a result, currant vineyards took a while to recover their pre-independence production. In 1828, because of the war, the Peloponnese was “a large stretch of uncultivated land.” The replanting of currant vineyards in the eparchy of Patras began in 1828 and was finished in 1847.82 While currant vineyards were being planted in Patras, they were also being planted all along the north coast of the Peloponnese, from Patras east to Corinth.

The continuing strength of the demand for currants in Britain made it more profitable to plant currants than it was to plant other crops. Tempted by higher prices and given the opportunity of a blank slate because of the destruction of the war, Greek peasants planted currants instead of food crops for household consumption. In 1829, the agronomist Christophoros Kontachis traveled the Peloponnese to teach peasants to grow potatoes. He wrote, “last February, while traveling the Peloponnese to teach potato cultivation, I saw many people in the region of Achaia planting currants, considering this plant more profitable than other products.”He observed that they were resistant to growing potatoes because it was much more profitable to grow currants. This first phase ended with the outbreak of the “vine sickness” of the early 1850s. This was caused by a fungus known as Uncinula necator, or Odium. This fungus covered the leaves, fruits,dutch buckets for sale and stems of grapevines with a powdery, white mildew. Odium was not just a problem for Greece—far from it. By 1852, the disease was endemic in vineyards all over Europe, Asia Minor, and North Africa. In Greece in 1852, the disease destroyed two thirds of the currant crop. From 1852 to 1855, currant production in Greece—and grape production in general in Greece and in many other countries—was effectively zero.In Greece, the Oidium crisis was compounded by the British blockade of Patras and other ports during the Crimean War from 1851 to 1853 and a rise in the price of wheat. As a result, the economy of the currant zone was very depressed during the 1850s. An indication of the suffering in Patras can be seen in the establishment of a foundling home in the city, and the number of foundlings increased from seven in 1852 to 48 in 1859.This crisis was overcome within a few years when a French botanist at Versailles developed a treatment. He discovered that dusting crops with a sulphur spray killed the fungus and protected vines from becoming infected. At this point, it became common practice in Greece and elsewhere to walk through the vineyards with spray cans, applying a thin spray of sulphur to protect the vines from Oidium . By the end of the decade, all vineyards were being treated in this way, and the Oidium pandemic was fought back.With the recovery from Oidium, Greece entered a second phase of expansion, lasting roughly from 1857 to 1878. The main impetus for growth during this period was the change in consumption patterns in Britain described above. The application of ring-cutting in the Peloponnese around the middle of the nineteenth century also enabled the currant zone to expand further south in the peninsula. Without the application of this technique, it was not possible to grow currants in soil that was too fertile. Before ring-cutting, attempts to transplant currant vines to the fertile plains of Ilia had failed because, “the currant vine, as soon as it was transplanted to rich and humid soils, turned wild and gave no fruit at all.”With ring-cutting, Ilia, which had been a center of cereal production, replaced cereals with currant vines and became the “capital of currant production.”The currant zone thus expanded south, but the currants produced south of the traditional currant-growing zone in Achaea were of an inferior quality.

The dryer soils of the northern Peloponnese produced sweeter fruit. Currants grown in Vostizza and Patras were classed as Α’ quality currants, and currants from other regions were Β’ or Γ’ quality. Nevertheless, because of the fertility of the soil, the quantity of production was much greater in the south.89 In the middle of the nineteenth century, for the first time since the sixteenth century, the center of Greek currant cultivation shifted from the Ionian Islands back to the Peloponnese. From the sixteenth century to 1847, over half of total Greek currant production came from the Ionian Islands of Kephalonia, Zakynthos, and Ithaki. In 1848, the Peloponnese finally overtook the Ionian Islands, and the North and West coasts of the Peloponnese became the center of currant cultivation. By 1870, production in the Peloponnese was almost 80% of overall Greek production. This is not to say that currant production in the Ionian Islands decreased; on the contrary, it also grew. However, production in the Peloponnese grew faster and eclipsed the islands.The final boost in the second phase of the extension of currant vineyards in the Peloponnese occurred after a political change that encouraged currant cultivation to spread even further south in the peninsula. After ring-cutting, the “age of pudding” in Britain, and improved steamship travel promoted the extension of vineyards south to Ilia, it was the land reform law of 1871, which sold the national estates to private land-owners, that allowed currant cultivation to spread south and for vineyards to colonize Messenia. The second phase of expansion stalled with yet another crisis. Responding to an everincreasing British demand for currants, Greek supply grew to the point that it outstripped demand, and Greece entered its first over-production crisis. This state of affairs was largely enabled by the land reform of 1871. In the years following the law, a large segment of the national estates in the Peloponnese were sold to private individuals and planted with currant vines. As mentioned above, it took six to seven years for new plantations to begin bearing fruit, so in 1877/1878, the market was overrun with a sudden flood of low-quality currants. Currant prices fell to all-time lows. In the spring of 1878, the price of currants on the London market barely covered the cost of shipping them from Greece. The Greek currant economy seemed to be on the verge of a crisis. Solutions were proposed by Greek ministers and currant merchants, including instituting a state monopoly on currants and restricting the planting of new vineyards. These plans received much opposition, and they were soon forgotten when rescue to the Greek crisis came from phylloxera and the sudden demand from France.91 The phylloxera crisis in Western Europe rescued Greece from the first over-production crisis. Under the influence of greatly increased global demand and the misfortune of their competitors, Greek currants in the Peloponnese became very profitable, and currant viticulture expanded in response.

To Lampe and Jackson, the Ottoman and Hapsburg empires exerted a greater influence on the Balkans from the sixteenth to the nineteenth centuries than did Northwestern European consumers or businessmen.Despite these and other criticisms, World Systems Analysis has left an indelible mark on the study of market integration in Southeastern Europe and the Eastern Mediterranean. The overall narrative of this process has remained largely unchallenged: over the course of the eighteenth and nineteenth centuries, growing foreign demand for Mediterranean agricultural products facilitated the integration of regions along the Mediterranean littoral into a larger market for goods and labor. This integration caused the states of the Mediterranean to develop in a subordinate—if not altogether dependent—position vis-à-vis Northwestern Europe. The terms “core” and “periphery,” moreover, are still widely used to characterize this unequal relationship, although the more precise terminology of World Systems Analysis, such as “semi-periphery” and “peripheralization,” have receded from use. Instead of “peripheralization,” with its Eurocentric and teleological connotations, this process may be referred to simply as “market integration.”The newer work from a world-systems perspective has attempted to move beyond teleological modernization frameworks. Recent scholarship on “working class cosmopolitanism” in Mediterranean port-cities, for example, utilizes world-systems narratives and terminology, but it conceives of class outside of a Marxian framework, and it also posits important cultural identities other than national ones. This literature shifts focus from the port-cities’ merchant bourgeoisies to their sailors, day laborers, outlaws, and prostitutes, arguing that they constituted a diverse “cosmopolitan” class.

Migration between port-cities in the Eastern Mediterranean created cultural identities that no longer exist and have receded from view because of the rise of national historiography—market integration and the consequent rise of the Mediterranean port cities not only created a non-Muslim bourgeoisie,hydroponic fodder system but it also created a lower class of cosmopolitans.Other world-system studies attempt to transcend the literature’s overwhelmingly urban focus, for example by studying the ways rural banditry helped incorporate the countryside into the world economy.This newer world-systems-inspired literature fits neatly with other historical approaches to the modern Mediterranean region. First, it fits surprisingly well with other economic historical approaches, such as the more classical and “cliometric” study of modern Mediterranean economies.These once-oppositional frameworks have converged—the Mediterranean was not fully dependent, and the post-Ottoman nation-states did not suffer from a failed modernity, but they did develop in a subordinate position vis-à-vis Northwestern Europe, and this was largely due to aspects of the international trade of agricultural commodities. Second, this literature fits well with cultural and intellectual historical approaches to the modern Mediterranean region, such as the study of modern Mediterranean diasporas and of political and intellectual networks.With respect to Greece specifically, the story of market integration with Western Europe begins in the second half of the eighteenth century. The main catalyst was the rise of Greek merchant houses which opened in all the major cities of Europe and the Mediterranean in the eighteenth century. The result was that Greeks in Ottoman port cities controlled a significant portion of the empire’s trade with Europe. This was further facilitated by the Treaty of Küçük Kaynarca, signed in 1774 between the Ottoman and Russian empires, which was interpreted to allow Orthodox Christians in the Ottoman Empire to sail under the Russian flag.

Over the course of the nineteenth century, market integration was further promoted by several forces, especially advances in technology such as steam ships, liberal trade policies in the UK, the establishment of an independent Greek nation-state in the 1830s that was able to trade more freely with the West, and industrialization in Western Europe, which caused an increase in aggregate demand for commodities produced in Greece and elsewhere. As a result of all these processes, over the course of the nineteenth century, there was a marked increase in the volume of trade between Greece and Western Europe.In the second half of the nineteenth century, this process of market integration accelerated to an even greater degree. Beginning around 1860, there was a sharp rise in global demand for agricultural products grown in the Mediterranean region, and the vast majority of nuts, citrus, and dried fruits consumed in Europe and North America came from Mediterranean Europe— Southern Spain specialized in raisins, for example, and Southern Italy in citrus and almonds. In the middle of the nineteenth century, demand for these and other Mediterranean agricultural products rose due to general demographic growth in importing countries and the growing prosperity of the middle class in Western Europe.At the same time, industrialization created an ever-growing need for cotton for the textile mills of England, and Britain’s colonies and trade associates in the Mediterranean felt the pull of this demand. As a result, production of these agricultural commodities in Mediterranean Europe intensified. In sum, for the Mediterranean in general and for Greece in particular, the focus of scholarship on market integration and the globalization of Mediterranean agricultural products has been on its social, economic, and political consequences. The environmental consequences and the effects on agricultural practice, however, are not well understood. While the sub-field of environmental history has enjoyed great success in other regions, above all in North America and Germany, there is no environmental history of modern Greece per se.

There is, however, great potential to construct an environmental history of globalization in nineteenth-century Greece by combining disparate approaches and putting them into conversation with environmental histories of other parts of the world in the nineteenth and twentieth centuries.These approaches include the literature on the economic history of Greece and the Mediterranean;the historical, geographical, anthropological, and archaeological literature on land use, historical demography, and agricultural practice in Greece and the Mediterranean; and historical ecologies of the Mediterranean.Scholarship on the Mediterranean has envisioned the region as a unit from antiquity to the early modern era. This literature has had difficulty, however, in dealing with the nineteenth and twentieth centuries. It is generally acknowledged that sometime in the nineteenth century, Mediterranean unity was destroyed by the fracturing of the region into nation-states and by the globalization of trade. As a result, scholarship divides the study of the Mediterranean in the nineteenth and twentieth centuries into the rival civilizational spheres of Europe and the Middle East. For the literature on the pre-modern Mediterranean, ecology and agricultural practice are often regarded as key commonalities—Mediterranean agriculture is understood as a series of integrated strategies developed in concert with the environment for making productive use of diverse micro-ecologies and for limiting the risk of subsistence failure. In this section, I adapt this model in order to apply it to the study of the nineteenth century. I contend that the agricultural system outlined in the literature on pre-modern Mediterranean agriculture and historical ecology was the norm in Greece and Mediterranean Europe generally at the beginning of the nineteenth century,fodder system and that it was transformed over the course of the century. In applying this model to the present study, I historicize “traditional” Mediterranean agricultural practice, arguing that it was not an unchanging structure, but a dynamic process that was influenced by a variety of factors, particularly economics, demography, and climate. The literature on the pre-modern Mediterranean is largely grounded in historical ecology, as studies of the Mediterranean in history identify it as a unit based either wholly or in part on environmental or ecological factors. One approach is to define the Mediterranean region as a unit based on a shared climate—the Mediterranean is the region with a “Mediterranean” climate, characterized by hot, dry summers and mild, wet winters.Other definitions rely on the areal extent of the production of certain crops associated with the region—the northern limit of the growth of the olive tree, for example, is offered as a border between Europe and the Mediterranean.Another approach which has gained in recent years employs the concept of “micro-ecologies” to describe the Mediterranean in history. This approach, particularly as elaborated by Horden and Purcell in their 2000 book Corrupting Sea, conceives of the premodern Mediterranean as a unit not because it is homogenous; on the contrary, the region is defined as such by its great internal diversity.This approach has attracted scholars studying the history of places along the Mediterranean littoral from antiquity to the early modern era.

The lands surrounding the Mediterranean Sea and the islands contained within it possess a myriad of physical features including Alpine mountains, arid deserts, lush forests, and volcanic islands, and the distance between two distinct ecologies can be very small. As Grove and Rackham write, “In Crete there is an immense contrast between the misty, well-vegetated rain-excess areas on the north sides of high mountains and the arid rain-shadows a few kilometers away on the south sides.”The result is that one slope of a snow-capped mountain is a desert, the other slope is a jungle, and at its base is a boggy marsh. The Mediterranean region is not unique for its ecological diversity and fragmented landscape, but it is exceptional for its degree of fragmentation as well as the degree of connectivity between fragmented landscapes. As one scholar has written, “Nowhere else is the weave of the world’s surface so fine.”Mediterranean micro-ecologies are understood to be shifting and unstable. Due to natural erosion, variations in precipitation, regular fires and occasional natural disasters, such as earthquakes and volcanic eruptions, micro-ecologies do not remain the same from year to year. They also transform due to changes in human interactions with the land.As a result of their differing productive strengths as well as their volatility from year to year, pre-modern Mediterranean micro-ecologies were highly interdependent. A single micro-ecology was unlikely to be able to support the various needs of its population, but various forms of connectivity are built into the landscape, the sea being the most important of these. This is a large part of what gave the Mediterranean its unity. It was very highly fragmented into small ecologies, the populations of these places needed products from other places in order to survive, and the sea and other forms of connectivity facilitated exchange between these micro-ecologies. In a Mediterranean region composed of shifting micro-ecologies, instability and uncertainty were built-in factors of life. The instability and uncertainty were caused above all by two forces: variable climate and variable markets. With respect to climate: from one year to the next, rainfall could vary dramatically. As a result, a given location might provide very productive agricultural land one year and be barren the next. The other factor that shifted from year to year and affected the characteristics of a micro-ecology is what Horden and Purcell call “its changing configuration within the web of interactions around it,”or what for the purposes of this study might more simply be called “markets.” Precipitation was variable, but so were the needs of the populations within a given micro-ecology. Moreover, precipitation and needs varied in neighboring micro-ecologies and in more distant ones that were nevertheless connected through exchange. All of these variables were relevant at the micro-scale to the productive capacities and the overall fate of a given locale from year to year. It was in this context that traditional Mediterranean agriculture took shape as a way to manage risk and ensure that subsistence needs were always met. As a result of the capricious Mediterranean climate and shifting interactions with other micro-regions, populations living in Greece had to be flexible in order to meet the needs of their own subsistence from year to year. In the words of Paul Halstead, “Each year the farmer may be aiming for a different production target, from a different area of land, with a different labour force and with the cushion of a greater or lesser amount of produce in store.”On the local scale, Greek populations adopted certain strategies in order to maximize their potential for meeting their subsistence needs as well as those of their families. The three over-arching strategies undertaken by Mediterranean populations in order to survive were “diversify, store, redistribute.”Diversification can be seen in every choice made by Greek populations to meet their subsistence needs. In terms of agricultural production, Greek populations knew that they could not rely on a single plot of land to meet the needs of their subsistence from year to year. As a result, they undertook strategies to diversify their production.

The more successful Turén farmers sought to diversify production to cope with price and yield fluctuations and also expanded into new areas to counter the loss of soil fertility the increasing chemical-dependent production system engendered . By 1990, the original colony had expanded from 15,000 to 250,000 hectares and had established a production system of rice, maize, sesame and sorghum, crops favorable to mechanization and that could feed into the agro-industrial system . Agricultural development, and the resultant growth in production of cereals and oilseeds, in Portuguesa between 1949-69 was considered a national agriculture ‘miracle’ as the government invested resources into irrigation projects, roads, windbreaks, housing and a rice processing plant that helped to solidify the new class of farmers in the area . However, while grower strategies of expansion and diversification were important for commercial farmers in Portuguesa, outcomes in the state varied. Successful commercial farmers in the Acarigua-Araure center grouped together in producer associations and used alternative sources of capital investment to expand into more profitable areas of the agroindustrial chain by developing processing plants for oilseed and cotton refining . Unlike the Acarigua- Araure growers, however, Turén producers didn’t have access to alternative financing to enable vertical integration, and although were able to expand and diversify production, became largely subordinated to the more powerful agro-industry sector as they assumed a role as producers of raw materials for processing centers . This dynamic intensified in the late 1970s and early 1980s as Venezuelan agriculture entered a crisis. A confluence of factors including reduced government subsidies and private investment in the sector, stagnant prices,hydroponic dutch buckets and the rapid increase of food imports contributed to a squeeze on the nation’s producers .

By 1983 vegetable production was 15% below 1977 levels, and the area under cultivation had fallen 25% . In the same time period, food imports rose from 35% to 65% of national consumption . Much of the disruption to the agriculture sector was due to OPEC’s—and by extension Venezuela’s—successful efforts to raise oil prices. The resultant influx of petro-dollars to Venezuela’s newly nationalized oil sector drove currency appreciation, which facilitated increased food imports and reduced the competitiveness of domestic producers. The crisis drove further mechanization and intensification in Portuguesa’s agricultural sector, as the state’s commercial elite saw increasing production as the solution to a context of stagnant prices coupled with rapidly rising costs of production . The agrarian malaise reflected the general political and economic crisis of the 1980s as oil prices dropped. The Venezuelan government implemented reforms to boost agricultural production, including deregulating controlled food prices, issuing of low-interest loans, increasing fertilizer subsidies, and mandating that commercial banks lend to a portion of their reserves to farmers . The policy prescriptions fed the so-called Venezuelan ‘agricultural miracle’ of 1983-87 that saw strong sectoral growth and production rises in a number of key crops. Maize, sorghum and cotton production levels doubled over 1983 levels . Continuing macroeconomic woes however pressured subsequent governments to accept orthodox conditionalities of the International Monetary Fund that began to restructure the economy at large and largely dismantled polices aimed at food self sufficiency by reducing agricultural price supports and input subsidies. The implementation of structural adjustment policies, however, resulted in severe social upheaval, including the 1989 Caracazo. The upswell of protest from Venezuela’s citizenry opened political space for the government to reinstate some subsidies to the agricultural sector. In sum, as the 20th century closed Portuguesa had been transformed into dominant agrarian player, with a vertically-integrated commercial agricultural sector.

With Acarigua-Araure serving as the agro-industrial core and as an important regional market for seeds, machinery and agricultural services in the state, Portuguesa functioned practically as an agrarian enclave economy as it became the premier agro-industrial center in the country . The success of the commercial sector was predicated on interventionist state policy that broke up landowner power, provided credit, input subsidies, infrastructure and technical support, and maintained government-protected, domestic markets . The emergent agro-industrial sector had little connection to the earlier agricultural export sector of coffee and cacao, although some traditional latifundio interests did evolve into commercial elite. The agrarian reform sector near agro-industrial commercial development was subordinated to the accumulation needs of the commercial sector. While commercial agriculture established itself in areas with well-developed and largely government-financed infrastructure much of the state remained largely untransformed. Agrarian development established two coexisting production systems: an agro-industrial model centered in the municipalities of Páez, Araure, Esteller, Turén and Ospino; and areas of continued peasant production, especially prevalent in Guanare, Guanarito and Sucre . The peasant sector in the immediate geographical path of commercial agriculture had been displaced and sometimes absorbed into the new industrial sector as labor, or had continued to function largely as before in areas further afield from Portuguesa’s agro-industrial corridors.Portuguesa’s commercial sector is concentrated along the number 5 highway, the major transportation artery in the area that links Portuguesa to the important commercial cities of Barquisiemto, Valencia and Caracas. Agro-industrial crop production is focused near the main transportation corridors while mostly small-scale coffee production is located primarily in the highland areas of Sucre, Ospino and Monseñor José Vicente de Unda municipalities.

Cattle ranching— primarily for milk production—remains in some savanna areas, particularly in low laying lands that seasonally flood and remain relatively far from infrastructure networks in Guanarito and Papelón. In 2001 Portuguesa accounted for 90.5% of domestic sesame production, 51% of rice, 41% of sorghum, 40% of corn and over 30% of sugarcane . In 2013, Portuguesa accounted for over half of all maize production in the country, producing 1,031,765 tons . Portuguesa is not a site of petroleum production or processing. Of theoretical note is that in the oil curse literature, oil development displaces agriculture in terms of share of national GDP, contributes to Dutch disease dynamics that favor imports over national production, and—at a regional level—can displace agriculture at specific sites of production.Yet, Portuguesa demonstrates—in areas with favorable conditions—agriculture can become a regionally dominant sector in particular historical contexts. According to Grinberg and Starosta , capitalist sectors in oil states are limited in their capital accumulation process by the nature of oil rent redistribution. While the capture oil rent allows for their reproduction on a domestic scale they are generally unable to compete in international markets . In Venezuela, a contingent of Portuguesa growers were successful in consolidating a dominant position in supplying domestic markets. Part of this success was also based in expanding vertically in domestic agro-industrial chains, and using smaller producers to help feed the local processing and packaging enterprises they now controlled. The issues of land reform and domestic food production have been prominent controversies within Venezuela in the Chavista period. The intense reaction of commercial grower associations to the 2001 Land Reform Law and its explicit calls for the elimination of Venezuela’s latifundia established an early context of conflict between agriculture elites and the state. The perceived attack on private property rights codified in the Land Reform Law has been cited as one of the primary drivers of sharpening opposition resistance to the Chavista government and of contributing to the 2002 coup de tat that briefly removed Chávez from power . The government’s anti-latifundia rhetoric was portrayed by government critics as generating class conflict, violence and sense of lawlessness in rural areas . Agriculture, food and land reform policies have, thus, served as important points of conflict between the Chavista government and its political opposition and cannot be separated from broader social conflict over the Chavista-era ‘revolutionary’ program. However,bato bucket conceptualizations of dynamics between the state and the commercial agriculture sector as primarily conflictive mask a set of policy relationships that are more ambivalent. A closer examination of policy dynamics reveal that state policies often support sectors of commercial agriculture and reinforce agribusiness socio-economic position in rural areas. Perhaps most salient issue in terms of conflict between commercial agriculture and the state is the threat of confiscation of land via the Land Reform Law. Indeed, the law was one of the most controversial components of the government’s 2001 reform package . Through 2013, 6,897,872 hectares have been recovered, and 11,901,752 hectares have been regularized by the state under the Land Reform Law .

Despite the quantity of land recovered by the state and political controversy and violence connected to the agrarian reform, the process of land expropriation has largely bypassed producers in much of the commercial agriculture sector. The relatively low land seizure pressure on commercial producers in Portuguesa results from government negotiations with estate owners, dynamics between state institutions and producers at the local level, and an increasing policy trend focused on maintaining agricultural production levels rather than on addressing levels of land inequality. It is difficult to ascertain how much land was seized by the government from private interests, especially on the level of individual states. At the time of writing, government data on land recovery and redistribution released by the MPPAT and INTI were national totals and did not break down numbers by individual states or municipalities. There were no available, reliable data on how many private estates in Portuguesa had been subject to recovery by the state or had been occupied by peasant groups. Commercial growers in Portuguesa, however, stated that the threat of expropriation was a central incentive to continue production in the face of low prices and other productive or profitability challenges . In Portuguesa, growers cited the cases of the 2,276 hectare Dos Caminos and the 1,779 hectare Palo Gordo estates recovered in 2012 by INTI as emblematic cases of seizures from landowners in the region. Negotiation with landowners for partial redistribution is often attractive for policymakers as it theoretically speeds up land redistribution and avoids drawn-out legal process and appeals. It also potentially diminishes opposition to reforms as landowners can receive payment for lands lying idle on estates, as under the Land Reform Law estate owners are entitled to compensation for seized lands. Oil revenue theoretically allows the government to pay market rates for seizures, giving it an advantage over more cash-poor countries attempting an agrarian reform that compensates landholders. It is unclear, however, to what degree compensation has been paid in the Venezuela land reform. A high-profile expropriation case involving estates owned by the British Vestey Group was resolved with the government and the company negotiating the transfer of two estates to the government in exchange for the retention of 8 other estates and a payment of £2.4 million . Yet there is no clear data on whether or not payment was delivered to landowners in the majority of cases of land recovery. Some seizures of sugar plantations in the state of Yaracuy, for example, were ultimately implemented under the rationale that private land titles were invalid due to the area being designated as an indigenous reserve before the establishment of the plantations . As the plantations occupied technically state land no indemnity was paid. Regardless, a strategy of negotiation with landowners by the state in policy implementation has implications for the nature of the reform. As in the case of many historical land reforms the division of estates with property owners can often leave the most productive land—with better soils and well-developed infrastructure—in the hands of landowners, which solidifies their relative position in the agriculture system even as it may diminish the size of absolute holdings. Redistribution pressure on private interests in the agrarian sector was also dependent on changing relationships between government institutions and commercial interests. In early periods of the reform government positions at the state or municipal level in some areas were in the hands of politicians that opposed the Land Reform Law. In Yaracuy and Cojedes states early land occupations by peasants were removed violently by state police forces under the control of opposition governors . The subsequent election of Chavista politicians to state-level offices was an important shift in local conditions that allowed peasant groups to re-occupy estates with a greatly reduced—although not entirely eliminated—threat of removal by state security forces . The control of key local offices by Chavista politicians or functionaries, however, did not ensure an even approach to policy implementation. Growers in Portuguesa cited that the changing of directors of MPPAT and INTI at the state level impacted how aggressively redistribution was promoted by the government.

The November 2016 state legalization of recreational cannabis prompted Siskiyou to examine a possible licensure and taxation system for local growers . Amidst sustained, vocal opposition, the proposal stalled for several reasons that further aggravated cultural and racial tensions: A key proponent of licensure was discovered to be running an unauthorized grow, three Hmong Americans died of carbon monoxide poisoning due to heaters in substandard housing, and a cannabis cultivation enterprise run by two Hmong-Americans attempted to bribe the sheriff. These developments were interpreted not as outcomes of restrictive regulations and criminalizing strategies, but as proof that, in the words of one supervisor, regulation was impossible until the county could “get a handle on the illegal side of things.” The sheriff encouraged this interpretation, arguing in an interview that statewide legalization was “just a shield that protects illegal marijuana” and efforts to regulate it would always be subverted by criminals. This anti-regulatory logic prevailed in August 2017 when the county placed a moratorium on cannabis commerce. Still, the sheriff argued for stronger powers, citing an “overwhelming number of cannabis cultivation sites,” which, according to the Sheriff’s Office, continued to “wreak … havoc [with] potentially catastrophic impacts” across the region . Just 1 month later, at the sheriff’s urging, the Siskiyou Board of Supervisors declared a “state of emergency” aimed at garnering new resources and alliances to address the cannabis cultivation problem. Soon, the Sheriff’s Office enlisted the National Guard, Cal Fire and the California Highway Patrol in enforcement efforts, and, by 2018, numerous other agencies joined,planting gutter including the Siskiyou County Animal Control Department, California Department of Toxic Substances Control, State Water Resources Control Board, California Department of Fish and Wildlife and a CDFA inspection station.

These alliances multiplied the civil and criminal charges cultivators might face . Ironically, California’s cannabis legalization has enabled a kind of multi-agency neoprohibitionism at the county level, one that reinforces older criminal responses with new civil-administrative strategies and authorities. The need to “get a handle” might be regarded as a temporary emergency measure, but it may also propagate new criminalizing methods and institutional configurations. The more enforcement occurs, the bigger the problem appears, requiring more resources and leading to a logic of escalation symmetrical to the much-critiqued War on Drugs . And the more cannabis cultivators are viewed as criminal, the less likely they are to be addressed as citizens, residents and farmers.Given concerns about biased county policy and enforcement, the Sheriff’s Office held the first Hmong American and Siskiyou County Leader Town Hall in May 2018 to “foster a closer, collaborative relationship with members of the Hmong-American community,” exchange information about Hmong and Siskiyou culture and educate attendees on county policies . According to public records, racial tensions surfaced at this meeting when some white participants expressed that “our county” had been “invaded” and that Hmong-Americans were not fitting into local cultural norms . Meeting leaders — both government officials and Hmong-Americans — however, identified cultural misunderstanding, rather than criminalization and racialized claims by whites on what constitutes local culture, as the core problem to be addressed. “Misunderstanding” was an inadequate framing, given that Hmong-Americans had attempted to make themselves understood by attending public meetings, forming advocacy groups, signing petitions, demanding interpreters and administrative hearings, and registering to vote since their arrival in Siskiyou. At the 2018 town hall, and numerous prior meetings, they emphasized their status as legitimate community members — veterans, citizens, consumers of county goods, local property owners, “good” growers and medical users — not nuisances, criminals, foreigners or outsiders.

In interviews and public forums many Hmong-American cultivators expressed a desire to comply with the rules. Their efforts, however, they said, were frustrated not only by linguistic and cultural differences, but also understaffed and underfunded permitting, licensing and community services agencies. Hmong-American cultivators routinely told us about their desires to settle down, build homes and plant other crops. “I’m growing watermelons, pumpkins and tomatoes,” one cultivator told us, but he was waiting for a permit to build his house, a process another interviewee reported took 3 years. Though the town hall meeting sought to address cultural misunderstanding, this framing overlooks how misunderstanding — of Hmong-Americans or cannabis producers generally — is produced by criminalizing enforcement practices. Properties given as gifts in the Hmong-American community were seen as evidence of criminal conspiracy, not generous family assistance; land financing networks evidenced drug trafficking organizations, not kin-based support and weak credit access; repetitive farm organization patterns suggested “organized crime” , not ethnic knowledge-sharing circuits. When Hmong-Americans, leery of engagement with government agencies and unfriendly civic venues, self-provisioned services, including firefighting teams, informal food markets and neighborhood watches, these actions were taken to confirm suspicions that they could not assimilate. Now that some Hmong-Americans are considering, or already are, moving away in response to county efforts, the sheriff’s prior description of them as temporary residents seems prophetically manufactured.Anti-cannabis pressure creates a precarious state of impermanence — a season’s crop might be destroyed, infrastructure confiscated and investments of limited resources lost at any moment, disallowing longer-term investments. The impermanence makes noncompliance and deleterious environmental and health effects more likely, thereby perpetuating perceptions of cannabis cultivators as nuisances and dangers.

As enforcement makes private land cultivation more risky, cultivators move “back up the hill,” namely onto ecologically sensitive public lands, thus substantiating characterizations of cannabis growers as criminal polluters. These stigmas even spread to county residents who do not grow cannabis themselves but if perceived to assist cannabis cultivation can face social sanctions. One agriculturalist reported receiving death threats after selling water to cannabis cultivators. Meanwhile, well-resourced cultivators have an advantage over small-scale producers. They can protect their crops from visibility and complaints by concealing them on large plots of land or inside physical infrastructures ; and for white growers there is the anonymity of not being marked as ethnically different and therefore subject to heightened scrutiny. Greater access to capital, land and racial privileges insulates some from visibility and criminalization, resulting in uneven development and disparities in California’s expanding cannabis industry. Additionally, jurisdictions like the Siskiyou municipalities of Mt. Shasta and Weed are welcoming regulated cannabis commerce, thus capitalizing on its expulsion from the rest of Siskiyou and benefiting entrepreneurs with social capital and network access to successfully navigate complex public regulatory systems.After a century of cannabis’s criminal exclusion in California, state voters have elected to integrate cannabis farmers into civil regulation. An important facet of evolving cannabis regulations is local determination. As one interviewee pointed out, a 1-acre farm might be permitted in rural San Joaquin County but would not make sense in downtown San Diego. Yet,gutter berries when cannabis cultivation is disqualified from consideration as agriculture by localities, as it has been in Siskiyou County, it can be substantively recriminalized and placed beyond the regulatory reach of civil institutions. Prohibitionist strategies that blur lines between civil and criminal enforcement lead to penetrating forms of visibility and vulnerability that produce inequity and disparity. The result, as this case illustrates, can be a narrow, exclusive definition of agriculture that affirms dominant notions of land use and community. The definition of cannabis cultivation as agriculture by the CDFA creates an opportunity for service providers and regulators — including agricultural institutions, public health departments and environmental agencies — to craft programs and policies that openly address the negative impacts of production. Owley advises that “if we treat cultivation of marijuana the same as we treat cultivation of other agricultural crops, we gain stricter regulation of the growing process, including limits on pesticide usage, water pollution, wetland conversion, air pollution, and local land-use laws.” Presently, however, many agencies are being enlisted in locally crafted criminalizing efforts, thus limiting their ability to work cooperatively with cultivators and address issues through customary civil abatement processes.

Though unregulated cannabis cultivation can pose threats to public health, safety and welfare, police enforcement is only one of many possible ways to address it. Siskiyou’s cannabis cultivators experience familiar agricultural challenges around access to land, water and credit. These challenges are amplified without technical assistance or institutional support. If recognized statewide as farmers, these cultivators would be better positioned to access agricultural training and support services, thus addressing ecological and social concerns around cannabis production. Additionally, new cannabis cultivators might be considered “beginning” farmers according to the CDFA, and minority farmers, including Hmong-Americans, who experience poverty at twice the national rate , would be considered “socially disadvantaged” under the California Farmer Equity Act of 2017 . Farmers with these designations would, in fact, be prioritized for technical assistance and support from farm service providers — if, that is, they were recognized as farmers. Uniformly treating cannabis cultivation as agriculture would also help enable the collection of accurate and robust data by researchers. This information base is necessary if agricultural institutions are to take an assistive and educational orientation toward cannabis farmers. Continued enforcement tactics that amplify distrust, frustration and confusion will further hinder data collection , leaving little basis to understand basic dynamics of complex, interdisciplinary systems like agriculture . In a criminalized situation, it is inevitable that information is metered and brokered by community leaders in ways that inhibit full understanding of cannabis cultivation. We suggest, for all these reasons, that a decisive break with enforcement-led, prohibitionist trajectories is needed and that agricultural institutions lead civil policy development and support farmers who cultivate cannabis. Agricultural service providers could play a leadership role in addressing the pressing needs of farmers — both those impacted by and engaging in cannabis cultivation. Yet, UC Agriculture and Natural Resources Cooperative Extension advisors, for instance, consistently report that they are currently prohibited from engaging with cannabis issues . Additionally, many county-based agricultural commissions, Siskiyou County’s included, feel that cannabis is not an agricultural enterprise and therefore do not see its cultivators as their clientele. Without leadership from agricultural institutions and agencies, the expanding cannabis cultivation industry is left to develop unevenly across the state — with wealthy private interests capitalizing in some locales while vulnerable and unregulated growers may retreat, to avoid criminalization, into ecologically sensitive areas. UC ANR and CDFA have an opportunity to fulfill their missions and facilitate, for a burgeoning farming population, greater parity in farmer rights, capacities and resource access.Organic strawberry production has become big business in California, generating more than $17 million in sales annually on over 1,200 acres—nearly 5% of California’s total strawberry acreage. But as producers have found, growing this specialty crop without conventional pesticides requires a new toolbox of pest and disease control techniques. For the past five years, researchers from the Center for Agroecology and Sustainable Food Systems have been refining the use of trap crops in organic strawberry systems as a way to limit damage from the western tarnished plant bug and boost populations of the pest’s natural enemies. A serious pest native to California’s central coast, WTPB feeds on developing strawberries, causing gnarled, “cat-faced” berries with enlarged, straw-colored seeds. These damaged fruit can’t be sold on the fresh market. Although some organically acceptable sprays exist to treat WTPB, they’re expensive and relatively ineffective.A broad range of winter weeds in central coastal California, including wild radish, mustards, chickweed, lupine and other legumes, and knotweed, offer a winter food source for WTPB. As the rainy season tapers off in the spring and wild vegetation dries out, the WTPB adults move to flowering crops, including strawberries, and begin feeding. Trap crops planted along the edges of crop fields or within the field have the potential to limit WTPB damage by offering the pests a food source they prefer over the crop itself. “That’s the definition of a trap crop—that it’s a preferred host or food source for the insect you’re targeting when compared with the main crop,” says Sean L. Swezey, the Center’s associate director, and director of the UC Sustainable Agriculture Research and Education Program. Trap crops can also serve as habitat for beneficial insects, which can supplement pest control efforts.Once attracted to the trap crop, pests must be managed so that they don’t eventually disperse into the fields and damage the crop you’re trying to protect.

One can therefore calculate the significance levels for the test of whether the aggregate impact is significantly different from zero. The‐values suggest that the impact becomes significant around 2°C . Using the classification of IPCC, the study found that a negative impact is very likely for the +2°C and +3°C scenarios. As pointed out above, the coefficient on the degree‐days variables are less robust, however, similar results are obtained in a comparable study covering a larger geographical and climatic range gives comparable results. At the same time, the potential decrease in water availability appears to more damaging, especially for junior holders. This analysis studies how climatic variables and the access to subsidized surface water capitalize into farmland values, and how these values would be affected by changes in the climatic variables. Using a micro‐level data set of individual farms in California researchers examined how degree‐days, a non‐linear transformation of temperature variables, and related changes in water availability, capitalize into farmland values. This study found that the standard OLS approach underestimates the true variance‐covariance matrix of the estimator and therefore overestimates the significance of the regression coefficients, including those on the climate variables, because it incorrectly assumes that observations are identically and independently distributed. Nevertheless, the estimates of the impact of a change in water availability remain highly significant, even when allowing for spatial correlation or including random effects, though the significance is of course reduced relative to OLS. Similarly, coefficients on the linear and quadratic degree‐days variables are in line with what one would expect from agronomic studies,dutch buckets system but the estimates seem less robust to the inclusion or exclusion of non‐climatic control variables.

Researchers note also that the limited temperature variation in the study area makes estimation of the effect of temperature or degree‐days on farmland value somewhat problematic. The team has conducted a similar analysis for the eastern United States and found that extending this analysis to a larger area characterized by greater variation in temperature gives highly significant degree‐days coefficients that are comparable in magnitude to the ones presented here. The average magnitude of the impact of a potential decrease in water availability on farmland value appears to be larger than the one caused by an increase in temperature, because a decrease in water availability is harmful for all farms in California—a state that crucially depends on irrigation. On the other hand, the effect of an increase in temperature is mixed, ranging from modest benefits of an increase in temperature to potentially large damages in the Imperial Valley. Several caveats apply to this analysis. Perhaps the most important is that data on water rights is difficult to obtain, and the research team is continuing to develop finer and more accurate measures that might change the coefficient estimates. Moreover, the team’s current measure of water supply uses average annual historical deliveries; in future work, they will include measures of supply reliability that reflect the uncertainty facing water districts each spring, at the time cropping decisions are made. In addition, since the analysis relies on cross‐sectional data it does not pick up any potential changes not reflected in the data, most notably changes in prices, technology, CO2 fertilization, or the potential reduced water‐requirements through CO2 fertilization. “Among the many sessions of the Third World Water Forum, held in Kyoto, Japan in March 2003 , there was one titled Sedimentation Management Challenges for Reservoir Sustainability. Two main messages emerged from that session: Whereas the last century was concerned with reservoir development, the 21 st century will need to focus on sediment management; the objective will be to convert today is inventory of non-sustainable reservoirs into sustainable infrastructures for future generations.

The scientific community at large should work to create solutions for conserving existing water storage facilities in order to enable their functions to be delivered for as long as possible, possibly in perpetuity.” Reservoirs are one of the most common forms of nonrenewable resources, yet their economic studies have been rare. Engineering literatures emphasize that even when reservoirs were structurally sustainable,they could nevertheless become unsustainable due to sedimentation accumulation. The loss of storage due to sediment accumulation is nontrivial and alarming: Mahmood, K. reports that the annual capacity loss of worlds reservoirs due to sediment accumulation is about 1%, though White recently put this agure at 0:5%~1% . A world bank report translated the loss as the need to add some 45 km3 of storage per year worldwide, costing US$13 billion per year exclusive of environmental cost. China, which alone accounted for more dams construction than the rest of the world during 1950 1980,fairs worse, mainly due to the nature of sediment rich Yellow river. Zhou reported that China’s 82; 000 reservoirs are losing their capacity at the average annual rate of 2:3%. Three other frequently cited example of storage capacity loss are Welbedacht dam , Mangaho River project in New Zealand and Tarbela reservoir in Pakistan. If sedimentation issue is not taken care of properly, reservoirs needs to be abandoned after the sedimentation reaches a critical level.But sedimentated sites can’t be easily recycled for reuse. Such recycling efforts could be extremely costly. For example, according to Morris and Fan ,it would cost $83 billion to restore Lake Powell in Colorado river assuming one could and the disposal site to dump 33km3 of sand.Furthermore, there are not many proper sites for constructing reservoirs. Such sites certainly are not growing. Also, since the best sites costs were taken up earliest, alternative sites will be progressively costlier. These facts attest to the reservoir being nonrenewable resource. Ruud et al claim that Green House gases emitted from the reservoirs are positively correlated with the area cooded. In particular, reservoirs which food either upland forest or peat lands in Canada are likely to produce more GHG.

Studies like these further reduce the number of suitable sites for reservoir and provide further evidence of them being nonrenewable resources. There are at least 50000 dams in the world that are more than15m tall, as reported by International Commission On Large Dams . However, the total number of dams in the world is much more. In particular, given that only 7% of dams in the United States are more than 15m tall,using the same proportion, the total number of dams in the world could be more than 1 million.Lots of these dams are reaching their age. Furthermore, public’s perception of large dams as a clean source of energy is also undergoing transformation, and their decomissioning is more frequently discussed topics now than ever. At the same time, one needs a rigorous framework to calculate the economic value of dam at the time it is decomissioned so such decomissioning could be justified by judging it from some economically rational framework. Such value of the reservoir at the time of its decomissioning is the salvage value of the dam. From an operators point of view,the salvage value of dam is stochastic for several reasons: the impact of sedimentation on ecology and human health are not clearly understood.Tolouie reported that desiccated deposits of one sediments could be eroded and transported by wind,dutch buckets causing health hazard to nearby population. Furthermore, Chen et al reported that the presence of sediment against dam could constitute earthquake hazard. The impact of sediment accumulation on ecology alteration and the impact of delta deposition on the probability of flooding are also actively researched field. In legal front, Thimmes et al reviewed recent court decisions on cases against dam operators and found that courts have issued reward against dam operators for the ecological damage caused during the dam operations, and overall conclude that judicial determinations of reasonable reservoir management and reasonable precautionary measures by landowners are generally highly speculative, controversial, and based on limited information. Pansic et al report that currently three major costs associated with dam decomissioning include sediment management , environmental engineering and infrastructure removal . Furthermore, regulatory agencies may continue to impose new conditions on the operators as the new information on the impact of dams arrive, including their impact on Green House Gas stock in the atmosphere.The cost of decomissioning could very well be astronomical if stringent conditions are applied to the operators in the future, and this is consistent with the overall uncertain time dam operators are living in right now. It is clear that the periodical removal of sedimentation is an integral part of the operation of a sustainable dam.There are several techniques to remove sedimentation from reservoirs. We can roughly divide them into four types: erosion prevention, sediment routing, flushing and dredging. Erosion prevention can always be used with the latter. Erosion prevention schemes include watershed management issues such as encouraging people upstream to get involved in the practices that are not going to contribute to soil erosion . The other alternative is trapping sand before it reaches reservoirs; for example, by constructing check dams, though they are not very effective. These methods involve emptying reservoirs periodically or just before the flood. Flushing involves opening a low level outlet to temporarily establish riverine flow through which eroded sediment is flushed. Flushing is distinct from routing as the former deals with settled sediment and involves release of sediment at the season which is different from the season used by sediment routing which releases sediment when they arrive. The timing aspect of sediment release also makes flushing not very popular among environmentalists. Dredging involves mechanically digging up the coarse deposit and removing them from the reservoir.

A detailed description of these methods can be found in Morris and Fan and is also presented in the next chapter.The challenge in finding the optimal sedimentation technology is that any such prescription necessarily relies on the topography of the region and on such minute details as the size of sediment and hence an economic model has to make trade off between the accuracy of representation and simplicity of modelling so that one achieves desired tractability to come up with reasonable insights. Our goal in this paper is to formally represent the reservoir management problem, taking into account the stochastic nature of salvage value of the dam at the time of its decomissioning. The formalization also provides us the following three major insights: ranking of different sedimentation removal techniques from the perspective of their impact on the age of dam is facilitated. optimal sedimentation management is retrieved as a result of a control problem of the operator and the value of the dam at any point. At the end, we are also able to discuss sustainability issue of the reservoir. We contribute to the literature in the following way: this paper is the first one to look at the sedimentation issue in a stochastic framework. We provide detailed study of techniques and discuss qualitative properties of key thresholds that trigger different decision makings . We also provide a new method that slightly modifies Judd’s projection method in solving the nonlinear equations that results from optimizing decision of the operator. We use data from Tarbela dam in Pakistan to calibrate our model. We conclude that for some given cost functions, the dam could be sustainably run. Economic studies of sediment removal techniques so far have been very rare. In 2003, the world bank’s resource economics group developed a policy maker’s manual-type report, called RESCON. Their work provided a brief survey of sedimentation technique and a “look-up table” type Excel based software to facilitate the economic and engineering evaluation of different sedimentation strategies. Another work by Palmieri et al used the RESCON software to show impact of different sediment strategies on sediment removal policy and life of the dam. Huffaker et al provided a detailed economic study of hydrosuction dredging sediment removal system. In particular, Huffaker et al constructed a multi-state model of endogenous reservoir operations and apply singular perturbation solution methods that reduced dimensionality of the optimality system and facilitated the solution of the optimal system. They uncovered a phenomenon called “sediment perching” due to which increased sedimentation in the reservoir makes the sediment control mechanims more effective in the long term. Though they take into account the positive effect of sediment perching on dredging cost, they fail to note that sediment perching alters the natural pattern of sediment flow downstream and may cause undesirable environmental cost and their estimate of the benefit of sediment perching may therefore be upward biased.

The second of these layers includes existing residential neighborhoods, which typically consist of small parcels of land owned by residents who are highly resistant to redevelopment, unless in the context of adding second units to existing houses. Even the process of creating secondary units tends to be slow and to produce relatively few units, despite some municipal programs to encourage it. Commercial and industrial land uses and apartment buildings are likely to be located near major and minor arterials and freeway ramps. Low‐density residential development is more likely to occur at a distance from these roads due to noise and traffic concerns. Mid‐ to high‐density residential development is likely to be attracted to downtown locations, neighborhood centers, and shopping centers; especially in the low‐GHG emissions scenarios in which public policy focuses on redeveloping and building up existing urban centers. Mid‐ to high‐density residential development is also likely to be attracted to railroad stations in these scenarios as new passenger service is added and public policy emphasizes “transit‐oriented development.” Some industrial development is likely to locate near railroad lines in these scenarios, since rail offers more energy‐efficient transportation of many goods. We assumed that locations currently slated for development that are distant from existing cities County, such as the Dunnigan area along Interstate 5 in the north of the county, will serve as urbanization attractors only in the scenario with higher GHG emissions. Census blocks with recent development are distributed fairly evenly between rural and urban areas of the county. We assumed that these blocks with recent growth would attract more urbanization in the future. This is in part because these areas are likely to possess infrastructure such as roads, water lines, sewer mains, and power lines which make development easier and cheaper.

It is also because these areas are likely to contain previously subdivided parcels of land that are not yet built upon,nft hydroponic and land owners that are more interested in subdividing, selling, or building on the land. In scenario with higher GHG emissions, in which planning controls are weaker, census blocks with growth will be a stronger attractor, particularly in exurban locations. In the lower GHG emissions scenarios they will play a weaker role in attracting urbanization, since public policy is more likely to protect non‐urban land, and less left‐over land is likely within urban areas. Previously, our larger research team developed a set of story lines for scenarios reflecting different climate change and urbanization policies for Yolo County in 2050 . These were intended to emulate for the county story lines developed in 2000 by the IPCC , with the addition of a scenario with very low GHG emissions corresponding to an even more stringent policy direction than established by California’s AB 32 legislation. Each scenario corresponds to a broad‐brush story line, which is built upon a set of political, economic, institutional, and demographic assumptions. Each story line is a possible future for urban growth and emissions for the county.As in IPCC scenario A2 , our A2 scenario assumes that population growth would remain high, with an approximate doubling of the current county population to 394,000 . With an increase in population, continued economic growth and technological innovation, the county would see urbanized areas increase by 50 percent. Current preservation and land use policies would remain in place and although new suburban subdivisions would be built, there would be some focus on improving land use through greater land use mix, higher densities, and more infill, and limiting sprawl. Agricultural land would be lost to urbanization while less participation in farmland preservation programs, such as the Williamson Act, would result in less farm acreage and fewer farmers. Even with an increase in population, vehicle miles traveled would remain stable through land use and pricing changes, increased use of alternative modes, and greater fuel efficiencies. Still, the A2 story line would be fossil fuel intensive as a result of more drivers and the dominance of automobiles as the main transportation mode.

In terms of climate, under A2, average temperatures are predicted to increase between 1°C and 3°C for 2050. Changes in cropping systems and technological support for agriculture would continue in about the same way as present, without major societal investment in alternative options to deal with the impacts of global warming. The A2 story line is a near continuation of current demographic, economic, technological, and environmental developments with some improvements and responses to current issues being addressed and implemented. We should emphasize that in terms of suburban sprawl, the A2 story line is by no means a worst‐case scenario. Rather, it should be seen as a continuation of practices in the 1990 to 2010 period. If this story line had been based on prevailing development patterns from 1950 to 1990, suburban densities would be in the range of 4–6 units per acre instead of 8, less development would occur in medium‐ and high‐density forms, and a higher percentage of larger 1–10 acre ranchettes would be created. Suburban sprawl would cover a much larger percentage of the county in that case, taking far more agricultural land out of production. In IPCC scenario B1 , societies become more conscious of environmental problems and climate change, and sustainable development efforts are implemented. Under our Yolo County B1 story line, population would grow slowly, reaching a mid‐range population size of 335,000 by 2050 . Economic development would be moderate, with a shift from the production of goods to a more service‐based economy that is connected to the larger global economy. Technological innovation remains high in the Sacramento region, with an emphasis on small‐scale, green technologies. B1 is a relatively low GHG emissions scenario in which the urban area extends only 20 percent as a result of compact growth through higher densities, increased infill, and a focus on small, locally owned retail stores rather than big box developments that require more driving. As current transportation and emission policies become more stringent and the use of high‐efficiency vehicles and alternative modes increases, vehicle miles traveled would be significantly reduced and transportation emissions with them. 

Agricultural land conversion would be lower in this story line as a result of less urban expansion and the use of farming easements and other incentives to maintain land in farming. Though long‐term temperatures may be lower than in the A2 story line, average temperatures in 2050 do not differ . Consistent with AB 32, voluntary actions in agriculture would place more emphasis on increasing carbon sequestration and decreasing N2O emissions through multiple crops per year, more ecologically intensive practices, reduction of fertilizer use, and efforts to capture methane emissions from livestock. Moreover, there would be greater societal investment in preparing ahead for climate change adaptation options, such as crop breeding, pest management, and resilience to intermittent droughts. Under B1, Yolo County experiences the benefits of slower population growth and improved urban land use practices, resulting in preservation of agricultural land and reduced GHG emissions.To the two IPCC‐based story lines, we add a third scenario with more stringent GHG emissions regulation than AB 32. Under our AB32+ story line, Yolo County experiences slower population growth reaching only 235,000 in 2050, which would have to occur through policies or voluntary actions that affect family planning and migration . In this story line, moderate economic growth focuses on value‐added production economic viability of the local rural sector, and support for ecosystem services generated by closer alignment between the rural and urban sectors . A less resource‐intensive lifestyle would dominate, coupled with an increase in the quality of life through an increase in ecosystem services in both sectors. Priorities would be placed on both regulating services and cultural services . The urban boundary remains at the current extent through strict land use planning policies and development emphasizing efficient use of land, mixed use, intense infill, increased densities,hydroponic gutter and growth in the urban core. More compact development patterns and the promotion of local development and payment for ecosystem services, coupled with many alternative modes of transportation and increased use of zero emission vehicles, would result in a reduction of vehicle miles traveled and GHG emissions from transportation. Although long‐term temperatures may be lowest under this scenario, 2050 temperatures are essentially the same as in the other story lines. In order to both mitigate and adapt to the changing climate, agricultural producers would make major changes in management practices, focusing on ecological intensification rather than on non‐renewable inputs. This would require substantial societal investment in development of new renewable technologies and for diversification of cropping systems to fit site‐specific situations. Practices such as farm scaping and revegetation of riparian buffer zones to mitigate and reduce GHG emissions would also be promoted for their co‐benefits, such as improved water quality .

Markets for products may become more locally based, and efforts would be made to reduce GHG emissions from processing and transport of agricultural products. Overall emissions would be the lowest under AB32+ with a reduction from urban areas due to denser, more balanced land development, less resource‐intensive lifestyles, and improved transportation options. Changes in crop choice and management practices would likewise reduce GHG emissions from agriculture. In addition to modeling these three scenarios using UPlan, we modeled additional versions of A2 and AB32+ in which population was held constant at the B1 level. This step allows us a more analogous comparison of the three story lines.After using UPlan to produce urban growth footprints for the above scenarios, we calculated two main categories of GHG emissions for the new urbanization produced by each. These calculations are very approximate, but help to give a sense of the magnitude of variations that can result from different policy approaches. One category of GHG emissions was from transportation. Household travel surveys done by SACOG show that household vehicle miles travelled vary by a factor of six between households in low‐density per acre and high‐density locations . Some of this difference may be due to household size and composition, but much is likely due to proximity to jobs, shopping, schools, and alternative transportation modes. In addition, many other policy steps in the lower GHG emissions scenarios are likely to reduce driving in the 2050 time frame. These other factors include rising gas or carbon taxes; improved balance of jobs, housing, and shopping within communities; improved bicycle, pedestrian, and public transit options; and other economic incentives such as higher parking charges and tolls. Transportation emissions are also of course dependent on the fuel efficiency of motor vehicles. Average fuel efficiency of American vehicles remained more‐or‐less unchanged from the mid‐ 1980s through 2010, and so for purposes of illustration, this was assumed in the A2 scenario until 2050. In the B1 scenario, we assumed modest efficiency increases of 2 percent a year , and for the AB32+ scenario we assumed improvements of 4 percent a year . Rather than continually improve conventional gasoline engines, these scenarios would most likely see increasing percentages of the motor vehicle fleet converting to hybrid or all‐electric propulsion, with an increasing proportion of the electricity produced by renewable sources.Household energy use was a second category of calculated GHG emissions. In Yolo County domestic energy comes almost entirely from electricity or natural gas, as oil heating is rare in California and use of wood stoves is also low and increasingly discouraged due to local air pollution concerns. Here again we can expect substantial differences in GHG emissions between infill urbanization and new residential development on agricultural land, due to larger unit sizes and a much higher percentage of stand‐alone single family homes in the former case. To calculate household energy use for the three scenarios, we used data from the 2009 California Residential Appliance Saturation Study , a collaboration of the state’s five largest utility companies that surveyed detailed consumption habits of nearly 26,000 households. This study breaks households down by climate zone, and compares energy consumption for single‐family homes, town homes, small multifamily buildings, large multifamily buildings, and mobile homes by California Energy Commission climate zone. Both electricity and gas use for the middle three categories were approximately half that of single family homes, probably in large part because average unit sizes were smaller, and perhaps also because shared‐wall construction tends to be more energy efficient than stand‐alone single‐ family homes.

The Clear Lake release schedule specifies how much water is available annually and monthly to the District during the peak agricultural season from April to September. The decree’s “Quantity” criteria sets allowable seasonal withdrawal limits based on April 1 water levels recorded at Rumsey, known as the Rumsey gauge. If the Rumsey gauge is at or above 7.54 feet, then 150,000 acre feet of water is available for the growing season from April 1 to October 31. Monthly percentages of the ASW are available for release each month. If Rumsey levels are below 3.22 feet, no water can be released that year apart from flood flows. For in‐between levels, ASW are set in the release schedule that increases to a maximum of 150,000 acre feet in what is known as the quantity criteria. As per these stipulations, the District did not make any releases in the severe drought of 1976–1977, as well as in 1990 at the end of several dry years. The Solano Decree also stipulates “Stage criteria” that set limits to draw down, posing an additional constraint to the District’s withdrawal of water in any given month. Clear Lake releases in the winter are also controlled by the 1920 Gopcevic Decree for flood control operation. The highly controlled nature of this lake can be attested by the historical monthly average lake levels which have varied only 5.7 ft on average within a water year, with a maximum range of 10.9 ft and a minimum of only 2.3 ft.The Cache Creek model, run at a monthly time step, uses climate and land cover information to simulate the water balance. It uses the results to simulate the management of Clear Lake and Indian Valley Reservoirs and water supply for irrigation downstream. The model simulates irrigation demand for 20 crop types within Yolo County, grow bags garden which is met through surface and groundwater sources .

The model was calibrated to a historical run from 1971–2000, which formed the baseline scenario. The calibrated model was then run under various combinations of climate and agricultural land use projections as described below. Figure 3.1 shows the study area along with the spatial discretization of the model. The spatial domain of the model covers 5027 square kilometers and includes the Cache Creek watershed up to Capay , and all of Yolo County. The focus of the irrigation water demand and supply analysis is on the District service area , although the model can also simulate irrigation demand for the rest of the county. Table 3.1summarizes each catchment’s characteristics. A water balance simulated for each catchment. Spatial data on elevation, watersheds, and land use were acquired and used to define and characterize each catchment. Elevation data were extracted from the Digital Elevation Model provided by the U.S. Geological Survey. Land cover information was assembled from two sources. For the non‐agricultural landscape, the National Landcover Data Set was used . For the agricultural areas, county reports and DWR Land Use Surveys were used . Upstream catchments were aggregated from the DWR watersheds layer. This aggregation was based on climate considerations, the locations of major infrastructure , in‐stream flow requirements, and flow gauges. Parameters of the rainfall‐runoff module were calibrated against the longest available continuous data from gauges in unimpaired watersheds. These were at Kelsey Creek and Hough Springs on the north fork of Cache Creek , in the headwaters of Clear Lake and Indian Valley, respectively. Goodness of fit metrics were computed for each set of simulated and observed hydrographs. Two groundwater objects were defined and conceptually aligned to the groundwater sub‐ basins delineated by DWR: one below Capay Valley receiving recharge as infiltration from the Capay Valley catchment, the other below the Yolo Valley floor, receiving recharge from the catchments downstream of Capay.

Our model’s treatment of groundwater is similar to the Central Valley application . It is capable of relative comparison among scenarios of groundwater recharge and extraction volumes, but not of simulating absolute groundwater depths. The model simulates the operations of Clear Lake, Indian Valley, and the water delivery through canals. Detailed description of how WEAP simulates reservoir releases through conservation storage and flood rules is available in Yates et al. . Reservoir physical characteristics were obtained from California Department of Water Resouces California Data Exchange Center and the District. Indian Valley operating rules were obtained from the District. Clear Lake operating rules were obtained from the District, and from documentation of the Solano and Gopcevic Decrees described earlier . Details, including the stepwise procedure on implementing the Solano Decree, are available in public documents and through the District. Clear Lake releases during the wet season are controlled by the Gopcevic Decree, for which target storage levels come into play from January to March. These target storages were set as WEAP’s “Top of Conservation” in the model’s Clear Lake reservoir object. The second operating constraint, also from the Solano Decree, is its stage limitation criteria. These criteria were programmed and set as “Top of Buffer” in the reservoir object. The third constraintis the hydraulic capacity of Clear Lake’s outlet channel. Hydraulic capacity varies by the stage; data obtained from the District was used to develop a hydraulic capacity constraint as a function of stage. This expression was set as a hydraulic constraint on the releases from Clear Lake in the model. Outlet flows were then constrained to be a minimum of the hydraulic capacity constraint, and the allowable monthly withdrawal as determined by the Solano decree’s Quantitative criteria—the latter also entirely encoded within WEAP. Clear Lake does not provide carryover storage for irrigation demand. Although Indian Valley does provide carryover storage, typically it is operated with no carryover storage . In general, the District attempts to utilize all its Clear Lake allocation each year. This means that Clear Lake usage is prioritized over Indian Valley as much as possible. In the model’s setting of supply priorities, this translates to a lower filling priority for Clear Lake over Indian Valley. Simulation of reservoir operations was verified by comparing simulated versus observed reservoir levels.

The District’s main conveyance is in the form of 175 miles of mostly unlined canals and arterial ditches that run off the West Adams and Winters Canals from Capay Diversion Dam on Cache Creek. In the model, these conveyances are aggregated into a single transmission link object, with capacity set to the total distribution’s capacity of 750 cubic feet per second , and with an estimated leakage of 40 percent of conveyance flows obtained from calibration attempts and informed by District estimates of mass balances . Seventeen crop categories were modeled for the catchments dominated by agriculture. Table 3.3 lists the different crop categories considered along with county‐wide acreages from four selected years. The crop categories are informed by DWR’s irrigated crop acres and water use portfolio,grow bag for tomato taking into consideration both the crop categories and corresponding acreages available through the county reports as well as estimates of the District scale cropping pattern. An annual time series of total irrigated acreage and irrigated crop areas was assembled at the county level . Individual crop acreages were spatially distributed among the four agricultural catchments using GIS datasets available for 1989 and 1997 through the DWR Land Use Surveys . This allowed a cropping pattern to be represented in the model for the historical period for each agricultural catchment. Each crop’s irrigation water needs were simulated using crop‐specific crop coefficients, irrigation schedules, and irrigation thresholds. Crop‐specific parameters pertaining to irrigation were adapted from the Central Valley application by Joyce et al. , who calibrated the crop and irrigation parameters at the spatial scale of the DWR Planning Area level against four annual estimates of applied water published by DWR for 1998,1999, 2000, and 2001 . In our model, we also used DWR portfolio data available for the same years, but at a finer spatial level—the Detailed Analysis Unit . The irrigation threshold parameter in WEAP was calibrated for each crop to match DWR’s applied water estimates for 1998, 1999, 2000, and 2001 for the DWR’s Lower Cache Creek DAU which closely follows the county boundaries. Figure 3.2 presents the calibrated irrigation schedules and thresholds for each crop. The model’s estimation of water demand represents a departure from the operations of the District. The District solicits water demands from its customers every year in March, and then decides by April how much total quantity will be available. This decision is based on water levels in the two reservoirs and a projection of the season ahead. Since our goal was to look to the future, we used a simulation approach instead of hard‐coding the historical demand based on the District’s historical roster. The latter would not have provided us the means of projecting demand into the future.Yolo County based on the relationship between historical crop acreage, a set of economic variables , and climate variables . To forecast cropping area from the present to 2050, climatic variables were calculated from daily climate projections for the A2 and B1 scenarios generated by the GFDL climate model described above. The second land use projection was based on a hypothetical scenario envisioning an agricultural landscape which adapts to climate change in two ways: by allocating a smaller fraction of land to crops that require large amounts water; and by increasing crop diversity. For example, the acreage of rice, alfalfa, and other water intensive field crops were gradually reduced to the lows observed during a period of severe drought in the mid‐1970s . Likewise, an increase in crop diversity over time was simulated by progressively allocating a larger fraction of land to vineyards, winter grains, almonds, deciduous orchards, subtropical orchards, tomatoes, cucurbits, and truck crops . Since this crop diversification projection is a hypothetical construct, rather than a statistically derived forecast, a future time frame of 2009–2099 was used.

It should also be noted that this approach assumes gradual changes in crop acreage and did not attempt to capture the year to year variability reflected in the historic record. Statewide there has been a notable shift in irrigation methods from surface water applied using flood or furrow irrigation towards low‐volume sprinkler and drip irrigation, particularly for vegetable crops, orchards, and vineyards . These methods can potentially reduce soil evaporation and applied water . Furthermore, a recent survey of grower perspectives on water scarcity and climate change in Yolo County indicates a strong inclination to expand their use of drip and low‐volume irrigation among local farmers . Likewise, incentive programs to promote adoption of improved irrigation technology are seen as a politically feasible water demand management strategy. However, one criticism is that, in some watersheds, such policies have failed to curtail groundwater extraction as some farmers use the “water savings” to expand irrigated acreage or grow more water‐ intensive crops . As such, we included a conceptual scenario which assumes that irrigation technology and efficiency will continue to improve in coming decades but overall irrigated acreage in the district will not. We reflect these trends in the model, by decreasing the irrigation threshold parameter, in a manner similar to the work of Joyce et al. and Purkey et al. . Beginning in 2010, irrigation thresholds for each crop, except for wine grapes, winter grains, and safflower, were assumed to decrease linearly so that by 2099 they reached 70 percent of the historic reference threshold. For the latter crops, no change in water‐saving irrigation technologies was assumed because vineyards are already on drip irrigation, winter grains are mostly supplied by rain and stored soil water, and safflower is already a low water consuming crop.Another measure of water shortage is the frequency of years receiving no water allocation from Clear Lake. For example, if the Rumsey gauge is below 3.22 feet, the initial ASW assessment is for no allocation of water that year. During the historical period the model predicted 6 such years . Model projections for the climate only scenario suggest that the number of years receiving no allocation will increase gradually with time, particularly during the latter half of the century. In the far term under A2, reservoir inflows are very low in some years in response to the warmer and drier conditions.

The sand fraction was separated from the clay and silt fractions by wet sieving through a 0.05 mm sieve. Water retention at various tensions was determined using a pressure plate. Plant-available water holding capacity was estimated as the volume fraction of water retained between 33 and 1500 kPa. A sample of < 2-mm , air-dry soil was placed on a porous ceramic plate and wetted by capillary action; gravimetric water content was measured following attainment of equilibrium at 33 and 1500 kPa. Soil pH was measured 1:2 in H2O and 1.0 M KCl. Phosphate retention was determined using the method of Blakemore et al. and the Bray-1 extraction was used as an estimate of available P . Exchangeable cations were displaced by 1 M NH4OAc at pH 7.0, then the cations were measured in the supernatant using an atomic absorption spectrometer . The cation exchange capacity was determined in 1 M NH4OAc after extraction of NH4 + by 10% NaCl as a measure of CEC. Base saturation was calculated as the sum of base cations by 1 M NH4OAc divided by CEC. Sulfate-sulfur was extracted using monocalcium phosphate as outlined by Schulte and Eik and available micro-nutrients were determined by DTPA extraction . All weight percent data were reported on an oven-dry basis . Non-sequential selective dissolution in Na-pyrophosphate and ammonium-oxalate was used to characterize Fe, Al and Si in various pedogenic pools. Total C and N concentrations were determined on ground samples by dry combustion using a Costech C/N analyzer . Soil microbial biomass C and N were measured using chloroform fumigation and direct extraction with 0.5 M K2SO4 . Briefly, 10 g oven-dry equivalent samples were fumigated for 48 h in the dark,plastic pot and then C and N were extracted with 0.5 M K2SO4. Similar extraction was applied for non-fumigated samples. The non-fumigated control values were subtracted from fumigated values as an estimate of microbial C and N. A Kec/Ken factor of 0.35 was applied for both C and N . Carbon mineralization was measured in the topsoil and subsoil by incubating duplicate soil samples in the dark under laboratory conditions over a 119-day period.

Soil moisture was adjusted to ∼ 80% of field capacity and pre-incubated for one week prior to starting the long-term incubation. Soils were incubated in sealed Mason jars fitted with septa. Carbon dioxide in the headspace of each soil sample and blanks with no soil was measured each week using an Infrared Gas Analyzer. The CO2 emission was normalized to initial total C content of each soil and expressed as CO2-C mg kg−1 soil C. In addition, net N mineralization was measured on these same samples at the end of the 119-day incubation by determining concentrations of mineral N in 1 M KCl extracts at time zero and at 119 days. Quantification of NO3 – used the vanadium chloride method and NH4 + the Berthelot reaction with a salicylate analog of indophenol blue . A correlation analysis was performed to assess soil properties most strongly affected by land-use changes, using IBM SPSS Statistics 22. 2013.All soils were well drained with an A horizon overlying Bw horizons that extended to the depth of investigation . Soil particle-size distribution was similar among the four sites with the majority of the horizons having a loam texture . Some distinct changes in particle-size distribution within various pedons are attributable to more recent tephra deposition that resulted in burial of the former soil profile. Bulk density in subsoil horizons was very low , characteristic of soils formed in volcanic ash . Db was also low in the A horizon of the pine forest , but was higher under agricultural management due to traffic compaction resulting in a reduced pore volume. The agricultural soils displayed a distinct increase in Db and a reduction in total porosity in the topsoil horizons compared to the pine forest soil. Given the low bulk densities, total porosity was correspondingly high, ranging between 60 and 77%, with values decreasing in surface horizons with agricultural management. Plant-available soil water was generally in a narrow range with the exception of the surface horizons of the pine forest soil . The water retention capacity varied from 37 to 53% in topsoil horizons and from 45 to 51% in subsoil horizons with the lowest values in the pine forest.

Soil pH-H2O increased from very strongly acid in the pine forest and tea plantation to moderately acid in the horticultural crops with fallow and intensive cultivation . Regardless of land use, all soils in this study had low CEC characteristic of acidic Andisols dominated by allophanic materials . The lowest values occurred in the pine forest and the highest values in the horticultural soils. The pHKCl-pHH2O values ranging between −0.1 and −0.5 were indicative of a soil colloidal fraction dominated by variable charge materials . Especially notable is the very low base saturation and concentrations of exchangeable Ca and Mg for the PF and TP soils . Exchangeable base cations are a common limiting factor for horticultural production in the studied Andisols since these nutrient cations are extremely low under pine forest. While the horticultural management practice of applying horse manure and lime did not appreciably increase the measured CEC, it was remarkably effective in increasing exchangeable base cations . For example, exchangeable Ca, Mg and K increased from 1.5, 0.3 and 0.2 cmolc kg−1 in the pine forest to 26.3, 3.5 and 1.0 cmolc kg−1 in the intensive horticultural crops, respectively . The high base saturation of over 100% under horticultural land uses compared to < 23% for the pine forest and tea plantation .Organic C concentration in A horizons was highest in PF and 1.0 to 2.0% lower under agricultural management . In contrast, organic C was lower in the PF subsoil while the agricultural sites had elevated organic C concentrations in several subsoil horizons. Organic C stocks in the upper 100 cm of the soil profile were calculated by summing the organic carbon stocks in each individual horizon were present). Organic carbon stocks followed : TP ≈ IH > FH > PF . The agricultural soils contained more organic carbon than the pine forest soil. While horse manure was added to the IH soil for the past 7 years, the TP and FH soils received no organic matter amendments and still had similar pedon organic matter stocks.

As a direct comparison, the IH soil receiving horse manure contained only slightly more organic C than the FH soil located 4 m away that received no horse manure and was fallowed over the past 7 years. Dissolved organic carbon concentrations were appreciably higher in the PF topsoil and throughout subsoil horizons of the TP profile . The horticultural soils tended to have lower overall DOC concentrations than PF and TP land uses. Total N concentrations followed a similar distribution to organic C concentrations among sites with total N stocks in the upper one meter of soil following : IH > FH ≈ TP > PF . The C:N ratio was lowest in the upper 50 cm of the IH and FH soil profiles , while values for PF, TP and lower soil horizons at all sites were generally in the range 16 to 19. The highest concentrations of inorganic N were found in the IH pedon and were dominated by NO3 – . In contrast to the IH soil dominated by NO3 – , inorganic N concentrations were dominated by NH4 + in the TP, FH and PF soils with the highest value in the TP soil and lowest under FH land use. High P fixation , characteristic of Andisols, was exhibited for all land-use types. Under forest vegetation , the soil P retention was consistent at 97% throughout the entire pedon . Change of land use to TP and FH did not appreciably affect P fixation. However,grow bag the IH land use receiving application of horse manure for the past 7 years showed appreciably lower P fixation in the upper 40 cm. Reflecting the high P fixation, available P content was below the detection limit for all horizons of all land-use types, except for the upper horizons of the IH land use .There were several significant correlations among soil properties . Oxalate-extractable Sio showed a positive correlation with the clay fraction, while Feo had a strong negative correlation with pH and exchangeable Ca and Mg. In contrast, Alo showed no significant correlations with other soil properties. For organo-metal complexes , Alp had highly negative and positive correlations with the clay fraction and organic C, respectively. However, Fep showed no significant correlations with other soil properties. Soil pH showed a highly negative correlation with P retention and Feo, along with a positive correlation with exchangeable cations , total N and Db. Soil bulk density showed a positive correlation with exchangeable cations and negative correlation with P retention. P retention had a negative correlation with exchangeable cations .Andisols are characterized by low Db and high porosity due to the abundance of amorphous and poorly crystalline materials and organic matter that contribute to highly stable and very well structured soils under natural conditions. However, the low natural Db may change due to anthropogenic activities.

The evidence was revealed by soil tillage under intensive horticultural crops contributing to increased Db from compaction by potential destruction of soil aggregates due to physical mixing/abrasion by tillage operations. Tillage was reported to destroy macropore pathways of Andisols in Mexico resulting in a lower in- filtration and permeability of topsoil horizons .Chemically, the exchangeable cations have positive significant correlation with Db, indicating the increase in soil exchangeable cations gave rise to the increased soil bulk density . This is probably due to the role of Ca and Mg ions derived from lime and manure in binding soil particles, resulting in the change of soil friable structure under forest to more compact aggregate formation under intensive horticultural cultivation. The water retention capacity varied from 37 to 53% in topsoil horizons and from 45 to 51% in subsoil horizons with the lowest values in the pine forest . These data indicate that the number of soil pores storing plant-available water is lower in the forest Andisols than those converted for agriculture. In other words, the water retention capacity has increased about 50% following conversion from pine forest to agriculture. This implies that the compaction associated with tillage is responsible for increasing the water retention capacity through conversion of macropores to meso/micropores. The water retention capacity in this study was higher than for cultivated Mexican Andisols reported by Prado et al. . The high water retention in Andisols is caused primarily by their large volume of meso/micropores . Formation of these meso/micropores is greatly enhanced by poorly crystalline materials and soil organic matter . Buytaert et al. studied toposequece of Andisols in south Ecuador and reported the large water storage capacity as revealed by water content ranges from 2.64 g g−1 at saturation, down to 1.24 g g−1 at wilting point. The long-term cultivation of agricultural soils in this study has not caused appreciable degradation to the overall Db, porosity or water retention characteristics of these Andisols. While macroporosity was decreased by tillage, the macropore content of topsoil horizons remained > 15% providing adequate infiltration and soil aeration. The loss of macropores is compensated for by the increase in meso/micropores that contribute to increased plant-available water holding capacity. In spite of the increase of bulk density and loss of macropore capacity, field observations confirmed that the agricultural soils in this study retained their high infiltration capacity with no evidence of surface runoff. In Italy, well developed Andisols on flow-like landslides over 70 years experienced low run off and minimal soil erosion owing to a good infiltration in spite of the high slope steepness and the anthropic pressure associated with land management .The pine forest soil was very strongly acidic owing to the strong leaching regime associated with the isothermic/perudic climatic regime. Applications of lime and more recently horse manure to the IH soil were effective in raising the pH of the horticultural soils . In spite of the low soil pH values in the tea plantation, the potential for Al3+ toxicity was not evident as ascribed to the low exchangeable Al3+ concentrations . Threshold values for Al toxicity are generally considered about 2 cmolc kg−1 for common agricultural crops and 1 cmolc kg−1 for Al-sensitive crops .

In order to enhance agricultural advisory service delivery, there is need to harmonize the efforts of extension providers to more effectively address the intensification of maize and adapt to climate change. The Diffusion of Innovations Theory was developed by Everett M. Rogers to analyze the diffusion and adoption of agricultural innovations among farmers. Considered the theoretical basis for agricultural extension, this theory asserts that the adoption of an agricultural technology communicated through specific channels occurs over time among members of a social network . Under this theory, individuals within the network are categorized according to their ability to adopt the technology. This theory follows the top-down “transfer of technology” model where innovations are developed by researchers, disseminated by extension personnel, and then adopted by farmers. In the context of Malawi, agricultural innovations are developed both by researchers within the hierarchical structure of the public extension system and are co-developed at the grassroots level with input and field testing from farmers . Therefore, it is useful to understand the basic elements of the Diffusion of Innovations Theory to evaluate Malawi’s public extension system, but also analyze the extension system as a network of actors that all develop, share, and improve agricultural innovations and information. To effectively analyze Malawi’s complex,cut flower bucket pluralistic extension system it is useful to develop a conceptual framework that draws from the Diffusion of Innovations Theory as well as Social Network Analysis.

Feed the Future’s Developing Local Extension Capacity project led by Digital Green in partnership with Care International, the International Food Policy Research Institute and the Global Forum for Rural Advisory Services developed a “best fit” framework for analyzing Malawi’s extension and advisory services that target key activities for improving the system . This framework outlines extension parameters and characteristics allowing stakeholders to understand the state of Malawi’s extension system and where critical levers for change exist .Within this framework, the frame conditions outside the manageable interests are meant to show factors that influence extension services in Malawi, but are not the focal area for change within the efforts of this study. The critical factors for change within the manageable interests of this study are the characteristics of AIS including 1) the governance structures which I will analyze using Social Network Analysis to understand the development of content, transfer of information, and engagement between stakeholders; 2) the organizational and management capacities which I will analyze as the capacity for organizations to provide EAS and ways in which organizations are structured; 3) the advisory methods used by providers to deliver EAS; 4) the connection to local and international markets; 5) the livelihood strategies integrated into the provision of EAS; 6) the engagement of community members, villages, and farmers in the process of EAS information development and dissemination; and 7) the performance of EAS with respect to climate change adaptation based on the messages communicated to farmers and the effectiveness of information delivery. GoM has developed a pluralistic extension policy that calls for the delivery of specialized services to farmers by governmental institutions, nongovernmental organizations, and private industry. These extension services support farmers to overcome barriers to increasing crop yields and adapting to changing climatic conditions.

Yet, inconsistent recommendations provided by different extension providers regarding best practices to adapt to climate change have remained significant challenges in Malawi. GoM has emphasized the need to improve coordination among extension providers in order to reduce inefficiency, redundancy, and confusion due to conflicting messages to farmers. In fact, few nongovernmental organizations or private companies coordinate their extension activities with DAES under MoAIWD. In order to improve stakeholder engagement amongst extension providers, communicate clear messages to farmers, and improve the adoption climate adaptation practices, there is a critical need to identify what climate change information is currently being communicated to farmers across the extension system.To meet the objectives of the study, I contacted key informants using the snowball sampling method to identify affiliate organizations and individuals who provide extension services to maize farmers in Malawi. The location for this study was chosen based on the projected severity of climate change impacts to Malawi’s maize production across all regions and high concentration of extension providers that operate throughout the country. I developed a professional network in Malawi that connected me to key organizations and individuals who work on extension. This network included staff from IFPRI where I interned, GFRAAS, MaFAAS, USAID, and faculty specializing in extension from LUANAR in Malawi. My researcher team at the University of California, Davis included my advisor and the CoPrincipal Investigator, Dr. Amanda Crump who has worked on agricultural extension issues in Malawi and an experienced thesis committee who provided additional contacts for this research. In total, 130 individuals were contacted through email and phone calls and 19 agreed to participate in virtual interviews through online platforms for this research study. Interviews were conducted in English over the phone from October 1, 2020 to January 1, 2021 with individuals from organizations who provide extension services to farmers. It should be noted that English if the official language of Malawi and is widely spoken among extension providers.

The table below shows how many individuals from each type of organization participated in the research study through in-depth interviews.Through this research, I sought to assess the challenges and successes in communicating climate change adaption information to maize farmers in Malawi in order to improve the development of content and delivery of information by extension providers. Therefore, I focused on understanding the development and dissemination of information throughout the extension system, messaging around climate risk and variability, curriculum and learning tools extension providers use to educate farmers, and engagement with other organizations that support farmers across the extension system in Malawi. I employed qualitative methods to develop a deeper understanding of the participants’ experiences, perspectives, and relationships which are essential to better understand Malawi’s extension system and the stakeholders involved . The research began with a literature review to understand climate change impacts to agriculture in Malawi, climate change adaptation practices for farmers, and the agricultural extension system in Malawi. This was followed by key informant interviews with a sample of identified organizations using an interview questionnaire. A detailed Interview Questionnaire was developed to administer in-depth interviews with all participants. The Interview Questionnaire introduced participants to the intention, goal, and dissemination of the research. This document also informed all participants that their participation was voluntary and asked if they consented to participating in the research. Participants who opted not to participate were thanked and no further communication was made. All participants were asked if they consented to being recorded on the my phone and all who participated consented to being recorded. In addition, a script was developed to introduce participants to questions and a question route was developed to ensure consistency across all interviews. A semi-structured questionnaire was used because I recognized that a detailed explanation of certain topics might be required, and certain responses could not be anticipated prior to the interview. The questions asked during interviews focused on climate smart agricultural practices shared with farmers, extension approaches, and key constraints in delivering effective climate change information to maize farmers. Specifically,flower display buckets the interviews gathered information about the following themes: organizational activities and partnership, information development and dissemination, educational tools, extension methods, climate smart agricultural practices, and communication successes and challenges . In order to evaluate the validity of the content obtained during interviews, I tested the instruments developed for this study prior to use with several members of my research team at UC Davis and at MaFAAS by phone. This allowed me to understand if the questions were clear and could be answered in the time allotted for the interview. After testing, I made several format and phrasing changes to the Interview Questionnaire to improve the quality of the guide and ensure that participants could understand the questions being asked.

Each interview lasted between 60-90 minutes depending on the participant’s responses and elaborations. In preparation for this study, I sought approval from the Institutional Review Board and Committee on the Use of Human Research Subjects at UC Davis and the Malawi Government through the National Commission for Science and Technology’s Framework for Guidelines for Research in the Social Sciences and Humanities. This process required the submission of a research proposal to be reviewed and approved by the National Commission for Science and Technology in Malawi. In order to comply with Malawi’s requirements, this research was first affiliated with a local research institution; LUANAR. This affiliation was initiated with an extension faculty member of LUANAR, Mr. Paul Fatch, on July 28, 2020. All appropriate forms and documents were provided to UC Davis and the Malawi Government. The UC Davis IRB deemed this study to meet the criteria of exemption on August 24, 2020. I obtained a permit from the Malawi Government on September 29th, 2020 was approved to proceed with all interviews.Qualitative data analysis used for these interviews involved analyzing the relationships between themes in my data in order to understand the phenomena and derive a theory about information generated during the interviews. The data for this research were collected through in-depth interviews with 19 participants who provide extension services to farmers in Malawi. All phone interviews were recorded using my mobile device or computer and were transcribed using Word. After all interviews had been transcribed, each interview was coded to identify common patterns and themes using NVivo. NVivo is a Qualitative Data Analysis computer software package that helps a researcher analyze qualitative data produced during interviews. Using NVivo significantly improves the quality of qualitative research analysis by reducing the number of manual tasks and allowing the researchers to easily discover themes in the data . The data analysis process began by developing a project database in NVivo. The unit of analysis for the study was the “organization.” Therefore, I analyzed patterns, themes, and relationships between organizations instead of the individuals representing those groups. A unique “case” was created for each organization to ensure that the organization’s associated information such as type of organization was linked to them and stored in the NVivo Classification Sheet in order to compare information between organizations. After building the NVivo project structure, coding took place in order to sort the data into meaningful segments. I used both inductive and deductive methods to develop theme codes that were generated both from the theoretical framework used and those that reflected emerging themes present in the data. The words and phrases directly mentioned by the participants were then combined to formulate a connection and relationship between related words or phrases in order to develop broader themes. The model explorer tool in NVivo was then used to visually map the ways in which different themes related to one another in order to derive greater meaning from the data. This analysis was then connected to existing concepts and the theoretical framework used and existing concepts discovered through the literature review. In addition to theme codes, relationship codes were also developed to record the relationships between stakeholders and the transfer of information between organizations. Relationship coding occurred any time an interview participant mentioned information sharing or a partnership between two organizations. Organizational relationships were categorized in three district ways. First, if an interview participant mentioned one organization receiving information from another the relationship was coded as “Organization X receives information from Organization Y.” Second, if an interview participant mentioned information sharing between two organizations, but did not specify which organization developed the information, the relationship was coded as “Organization X shares information with Organization Y.” Finally, if one organization was associated with another, such as the Department of Agricultural Extension Services is part of the Ministry of Agriculture, the relationship was coded as “Organization X is associated with Organization Y.” Relationship coding allowed me to visualize the stakeholder network and the dissemination of information through a Network Sociogram that was exported from NVivo into a data visualization software, Gephi. The Network Sociogram produced through Gephi allowed for the visualization of the complex network of relationships and organizations that are central to information sharing within Malawi’s extension network, and organizations that are not as closely connected to others.Social network analysis was used as the analytical method for understanding and evaluating Malawi’s extension network.