Дисертації з теми "Farm transitions"

Food systems are facing increasing pressure to adapt to the local, regional and global implications of the climate crisis while reducing the environmental impacts of food production and retaining their competitiveness on increasingly connected agri-food markets. Many suggested aspects of a more resilient, sustainable model of food production are directly linked to decisions made on individual farms. However, there are known social-ecological traps that limit farmers’ capacity to break away from unsustainable paths. This thesis investigates the impact of trap dynamics on the incidence of sustainability transitions on Finnish farms – for example, transitions from animal to plant agriculture, or from monoculture to crop diversity. I use national tax records and interviews with regenerative farmers to identify patterns and circumstances that preclude farmers’ ability to carry out sustainability transitions, and to describe strategies used by regenerative farmers to enhance their agency and avert traps. My findings indicate that rigid governance and market structures, an increasing burden of debt and intensifying ecological pressures converge to create, sustain and exacerbate social-ecological traps. Finally, this thesis suggests that the existence of farm-level traps may hamper attempts to address food system lock- ins across scales, diminishing the system’s capacity to respond to shocks and changing circumstances.

This study focuses on determining how Virginia farmers are planning for farm retirement and succession and whether they will be financially prepared for their retirement years. The Virginia farming population is aging, life expectancy is increasing, and Social Security benefits are not a stable source of retirement income presenting challenges for Virginia farmers who are planning to either retire from the family farm or transition it to the next generation. In this study a 59-item survey was sent to 2000 randomly selected Farm Credit agricultural customers. Results from the survey were analyzed using chi-square tests and correlations to determine statistically significant relationships between the variables. The analysis indicates that Virginia farmers planning to retire from the farm face high levels of debt and plan to sell the farm operation. Virginia farmers planning to transition the farm are generating higher profits from the farm operation and their successor has been identified. The majority of Virginia farmers are financially prepared for retirement with Social Security support; however, without supplemental income from Social Security the majority of the Virginia farming population is not financially prepared for retirement. The results indicate necessary action from the private, academic, and public sectors. Financial professionals should offer retirement planning seminars, academia should continue to research the issues, and the government should consider developing a savings plans specifically for the agricultural community that offer tax advantages.
Master of Science

The ability to maximise learning efficiently is of concern to all who are involved in an educational environment. The process of learning that will facilitate change is well documented. This documentation suggests that: (1) the understanding of what is occurring in the process of change is essential for it to be successful, and (2) this process includes certain specific traits that will facilitate change. In this study, a design to acquire data from individuals involved in this process of change is developed. To acquire the data sought in this study, observation was made of ten trainees involved in a skills enhancement programme at Caloola Farm; a training centre sponsored by the Federal Government and operated through the Baptist Community Services (A.C.T.). The conclusion reached supported the original premise that recognisable traits exist and aid in the process of accepting change.

For many of Latin America’s small farmers, a future in agriculture may be short lived. Due to increasing mechanization, land consolidation, and globalization, the demand for agricultural labor is declining, and small landowners are feeling the brunt of this change. Given this reality, the non-farm rural economy should become a much greater priority on the rural development agenda. Many non-farm positions demonstrate significant potential for poverty alleviation, but these jobs often present substantial barriers to entry. In order for smallholders to access these positions rather than low-skilled, low-productivity, and low-paying jobs, government involvement is essential. By helping small farmers build non-farm skills and knowledge, facilitating profitable land transactions, and fostering a business environment that supports rural job creation, governments can ensure that small farmers are not only able to transition to non-farm employment, but that they are able to do so in a way that maximizes the impact on overall rural welfare.

Master of Agribusiness
Department of Agricultural Economics
Terry Griffin
Rosburg Farms is a crop farm in Northwest Iowa that specializes in corn and soybean production. The oldest farm operator, Richard was looking ahead to retirement while the next generation, Brian has been working to identify an entry strategy into the operation as a beginning farmer. The purpose of this research was to identify and evaluate candidate alternatives that Brian could bring to Rosburg Farms and to understand if the operation was at a point where Brian was needed as full time labor. Three candidate scenarios including renting additional crop acreage, building a hog facility, and building a poultry layer house were evaluated via SWOT analyses. The SWOT analysis results indicated that renting additional crop acres was the best candidate alternative for the farming operation. To understand how adding the additional acreage to crop production affects the timeliness of the operation and to identify binding resources a whole-farm linear programming planning model was parameterized. Parameters included available labor, machinery, days suitable for field work, crop rotations and available acreage. Production enterprise budgets for corn and soybean production and a projected cash flow were developed to understand if this acreage expansion would be profitable for the multi-family farming operation. The results of the planning model indicated that the field work operations would be completed with the available labor, machinery, and days suitable for fieldwork. The production budgets and cash flow results indicated that Rosburg Farms would remain profitable once farm size was expanded with additional rented acreage. Considering Brian employed off the farm, it was not necessary for him to quit his job to farm full time at this point. Future analysis should be used to understand at what farm size are needed to justify Brian leaving his off-farm employment to farm full time. These results are applicable beyond the Rosburg farm and are of interest to beginning farmers, farms anticipating transition to next generation, and professional specializing in succession planning.

This study explored the responses of Amish agrarians in northern Indiana to the mechanization and modernization of rural life in the early twentieth century. This period was marked by a shift towards agribusiness as well as the increased usage of farm machines. In addition to the increased emphasis on farm efficiency, reformers sought to modernize or update rural life. Within the context of these transformations, the Amish maintained their identity by exploring the necessity and the consequences of adapting to life in the modern world. Their responses to modernization defined not only their cultural boundaries in the modern world but also created their identity in twentieth century America. In stark contrast to the ideal of the independent farmer, the Amish used the strength of their community (both Amish and non-Amish) and their agrarian roots to endure and overcome the challenging events of the early twentieth century. The purpose of this study was to expand the scholarship of Amish studies in northern Indiana as well as place the Amish experience within the context of agrarian historiography. Resources used to examine this period included Amish writings, farm publications from Indiana and data from the agricultural census.
ID: 031001352; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Title from PDF title page (viewed April 22, 2013).; Thesis (M.A.)--University of Central Florida, 2012.; Includes bibliographical references (p. 94-99).
M.A.
Masters
History
Arts and Humanities
History; Public History

Le premier mai 2004, la Pologne a fait son entrée dans l'Union Européenne après quinze ans de transition d'un régime communiste à une économie de marché. L'objectif de cette thèse était de connaître les raisons de la persistance de structures anciennes et obsolètes dans le secteur agricole. La productivité des exploitations agricoles polonaises a été g^enée par un manque de terres agricoles et un excès de capital et de main d'oeuvre. Les meilleures performances ont été réalisées par des agriculteurs jeunes et diplômés, endettés et avec des terres de qualité. Les imperfections sur le marché du crédit rural polonais ont contraint les décisions d'investissement des exploitations les plus productives, alors que les moins productives n'ont pas été affectées. L'adhésion du pays à l'UE pourrati avoir des implications favorables à l'amélioration de la productivité et à la prévention d'un désastre social
On the first May 2004 Poland became a member of the European Union (EU) after 15 difficult years of transition from communist regime to market economy. This thesis' objective was to investigate the reasons for the persistence of small farms, abundant labour and obsolete capital on farms. Farms' productivity was hampered by a lack of land and an excess of capital and labour. The best performers were young and educated farmers who were indebted and had good land quality. The imperfections on the rural credit market constrained the investment decisions of the most productive farms, while the least productive farms were not affected. The accession to the EU could be beneficial to the productivity improvement and to avoid a social disaster

Precision dairy monitoring is used to supplement or replace human observation of dairy cattle. This study examined the value dairy producers placed on disease alerts generated from a precision dairy monitoring technology. A secondary objective was calculating the accuracy of technology-generated disease alerts compared against observed disease events. A final objective was determining the economic viability of investing in a precision dairy monitoring technology for detecting estrus and diseases. A year-long observational study was conducted on four Kentucky dairy farms. All lactating dairy cows were equipped with a neck and leg tri-axial accelerometer. Technologies measured eating time, lying time, standing time, walking time, and activity (steps) in 15-min sections throughout the day. A decrease of ≥ 30% or more from a cow’s 10-d moving behavioral mean created an alert. Alerts were assessed by dairy producers for usefulness and by the author for accuracy. Finally, raw information was analyzed with three machine-learning techniques: random forest, least discriminate analyses, and principal component neural networks. Through generalized linear mixed modeling analyses, dairy producers were found to utilize the alert list when ≤ 20 alerts occurred, when alerts occurred in cows’ ≤ 60 d in lactation, and when alerts occurred during the week. The longer the system was in place, the less likely producers were to utilize alerts. This is likely because the alerts were not for a specific disease, but rather informed the dairy producer an issue might have occurred. The longer dairy producers were exposed to a technology, producers more easily decided which alerts were worth their attention. Sensitivity, specificity, accuracy, and balanced accuracy were calculated for disease alerts that occurred and disease events that were reported. Sensitivity ranged from 12 to 48%, specificity from 91 to 96%, accuracy from 90 to 96%, and balanced accuracy from 50 to 59%. The high number of false positives correspond with the lack of usefulness producers reported. Machine learning techniques improved sensitivity (66 to 86%) and balanced accuracy (48 to 85%). Specificity (24 to 89%) and accuracy (70 to 86%) decreased with the machine learning techniques, but overall detection performance was improved. Precision dairy monitoring technologies have potential to detect behavior changes linked to disease events. A partial budget was created based on the reproduction, production, and early lactation removal rate of an average cow in a herd. The cow results were expanded to a 1,000 cow herd for sensitivity analyses. Four analyses were run including increased milk production from early disease detection, increased estrus detection rate, decreased early lactation removal from early disease detection, and all changes in combination. Economic profitability was determined through net present value with a value ≥ $0 indicating a profitable investment. Each sensitivity analysis was conducted 10,000, with different numbers for key inputs randomly selected from a previously defined distribution. If either milk production or estrus detection were improved, net present value was ≥ 0 in 76 and 85% of the iterations. However, reduced early lactation removal never resulted in a value ≥ 0. Investing in precision dairy technology resulting in improved estrus detection rate and early disease detection was a positive economic decision in most iterations.

Among the many non-equilibrium processes encountered in nature we deal with two different but related aspects. One is the non-equilibrium relaxation process that is at the origin of \'aging phenomena••, and the other one is a non-equilibrium phase transition, called ••dynamic phase transition••. One of the main purposes of our research is to explore more realistic situations than studied previously. Indeed, in the study of aging phenomena certain kinds of disorder effects are considered, and we introduce the ••surface•• as a spatial boundary to the system undergoing the dynamic phase transition. In order to observe these processes as clearly as possible, we study in both cases simple spin systems. Using Monte Carlo simulations we first investigate aging in three-dimensional Ising spin glasses as well as in two-dimensional Ising models with disorder quenched to low temperatures. The time-dependent dynamical correlation length L(t) is determined numerically and the scaling behavior of various two-time quantities as a function of L(t)/L(s) is discussed where t and s are two different times. For disordered Ising models deviations of L(t) from algebraic growth law show up. The generalized scaling forms as a function of L(t)/L(s) reveal a generic simple aging scenario for Ising spin glasses as well as for disordered Ising ferromagnets. We also study the local critical phenomena at a dynamic phase transition by means of numerical simulations of kinetic Ising models with surfaces subjected to a periodic oscillating field. We examine layer-dependent quantities, such as the period-averaged magnetization per layer Q(z) and the layer susceptibility ¥ö(z), and determine local critical exponents through finite size scaling. Both for two and three dimensions, we find that the values of the surface exponents differ from those of the equilibrium critical surface. It is revealed that the surface phase diagram of the non-equilibrium system is not identical to that of the equilibrium system in three dimensions.
Ph. D.

The transition from conventional to sustainable farming has been limited in Quebec by the absence of a comprehensive strategy, applicable at the farm level, to facilitate the transition process. This study summarizes the popular discussion pertaining to planning the farm transition, and the following six concepts that are useful to take into account when designing sustainable systems: vision, creativity, values, the efficiency - substitution - redesign spectrum, an holistic, systems perspective of the farm, and popular participation in the development process. Case studies of six farms in the early phase of transition are presented. Farm and farmer characteristics are detailed as well as the potential of each to influence the evolution of the farm. The outcomes of farm-level planning and activities in the first two transitional years are described. Particular attention is paid to the implications of creative visioning and approaches to problem solving, value adjustments, decision-making criteria, and the farmers' perceived restraining forces. A comprehensive, practical strategy designed to facilitate the farm transition process is constructed. This combines the current popular template for appropriate planning and the theoretical constructs of sustainable development, with insights gathered from the six case study farms. Finally, procedures for using the strategy are outlined, together with some requirements for its further development.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2008.
Includes bibliographical references (p. 299-309).
My dissertation examines an unexpected outcome of post-socialist agricultural transformation in the Central and Eastern European countries. Contrary to the initial expectations of Neoliberal transition policy-makers, various forms of agricultural associations emerged throughout the former communist countries, following the distribution of private property rights to individuals. The reallocation of land in associations occurred while this institutional arrangement was criticized in the literature and individual farming was portrayed as the panacea for these countries. The main research question that frames my dissertation is: Why do farmers still persist in joining associations despite perceived collective action problems and the availability of leasing as a close substitute? Additional questions are also examined: Why did associations emerge in some regions and not in others? What are the factors that affect landowners' choices between associations and leasing transactions? How different, or similar are associations from the old socialist collective farms? While earlier literature focused on explaining why landowners choose to farm the land individually, the choice between associations and leasing has not been previously researched. Using statistical analysis on household surveys and qualitative fieldwork I explain why and under what conditions associations are the optimal farming alternatives for landowners. Going beyond the capital constraints argument, I examine the role of institutional legacies and the effect of collectivization in explaining regional differences in land reallocation during transition.
(cont.) Based on my findings, theories of institutional change that view transition as a homogeneous and atemporal process across and within countries do not fully capture the interdependencies between different factors that shape individuals' responses to the incentives and constraints imposed by transition. This research provides policy recommendations especially for land consolidation efforts. Given high transaction costs associated with participating in land markets, farming associations should be strongly emphasized as a channel for achieving land consolidation. Support measures, such as improved access to credit and marketing channels, can enhance the competitiveness of associations.
by Georgeta Vidican Sgouridis.
Ph.D.

FINANCIADORA DE ESTUDOS E PROJETOS
Nas Forças Armadas do Brasil existe uma forte demanda pelo desenvolvimento de detectores de infravermelho nacionais para uso em diversas aplicações sujeitas a rígidas restrições de importação, como sistemas de imageamento infravermelho para visão noturna, guiamento de mísseis, sistemas de mira, etc. O objetivo deste trabalho foi desenvolver fotodetectores para o infravermelho distante em 10µm, baseados em estruturas semicondutoras de poços quânticos múltiplos de GaAs/AlGaAs utilizando transições intrabanda. Os materiais foram crescidos pela técnica de epitaxia de fase vapor de metalorgânicos (MOVPE). A calibração dos parâmetros de crescimento foi realizada por meio de medidas de difração de raios x, efeito Hall, e fotoluminescência. Devido à regra de seleção de que não é possível haver absorção intrabanda da luz sob incidência normal, foram aplicadas duas técnicas de acoplamento: geometria de guia de onda com incidência a 45º pela borda, e utilização de grades de difração metalizadas. Os detectores produzidos foram caracterizados quanto à corrente de escuro e quanto aos espectros de absorção óptica e de fotocorrente, ambos obtidos por espectroscopia FTIR. Ao final dos trabalhos, foi obtido um fotodetector de GaAs/AlGaAs do qual foi possível medir a fotocorrente através dos contatos elétricos do dispositivo, com pico em 9µm. Os resultados obtidos são promissores no sentido de que apontam para a possibilidade de se produzir detectores de infravermelho nacionais para diversas aplicações (defesa, medicina, astronomia, telecomunicações, etc).
In the Brazilian Army there is a strong demand for the development of national infrared detectors for use in many applications subjected to severe trade restrictions, like infrared imaging systems for night vision, missile guidance, sight systems, etc. The aim of this work was to develop far- infrared photodetectors for 10µm, based on semiconductor structures of GaAs/AlGaAs multi-quantum wells using intraband transitions. The materials were grown by metalorganic vapor phase epitaxy (MOVPE). The calibration of the growing parameters was done by x ray diffraction, Hall effect, and photoluminescence measurements. Since intraband transition of light is not possible to normal incidence, due to selection rules, two coupling techniques were applied: waveguide geometry with 45o incidence on the edge, and metalized diffraction gratings. The produced detectors were characterized in terms of dark current, optical absorption and spectral response. Infrared measurements were made using FTIR spectroscopy. A GaAs/AlGaAs photodetector was obtained. The photocurrent through the electrical contacts of the device showed a peak at 9µm. The results are promising in the sense of revealing the possibility of producing national infrared photodetectors for many applications (defense, medicine, astronomy, telecommunications, etc).

The study investigates traces and historical origins, socio-economic, political and cultural lives of 'black servants' who worked and lived at the Zwartkoppies Farm and other establishments owned by Sammy Marks through photographs, oral histories and Archives. Furthermore, I interrogate the notion of representation by exploring the house as a colonial object and the site as exclusive and perpetuating divisions in a democratic South Africa. The decision to employ oral histories is so as to give these servants the freedom to represent themselves in a space where their voices have been muted in their presence. The history of labour in Southern Africa serves as my point of departure so as to better frame my research. This study reflects on the effects of colonisation and apartheid characterised by injustices and marginalisation which is to this day still are reflected in the silenced narratives of South Africa's dark history.
Dissertation (MSoSci)--University of Pretoria, 2020.
University of Pretoria Bursary and DITSONG Museums of South Africa Bursary
Historical and Heritage Studies
MSoSci (Heritage and Museum Studies)
Unrestricted

Thesis (Ph.D.)--Boston University PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
The metal insulator transition in vanadates has been studied for decades and yet new discoveries still spring up revealing new physics, especially among two of the most studied members: Vanadium sesquioxide (V203) and Vanadium dioxide (V02). Although subtleties abound, both of the materials have first order insulator to metal phase transitions that are considered to be related to strong electron-electron (e-e) correlation. Further, ultrafast spectroscopy of strongly correlated materials has generated great interest in the field given the potential to dynamically distinguish the difference between electronic (spin) response versus lattice responses due to the associated characteristic energy and time scales. In this thesis, I mainly focus on utilizing ultrafast optical and THz spectroscopy to study phase transition dynamics in high quality V203 and V02 thin films epitaxially grown on different substrates. The main findings of the thesis are: (1) Despite the fact that the insulator to metal transition (IMT) in V203 is electron-correlation driven, lattice distortion plays an important role. Coherent oscillations in the far-infrared conductivity are observed resulting from coherent acoustic phonon modulation of the bandwidth W. The same order of lattice distortion induces less of an effect on the electron transport in V02 in comparison to V203. This is directly related to the difference in latent heat of the phase transitions in V02 and V203. (2) It is possible for the IMT to occur with very little structural change in epitaxial strained V02 films, like in the case of Cr doped or strained V203. However, in V02, this necessitates a large strain which is only possible by clamping to a substrate with larger c axis parameter through epitaxial growth. This is demonstrated for V02 films on Ti02 substrates. (3) Initiating an ultrafast photo-induced insulator-to-metal transition (IMT) is not only possible with above bandgap excitation, but also possible with high-field far-infrared excitation. With the help of the field enhancement in metamaterial split ring resonator gaps, we obtain picosecond THz electric field transients of several MVIem which is sufficient to drive the insulator to metal transition in V02.

This thesis draws on oral histories to explore the lives of the Carolina Piedmont's farm to factory families from the 1880s through 1930s. Utilizing gender and race as analytical tools, it examines how women lived everyday life on the farm and in the mill, how the blurring of the sexual division of labor by women challenged southern farming masculinity that was protected by gendered language and public silence, and how social and economic changes in the mill undermined the language and silence of the farm. In so doing, this thesis provides an understanding of the farm to factory adjustment within the context of an examination of masculinity as an historical, ideological process. As cultural conceptions of masculinity changed with economic shifts from subsistence farming to commercial agriculture to millwork, women's cash-producing work, which had been hidden on the farm, was made visible by a daily wage in the mill.

Esta dissertação consiste na análise da evolução da política de segurança do governo colombiano entre 2008 e 2016 para lidar com as FARC, conjuntamente com a análise da evolução das preferências de atores políticos domésticos e internacionais que compuseram uma representação da sociedade colombiana e de suas relações internacionais em momentos-chave desta transição. As preferências destes atores foram agrupadas em tipos ideais: a favor da exclusividade do combate militar ou de negociações que, informalmente reunidas, formam coalizões multiníveis em prol de uma ou outra diretriz. O objetivo foi identificar qual sustentação política possibilitou uma ruptura na política de segurança colombiana antes exclusivamente voltada ao combate e que se direcionou para o início de negociações dado que, diferentemente das duas rupturas anteriores, esta não foi resultado de uma escolha direta da população nas eleições presidenciais. A hipótese sustentada na pesquisa é que mudanças contextuais ocorreram simultaneamente nos âmbitos doméstico e internacional e que ambas foram igualmente necessárias para o sucesso desta transição. Estas mudanças contextuais geraram também uma mudança de narrativa da promoção da imagem da Colômbia como um Estado frágil para a de um país em franco desenvolvimento. A contribuição a que esta pesquisa se propõe é romper a barreira de análise destes dois âmbitos tratados na literatura primordialmente de forma cindida, impondo um empecilho para a compreensão desta política que é simultaneamente doméstica e internacional, impedindo uma maior compreensão dos mecanismos causais da sua evolução. Esta análise simultânea permitiu identificar um descompasso entre o entusiasmo internacional com a negociação e um cenário doméstico polarizado com preferências conflitantes. Os elementos que a pesquisa encontra como determinantes para esta transição são que este conflito, que fora intensamente internacionalizado, ter passado por um processo de \"renacionalização\" e também de estagnação em um confronto de baixa intensidade, redistribuindo os custos e os pesos dos atores politicamente determinantes. Em relação aos atores políticos, a pesquisa identifica que foram necessários para a transição: o presidente colombiano e as FARC, o Congresso colombiano, EUA e Venezuela. O apoio direto da mídia, da opinião pública e da União Europeia não teriam sido necessários, mas são importantes para a consistência política e para o sucesso na implementação da negociação e do processo transicional.
This work is an analysis of how the Colombian security policy to deal with FARC evolved between 2008 and 2016 and an analysis of how evolved the preferences of domestic and international political actors that composed a representation of the Colombian society and its international relations around key moments of this transition. The preferences of those actors were grouped in two ideal types: in favor of the military combat versus those favoring negotiations. Informally united, those actors formed multilevel coalitions in favor of one of those preferences. The goal was to identify which was the political support that enabled a radical change in the Colombian security policy from the military combat to negotiation considering that, differently from the two preceding political changes, this was not the result of a direct popular choice through presidential elections. The hipotesis sustained in this research is that contextual changes happened both in the domestic and international spheres and that both were necessary to enable this policy transition. Those contextual evolutions also generated the change of the main Colombian political narrative, from the promotion of the Colombian image as a fragile State to the one of a country in full development. This work contributes to break the analytical barrier between the domestic and international spheres, treated mostly as separated parts in the academy, which constitutes a barrier to the comprehension of this policy that is simultaneously domestic and international, demanding a double level analysis to understand its causal mechanisms. This simultaneous analysis enabled the identification of a large imbalance among the constant international enthusiasm and many conflicting preferences at the polarized domestic sphere. The factors that the research finds as determinant to this transition were the fact that this conflict that was intensely internationalized passed by a process of \'renationalization\' and by a process of stagnation at a low intensety confrontation redistributing the operational and political costs and also the relative relevance of the intervening political actors. Regarding these political actors, the research identified that the Presidency, FARC, Colombian congress, USA and Venezuela were necessary to the policy transition. The direct support from the Colombian population, the media and the European Union were not necessary, but were important to the political consistency and will be crucial to the success of the transitional process.

Master of Science
Department of Communications and Agricultural Education
Lauri M. Baker
The purpose of this study was to identify the needs of Kansas' agricultural producers in relation to financial and legal matters at a local level. The following research questions guided this study: 1) what services, identified by local producers, are needed in communities across Kansas to assist producers in times of financial and legal distress; 2) what are the perceptions among producers of the Kansas Agricultural Mediation Services (KAMS); 3) what brand attributes, names, and taglines would appeal to producers for an organization addressing their financial and legal distress; 4) how can organizations effectively market financial and legal services to producers? A qualitative study design was used in order to assess the research questions. Six focus groups were performed throughout the state in three different geographic locations. Participants were selected using purposive sampling in order to have one group of people familiar with the organization (KAMS) currently helping producers with their legal and financial issues and one unfamiliar group in each location. Grunig’s excellence in public relations model served as the conceptual framework for this study. Results of this study concluded that rural Kansas’ communities see a need for service organizations similar to KAMS. Participants value assistance with family farm transition planning as well as financial assistance. Participants saw marketing and promotion of the current services offered just as critical as having the services themselves. Participants felt these services should be marketed through two-way communication channels, such as social media, an organizational representative for face-to-face interaction, and collaboration with extension. Additionally, participants voiced strong opinions about various brand attributes.

Les consommateurs demandent aux producteurs de fruits, via leurs achats ou leurs représentants politiques, de réduire les impacts négatifs des pratiques agricoles sur l’environnement et la santé. Les pratiques agroécologiques, mobilisant des processus ou produits naturels, permettent de réduire l’utilisation problématique des produits de synthèse. Mais les agriculteurs font face à des décisions complexes pour organiser la transition agroécologique dans leurs exploitations, souvent diversifiées, et l’accompagnement politique de ces transitions est encore hésitant. Face à ces défis, notre étude s’est intéressée aux processus de transition agroécologique dans les exploitations agrumicoles de La Réunion pour comprendre la diversité de leurs dynamiques et mieux les accompagner via des politiques d’aides. La diversité des transitions agroécologiques au sein de 31 exploitations diversifiées a été analysée dans une première étape. Une typologie d’exploitations a été formalisée, sur laquelle s’est appuyée la deuxième phase de la démarche basée sur la conception d’un outil opérationnel d’évaluation ex-ante des politiques publiques. L’outil ENTICIP (EvaluatioN Territoriale des Interactions entre Consommation, Interventions publiques et Production agricole) est un modèle bioéconomique d’optimisation couplant les échelles exploitation et bassin de production. ENTICIP permet de simuler les choix des agriculteurs et leurs conséquences économiques, environnementales et sociales pour des scénarios exploratoires de politiques d’aides sous divers contextes de marché.De nombreux facteurs internes et externes à l’exploitation interviennent dans l’adoption de pratiques agroécologiques, les principaux étant le circuit de vente, la sensibilité environnementale de l’agriculteur et le rôle économique de la production dans l’exploitation. Au sein des exploitations diversifiées, des interactions entre productions favorisant les pratiques agroécologiques apparaissent : échanges de biomasse et de connaissances, ou mutualisations d’intrants alternatifs. L’étude a mis en évidence quelques trajectoires « en rupture » conduisant rapidement à une forte écologisation, mais la majorité des trajectoires est beaucoup plus progressive, avec parfois des retours en arrière. Les vitesses d’écologisation des productions peuvent être hétérogènes au sein de l’exploitation, permettant notamment de minimiser les risques liés à l’adoption de pratiques agroécologiques. ENTICIP a été appliqué au cas de l’ananas et du tangor à La Réunion (Ananas comosus (L.) Merr. et Citrus reticulata Blanco x Citrus sinensis (L.) Osb.). Des scénarios d’augmentation des aides pour l’Agriculture Biologique (AB) dans un contexte de marché favorable ont permis d’identifier les conditions d’un développement massif de l’AB. Les montants d’aides déclenchant la conversion à l’AB sont variables selon la production et le type d’exploitation, en fonction de leurs conditions bioclimatiques et de leurs circuits de vente. Plus les produits conventionnels sont bien valorisés, comme sur le marché export, plus le montant d’aides nécessaire pour passer à l’AB est élevé. Ces scénarios ont été présentés à des décideurs politiques réunionnais, avec qui le modèle a été utilisé de manière participative. La démarche permet de rassembler des connaissances sur le fonctionnement des systèmes productifs et de proposer des pistes d’améliorations pour les politiques agricoles à visée environnementale. Ce travail devrait contribuer à renforcer le partenariat chercheurs-décideur politiques initié à La Réunion, afin de doter les acteurs locaux d’outils pour d’organiser la transition agroécologique de leur territoire. Dans cette perspective, les efforts de recherche pourraient s’orienter vers le développement d’un dispositif multi-échelles et interdisciplinaire autour de l’analyse et de l’accompagnement des changements des agriculteurs
Through their purchase choices and political representatives, consumers are putting an increasing pressure on fruit growers to reduce the negative environmental and sanitary impacts of their agricultural practices. Agroecological practices enhancing natural processes can help reducing synthetic inputs use. However, proceeding to an agroecological transition is a complex management challenge for farmers who often combine diverse activities. Moreover, policy support for agroecological transitions remains to be improved. In this context, our study focused on agroecological transition processes in diversified citrus farms in La Réunion Island in order to understand the diversity of their dynamics and improve their support through public incentives.The first step of the study aimed at describing and explaining the diversity of agroecological transitions on 31 diversified farms. A farm typology sorting this diversity was built in order to be communicated to policy makers. The second step used this diagnosis to design an ex-ante evaluation tool of public policies linked to fluctuating market at the productive system scale. The tool, named ENTICIP (Territorial Evaluation of Interactions between Consumption, Public grants and agricultural Production), is a bioeconomic optimization model combining farm and productive system scales. ENTICIP can run exploratory scenarios of policies supporting agroecological transition under various market conditions. It estimates farmers’ choices and economic, environmental and social consequences at the productive system scale. Agroecological practices adoption depended on numerous internal and external factors at farm scale, the most significant being the marketing channel, the farmer eco-friendliness and the economic role of the production for the farm. Beneficial interactions for agroecology occurred within diversified farms, such as synergetic exchanges of biomass and knowledge, or alternative input and equipment sharing. Some cases of radical trajectories leading rapidly to a strong ecologization level were identified, but most of the trajectories were really progressive, eventually with back steps. The ecologization speeds differed depending on productions in diversified farms. This process helped minimizing risks induced while adopting agroecological practices.Based on this knowledge ENTICIP was used on the cases of pineapple (Ananas comosus (L.) Merr) and tangor (Citrus reticulata Blanco x Citrus sinensis (L.) Osb.) productive systems in La Réunion. Conditions for a massive development of organic farming were explored in scenarios with increased organic farming subsidies and favorable organic market context. Subsidies rates to trigger organic conversion are variable regarding the kind of production and the farm type, according to their bioclimatic conditions and their marketing channels. Moving to organic production required the highest amounts of subsidies when high prices for conventional products were available, such as in export markets. Local policy makers were presented these scenarios and involved in a participatory process to use the model and evaluate the results of scenarios.The research process enabled to gather knowledge on productive systems functioning, and to suggest orientations to improve agricultural policies with an environmental perspective. Prospects could be to strengthen the partnership between policy makers and scientists in La Réunion, to provide local stakeholders with tools to manage the agroecological transition in their territory. Research efforts could target the development of a multi-scale and interdisciplinary program on the issue of farmers’ changes

Mi tesis doctoral trata los factores que influyen la aparición de organizaciones de extrema derecha contemporáneos en Rusia y subraya el papel clave de liderazgo en dichas organizaciones. Las preguntas de investigación son: ¿Hasta que punto ha cambiado el movimiento de derecha radical ruso a lo largo del tiempo? ¿Qué factores son responsables de la transformación interna (la aparición y la evolución) del movimiento de derecha radical en Rusia? Las variables dependientes centrales de mi estudio son el surgimiento y el cambio de los modelos organizativos de la derecha radical rusa y tienen que ver con el por qué, el cuándo y el cómo emergen nuevas estructuras movilizadoras y como cambian su forma, sus estrategias, discursos, y modelos. El objeto de mi estudio es el movimiento nacionalpatriota ruso, lo cual llamaré "oposición nacionalista-patriota" y definiré como: el amplio espectro de organizaciones nacionalistas extra-parlamentarias (partidos, movimientos y milieus), así como sus aliados dentro de la Duma. Utilicé una serie de métodos de recolección de datos que incluyen la observación participante, entrevistas semiestructuradas (entrevistas a informantes claves), el uso de documentos generados por los movimientos bajo investigación, artículos de prensa e investigación de archivos. Mi estudio utiliza un enfoque interdisciplinario que combina diferentes disciplinas (ciencia política, sociología, economía) y diferentes métodos, y su objetivo es forjar un puente entre la documentación existente de ciencia política y de sociología sobre el fenómeno de la derecha radical. Queriendo entender el surgimiento y evolución de los movimientos, mi tesis aborda el desafío analítico de identificar las circunstancias que incluyen procesos estructurales y culturales y los combina con un enfoque basado en la actividad humana. Se basa en el esfuerzo continuo de fusionar las teorías de nacionalismo y de los movimientos sociales con el fin de contribuir a la construcción de una teoría más sólida sobre la protesta de los movimientos de la derecha radical. Mi argumento es que las organizaciones rusas de derecha radical contemporáneas cambian su forma, la estrategia, el discurso y el modelo a través de un proceso de adaptación basado en nuevas divisiones socioeconómicas (en la línea de estado-nación/ confederación sin la dominancia de una nación, cívica ciudadanía basada en derechos cívicos/ en sangre, y organizaciones políticas parlamentarias/ extra- parlamentarias), en la respuesta del gobierno hacia estas divisiones (en particular a través de la política de migración), y en las oportunidades que el régimen u otros factores externos (por ejemplo la tecnología) se abre o se cierra a ellos. Las oportunidades están determinadas por el contexto estructural que incluye elementos culturales, sociales y políticos. La movilización y los resultados del movimiento nacionalista-patriota pueden alimentar de nuevo en ambas estructuras de movimiento y estructuras de contexto. Durante este proceso, el papel del liderazgo es crucial, para capitalizar las oportunidades existentes, para construir una atracción al mensaje público de que es capaz de atraer el apoyo del público, y para transformar sus formas y estructuras organizativas de una manera que les permita sobrevivir y lograr sus objetivos. La realización de las entrevistas con líderes de los movimientos nacionalistas patriotas muestra que su actividad es fundamental para la creación y supervivencia de los movimientos. Mi estudio elabora una serie de movimientos conceptuales, incluyendo la introducción de una definición más amplia de la derecha radical que toma en cuenta las complejas relaciones que existen dentro y entre las organizaciones que la componen y su interacción con las organizaciones de oposición; la introducción del término estructuras de oportunidades tecnológicas; y la evolución del partido La Otra Rusia (anterior Partido Nacional-Bolchevique) del frente nacional-patriota. La investigación presente contribuye a la obtención de una visión más clara de los patrones y la dinámica de la derecha radical en contextos de transición, especialmente en los no-democráticos. El caso de estudio de Rusia se integra en el debate de las ciencias sociales enfocado en la aparición y el desarrollo de los movimientos de extrema derecha y pretende aportar herramientas para entender mejor casos similares que atraviesan un cambio sistémico rápido. Cuenta con implicaciones más amplias sobre el papel de las organizaciones nacionalistas en la transición democrática; el entendimiento de los movimientos similares en otros entornos de transición, como en Ucrania, o en contextos occidentales con características similares, por ejemplo los entornos de crisis económica del sur de Europa; y la mejor comprensión de presiones en la política interna que puedan afectar la toma de decisiones gubernamentales en una serie de cuestiones, como podría ser en la política exterior.
My PhD dissertation deals with the factors that influence the emergence of contemporary far right organizations in Russia and underlines the key role of leadership in those organizations. The research questions addressed in my research are: To what extent does the Russian radical right movement vary over time? What accounts for the internal transformation (the emergence and further evolution) of radical right organizations in Russia? The central outcome variable of my study are the emergence and organizational change of the Russian radical right movement that has to do with the why,when, and how mobilizing structures arise and how they change their form, strategy, discourse, and model. The population of my study is the broader radical right movement in Russia, which I will call “nationalist-patriotic opposition” and define as: the wide spectrum of extraparliamentarian nationalist organizations (parties, movements, and milieus), as well as their allies within the Duma. I used a number of data-gathering methods that include participant observation, semi-structured interviewing (key informant interviews), the use of indigenously generated documents by social movement organizations, newspaper articles, and archival research. My study uses an interdisciplinary approach that combines different disciplines (political science, sociology, and area studies) and different methods based on extensive fieldwork (key-informant semi-structured interviewing, participant observation, and archival research) and aims to forge a bridge between political science and sociology literature on this topic. It addresses the analytical challenge of identifying circumstances that include both structural and cultural processes and combine them with an agent-based approach in order to understand movement emergence and development. It is based on the ongoing effort of merging nationalism and social movement theories in order to contribute to the construction of a more solid theory of radical right protest. My argument is that Russia's contemporary radical right organizations have changed their form, strategy, discourse, and model through an adaptation process under the influence of new socioeconomic cleavages (along the lines of nation-state/ nationless confederacy, civic/ blood citizenship, and parliamentarian/ extraparliamentarian political organizations), the government's response towards these cleavages (particularly through migration policy), and opportunities the regime or other external factors (e.g. technology) opens or closes to them. Opportunities are shaped by the structural context which includes cultural, social, and political elements. The mobilization and outcomes of the nationalist-patriotic movement may feed back into both movement structures and context structures. During this process, the role of leadership is crucial, for capitalizing on the existing opportunities, for constructing a message attractive to the public, and for transforming their organizational forms and structures in a way that will enable them to survive and to accomplish their goals. Evidence from interviews with leaders of nationalist-patriotic movements shows that their agency is fundamental for the movements' creation and survival. My study makes a series of conceptual contributions, including the introduction of a broader definition of the radical right that accounts for the complex relations that exist within and among the organizations that comprise it and their interaction with opposing organizations; the introduction of the term “technological opportunity structures”; and the disentanglement of the existent form of the National- Bolshevik Party- The Other Russia- from the nationalist-patriotic front. The present research contributes to obtaining more insight into the patterns and dynamics of right-wing radicalism in transitional settings, especially non-democratic ones. The case study of Russia seeks to contribute to the debate in social science on the emergence and development of radical right wing movements about a broader category of similar cases that undergo rapid systemic change. It has further implications for our understanding of the role of nationalist organizations in democratic transition; on the understanding of similar movements in other transitional settings, e.g.. Ukraine, or in Western non-transitional settings with similar characteristics, e.g. Southern European economic crisis environments; and for the better understanding of pressures in domestic policy that may impact governmental decision-making in a series of issues, e.g. foreign policy.

Humanity is facing massive sustainability challenges, such as climate change and the associated loss of biodiversity, water scarcity and food insecurity. Capitalist urbanisation drives furthermore profound transformations in rural and urban areas and thus in the agriculture and food systems, presenting both challenges and opportunities. Urban agriculture as a part of a local food system, where food is produced in an urban area and sold to consumers in that area, presents a new food production model, generating innovative tools to lower agricultural land use, improving resource use efficiency and biodiversity. Consequently, great potential can be attributed to a sustainable transformation of the agri-food system through urban agriculture.  Like many cities around the world, Malmö has recognised the need for sustainable development. Therefore, the city of Malmö has been addressing environmental, social and economic challenges for several years and is committed to a holistic and sustainable urban development. Although the city is aware of the benefits of small-scale urban agriculture, there are no policies that enable the upscaling of urban agriculture in the city. Botildenborg, a sustainable urban farm and meeting place in Malmö, on the other hand, has recognised the potential for sustainable business and development through urban agriculture for several years, by setting itself the goal to increase the local and ecologically produced food within the city through this form of agriculture. Botildenborg serves therefore as a case study of this research.  In order to be able to provide indications for policies to shape the transformation steps towards sustainability within the agri-food system in Malmö, structures and patterns, as well as possible drivers and potential obstacles of a sustainable transition, are examined in the course of this research. The empirical results from qualitative and quantitative data are systematically processed using the multi-level perspective in combination with the urban political ecology.  The results indicate that the identified barriers tend to be structural and are predominantly located in the economic and especially the political sphere. It seems that the non-monetary added value from urban agriculture is not perceived to its full potential by the city of Malmö. Botildenborg is stabilising itself mainly through knowledge sharing and network building, and thus will sooner or later be able, through the movement behind the network, to change the dominant agri-food regime. The rapidity of the transformation depends on the political ii willingness of the city of Malmö to explicitly integrate urban agriculture into its policies and regulations.

Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências da Educação: Educação Especial, área de especialização em Domínio Cognitivo e Motor
Este estudo enquadra-se numa abordagem descritiva sobre a operacionalização do processo de transição para a vida pós escolar de alunos com necessidades educativas especiais. O objetivo é compreender, descrever e refletir sobre a forma de implementação deste processo nas escolas básicas dos 2º e 3º ciclos e ensino secundário do Concelho de Faro, dando especial enfoque às perceções, práticas e opções de mudança manifestadas pelos diretores de turma e professores de educação especial a exercer funções no ano letivo 2012/2013. No estudo em apreço participaram 48 diretores de turma e 12 professores de educação especial, num total de 60 questionários com perguntas predominantemente fechadas e outras que remetiam para uma escala de atitudes do tipo Likert. Das nove hipóteses formuladas, três foram validadas e seis foram rejeitadas. Concluiu-se do estudo que para os professores no geral, os alunos devem iniciar o processo de transição para a vida pós escolar aos 13 anos, com atividades e competências funcionais, direcionadas para a integração na vida da comunidade envolvendo a cooperação dos pais de forma a promover a integração laboral. Apurou-se que o estabelecimento de parcerias e os locais de estágio são muito valorizados pelos professores e que a avaliação e coordenação da transição para a vida pós escolar é regular, sendo sobretudo realizada pelos professores de educação especial e pelo psicólogo. Do mesmo modo constatou-se que cabe a estes profissionais e aos pais a intervenção no processo de transição para a vida pós escolar. Concluiu-se também que nos planos individuais de transição devem constar as tarefas realizadas durante o estágio e a avaliação do aluno, sendo que o professor de educação especial é, novamente, a figura mediadora do processo. Apurou-se que ambas as tipologias de professores reconhecem existir dificuldades no processo de transição para a vida pós escolar, independentemente do tipo de necessidades educativas especiais, sendo que estas são sobretudo a falta de estágios e empregos. A maioria dos professores revelou-se otimista sobre a possibilidade de melhoria na transição para a vida pós escolar, no entanto admitem não ter opinião sobre a legislação em vigor sobre esta matéria.
This study aims to describe in a comprehensive way the process of transition to adulthood of students with special educational needs. The goals is also to understand, describe and overthink how this process is developed in the second and third grade schools as well as in the secondary schools that belong to the city of Faro. It is specially emphasized the teachers´ perceptions, practice and changing points of view, not only of the special educational needs teachers, but also of the regular teachers teaching in the school year 2012/2013. On this study it took part in answering a questionnaire 48 teachers, who are in charge for regular classes, as well as 12 special education teachers, summing up 60 questionnaires with mainly closed answers, however there were other questions in which it was used an attitude Likert scale. There were nine hypotheses, three of them were validated and six were rejected. According to the results of the study the students start the process of transition to adulthood at thirteen, during which they develop functional activities and abilities so they can integrate their community easier. Family takes part in this process and the main goal is to integrate the students professionally, that´s why the establishment of partnerships and places where students can learn a job are so important. The evaluation and coordination of the process are done on a regular basis, mainly by the teachers of special educational needs and by the psychologist. As for its evaluation it is also done by the teacher of the regular classes. On the other hand, the implementation of the process of transition to adulthood is done by the special educational needs teachers, the parents and the psychologist. In the transition plans there should be written the tasks and the evaluation during the students´ internship. The study points out that both teachers recognize existing difficulties, namely the lack of jobs or places where students can learn a profession. The teachers also think irrelevant the kind of special educational needs the students have to develop. Mostly teachers are optimistic about the improvement of the process, however they acknowledge not knowing much about the legislation on the subject.

The purpose of the study was to investigate how farmers in Quang Bing Province, Vietnam have been making the transition from subsistence farming to commercial agriculture. This process began in 1986 when the Vietnam economy changed from central planning to a market orientation. The research strategy was based on case study analysis of two communes in each of three agro-ecological zones, defined as coastal, plains and mountains. Within each commune there were six embedded household case studies, i.e 36 in total. Case studies were selected purposively to capture diversity of agro-ecological zones, market access and communications, wealth and income status, and ethnic communities. Households were interviewed twice; first in either late 2006 or early 2007, and again in late 2008. The study was approached using a constructivist paradigm and a lens of livelihood analysis, focusing on resources, institutions, interventions and the dynamics of change. Particular attention was given to the development of markets (inputs, outputs, land, labour and credit) and supply chain factors. Separate measures of commercialisation were constructed based on outputs and inputs, and at the level of both individual activities and the overall household. Investigations were informed by existing theory, but no hypotheses were tested. Instead, the research focused on emergent patterns and insights, and the enrichment and modification of existing theory. A review of literature indicated that the transition from subsistence farming to commercial agriculture in Vietnam was different from other countries on account of the specific combination of low technology agriculture, typical of much of developing Asia, combined with the transformation from a centrally planned economy to a market orientation as occurred in Central and Eastern European countries. At commune level, the key determinants of commercialisation were strong physical connections to markets, with good road access being paramount. Once all weather road access for motorised vehicles was available, then rapid commercialisation occurred. Supply chains typically developed faster for outputs than inputs. New technologies that increased the yield of basic food crops, and facilitated by Government and NGO programs, led to the release of land resources no longer required for meeting food security needs. Households retained their production of food crops that provided food security, and added additional cash earning activities. At the level of individual households, the commercialisation process was led by entrepreneurial families who perceived opportunities relating to profitable activities, and combined this with hard work. Often these opportunities were linked to what they had observed or learnt elsewhere. Once first movers took up a new technology, others observed and followed. There were many enabling factors, such as access to land, access to capital, and access to credit. However, none of these could be considered a determinant, in that the absence of any one factor did not by itself preclude successful commercialisation. Absence of an active male worker was a major constraint to commercialisation, as was lack of necessary crop and livestock skills. There was evidence that income disparities were increasing between the wealthy and the poor. Output commerciality across all households averaged 88 % in 2008 and was higher for wealthy households (95 %) than poor households (83 %). All households still produced their own food crops, but these crops had low market values and hence had a low impact on the output commerciality index. Output commerciality measured in percentage terms obscured that wealthy families had net incomes almost 13 times greater than poor households. A major theoretical insight was that key commercialisation factors are multiple and context dependent. Accordingly, there is a need in any investigation for a holistic approach, based on a livelihood framework that incorporates the complexities associated with the development of markets, as well as giving consideration to the range of interventions and institutional policies that impact on livelihood development.

This thesis examines Karen childhood transitions in a context of expansion of the cash economy, formal education and modern institutions. Since the 1960s, Thai state development has had a significant impact on the organisation of work and learning among highland populations. Today, household economies largely depend on cash income and children aspire towards an adult life in which paid work is central. Formal education is highly valued as a means to reach this goal. Children often migrate for education to better-resourced locations and access scholarships provided by national and international institutions. On the basis of 12 months of ethnographic fieldwork undertaken between October 2007 and September 2009, the thesis seeks to understand the effects of globalisation on politically and economically marginalized children in northern Thailand through the lens of changing modes of production and learning. Findings indicate that children’s migration for education reflects broad political economic inequalities among Karen households as well as between them and mainstream Thai lowland populations. International dimensions of unequal relations are revealed in local peoples’ collective negotiations with Japanese and Catholic Christian NGOs. Although socio-cultural constructs like ‘gender’, ‘generation’, and ‘ethnicity’ shape Karen childhoods, this study found that their economic and political status are more fundamental in shaping all aspects of their social lives, including their socio-cultural identities. Childhood transitions emerge as multidimensional learning processes towards mastery of ‘translocal identities’, the skill to manage identities and relationships across multiple spaces and institutions. This is a culturally valued skill evidenced when minority children tactfully negotiate differing modes of compliance, resistance, and adaptation, especially in the domains of work and education. Thus, children participate in the moulding of local versions of the modern political economy of northern Thailand.

L’introduction d’espèces de diversification, voie incontournable pour assurer la transition agroécologique pose aujourd’hui une question majeure : comment produire de manière économe les connaissances nécessaires sur ces espèces, orphelines de recherche ?Nous avons proposé et mis en œuvre une démarche articulant conception et production de connaissances, et combinant différents dispositifs multi-acteurs pour accompagner l’introduction d’une nouvelle espèce dans les systèmes de culture. Ce travail s’appuie sur le cas de la cameline, introduite soit en culture principale soit en double culture dans les systèmes de culture de l’Oise, en vue du développement d’une bioraffinerie oléagineuse.Nous avons combiné un atelier multi-acteurs -regroupant agriculteurs, conseillers, chercheurs, ingénieurs en R&D agricole et industriels- et des essais de modalités de conduite de la cameline en double culture, conçus, gérés et évalués par des agriculteurs dans leur ferme. Cette approche a permis d’identifier des trous de connaissances (ex : l’effet précédent de la cameline sur la betterave) et de produire des connaissances utiles pour la conception (ex : des règles de décision pour la conduite).En parallèle, nous (chercheurs) avons conçu et évalué, au sein d’un réseau multi-local et pluriannuel de parcelles agricoles, trois itinéraires techniques de la cameline de printemps sans herbicide. Nos résultats montrent que l’augmentation de la densité de semis de cameline ou l’association de la cameline avec une autre espèce (orge ou pois) sont des leviers agroécologiques efficaces pour maîtriser les adventices dans la culture de cameline. De plus, le diagnostic de la variabilité du rendement, de la teneur en huile des graines, et de leur composition en acides gras, réalisé au sein de ce même réseau d’essais, a permis d’identifier (i) les principaux facteurs responsables (ex : le statut azoté de la culture pour le rendement), et (ii) les conditions environnementales (ex : fourniture d’azote minéral par le sol) et les pratiques (ex : association d’espèces) déterminant ces facteurs.Ces connaissances produites ont conduit lors d’un atelier de conception à élargir la gamme des modalités d’insertion et de conduite de la cameline, conçues par les agriculteurs.Enfin, nous discutons en quoi cette combinaison originale de dispositif multi-acteurs, permet (i) de produire à moindre coût des connaissances situées et génériques, utiles pour la conception, et (ii) d’outiller à la fois l’agriculteur-concepteur, le conseiller agricole et le chercheur, pour accompagner la diversification des systèmes de culture d’une région
Crop diversification, which is a way to ensure agroecological transition, raises a major question: how to produce, at low cost, knowledge on these minor species, often poorly studied by agronomic research?Here, we proposed and implemented an approach combining design and knowledge production, within different multi-stakeholders platforms, to support the introduction of new species into cropping systems. The case study of camelina, introduced either as a main crop or as a second crop in the cropping systems of the Oise department, in the context of the development of a local oilseed biorefinery, was used.First, we combined a multi-stakeholders workshop - bringing together farmers, advisors, researchers, agronomist from agricultural R&D and industrials - with on-farm trials on camelina crop management routes as second crop, designed, managed and appraised by farmers themselves. This approach made it possible to identify knowledge gaps (e.g. the previous effect of the camelina on sugar beet), but also to produce knowledge useful for design (e.g. decision-making rules).In parallel, we (researchers) designed and evaluated, within a multi-environments on-farm trials network, three herbicide-free crop management routes for spring camelina. Our results show that increasing camelina sowing rates or intercropping camelina with another species (barley or peas) are effective agroecological ways to control weeds in camelina crop. In addition, the diagnosis of the variability of the yield, the oil seed content, and the fatty acid composition, carried out within the same experimental network, made it possible to identify (i) the main explaining factors (e.g. nitrogen status of the crop for yield), and (ii) environmental conditions (e.g. supply of mineral nitrogen from the soil) and practices (e.g. species intercropping) determining these factors.This knowledge production led, during a design workshop, to broaden the range of modalities of introduction and management of camelina designed by farmers.Finally, we discuss how this original combination of multi-stakeholder platforms makes it possible (i) to produce at a lower cost located and generic knowledge, useful for design, and (ii) to equip both the farmer-designer, the agricultural advisor and the researcher, to support crop diversification within a territory

Considerable number of studies are produced to deal with one of the most important challenges of the 21th century, which is the triple challenge of: regenerating the life supporting services provided by the Earth system, achieving food and nutrition sovereignty that leaves no one behind, and ensuring that global food systems support socio-environmental justice. This triple challenge is intrinsically linked to the Gordian knot that characterizes present-day global agriculture, at once vital and threatening to human society. In the present study, this global Gordian knot is explored through the lens of the trajectories of a few dozen farming systems, all located in a micro-territory of Wallonia (Southern Belgium) at the heart of the old industrial Europe. The agroecosystems under study are all family farms, which are among the survivors of a socio-professional group that has shrunk dramatically in just a few decades. Our broad objective is to gain insight into the tenets of transition towards sustainable farming systems in Wallonia.An exploratory research phase contributes to set the scene of our 'core research'. The exploratory study shows that three types of discourses, and two opposite paradigms, split the conversation among Walloon stakeholders on the path to improve agriculture; moreover, it suggests that transition is mainly a matter of cognitive lock-in. Our core research builds upon these premises, while the 'Peasant Principle' (put forward by J.D. van der Ploeg) stands out as its main theoretical background. Our broad objective may therefore be reformulated as 'gaining insight into the tenets of repeasantization in Wallonia'. This is addressed through three research questions, namely: 'What makes a farming system more or less peasant?'; 'What is the link between farm survival strategies and the cognitive (un)locking process?'; and 'How to support repeasantization?'. Our approach is grounded into two deep-probing field studies. The first one is empirical, and essentially stems from a sample of 23 neighbouring farm families located in a homogeneous window of Wallonia, and whose trajectories have been explored through semi-structured interviews and participant observation. The second field study is the in-depth review of what we term 'Farming Assessment Normal Science' (FANS), which refers to usual (i.e. mainstream) farm productivity assessment, with or without sustainability concerns, and encompassing both agronomic and economic farm productive performance. Following an abductive and interdisciplinary approach, we make the realities of encountered farm families dialoguing with a set of theories and disciplines all along the four chapters of the core research – this set includes the Peasant Principle, agricultural accounting, orthodox economics, economic history, (agro)ecology, heterodox economic schools, thermodynamics and psychodynamics of work.The core research begins with the first proposal framework to build a situated tool assessing farm 'peasantness degree' (PD), and framed by the Peasant Principle. The application of this framework to our Walloon case study results in a 'PD tool' specifically designed to assess the relative peasantness of farms under study. By translating the broad dimensions of the Peasant Principle into 168 very tangible situated indicators, the resulting PD tool provides a fine-grained insight on what makes a farm more or less peasant in Wallonia. Economic and agronomic productivity indicators, usually used to compare farms, had to be left out from our comparative analysis. The reflexive process inherent to the PD tool construction has thus raised the following question: 'Why usual (economic and agronomic) productivity indicators turn out to be unfit to compare farming styles?'. This emerging question is first addressed by showing that FANS is rooted into orthodox economics, meaning that, with or without sustainability concerns, usual assessment views farms through the 'Firm model', and thus relies on input-output analysis to assess farm agronomic and economic performance. Through the lenses of both, (i) the diverging realities and peasantness degrees of investigated Walloon families, and (ii) the nature of the farming process, five categories of issues affecting the validity of FANS are put forward. The first category is about practical issues, and the other categories relate to conceptual issues. The three first categories only relate to farm economic assessment, whereas the fourth and fifth categories relate to both, agronomic and economic farm productivity assessment.Altogether, these issues not solely evidence that usual productivity indicators and usual sustainability assessment provide misleading insights on farm performance, but that they provide 'bias-asymmetry' insights, that is: the more a farming style depletes the (re)productive capacity of its agroecosystem, the more its productive performance is overestimated; in contrast, the more a style cares to replenish the (re)productive capacity of its agroecosystem, the more its productive performance is underestimated. Hence we evidence that FANS tailored, and keeps sustaining, 'the productivity myth' and. As this mainstream science has (and continue to) shape(d) agricultural prescriptions and development, we also show that these are oriented towards the loss of agroecosystems' (re)productive capacity.While unveiling the productivity myth and its real-life implications, a framework drawing on the 'Flow-Fund model' (put forward by the heterodox economist N. Georgescu-Roegen) emerged as a sound alternative to assess farm productivity performance. Through the lens of the flow-fund balance, we rely on the distinctly different ways Walloon farmers manage their agroecosystem, and on the metabolic nature of the farming process, to empirically and theoretically demonstrate that: the more a farming style complies with the peasant mode, the more the farming process (or flow-fund balance) is managed with art, and coproduces negentropy; conversely, the less a farming style entails peasantness, the more the farming process is denatured, and the more entropy is by-produced. Thus, at the same time, a metabolic interpretation of the Peasant Principle is drawn up.From all these empirical and theoretical insights, the following question emerges: 'How do surviving farm families cope with decennia of prescriptions oriented towards the depletion of the (re)productive capacity of agroecosystems, and thus towards of the depletion of their own capacity to remain farmers?'. Dealing with this emerging question merges with one last aspect that needed to be addressed, namely the social phe- nomena of suffering, deactivation and suicide that undermine the modern farming world of Wallonia and beyond. Assuming that these social phenomena are closely tied, we focus on the root causes of social suffering among surviving farmers, and give the floor to the statements of encountered farm families. After highlighting strong identity markers that set Walloon farmers as a singular socio-profes-sional group, the sensitive issue of suffering is addressed through collective narratives of encountered farmers on :the post- WW2 mutation of the Walloon farming work environment towards a modern environment with increased and plural hostility. Then we propose a typology of the strategies, deployed by the investigated farmers of Piccard Wallonia, to survive such hostility. By articulating our peasantness framework and the 'psychodynamic model of work-related suffering' (put forward by Ch. Dejours), five types of survival strategies are described, and labelled according to their corresponding category of farmers: the new peasants, the TMCE-ists (i.e. conservation agriculture farmers), the racing strugglers, the lost strugglers and the near-deactivated. These insights on farmers' narratives into the plurality of the hostility, on the contrasting degrees to which it undermines farmers' psychosocial health, and on farm diverging strategies, altogether challenge the commonly held vision that economic hardship is the root cause of agricultural pro- pensity to suffering, deactivation and suicide. Instead these empirical insights verify our interpretative hypothesis, i.e. the mechanical link between farmers' suffering and their relation to prescriptions. The loss of peasantness indeed appears as a root cause of the ill-being of the modern farming world.To conclude, this work evidences that the productivity myth has given rise to the (miscalled) 'productivist' paradigm and to a system of prescriptions oriented towards the depletion of the (re)productive capacity of agroecosystems – in turn undermining the Earth system's (re)production capacity. The psychosocial health of farmers clearly is a key fund element, and its depletion appears as the ultimate bend of the vicious downward spiral fueled by the productivity myth. We furthermore conclude that the peasant mode of production stands for managing the farming process in a coherent and sustainable manner, whereas non- peasant (so-called entrepreneurial and capitalistic) modes incoherently and unsustainably denature the farming process. Hence 'completed' repeasantization appears as a negentropic process of fund replenishment, ensuring wealth coproduction at all scales – from the farm to the Earth system. 'Completed' de-peasantization (or industrialisation), for its part, appears as an entropic process of fund depletion, causing illth at all scales.On this basis, we suggest an alternative representation of agricultural modes and processes, which comes down a metabolic reconfiguration of the triangle proposed by J.D. van der Ploeg, and takes the form of a multidimensional continuum opposing two poles.The main lesson learned from this research thesis is that, to unravel the Gordian knot bound to modern agriculture, we need to break free from the productivity myth. In the face of today's challenges, the usual yet fallacious statement that 'losing peasantness may enhance farm productive performance and sustainability', is no longer be an option. To support the transition towards sustainable farming worlds, transformative support systems are needed, and such systems require to design and rely on indicators assessing the real performance of farms and agriculture. Therefore, as a perspective for further research, we propose the 'Farm Metabolism (FM) framework', i.e. a conceptual and analytical proposal that basically implies to rely on agroecosystem's flow-fund analysis. The metabolic (or biophysical) assessment framework sketched out here therefore paves the way to a strong sustainability assessment of farm productive performance. In turn, it could contribute to support the necessary repeasantization of 'modernized' farmers, for the well-being of farmers and human society as a whole.
Un nombre considérable d'études sont réalisées pour répondre à l'un des plus importants défis du 21ème siècle, à savoir le triple défi de parvenir à la souveraineté alimentaire et nutritionnelle de tous, de régénérer les services vitaux fournis par le système Terre, et de veiller à ce que les systèmes alimentaires globaux contribuent à la justice socio-environnementale pour tous. Ce triple défi est foncièrement lié au nœud gordien qui caractérise l'agriculture moderne :une activité vitale et menaçante à la fois pour la société humaine. Dans la présente étude, ce nœud gordien à l'échelle globale est exploré à travers le prisme des trajectoires de quelques dizaines de systèmes agricoles situés dans un micro-territoire de la Wallonie (Belgique du Sud), soit au cœur de la vieille Europe industrielle. Les agroécosystèmes étudiés sont tous des fermes familiales, et les fermiers rencontrés comptent parmis les survivants d'un groupe socioprofessionnel qui s'est considérablement réduit en quelques décennies seulement. Notre objectif général consiste à com- prendre les tenants et aboutissants de la transition vers des systèmes agricoles durables en Wallonie.Une phase de recherche exploratoire contribue à poser le contexte empirique du cœur de notre recherche. Cette étude exploratoire montre que trois types de discours, et deux paradigmes opposés, divisent la 'conversation' des acteurs wallons sur la manière d'améliorer l'agriculture; de plus, ce premier apercu empirique suggère que la transition est avant tout une question de verrou cognitif. Le cœur de notre recherche se fonde sur ces prémisses, et le 'Principe Paysan' (proposé par J.D. van der Ploeg) s'impose comme le cadre théorique principale. Notre objectif général peut dès lors être reformulé comme suit :'comprendre les tenants et aboutissants de la repaysannisation wallonne. Pour ce faire, trois questions de recherche sont posées :'En quoi un système agricole wallon est-il plus ou moins paysan qu'un autre ?', 'Quel est le lien entre les stratégies de survie des familles agricoles et le processus de (dé)verrouillage cognitif ?', et 'Comment favoriser le processus de repaysannisation ?'. Notre approche est fondée sur deux études de cas approfondies. La première est empirique, et concerne essentiellement un échantillon de 23 familles agricoles voisines, situées dans une fenêtre homogène de Wallonie ;leurs trajectoires ont été explorées par des entretiens semi-structurés et de l'observation participante. Notre deuxième étude de cas est un examen approfondi de ce que nous appelons la 'science normale de l'évaluation des fermes' (FANS, en anglais), c’est-à-dire l'évaluation scientifique usuelle de la productivité des fermes, dans le cadre ou non d'une évaluation de durabilité, et qui concerne à la fois la performance agronomique et économique des fermes. De par l'abductivité et l'interdisciplinarité qui caractérisent notre approche, nous faisons dialoguer les réalités des familles agricoles rencontrées avec un ensemble de théories et de disciplines tout au long des quatre chapitres qui forment le coeur de notre recherche – cet ensemble inclut le Principe Paysan, la comptabilité agricole, l'économie orthodoxe, l'histoire économique, l'(agro)écologie, des écoles économiques hétérodoxes, la thermodynamique et la psychodynamique du travail.Le cœur de la recherche débute avec la proposition d'une démarche analytique fondée sur le Principe Paysan, et visant à construire un outil comparatif du 'degré de paysanneté' (DP) de fermes. L'application de cette démarche donne lieu à un 'outil DP' adapté au contexte spécifique de notre étude de cas wallon. Cet outil traduit les dimensions générales du Pincipe Paysan en 168 indicateurs 'situés' très concrets, permettant ainsi de fournir un aperçu finement détaillé de ce qui rend une ferme wallonne plus ou moins paysanne qu'une autre. Les indicateurs de productivité agronomique et économique usuellement utilisés pour comparer les fermes, n'ont pas pu être inclus dans notre analyse comparative. Le processus réflexif inhérent à la construction de l'outil DP a ainsi soulevé la question suivante :'Pourquoi les indicateurs usuels de productivité agricole se sont-ils révélés inadaptés à la comparaison des styles agricoles ?'.Cette question émergeante est d'abord abordée en montrant que FANS est ancré dans l'économie orthodoxe. Cela implique que la manière usuelle d'évaluer les fermes – qu'il s'agisse ou non d'une évaluation de durabilité – utilise le 'modèle de la Firme' et, dès lors, se fonde sur des analyses intrants-extrants pour comparer les performances agronomiques et économiques des fermes et de l'agriculture. A travers les prismes, (i) des réalités et des degrés de paysanneté contrastés des familles agricoles enquêtées et (ii) de la nature du processus agricole, nous mettons en évidence cinq catégories de problèmes qui contestent la validité de FANS. La première catégorie se rapporte à des problèmes pratiques, et les quatre suivantes soulèvent des problèmes conceptuels. Non seulement l'ensemble de ces problèmes démontre que les indicateurs usuels de productivité (économique et agronomique) agricole, et les évaluations usuelles de durabilité agricole, donnent lieu à des arguments scientifiques erronés. Mais de plus, il est démontré que ces arguments comportent le biais-asymmétrique suivant :au plus un style agricole épuise la capacité (re)productive de l'agroécosystème, au plus sa performance productive est sur-estimée ;au contraire, au plus un style agricole veille à régénérer la capacité (re)productive de l'agroécosystème, au plus sa performance productive est sous-estimée. Nous montrons ainsi que FANS a conçu, et continue à entretenir, le 'mythe de la productivité'. Or ce mythe a façonné les prescriptions et le développement agricoles qui, par conséquent, sont orientés vers la perte de la capacité (re)productive des agroécosystèmes.Parallèlement à la mise en lumière du mythe de la productivité et de ses implications réelles, un cadre s'inspirant du 'modèle Flow-Fund' (formalisé par N. Georgescu-Roegen) laisse entrevoir une alternative prometteuse pour évaluer la productivité (agronomique et économique) réelle des fermes. A travers le prisme de la balance flow-fund, nous nous fondons sur les manières distinctement différentes dont les fermiers wallons gèrent leur agroécosystème, et sur la nature métabolique du processus agricole, pour démontrer empiriquement et théoriquement l'argument suivant :au plus un style agricole est proche du mode paysan, au plus le processus agricole (ou la balance flow-fund) est géré(e) avec art et co-produit de la néguentropie ;à l'inverse, au moins le style est paysan, au plus le processus agricole est dénaturé et au plus de l'entropie est coproduite. Ainsi, dans le même temps, nous établissons une interprétation métabolique du Principe Paysan.De tous ces constats empiriques et théoriques, la question suivante émerge :'Comment les familles agricoles qui ont survécu font-elles face aux décennies de prescriptions orientées vers l'épuisement de la capacité (re)productive de leurs agroécosystèmes, et donc vers l'épuisement de leur capacité à demeurer fermiers ?'. Cette question rejoint un dernier aspect qu'il était nécessaire d'aborder, à savoir les phénomènes sociaux de souffrance, de désactivation et de suicide qui minent le monde agricole moderne de Wallonie et d'ailleurs. Partant du postulat que ces phénomènes sociaux sont étroitement liés, nous nous concentrons sur les causes profondes de la souffrance sociale des fermiers subsistants, en veillant tout particulèrement à laisser la parole aux familles et fermiers que nous avons côtoyés. Nous commençons par souligner des marqueurs identitaires forts qui montrent que les agriculteurs wallons, au delà de leur hétérogénéité, forment un groupe socio-professionnel singulier. La question épineuse de la souffrance est abordée à travers le récit collectif des fermiers sur la mutation d'après-guerre, de l'environnement de travail agricole vers un environnement moderne caractérisé par une hostilité accrue et plurielle. Nous proposons alors une typologie des stratégies, déployées par les fermiers enquêtés de Wallonie picarde, pour subsister face à une telle hostilité. L'exercice typologique se fonde sur l'articulation de notre cadre de paysanneté et sur le 'modèle dynamique de la souffrance psychique au travail' (proposé par Ch. Dejours), mettant en évidence cinq types de stratégies de survie. Celles-ci sont désignées par la catégorie de fermiers qui leur est associée :les nouveaux paysans, les TMCE-istes (soit les fermiers en agriculture de conservation), les fonceurs à leur perte, et les désorientés. Cet aperçu empirique sur des récits et des stratégies de fermiers, réfute la vision communément véhiculée selon laquelle les difficultés économiques sont la cause profonde de la propension agricole à la souffrance, à la désactivation et au suicide. En revanche, cet aperçu confirme notre hypothèse interprétative, à savoir :l'existence d'un lien mécanique entre souffrance des fermiers et leur rapport aux prescriptions. La perte de paysanneté apparaît en effet comme une cause profonde du mal-être du monde agricole moderne. Pour conclure, ce travail démontre que le mythe de la productivité a engendré le paradigme (appelé à tort) 'productiviste' et le système de prescriptions agricoles qui dominent le monde agricole et l'orientent vers l'érosion de la capacité reproductive des agroécosystèmes – contribuant ainsi à l'érosion de la capacité reproductive du système Terre. La santé psychosociale des fermiers émerge clairement comme un des élément-clé du fund des agroécosystèmes, et son érosion apparaît comme le stade ultime de la spirale délétère alimentée par le mythe de la productivité. Nous parvenons également à la conclusion que le mode de production paysan signifie gérer le processus agricole de manière cohérente et durable; les modes non paysans (dits entrepreneuriaux et capitalistiques) eux dénaturent le processus agricole de manière incohérente et non durable. La repaysannisation 'aboutie' apparaît ainsi comme un processus néguentropique, producteur de richesse à tous les niveaux – du système agricole à celui de la Terre. La dépaysannisation (ou industrialisation) avancée des agroécosystèmes apparaît comme un processus entropique d'épuisement du fund, hautement producteur de coûts et de maux ('illth' en anglais) à tous les niveaux. C'est sur cette base, que nous proposons une représentation alternative des modes et processus agricoles. Essentiellement, cette représentation est une reconfiguration métabolique du triangle proposé par J.D. van der Ploeg, et se présent sous la forme d'un continuum multidimensionnel opposant deux pôles.La principale leçon tirée de cette thèse se résume ainsi :pour trancher le nœud gordien de l'agriculture moderne, il faut rompre avec le mythe de la productivité. Face aux défis actuels, l'argument usuel selon lequel 'la perte de paysanneté permet d'accroître les performances productives et la durabilité des fermes', n'est plus une option. Pour favoriser la transition vers des mondes agricoles durables, des systèmes de soutien transformateurs sont nécessaires, et ces systèmes requièrent de s'appuyer sur des indicateurs aptes à évaluer la performance réelle des styles agricoles et de l'agriculture. Nous proposons, en tant que perspective de recherche, le cadre 'Métabolisme de Ferme'. Cette proposition conceptuelle et analytique implique de se fonder sur des analyses flow-fund au niveau des agroécosystèmes, ouvrant ainsi la voie à une évaluation de la performance productive réelle des styles agricoles, et ce dans une perspective de durabilité forte. Le cadre 'Métabolisme de Ferme' pourrait dès lors contribuer à soutenir la repaysannisation des agroécosystèmes 'modernisés', nécessaire au bien-être des fermiers et à celui de l'ensemble de la société humaine.
Doctorat en Sciences agronomiques et ingénierie biologique
info:eu-repo/semantics/nonPublished

En 2008, la Banque mondiale a consacré son « rapport annuel sur le développement » à l'agriculture. Cela n’avait plus été le cas depuis 25 ans. Elle y montre que la croissance agricole est plus efficace que celle d’autres secteurs pour réduire la pauvreté. La productivité du travail agricole des actifs agricoles y est paradoxalement à peine citée : ses facteurs explicatifs de court terme comme ses variables structurantes sur le long terme ne sont pas analysés. Cette thèse entend contribuer à une meilleure compréhension des relations dynamiques qu’entretiennent la démographie et le développement non agricole avec le développement agricole (élévation de la productivité du travail agricole). Sous quelles conditions démo-économiques la transformation structurelle d'une économie (baisse du poids relatif du secteur agricole dans l’économie (actifs et valeur ajoutée)) peut-elle s'accompagner d'un développement agricole ? Alors qu’un secteur industriel ou tertiaire qui se développe est généralement attracteur d’actifs, une loi inverse existe-t-elle pour le secteur agricole ? Celui-ci doit-il nécessairement se vider de ses actifs pour se développer ? Y’a-t-il jamais eu, et peut-il y avoir développement agricole dans un contexte de croissance continue du nombre des actifs agricoles ?Notre (hypo)thèse principale est que la combinaison dynamique des facteurs «terre » et «actif agricole », dont la résultante est la « surface travaillée par actif agricole », est la véritable clé du développement agricole, davantage que la productivité de la terre. Nous analysons les déterminants des niveaux et taux de croissance de la productivité du travail agricole au cours de la période 1980 - 2007, à différentes échelles géographiques. Une attention particulière est mise sur la variable « nombre d’actifs agricoles », à l'aide de différents jeux de données (internationales, nationales, données d’enquêtes de terrain), à différentes échelles (monde, Mexique, 31 états fédérés et 2400 Municipes mexicains) et avec diverses méthodes (décomposition factorielle, cartes, classifications ascendantes hiérarchiques, inférence statistique, enquêtes de terrain auprès de ménages agricoles, non agricoles, d’institutions). Au niveau mondial, nous mettons en évidence une « course de vitesse » entre actifs agricoles et terre dans certaines régions du monde et proposons le concept de «transition agricole démographique » ainsi que sa typologie associée. Le Mexique est ensuite choisi pour ses agricultures présentant des niveaux de développement très contrastés, en synchronie comme en diachronie. Nous cherchons à expliquer les différences de trajectoires de développement agricole observées au Mexique. Nous analysons l’influence de variables caractérisant l’économie non agricole, la substitution du capital machine au travail, la libéralisation foncière, la géographie (physique et humaine). Dans les comparaisons internationales comme au Mexique, nous montrons que le taux de croissance de la surface par actif agricole a une influence marginale plus forte sur le taux de croissance de la productivité du travail agricole, que le taux de croissance de la productivité de la terre. Enfin, nous analysons les stratégies économiques de ménages et actifs agricoles, du Municipe de Teopisca dans la région de Los Altos de Chiapas, « piégés » dans un contexte de « transition agricole démographique bloquée » (décroissance tendancielle de la surface travaillée par actif) : diversification des sources de revenus (vers le non agricole) et tentatives d’élévation de la productivité de la terre sont les deux principales stratégies déployées sous contraintes de défaillances des marchés (travail, crédit) et d’accès à l’eau d’irrigation
In 2008, the World Bank has dedicated its "Annual Report on Development" to agriculture. This had not been the case for 25 years. It shows that agricultural growth is more effective than other sectors to reduce poverty. The agricultural labor productivity of the agricultural workforce is paradoxically barely mentioned: its explanatory factors for the short term as its structural variables in the long term are not analyzed. This thesis aims to contribute to a better understanding of the dynamic relationship between demography and non-agricultural development with agricultural development (increased productivity of agricultural labor). Under what demo-economic conditions can the structural transformation of an economy (i.e. the decline in the relative weight of the agricultural sector in the economy (workers and value added)) be accompanied by agricultural development? While an industrial or service sector that develops generally attracts workers, is there an opposite relationship in the agricultural sector? Does the agricultural sector have to lose its workers to develop? Has an agricultural sector ever developed in a context of continuous growth in the number of agricultural workers? Our main (hypo)thesis is that the dynamic combination of factors « land » and « agricultural worker », whose resultant is the « agricultural area worked per agricultural worker », is the real key to agricultural development, more than the productivity of the land.We analyze the determinants of the level and of the growth rate of the agricultural labor productivity over the 1980-2007 period, at different geographical levels. Special focus is put on the evolution of the « number of agricultural workers », using different sets of data (international, national, field surveys data), at different scales (world, Mexico, and 31 federal states 2400 Mexican municipalities) and with various methods (factor decomposition, maps, hierarchical ascending classifications, statistical inference, field surveys of farming households).Globally, we highlight a « race » between land and the number of agricultural workers in certain regions of the world and propose the concept of « demographic transition agriculture » and its associated typology.Mexico is then chosen for its agriculture showing very contrasting levels of development, for both synchronic and diachronic observation. We seek to understand the differences in agricultural development paths observed in Mexico by analyzing the influence of variables characterizing the non-farm economy, the substitution of machinery capital for labor, land liberalization, geography (physical and human).In international comparisons as within Mexico, we show that the growth rate of the area by agricultural worker has a marginally stronger influence on the growth rate of agricultural labor productivity, than the growth rate of land productivity.Finally, in the Municipality of Teopisca in the Los Altos region of Chiapas, we analyze the economic strategies of farm households « trapped » in a context of « blocked demographic agricultural transition » (downward trend of the agricultural area per worker): income diversification (toward the non-agricultural sector) and attempts to rise the land productivity are the two main strategies deployed under local severe constraints of market failures (labor, credit) and difficult access to irrigation water

Après 50 ans d’avancée des fronts pionniers, l’Amazonie orientale brésilienne aborde une phase de transition agraire. Face à la fermeture de la frontière limitant l’accès au foncier et à la fertilité forestière, les éleveurs bovins ont initié un mouvement d’intensification de l’usage des sols. Malgré les enjeux environnementaux que soulèvent de tels changements, cette dynamique d’intensification est encore mal comprise, notamment dans sa dimension spatiale et dans sa capacité à favoriser des paysages éco-efficients, c’est-à-dire des paysages au sein desquels les pratiques et leur localisation optimiseraient l’utilisation des ressources naturelles. Pour adresser ces questions, cette thèse propose de décrire et modéliser les interactions entre le système de décision des exploitants, les paysages et leurs ressources dans une diversité de fermes d’élevage.Dans un premier temps, un travail de terrain a été conduit dans deux territoires au sud et sud-est de l’Etat du Pará, Paragominas et Redenção. A partir d’enquêtes et d’une analyse des trajectoires d’exploitation et des paysages, nous avons caractérisé six types de stratégies d’intensification, qualifié leurs effets sur un certain nombre de ressources naturelles et étudié les perceptions des éleveurs sur ces ressources. Dans un deuxième temps, nous avons développé un modèle multi-agents afin de simuler sur 20 ans les effets des stratégies d’intensification sur les paysages et leurs ressources et évaluer la faisabilité d’adoption de ces stratégies dans différentes situations agraires. Le modèle a été utilisé pour explorer deux scénarios d’intensification : l’un semi-intensif basé uniquement sur une conduite améliorée des pâturages, et l’autre intensif basé sur l’intégration agriculture-élevage et l’irrigation.Les résultats montrent que le processus d’intensification conduit à une reconfiguration des usages des sols dans les paysages. Après une phase de colonisation où l’occupation des sols était essentiellement guidée par l’appropriation du foncier, les éleveurs ont tendance à intensifier les parcelles aux conditions biophysiques les plus favorables à la production fourragère et les plus proches et accessibles. Ces stratégies visent à mieux valoriser diverses ressources naturelles (topographie, fertilité et drainage des sols, eau de surface ou souterraine pour l’irrigation) et à optimiser les déplacements. Les éleveurs choisissent toutefois différentes pratiques et agencements spatiaux en fonction de la situation agraire de l’exploitation et du degré d’hétérogénéité de l’environnement biophysique. Par ailleurs, les sorties des simulations soulignent que le processus d’intensification permet de réduire les besoins en surface fourragère pour un même niveau de production animale. Les éleveurs sont ainsi capables d’augmenter la taille de leur troupeau tout en régénérant des forêts sur les zones sensibles et marginales. Cependant, faute de main d’œuvre disponible, le processus d’intensification reste limité dans l’espace. En termes d’évolution des paysages, les éleveurs positionnent différemment les usages des sols en fonction du type d’unités géomorphologiques, ce qui se traduit par une dynamique spatio-temporelle des ressources naturelles contrastée.Concilier élevage et forêt dans des paysages éco-efficients constitue un défi important pour la région amazonienne. A cet effet, cette thèse montre l’importance de raisonner les espaces voués à l’intensification et à la conservation en tenant compte des projets des exploitations et des effets de leurs pratiques et de leur agencement sur les ressources naturelles. Elle identifie plusieurs leviers et blocages pour accompagner cette transition. Enfin, elle suggère de futures perspectives de recherche portant sur la compréhension des décisions, la modélisation et l’élargissement de l’échelle d’analyse afin d’apprécier l’influence de facteurs externes sur les stratégies et intégrer un plus grand nombre d’interactions écologiques et sociales
After 50 years of agricultural expansion in Eastern Brazilian Amazon, environmental policy to reduce deforestation and a set of socio-economic drivers are putting constraints on extensive cattle ranching systems. In response, land use intensification has been gaining momentum as a way to improve livestock production in limited land areas and conserve forest. The process of land-use intensification is poorly understood in this region, particularly in its spatial dimension and in its contribution towards building eco-efficient landscapes, i.e. landscapes where practices and their spatial distribution optimize the use of natural resources. In this regard, the purpose of this research is to document and model the interactions between cattle ranchers’ decisions, landscapes and natural resources in a diversity of cattle farms.Firstly, we conducted a field research in two livestock-oriented regions of Pará state, Paragominas and Redenção. Drawing on interviews, landscape and farm trajectories analysis, we characterized six patterns of intensification, studied what perceptions cattle ranchers have on certain types of natural resources and described the effects of land-use management on such resources. Secondly, we developed an Agent-Based Model to simulate over 20 years the effects of intensive farming strategies on landscape and their natural resources, and assess the feasibility of adopting such management in various agrarian situations. We used the model to compare two scenarios of intensification: one semi-intensive solely based on improved pasture managenement and one intensive based on crop-livestock integration and irrigation.The results show that the process of intensification has led to a spatial rearrangement of land uses. Cattle ranchers prefer to intensify fields with the best biophysical conditions for forage production, as well as those closest to and most accessible from the farmstead. The intensification strategies aim at enhancing the use of multiple natural resources (topography, soil fertility, soil drainage, access to surface and groundwater for irrigation) and optimizing land-use configuration at farm scale. By contrast, during the colonization period, land-use organization was much less correlated to the spatial distribution of natural resources (except for soil fertility from forest ash and surface water), the main goal of farmers being land appropriation. Nevertheless, choice of farming practices and their spatial location differ among farms and according to the degree of heterogeneity of biophysical conditions. Moreover, simulation results show that the process of intensification can reduce the area necessary for animal production. Thus, cattle ranchers can increase herd size while sparing land for forest regeneration. However, low labor availability limits the spatial extent of land-use intensification at farm scale. In terms of landscape dynamics, cattle ranchers locate land-uses according to geomorphological units differently, which leads to various spatio-temporal dynamics of natural resources.Reconciling cattle ranching production and forest conservation in eco-efficient landscape remains an important challenge for Brazilian Amazon. The findings illustrate the importance of assessing the landscape areas most suitable for agricultural intensification and for conservation drawing on knowledge about cattle ranchers projects and the effects of their practices and spatial location on natural resources. Several opportunities and challenges are identified to tackle such challenge. New research perspectives related to decisions understanding, modeling and extension of the scale of analysis are proposed in order to take into account the influence of external factors on decisions and include more ecological and social interactions

This thesis examines the use of amnesty as a tool for ending civil wars. The thesis is innovative in its focus on amnesties during civil wars and their impact on conflict termination. I examine the conditions under which governments grant amnesties, and the various mechanisms through which amnesty acts as an incentive to stop fighting. I then study how international laws and norms against impunity for atrocious crimes influences the use of amnesty. The thesis combines in-depth quantitative and qualitative analysis by using statistical analysis of all conflict episodes from 1975-2011, as well as an intensive study of the peace negotiations in Colombia. The thesis has a number of innovative findings. I show that governments are more likely to use amnesty as an instrument of war, and they use it to pick off weaker groups with whom it is easier to settle. Secondly, I find that amnesties are effective both as a direct incentive, but also because they give the government military advantages. Thirdly, I demonstrate that governments balance amnesty against other transitional justice measures to avoid giving political concessions. The thesis makes various contributions to different literatures. To the transitional justice literature, I bring a comprehensive study of amnesty during civil war, and empirical findings on its determinants and effectiveness. To the civil war literature, I bring a theory of amnesty as an incentive in conflict termination, and a model of the impact of legal intervention as an external action. Overall, this thesis offers both a comprehensive study and theoretical insights into the use of amnesty during civil war.
Aquesta tesis examina la utilització d’amnisties com a eines per a finalitzar guerres civils. La tesis és innovadora pel seu enfoc específic sobre amnisties en guerres civils i el seu impacte en la finalització del conflicte. Examino les condicions sota les quals els goberns atorguen amnisties, així com els mecanismes pels quals les amnisties actúen com a incentiu per deixar la lluita. A continuació estudio com les lleis i normatives internacionals contra la impunitat per atrocitats contra la humanitat influeix sobre l’us de les amnisties. La tesis combina anàlisis en profunditat quantitatius i qualitatius, incloent una anàlisis estadística de tots els episodis de conflicte en el període 1975-2011, així com un estudi a fons de les negociacions de pau a Colòmbia. Aquesta tesis presenta resultats innovadors. Demostro que els governs són proclius a fer servir les amnisties com a armes de guerra, amb la intenció de dividir i separar els grups rivals més febles, amb els quals és més fàcil arribar a acords. En segon lloc, trobo que les amnisties efectivament funcionen no sols com a incentius directes, sinò també perquè dónen avantatges militars als governs. En tercer lloc, demostro que els govern utilitzen les amnisties com una mesura més per a evitar concessions polítiques més costoses. Aquesta tesis contribueix a dues branques de la bibliografia política. A l’àrea de justícia transicional, hi aporto un estudi exhaustiu de les amnisties en guerres civils, amb resultats empírics sobre els seus factors determinants i efectivitat. A la literatura en guerres civils, hi aporto una teoria sobre la utilització d’amnisties com a eines en la terminació de conflictes, i un model sobre l’impacte de les intervencions legals externes. En conjunt, aquesta tesis presenta un estudi a fons i noves idees teòriques sobre l’us d’amnisties en guerres civils.

Interpretation des resultats experimentaux par un modele de transmission optique en presence de champ magnetique externe, developpe dans le formalisme de la fonction reponse; mise en evidence de l'absence d'interaction electron-phonon to etrange et d'une interpretation satisfaisante sans recours a l'interaction electron-phonon lo, indiquant l'importance de l'effet ecran dans la theorie de l'effet polaron resonnant. Etude de l'interaction spin-orbite induite par le champ electrique existant a l'interface; calcul des regles de selection des transitions entre niveaux de landau dans les differentes configurations magnetooptiques, differences par rapport aux semiconducteurs massifs

In dieser Arbeit wird das Wachstum von dünnen quasi-kristallinen Ge-Sb-Te (GST) Schichten mittels Molekularstrahlepitaxie demonstriert, die zu einer geordneten Konfiguration von intrinsischen Kristallgitterfehlstellen führen. Es wird gezeigt, wie es eine Strukturanalyse basierend auf Röntgenstrahlbeugungssimulationen, Dichtefunktionaltheorie und Transmissionselektronenmikroskopie ermöglicht, eine eindeutige Beurteilung der Kristallgitterlückenanordnung in den GST-Proben vorzunehmen. Das Verständnis für die Ordnungsprozesse der Gitterfehlstellen erlaubt eine gezielte Einstellung des Ordnungsgrades selbst, der mit der Zusammensetzung und der Kristallphase des Materials in Zusammenhang steht. Auf dieser Basis wurde ein Phasendiagramm mit verschiedenen Wachstumsfenstern für GST erstellt. Des Weiteren wird gezeigt, dass man eine hohe Ordnung der Gitterfehlstellen in GST auch durch Ausheizprozesse und anhand von Femtosekunden-gepulster Laserkristallisation von amorphem Material erhält, das zuvor auf einem als Kristallisationsgrundlage dienenden Substrat abgeschiedenen wurde. Diese Erkenntnis ist bemerkenswert, da sie zeigt, dass sich kristalline GST Schichten mit geordneten Kristallgitterlücken durch verschiedene Herstellungsprozesse realisieren lassen. Darüber hinaus wurde das Wachstum von GeTe/Sb2Te3 Übergittern durchgeführt, deren Struktur die von GST mit geordneten Gitterfehlstellen widerspiegelt. Die Möglichkeit den Grad der Gitterfehlstellenordung in GST gezielt zu manipulieren wurde mit einer Studie der Transporteigenschaften kombiniert. Die Anwendung von großflächigen Charakterisierungsmethoden wie XRD, Raman und IR-Spektroskopie, erlaubte die Bestimmung der Phase und des Fehlstellenordnungsgrades von GST und zeigte eindeutig, dass die Fehlstellenordnung für den Metall-Isolator-Übergang (MIT) verantwortlich ist. Insbesondere wird durch das Vergleichen von XRD-Messungen mit elektrischen Messungen gezeigt, dass der Übergang von isolierend zu leitend erfolgt, sobald eine Ordnung der Kristallgitterlücken einsetzt. Dieses Phänomen tritt in der kubischen Kristallphase auf, wenn Gitterfehlstellen in GST von einem ungeordneten in einen geordneten Zustand übergehen. Im zweiten Teil des Kapitels wird eine Kombination aus FIR- und Raman-Spektroskopie zur Untersuchung der Vibrationsmoden und des Ladungsträgerverhaltens in der amorphen und der kristallinen Phase angewendet, um Aktivierungsenergien für die Elektronenleitung, sowohl für die kubische, als auch für die trigonale Kristallphase von GST zu bestimmen. Hier ist es wichtig zu erwähnen, dass, in Übereinstimmung mit Ergebnissen aus anderen Untersuchungen, das Auftauchen eines MIT beim Übergang zwischen der ungeordneten und der geordneten kubischen Phase beobachtet wurde. Schlussendlich wurden verschiedene sogenannte Pump/Probe Technik, bei der man das Material mit dem Laser anregt und die Röntgenstrahlung oder Terahertz (THz)-spektroskopie als Sonde nutzt, angewandt. Dies dient um ultra-schnelle Dynamiken zu erfassen, die zum Verständnis der Umschaltmechanismen nötig sind. Die Empfindlichkeit der THz-Messungen hinsichtlich der Leitfähigkeit, sowohl in GST, als auch in GeTe/Sb2Te3 Übergittern zeigte, dass die nicht-thermische Natur der Übergitterumschaltprozesse mit Grenzflächeneffekten zusammenhängt und . Der Ablauf wird mit beeindruckender geringer Laser-Fluenz erreicht. Dieses Ergebnis stimmt mit Berichten aus der Literatur überein, in denen ein Kristall-zu Kristallwechsel von auf Übergittern basierenden Speicherzellen für effizienter gehalten wird als GST Schmelzen, was zu einen ultra-schwachen Energieverbrauch führt.
The growth by molecular beam epitaxy of Ge-Sb-Te (GST) alloys resulting in quasi-single-crystalline films with ordered configuration of intrinsic vacancies is demonstrated. It is shown how a structural characterization based on transmission electron microscopy, X-ray diffraction and density functional theory, allowed to unequivocally assess the vacancy ordering in GST samples, which was so far only predicted. The understanding of the ordering process enabled the realization of a fine tuning of the ordering degree itself, which is linked to composition and crystalline phase. A phase diagram with the different growth windows for GST is obtained. High degree of vacancy ordering in GST is also obtained through annealing and via femtosecond-pulsed laser crystallization of amorphous material deposited on a crystalline substrate, which acts as a template for the crystallization. This finding is remarkable as it demonstrates that it is possible to create a crystalline GST with ordered vacancies by using different fabrication procedures. Growth and structural characterization of GeTe/Sb2Te3 superlattices is also obtained. Their structure resembles that of ordered GST, with exception of the Sb and Ge layers stacking sequence. The possibility to tune the degree of vacancy ordering in GST has been combined with a study of its transport properties. Employing global characterization methods such as XRD, Raman and Far-Infrared spectroscopy, the phase and ordering degree of the GST was assessed, and unequivocally demonstrated that vacancy ordering in GST drives the metal-insulator transition (MIT). In particular, first it is shown that by comparing electrical measurements to XRD, the transition from insulating to metallic behavior is obtained as soon as vacancies start to order. This phenomenon occurs within the cubic phase, when GST evolves from disordered to ordered. In the second part of the chapter, a combination of Far-Infrared and Raman spectroscopy is employed to investigate vibrational modes and the carrier behavior in amorphous and crystalline phases, enabling to extract activation energies for the electron conduction for both cubic and trigonal GST phases. Most important, a MIT is clearly identified to occur at the onset of the transition between the disordered and the ordered cubic phase, consistently with the electrical study. Finally, pump/probe schemes based on optical-pump/X-ray absorption and Terahertz (THz) spectroscopy-probes have been employed to access ultrafast dynamics necessary for the understanding of switching mechanisms. The sensitivity of THz-probe to conductivity in both GST and GeTe/Sb2Te3 superlattices showed that the non-thermal nature of switching in superlattices is related to interface effects, and can be triggered by employing up to one order less laser fluences if compared to GST. Such result agrees with literature, in which a crystal to crystal switching of superlattice based memory cells is expected to be more efficient than GST melting, therefore enabling ultra-low energy consumption.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1998.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 176-230).