L’aptitude des symbioses rhizobium-légumineuses à fixer l’azote atmosphérique, peut offrir d’importants services aux agro-écosystèmes. Cependant, associés à des contraintes biotiques (i) absence et/ou (ii) inefficacité symbiotique des rhizobiums du sol, des facteurs abiotiques (i) excès d’intrants azotés et/ou (ii) carences en phosphore (P) peuvent limiter la fixation symbiotique d’azote (FSN). Le Myo-inositol hexakisphosphate (phytate), principale composante de P organique (Po) du sol, représente une potentielle source de P disponible du sol, bio-disponible pour la plante, en lien à des activités phytases microbiennes, minéralisatrices du phytate. Afin de rechercher des rhizobiums, symbiontes de Vicia faba, efficaces dans l’utilisation du P (EUP) pour la FSN, nous avons réalisé un diagnostic nodulaire multilocalisé, en agro-écosystèmes sud de France. Le niveau d’efficacité d’utilisation de la symbiose rhizobienne (EUSR), en intra- et inter-placettes agricoles et en conditions hydroaéroponiques en serre, a été déterminé en corrélation des biomasses aériennes et nodulaires de plants de V. faba, à floraison. Parmi 59 isolats de V. faba, 26 sont aptes à minéraliser le phytate (Phy +), en milieu solide et six d'entre eux confirment une activité phytase, en culture liquide. L’intérêt d’une sélection de rhizobiums locaux aptes à une EUP pour FSN, nous a conduits à une avancée dans la sélection de marqueurs moléculaires phytases pour le criblage d’isolats rhizobiens Phy+. Mots ClésRhizobium, diversité, phytase, féverole, Vicia faba, nodulation, France-sud, agro-écosystème. / The ability of rhizobium-legume symbiosis to fix atmospheric nitrogen can provide important services to agro-ecosystems. However, associated with biotic constraints (i) missing and/or (ii) phosphorus (P) deficiency, can limit symbiotic nitrogen fixation (SNF). Myo-inositol hexakisphosphate (phytate), the main soil organic P (Po) component, represents a potential source of soil P available for plant P bio-availability, connected with microbial phytate-mineralizing activities. In order to look for rhizobium-Vicia faba, in P use efficiency (PUE) for SNF ability, nodular diagnosis was performed from a multi-location survey in an agro-ecosystem in South France. The efficiency in use of rhizobial symbiosis (EURS) was deduced from V. faba nodule and shoot dry weight values at flowering state, and compared in intra- and inter agricultural fields and in greenhouse hydroaeroponic conditions. Among 59 V. faba isolates, 26 were able to mineralize phytate (Phy+) in solid medium and six of them confirmed phytase activity in liquid culture. Looking for local rhizobiums with PUE for SNF ability, led us to a forward step in molecular marker selection for Phy+ rhizobium isolate screening. KeywordsRhizobium, diversity, phytase, faba-bean, Vicia faba, nodulation, South-France, agro-ecosystem.

Texte remanié de : Thèse doctorat : Droit : Nice : 2003. / Titre provenant de la page de titre du document numérisé. Bibliogr. Index.

Made available in DSpace on 2014-06-11T19:32:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-01-20Bitstream added on 2014-06-13T21:05:14Z : No. of bitstreams: 1 costa_sgvao_dr_rcla.pdf: 982367 bytes, checksum: 52f037ca5cb5fbb958ef2b1a4f53f13c (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho visou estudar a produção de biossurfactante e PHAs de Pseudomonas sp. em substratos alternativos oriundos do processamento de alimentos bem como determinar as propriedades, composição química e aplicações dos compostos obtidos. Foram isoladas 21 cepas bacterianas, sendo que duas cepas demonstraram capacidade de crescer no meio de cultivo proposto e produzir ramnolipídios e PHAs. Estas cepas foram identificadas como Pseudomonas aeruginosa e receberam as seguintes terminações: P. aeruginosa L2-1 e P. aeruginosa B1-3. Com relação a caracterização de ramnolipídios e PHAs, suas composições variaram de acordo com a fonte de carbono e a linhagem utilizada na fermentação. O meio manipueira adicionado com óleo de fritura (MOF) apresentou os melhores resultados, alcançando uma produção de PHA de 39% do peso seco de células e uma produção de ramnolipídios de 660 mg/L. A manipueira se mostrou um substrato alternativo com potencial para a produção de ramnolipídios e PHAs, principalmente quando adicionada com óleo de fritura, além de ser uma solução do ponto de vista ambiental e também agregar valor a estes resíduos. A manipueira adicionada de óleo de fritura pode reduzir os custos de produção permitindo a obtenção concomitante de ramnolipídios e PHAs. O ramnolipídio produzido pela linhagem P. aeruginosa L2-1 no substrato manipueira adicionado de óleo de fritura foi recuperado e apresentou excelentes propriedades tenso-ativas, (baixos valores de concentração micelar crítica e de tensão superficial e interfacial, excelente atividade emulficante e estabilidade da emulsão), além de potencial para uso na remediação de ambientes contaminados, removendo até 89% de petróleo na areia após processo de lavagem, conferindo características semelhantes e algumas vezes melhores que o ramnolipídio comercial JBR599 (Jeneil Biosurfactant Co.) / This work evaluated the rhamnolipid and PHAs production by Pseudomonas sp. in alternative low-cost substrates from food processing, determining the properties, applications and chemistry composition of compounds obtained. Were isolated 21 strains, being that 2 isolates were able to growth and produce rhamnolipids and PHAs in the substrates. These bacteria were identified as Pseudomonas aeruginosa. The polymers and surfactants produced were characterized by gas-chromatography mass spectrophotometry (GC-MS) and by high performance liquid chromatography-MS (HPLC-MS), and their composition was found to vary with the carbon source and the strain used in the fermentation. The best overall production of rhamnolipids and PHAs was obtained with cassava wastewater added with waste cooking oil (CWO) as the carbon source, with PHA production corresponding to 39% of the cell dry weight and rhamnolipids production being 660 mg/L. It would appear that CWO has the highest potential as alternative substrate, and its use may contribute to a reduction in the overall environmental impact generated by discarding such residues. The rhamnolipid produced by P. aeruginosa L2-1 in CWO showed excellent tension-active properties (low values of critic micellar concentration and superficial and interfacial tensions) and potential to use in remediation of contaminated environmental, removing 89% of petroleum after washing process in sand, with characteristics similar or better than commercial rhamnolipid JBR599 (Jeneil Biosurfactant Co.)

Made available in DSpace on 2014-06-11T19:24:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-28Bitstream added on 2014-06-13T19:31:34Z : No. of bitstreams: 1 luchesi_d_me_botfca.pdf: 1478619 bytes, checksum: fe1ce4874b37fec4f5c704c741316db9 (MD5) / A agroinformática, termo criado para referenciar a informática aplicada à agricultura, vem ganhando espaço e se organizando nesse novo processo de modernização da agricultura na tentativa de contribuir tanto no aumento da produtividade quanto da qualidade. A informática no ambiente agrícola se encontra presente em diversas propriedades rurais, tanto na área administrativa como na área de gestão proporcionando coordenação nas atividades, uma maior agilidade no fluxo de informações e redução de erros nas operações internas. Em função da crescente presença da informática na agricultura e da utilização de dispositivos de aquisição automática de dados no campo, a presente pesquisa apresenta o desenvolvimento de um programa computacional, Ener Sys, desenvolvido com o objetivo de transformar dados meteorológicos no setor de agroenergia. A partir de um dispositivo automático de aquisição de dados (Campbell Scientific modelo CR23X), desenvolveu-se um sistema computacional para melhor classificar e visualizar os dados de uma forma rápida e simples para o profissional envolvido com as alterações meteorológicas da área sob estudo. O sistema proposto utilizou as seguintes tecnologias computacionais: a linguagem de programação Personal Home Page Hypertext Preprocessor e o banco de dados Firebird. Os resultados obtidos ao término da pesquisa apontam que a abordagem deste trabalho facilitou o acesso a informações armazenadas em grandes massas de dados. O 2 programa computacional desenvolvido, reuniu em uma base unificada, os dados coletados através de um sistema eletrônico de aquisição de dados e facilitou o processamento dos dados proporcionando ganhos na visualização das informações como temperatura (oC), umidade (%), velocidade do vento (m.s-2), direção do vento (graus), chuva (mm) e irradiância (horizontal e vertical). / The agro-informatics, term used as reference to the informatics applied to the agriculture, it has been gaining space and getting organized on this new process of agriculture modernization to try to contribute both to the productivity increase and quality. The informatics at the agricultural environment can be found in many rural properties both in the administrative area and management area, providing coordination in the activities, a better agility with the information flow and error cutback in the internal operations. Due to the growing presence of the informatics in the agriculture and the use of automatic data acquisition devices in the field, this study presents a computer program, Ener Sys, developed with the purpose of transform meteorological data in the agro sector. From an automatic device of data acquisition (Campbell Scientific model CR23X) it was developed a computer system to better classify and visualize the data on a fast and simple way to the professional involved with the study of meteorological variations in this area. The suggested system used the following computer technologies: the Personal Home Page Hypertext Preprocessor programming language and the database Firebird. The results obtained at the end of the research show that the approach of this study made easier the access to the information stored in large amounts of data. The computer program developed, put together in one base, the data collected through an electronic system of data acquisition and made easy the data processing providing a gain on the visualization of information such as temperature (oC), humidity (%), wind speed (m.s-2), wind direction (degrees), rain (mm) and irradiance (horizontal and vertical).

Orientador: Saulo Philipe Sebastião Guerra / Banca: Odivaldo José Seraphim / Banca: Carlos Roberto Pereira Padovani / Resumo: A agroinformática, termo criado para referenciar a informática aplicada à agricultura, vem ganhando espaço e se organizando nesse novo processo de modernização da agricultura na tentativa de contribuir tanto no aumento da produtividade quanto da qualidade. A informática no ambiente agrícola se encontra presente em diversas propriedades rurais, tanto na área administrativa como na área de gestão proporcionando coordenação nas atividades, uma maior agilidade no fluxo de informações e redução de erros nas operações internas. Em função da crescente presença da informática na agricultura e da utilização de dispositivos de aquisição automática de dados no campo, a presente pesquisa apresenta o desenvolvimento de um programa computacional, Ener Sys, desenvolvido com o objetivo de transformar dados meteorológicos no setor de agroenergia. A partir de um dispositivo automático de aquisição de dados (Campbell Scientific modelo CR23X), desenvolveu-se um sistema computacional para melhor classificar e visualizar os dados de uma forma rápida e simples para o profissional envolvido com as alterações meteorológicas da área sob estudo. O sistema proposto utilizou as seguintes tecnologias computacionais: a linguagem de programação Personal Home Page Hypertext Preprocessor e o banco de dados Firebird. Os resultados obtidos ao término da pesquisa apontam que a abordagem deste trabalho facilitou o acesso a informações armazenadas em grandes massas de dados. O 2 programa computacional desenvolvido, reuniu em uma base unificada, os dados coletados através de um sistema eletrônico de aquisição de dados e facilitou o processamento dos dados proporcionando ganhos na visualização das informações como temperatura (oC), umidade (%), velocidade do vento (m.s-2), direção do vento (graus), chuva (mm) e irradiância (horizontal e vertical). / Abstract: The agro-informatics, term used as reference to the informatics applied to the agriculture, it has been gaining space and getting organized on this new process of agriculture modernization to try to contribute both to the productivity increase and quality. The informatics at the agricultural environment can be found in many rural properties both in the administrative area and management area, providing coordination in the activities, a better agility with the information flow and error cutback in the internal operations. Due to the growing presence of the informatics in the agriculture and the use of automatic data acquisition devices in the field, this study presents a computer program, Ener Sys, developed with the purpose of transform meteorological data in the agro sector. From an automatic device of data acquisition (Campbell Scientific model CR23X) it was developed a computer system to better classify and visualize the data on a fast and simple way to the professional involved with the study of meteorological variations in this area. The suggested system used the following computer technologies: the Personal Home Page Hypertext Preprocessor programming language and the database Firebird. The results obtained at the end of the research show that the approach of this study made easier the access to the information stored in large amounts of data. The computer program developed, put together in one base, the data collected through an electronic system of data acquisition and made easy the data processing providing a gain on the visualization of information such as temperature (oC), humidity (%), wind speed (m.s-2), wind direction (degrees), rain (mm) and irradiance (horizontal and vertical). / Mestre

On a assisté, au cours des dernières décennies, à une intensification des impacts environnementaux générés par le modèle de production agricole conventionnel (dégradation des sols, contamination des ressources hydriques, réduction de la biodiversité). Celle-ci, associée à une concentration des terres et des revenus - entraînant à leur tour une exclusion des travailleurs ruraux et de la violence dans la campagne - a été propice à l’émergence de propositions pour un développement rural qui inclut l’adoption de pratiques agricoles durables. Dans une approche agro-écologique, l’implantation de nouvelles pratiques agricoles est insérée dans un processus graduel et multilinéaire de changement, dénommé transition agro-écologique, qui vise le passage d’un modèle agricole basé sur l’utilisation d’intrants chimiques à des formes de production plus durables. C’est dans la communauté de São Francisco da Costa da Terra Nova, que la recherche s’est effectuée. A partir de modèles de production existants, cette transition agro-écologique a déclenché une série d’innovations techniques et organisationnelles qui ont conduit à la fois à des changements dans le processus productif, dans les formes d’organisation du travail, et dans l’inclusion d’une nouvelle activité de travail : la commercialisation des produits agro-écologiques. En plus de recadrer les pratiques productives et les formes d’organisation du travail, la transition agro-écologique conduit à des nouvelles perspectives de performance pour les agriculteurs, par exemple constitution d’un nouveau marché, des foires agro-écologiques. Ainsi, nous pensons que les changements résultant du processus de transition agro-écologique peuvent contribuer au développement, à l’amélioration et à la diffusion de procédés innovants qui visent à améliorer les conditions de travail des agriculteurs familiaux, en vue de valoriser et d’élargir les perspectives de travail dans le contexte d’une agriculture durable. / During the last decades, there has been an intensification of environmental impacts generated by the conventional agricultural production model (degradation, contamination of water resources, reduction of biodiversity). Coupled with a concentration of land and income -producing exclusion of rural workers and violence in campagne- this intensification has been lead to the emergence of proposals for rural development which includes the adoption of sustainable agricultural practices. In this agroecological approach, the implementation of new agricultural practices is inserted into a gradual process and multilinear change, called agro-ecological transition, which is the transition from an agricultural model based on the use of chemical inputs to forms more sustainable production. The research was conducted in the community of São Francisco da Costa da Terra Nova. From existing production models, this agro-ecological transition has triggered a series of technical and organizational innovations, that have led both to changes in the production process, in the forms of work organization, and in the inclusion of a new work activity: the marketing of agro-ecological products. In addition to crop production practices and forms of work organization, agro-ecological transition leads to new performance prospects for farmers, for example formation of a new market, the agro-ecological fairs. The research shows that changes resulting from agro-ecological transition process may contribute to the development, enhancement and dissemination of innovative processes that improve the working conditions of farmers, and that adds value and expand the work opportunities in the context of sustainable agriculture. / Nas últimas décadas, a intensificação dos impactos ambientais gerados pelo modelo de produção agrícola convencional (degradação dos solos, contaminação dos recursos hídricos, redução da biodiversidade); associado à concentração fundiária e de renda e, consequentemente, à exclusão de trabalhadores rurais e à violência no campo; propiciou o surgimento de propostas de desenvolvimento rural que incluíam a adoção de práticas agrícolas sustentáveis, a fim de fomentar alternativas viáveis à produção de alimentos e ao fortalecimento da agricultura familiar. Na abordagem agroecológica, a implementação de novas práticas agrícolas está inserida em um processo gradual e multilinear de mudança, denominado transição agroecológica, que visa a passagem de um modelo agrícola baseado no uso de insumos químicos à formas de produção mais sustentáveis. Na comunidade São Francisco da Costa da Terra Nova, lócus da pesquisa, observou-se, a partir dos modelos de produção existentes, que essa transição desencadeou uma série de inovações técnicas e organizacionais que resultaram em mudanças no processo produtivo, nas formas de organização do trabalho e na inclusão de uma nova atividade: a comercialização dos produtos agroecológicos. Além de ressignificar as práticas produtivas e as formas de organização do trabalho, a transição agroecológica conduziu à possibilidades inéditas de atuação dos agricultores, através dos novos espaços de comercialização, as feiras agroecológicas. Acredita-se que as mudanças decorrentes do processo de transição agroecológica possam contribuir para o desenvolvimento, aprimoramento e difusão de processos inovadores que visam a melhoria das condições de trabalho dos agricultores familiares, com vistas a valorizar e ampliar as perspectivas do trabalho no contexto da agricultura sustentável.

Agro-biodiversity in the desert oases of Baja California, Mexico is a product of isolation and integration through time and across the various spaces of the peninsula. The oases hold heirloom perennial crop species first introduced by Jesuit missionaries (1697-1768) and represent geographies of historical dissemination. I selected fifteen Jesuit mission oases and surveyed the oasis gardens for species richness and abundance. To understand the cultural, political and economic forces that create these patterns of persistence within the oases, I conducted interviews on farming system practices, geographical remoteness, market integration, land tenure, tourism, protected area status and cultural practices. In all, I surveyed 241 gardens and documented eighty-nine total perennial crop species. Historical records in 1774 describe twenty-one perennial crop species in cultivation after the Jesuit expulsion. I calculated species-area relationships and rank-abundance for total perennial and mission crop species in each oasis and inventory comparisons for those oases with quantitative historical data to analyze retention of historic mission species. A high persistence of mission species indicates that oases serve as agro-biodiversity refugia, or protected source areas for agricultural species. These mission-oases act as a network of interconnected sites that are also isolated from one another and the Mexican mainland by the rugged environment, limited transportation infrastructure, and by sea. Within the network, these fifteen oases span a range of small and hours distant from the nearest resource center, to fully urbanized with international ports and airports. I describe how phases and processes of isolation and connectivity shape and transform the agro-biodiversity profiles in this archipelago of peninsula oases.

The Maasailand of Kenya and Tanzania supports one of the richest wildlife populations remaining on Earth. However, over the last century, Maasailand has experienced land transformation notably through conversion of former rangelands to croplands. With the anticipated human population increase in East Africa, more impacts should be envisaged on these rangelands. This thesis investigates the root causes and underlying drivers of land-use change in the Maasai-Steppe ecosystems, stemming from historical, socio-cultural, political as well as the biophysical conditions. To analyse the different drivers of change, an integrated methodological approach was employed. This included a collation of historical data and information derived from both gray and published literature, analysis of remote sensing and Geographical Information Systems (GIS) data, field surveys, workshops, observations, as well as personal communications. Observed land-use change from savannah rangelands to expansive croplands are mainly linked to government policies, land tenure, human population growth (which is also likely to be the largest future driver) and climatic conditions. Consequently these changes have impacted the agro-pastoralist community, whose main incomes for their livelihoods depend on pastoralism. Subsequent loss of formerly communal grazing lands to establish protected areas; large-scale farming and/or private ranches have aggravated the problems of sedentarization due to villagization and privatization policies of the formally mobile agro-pastoral communities. Land-use change also had negative impacts on migratory wildlife species, particularly those utilizing both protected areas and dispersal ranges in communal and/or private lands. The impacts ranged from loss of their migratory routes and corridors to massive declines of populations due to the loss of access to grazing resources. The study recommends government’s interventions for keeping the land open for access to grazing resources as well as opening up wildlife corridors, where it is deemed necessary for national interests.

Cette recherche de géographie rurale est consacrée à l'étude des paysages et des pratiques des agriculteurs en prenant pour champ géographique d'étude le bassin versant du Madon. Comprendre les élaborations actuelles des paysages en relation avec des stratégies agricoles plurifonctionnelles conciliables avec les nouvelles attentes qualitatives des territoires sont désormais au coeur de problématiques multiples et variées. Après avoir établi une cartographie précise, permettant de formuler l'identité paysagère des communes en caractérisant des paysages agricoles d'égale apparence, les règles liant les unités de paysages aux activités des agriculteurs sont fournies. Les unités paysagères décrites permettent de dresser des constats et des interrogations à propos des impacts des pratiques agricoles sur les paysages et la qualité de l'eau. Désormais, le défi de l'agriculture est de concilier la taille critique de la concurrence avec une ambition durable de l'agriculture. / This research about rural geography is to describe lanscape units of the watershed of the Madon located on the left bank of the Moselle river. To provide an understanding of the link between these lanscape units and the country population (mainly agricultors) activities. The first part of this research will present the tools and the methods used. It is mainly based on the description of the landscape of the watershed of the madon. From this description is drawn a lanscape map, allowing to differentiate precise lanscape typologies and identities for each village based on their landscape features. The second part of this research focus on explaining the historical and technical reasons which led to the differentiation of landscapes, showing the rules linking human activity and landscape and demonstrating the importance of agricultural activities in shaping landscapes. The third part will focus on the impact of agricultural practices on landscape and on water quality. Finally, I explained the future challenges of agriculture, teared between conflicting priorities

Increases in agricultural intensification over the past century have resulted in significant alterations to the rural landscape across the Midwest. Pollinators are essential to sustain natural and managed ecosystems. They are vital for food production and their declines have been linked, in part, to a rise in intensive agricultural practices. There is a recognized need among numerous stakeholders to build sustainability into the management of agroecosystems to protect both the biotic and abiotic resources of these systems. The use of cover crops is gaining interest among agricultural producers for benefits such as improving water quality and soil health. Cover cropping systems have the potential to provide floral resources to pollinators and suppress problematic driver weeds. The overall objective of this study was to quantify the effects of cover crops on plant and pollinator biodiversity within agricultural systems. This study aimed to characterize the pollinator diversity indicative of the patchwork mosaic forest-agroecosystem of Crab Orchard National Wildlife Refuge; evaluate the roles cover crop treatments play in supporting pollinator diversity and weed suppression benefits in a conventionally managed system; and provide the basis of recommendations for sustainable weed suppression tactics and for enhancing the quality of pollinator habitat within agricultural systems.