991 resultados para Alentejo (Portugal)


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Dissertação mest., Gestão Sustentável de Espaços Rurais, Universidade do Algarve, 2009

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Tese de doutoramento, Turismo, Faculdade de Economia, Universidade do Algarve, 2015

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The utilization and management of arbuscular mycorrhiza (AM) symbiosis may improve production and sustainability of the cropping system. For this purpose, native AM fungi (AMF) were sought and tested for their efficiency to increase plant growth by enhanced P uptake and by alleviation of drought stress. Pot experiments with safflower (Carthamus tinctorius) and pea (Pisum sativum) in five soils (mostly sandy loamy Luvisols) and field experiments with peas were carried out during three years at four different sites. Host plants were grown in heated soils inoculated with AMF or the respective heat sterilized inoculum. In the case of peas, mutants resistant to AMF colonization were used as non-mycorrhizal controls. The mycorrhizal impact on yields and its components, transpiration, and P and N uptake was studied in several experiments, partly under varying P and N levels and water supply. Screening of native AMF by most probable number bioassays was not very meaningful. Soil monoliths were placed in the open to simulate field conditions. Inoculation with a native AMF mix improved grain yield, shoot and leaf growth variables as compared to control. Exposed to drought, higher soil water depletion of mycorrhizal plants resulted in a haying-off effect. The growth response to this inoculum could not be significantly reproduced in a subsequent open air pot experiment at two levels of irrigation and P fertilization, however, safflower grew better at higher P and water supply by multiples. The water use efficiency concerning biomass was improved by the AMF inoculum in the two experiments. Transpiration rates were not significantly affected by AM but as a tendency were higher in non-mycorrhizal safflower. A fundamental methodological problem in mycorrhiza field research is providing an appropriate (negative) control for the experimental factor arbuscular mycorrhiza. Soil sterilization or fungicide treatment have undesirable side effects in field and greenhouse settings. Furthermore, artificial rooting, temperature and light conditions in pot experiments may interfere with the interpretation of mycorrhiza effects. Therefore, the myc- pea mutant P2 was tested as a non-mycorrhizal control in a bioassay to evaluate AMF under field conditions in comparison to the symbiotic isogenetic wild type of var. FRISSON as a new integrative approach. However, mutant P2 is also of nod- phenotype and therefore unable to fix N2. A 3-factorial experiment was carried out in a climate chamber at high NPK fertilization to examine the two isolines under non-symbiotic and symbiotic conditions. P2 achieved the same (or higher) biomass as wild type both under good and poor water supply. However, inoculation with the AMF Glomus manihot did not improve plant growth. Differences of grain and straw yields in field trials were large (up to 80 per cent) between those isogenetic pea lines mainly due to higher P uptake under P and water limited conditions. The lacking N2 fixation in mutants was compensated for by high mineral N supply as indicated by the high N status of the pea mutant plants. This finding was corroborated by the results of a major field experiment at three sites with two levels of N fertilization. The higher N rate did not affect grain or straw yields of the non-fixing mutants. Very efficient AMF were detected in a Ferric Luvisol on pasture land as revealed by yield levels of the evaluation crop and by functional vital staining of highly colonized roots. Generally, levels of grain yield were low, at between 40 and 980 kg ha-1. An additional pot trial was carried out to elucidate the strong mycorrhizal effect in the Ferric Luvisol. A triplication of the plant equivalent field P fertilization was necessary to compensate for the mycorrhizal benefit which was with five times higher grain yield very similar to that found in the field experiment. However, the yield differences between the two isolines were not always plausible as the evaluation variable because they were also found in (small) field test trials with apparently sufficient P and N supply and in a soil of almost no AMF potential. This similarly occurred for pea lines of var. SPARKLE and its non-fixing mycorrhizal (E135) and non-symbiotic (R25) isomutants, which were tested in order to exclude experimentally undesirable benefits by N2 fixation. In contrast to var. FRISSON, SPARKLE was not a suitable variety for Mediterranean field conditions. This raises suspicion putative genetic defects other than symbiotic ones may be effective under field conditions, which would conflict with the concept of an appropriate control. It was concluded that AMF resistant plants may help to overcome fundamental problems of present research on arbuscular mycorrhiza, but may create new ones.

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No tillage, minimum tillage and conventional tillage practices are commonly used in maize crops in Alentejo, affecting soil physic conditions and determining seeders performance. Seeders distribution can be evaluated in the longitudinal and vertical planes. Vertical plane is specified by seeding depth (Karayel et al., 2008). If, in one hand seeding depth uniformity is a goal for all crop establishment , in the other hand, seeders furrow openers depth control is never constant depending on soil conditions. Seed depth uniformity affects crop emergence, Liu et al. (2004) showed an higher correlation between crop productivity and emergence uniformity than with longitudinal plants distribution. Neto et al. (2007) evaluating seed depth placement by measuring maize mesocotyl length under no tillage conditions in 38 farms concluded that 20% of coefficient of variation suggests the need of improvement seeders depth control mechanisms. The objective of this study was to evaluate casual relationships and create spatial variability maps between soil mechanic resistance and vertical distribution under three different soil practices to improve seed depth uniformity.

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Among the various factors that contribute towards producing a successful maize crop, seed depth placement is a key determinant, especially in a no-tillage system. The main objective of this work was to evaluate the spatial variability of seed depth placement and crop establishment in a maize crop under no-tillage conditions, using precision farming technologies. The obtained results indicate that seed depth placement was significantly affected by soil moisture content, while a very high coefficient of variation of 39% was found for seed depth. Seeding depth had a significant impact on mean emergence time and percentage of emerged plants. Shallow average depth values and the high coefficient of variation suggest a need for improvement in controlling the seeders sowing depth.

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Entre os vários fatores que contribuem para a produção de uma cultura de milho, a distribuição vertical dos semeadores avaliada através da localização da semente em profundidade é um fator-chave, especialmente na técnica de sementeira direta. Simultaneamente, dada a complexidade dos ecossistemas naturais e agrícolas em sistemas de agricultura de conservação, a gestão diferenciada e localizada das parcelas assume um importante papel na análise e gestão da variabilidade das propriedades do solo e estabelecimento das culturas, nomeadamente utilizando informação geo referenciada e tecnologia expedita. Assim, o principal objetivo desta Tese foi a avaliação em culturas de milho da variabilidade espacial da localização de semente em profundidade e estabelecimento da cultura em sementeira direta usando sistemas convencionais de controlo de profundidade, tendo-se comparado com diferentes sistemas de mobilização e recorrendo a tecnologias de agricultura de precisão. Os ensaios decorreram na região Mediterrânea do Alentejo, em propriedades agrícolas no decorrer das campanhas de 2010, 2011, 2012 e 2015 em 6 diferentes campos experimentais. O trabalho experimental consistiu em ensaios com avaliações in loco do solo e cultura, consumo de combustível das operações e deteção remota. Os resultados obtidos indicam que não só o sistema de mobilização afetou a localização da semente em profundidade, como em sementeira direta a profundidade de sementeira foi afetada pelo teor de humidade do solo, resistência do solo à profundidade e velocidade da operação de sementeira. Adicionalmente observaram-se condições heterogéneas de emergência e estabelecimento da cultura afetadas por condições físicas de compactação do solo. Comparando os diferentes sistemas de mobilização, obteve-se uma significativa redução de combustível para a técnica de sementeira direta, apesar de se terem observado diferenças estatísticas significativas considerando diferentes calibrações de profundidade de sementeira Do trabalho realizado nesta Tese ressalva-se a importância que as tecnologias de agricultura de precisão podem ter no acompanhamento e avaliação de culturas em sementeira direta, bem como a necessidade de melhores procedimentos no controlo de profundidade dos semeadores pelo respetivos operadores ou ao invés, a adoção de semeadores com mecanismos ativos de controlo de profundidade. ABSTRACT Among the various factors that contribute towards producing a successful maize crop, seeders vertical distribution evaluated through seed depth placement is a key determinant, especially under a no-tillage technique. At the same time in conservation agriculture systems due to the complexity of natural and agricultural ecosystems site specific management became an important approach to understand and manage the variability of soil properties and crop establishment, especially when using geo spatial information and affording readily technology Thus, the main objective of this Thesis was to evaluate the spatial variability of seed depth placement and crop establishment in maize crops under no-tillage conditions compared to different tillage systems, using conventional seed depth control no till seeders and precision farming technologies. Trials were carried out in the Mediterranean region of Alentejo, in private farms along the sowing operations season over the years 2010, 2011, 2012 and 2015 in 6 different experimental fields. Experimental work covered field tests with in loco soil and crop evaluations, fuel operation evaluations and aerial sensing. The results obtained indicate that not only tillage system affected seed depth placement but under no till conditions seed depth was affected by soil moisture content, soil resistance to penetration and seeders forward speed. In addition uneven crop seedling and establishment depended on seed depth placement and could be affected by physical problems of compaction layers. Significant reduction in fuel consumption was observed for no till operations although significant differences observed according to different setting calibrations of seed depth control. According to the results, precision agriculture is an important tool to evaluate crops under no till conditions and seed depth mechanisms should be more accurate by the operators or is determinant the adoption of new active depth control technology to improve seeders performance.

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Neste trabalho analisa-se a problemática da definição de territórios para os períodos mais recuados da Pré e Proto-História do Alentejo. O processo de ocupação do espaço das primeiras sociedades camponesas variou em função das suas estratégias de exploração do território mas, também, em função da sua evolução e complexificação técnica, económica e social. A necessidade de protegerem pessoas e bens levou-os a construir os primeiros castelos do Alentejo.

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In this work we advocate the use of geothermal pumps to cool the isolated houses that can be observed in the plain of Alentejo. Passive cooling of the houses, made for centuries, becomes insufficient when it aims to promote tourism in the region. The climatic characteristics of the region and the relatively high values of the thermal conductivity of the ground favour this type of use. The available land around the houses provide places where you can drill or make trenches to put the pipes under the surface . Some values of pipe lengths were obtained using values appropriate for the region. The need to try to preserve the shape of the typical houses of the region discourages the use of solar panels placed on the roofs. The length and time of use of the equipment is another factor to take into account in the analysis of the costs.

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In this paper we will present the latest results chronometric and their contexts of the main menhirs northern Alentejo in Portugal. The date now obtained for the Menhir of Patalou, located in Nisa municipality, (Cal BC 4340-4235) confirms that for more than two decades, in a similar context, we obtained the Menhir of the Meada, located in the Castelo de Vide municipality, (Cal BC 4810-5010) and so many doubts and controversies raised in view of its great antiquity. They position themselves in this way and safely in the old Neolithic the erection of these great phallic monuments.

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This communication will be presented rehabilitation examples of megalithic monuments resulting from over 30 years of archaeological investigations carried out in northern Alentejo (Portugal). Being the oldest megalithic structures monumental architectural buildings of humanity pathologies that present are multiple and very different from each other. Typically, the recoveries of these structures have to be preceded by an archaeological nature of action to identify and recognize the best solutions for their preservation. Thus, this communication will present the results of the work carried out in different dolmens and menhirs, with timelines ranging from the 6th and 3th millenniums before Christ.

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Entre a primavera de 1931 e a primavera de 1945, Manuel Heleno, Diretor do Museu Etnológico e Professor na Faculdade de Letras da Universidade de Lisboa, dedicou-se ao inventário e escavação de centenas de monumentos megalíticos no Alentejo Central. Apesar do volume de informação recolhido este investigador, acabou por não publicar os seus dados o que trouxe graves consequências para o estudo do megalitismo funerário alentejano. Para além de uma caracterização dos trabalhos realizados por Manuel Heleno, apresenta-se um conjunto de reflexões sobre questões relacionadas com a produção e divulgação de informação, em Arqueologia e a responsabilidade social do arqueólogo.

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Background and Aim: Grasses and olive are the most relevant allergenic species in the Alentejo region. However, aggravation of allergic symptoms has been reported in the early spring, before grass and olive pollen seasons. Quercus pollen is the most abundant pollen type in the early spring in Alentejo, nonetheless its allergen profile has not yet been evaluated. The aim of this work was to characterize the allergen profile of pollen from Quercus rotundifolia among the most representative species showing pollination in April, prior to the main pollen season in Alentejo. Methods: Pollen from Quercus rotundifolia, Olea europaea and Dactylis glomerata was extracted with ammonium bicarbonate buffer, lyophilized and stored at -80ºC until analysis. Extract from Quercus ilex pollen was kindly offered by Bial. Protein content was determined by the Bradford method. SDS-PAGE followed by western blot, using allergic patient sera (obtained from the Hospital do Espírito Santo de Évora – HESE), were performed to evaluate the allergen profile of the pollen. Sensitization and cross-reactivity was assessed by solid phase immunoblot. Results: Most of the patient evidenced sensitization to pollen extracts of Q. rotundifolia. Protein profile of Q. rotundifolia has shown several bands in the Mr 10-90 kDa, mostly overlapping with Q. ilex. Western blot have shown several immunoreactive bands. Immunoreactive bands were also observed in the protein profile according to the pI in the range 4.0-6.1. Cross-reactivity between Q. rotundifolia with O. europaea and D. glomerata was found. Conclusion: These results evidenced allergens found in Q. rotundifolia pollen. It also shows that protein profile of Q. rotundifolia and Q. ilex are mostly alike suggesting that similarities in allergen profile are expected. Moreover, cross–reactivity between Q. rotundifolia and highly allergenic species such as O. europaea and D. glomerata was found which probably contributes to the aggravation of pollinosis in the early spring. Acknowledgments: This work was supported by FEDER through the “Programa Operacional Fatores de Competitividade – COMPETE” (Strategic projects of ICAAM and ICT 2013-2015). We also aknowledge Bial-Aristegui for supplying pollen and extract samples of Q. ilex.

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Como se poderá melhorar a imagem do agricultor e da atividade agrícola nos territórios rurais e na sociedade em geral? Para dar resposta a este problema foi realizado um estudo num território do Alentejo (Portugal) e num território do centro de França com os seguintes objetivos: i) Conhecer a perceção de população urbana e rural sobre a profissão de agricultor; ii) Conhecer a perceção dos jovens agricultores sobre o desenvolvimento sustentável; iii) Encontrar ameaças e oportunidades para o desenvolvimento da atividade dos agricultores, e iv) Elaborar um plano de ação conjunto para prestigiar e melhorar a representação social da profissão de agricultor e da atividade agrícola. Para atingir estes objetivos recorreu-se à análise bibliográfica, e à aplicação de entrevistas e questionários a uma amostra de conveniência, o que resultou no conhecimento das características dos agricultores e da atividade agrícola nos dois territórios, e no conhecimento de questões específicas relacionadas nomeadamente com: i) perceção sobre o desenvolvimento durável, ii) auto-avaliação da exploração agrícola, iii) perceção (por parte de uma amostra da população) dos agricultores e da agricultura e iv) perspetivas futuras no enquadramento do Quadro Estratégico Comum 2020. Os resultados da pesquisa são apresentados através dos seguintes pontos: i) Introdução; ii) Metodologia; iii) Apresentação do projeto; iv) Análise comparativa da perceção dos diferentes atores, v) Que novas perspetivas para o caso do Alentejo?, e vi) Considerações finais e Conclusões.

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O Alentejo Central é detentor de um dos mais importantes conjuntos megalíticos a nível europeu. Esta importância decorre não só do elevado número de monumentos megalíticos conservados, mas também do numeroso e variado espólio progressivamente recolhido que nos permite compreender, em parte, a forma como viviam estas sociedades. Os projetos de investigação realizados nas últimas décadas em torno de alguns núcleos megalíticos alentejanos permitiu, por um lado, proceder a uma revisão e medição da orientação das antas e, por outro, compreender melhor as suas diversas e originais manifestações artísticas que se encontram profundamente marcadas por um simbolismo associado aos astros. De fato, em termos gerais, existe algum consenso sobre o simbolismo existente em torno da escolha das orientações dos monumentos megalíticos (funerários e não funerários) marcadamente associados ao Sol e/ou à Lua, ou hipoteticamente, a outras constelações. Nesta comunicação apontam-se e caracterizam-se sucintamente algumas destas orientações e as representações gráficas em espólios (cerâmicas, placas de xisto…) mais significativas e exemplificativas da importância da LUZ, na vida e nas crenças religiosas destas primeiras sociedades camponesas.

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A problemática que constitui o ponto de partida do presente estudo evidencia a importância de se conhecer e compreender a forma como se processa a inserção profissional dos recém-diplomados em Ensino Básico - 1º Ciclo. De entre distintas ópticas possíveis, considerou-se importante assumir, como elemento estratégico deste processo, e na linha do pensamento de M. Alves (2001), o entendimento de que o processo de inserção profissional assume um carácter dinâmico, que envolve três actores fundamentais: os diplomados, os empregadores e os estabelecimentos de ensino superior. É tendo como base de trabalho esta perspectiva (conceito de inserção profissional articulado com o paradigma da aprendizagem ao longo da vida) que se edifica o presente estudo, estruturando-se em quatro partes. A primeira delas visa, embora não de forma exclusiva, a explanação dos principais referenciais teóricos relativos à temática em questão; a segunda parte explicita as opções metodológicas adoptadas; a terceira debruça-se sobre a análise e interpretação dos resultados e a quarta remete para algumas conclusões que emergiram de todo o processo de investigação empreendido. Procurando desenvolver-se uma investigação descritiva assente numa metodologia integrada e complementar com abordagens qualitativas e quantitativas, a recolha de dados incide num questionário e numa entrevista, tendo-se sempre em consideração os objectivos subjacentes ao estudo e optando-se, para tal, como sujeitos, pelos licenciados em Ensino Básico - 1.° Ciclo que realizaram a sua formação nas instituições formadoras do Alentejo (Escolas Superiores de Beja e Portalegre e Universidade de Évora), no período compreendido entre 2001 e 2003. As trajectórias profissionais destes licenciados ficam marcadas por sentimentos de ilusão, incerteza e indignação, mas também por um forte sentimento de frustração. Não foi pacífico, para muitos deles, aceitar que a realização do curso não lhes conferiu o acesso ao emprego esperado. A sua maioria encontrava-se integrada em sectores profissionais que não estavam directamente relacionados com o curso ou, então, permaneciam desempregados. A esperança de virem a exercer a profissão docente parecia ser cada vez mais ténue. /***Abstract - The problem that constitutes the start of the present study emphasizes the importance of knowing and understanding the way it proceeds the professional insertion of the new graduates of the Ensino Básico — V Ciclo (primary school).Between several visions, it has been important, as a strategic element of this process and following the line of M. Alves (2001), the understanding that the professional insertion assumes a dynamic character, that envolves three fundamental elements: the graduates, the employers and. the universities. This study, structured in four parts, is based in the concept that links profession insertion with life long learning. The purpose of the first part is to expose, not in an exclusive way, the several theories connected with the theme in question the second part explains the methodology used; the third consists of the analysis and interpretation of the results and the fourth and. last one, exposes some conclusions that carne out of the investigation process. It has been tried in this study to develop a descriptive investigation, based on an integrated and complementary methodology that includes a qualitative and quantitative analysis. Therefore, the gathering of data is based on a questionnaire and an interview. Always considering the underlying objectives of the study, we have chosen, as subjects, the graduates in Ensino Básico - 1º Ciclo that performed their formation in the institutes of Alentejo (Escola Superior de Educação de Beja, Escola Superior de Educação de Portalegre e Universidade de Évora), in the period between 2001 and. 2003. The professional trajectory of these graduates is full of uncertainty, indignation and also full of strong feelings of frustration. It was not easy for many of them to accept that the course they have completed doesn't open the doors for the job they've dreamed of and expected. The majority was integrated in professional areas not directly connected with their course or then remained unemployed. The hope of becoming teachers was turning more and more tenuous.