Made available in DSpace on 2016-12-08T16:44:36Z (GMT). No. of bitstreams: 1 PGPV10MA060.pdf: 3544376 bytes, checksum: 70aba0d2ca5ce86d930375b17637c798 (MD5) Previous issue date: 2010-05-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this research was to obtain information that may assist in insertion and cultivation of species of the genus Salix in agroforestry systems. For the ethno knowledge study that deals with willow crops and local plant diversity was performed 30 semi-structured interviews applied to willow growers settled in typically willow crops communities. In the experiment that simulated levels of shadow, 20 cm willows cuttings were planted into box filled with a mixture of soil and manure and submitted to 0%, 50% and 70% shading levels. The diameter and length of the willow branches, fresh and dry weight of the branches and roots and branches winding resistance were evaluated 60 and 90 days after the starting of the experiment. For verifying the response of tree willow species to different water soil contents, the experiment was conducted into a greenhouse in a completely randomized design, in a factorial arrangement of 2 x 3 x 4. Each plot was composed by a plastic vase filled with Haplumbrepts or Latosols soil. In each vase was planted three willow cuttings of Salix x rubens, Salix viminalis or Salix smithiana species. The water soil regime tested was irrigation to soil water retention capacity to 100, 80, 60, 40 %. At 90 days after after the starting of the experiment were evaluated length of branches, number of buds, fresh and dry weight of shoots and roots of each plant. The willow growers showed to be prepared to do the harmonization of willow crop as agroforestry systems once it is done with native and commercial plant species, that could be panted and cultivated in the around of willow cropped areas. In order to obtain the highest yields and branches qualities in agroforestry systems plants of Salix viminalis and Salix x rubens should be cultivates in no shading areas. The biomass production of Salix x rubens, Salix viminalis and Salix Smithiana is greater between 80 and 100% capacity retention of moisture in the soil. Therefore, the willows fields outside of permanent legal areas with low wet areas should guarantee plenty of water to the willows plants / O objetivo desta pesquisa foi obter informações que possam auxiliar na inserção e cultivo de espécies do gênero Salix em sistemas agroflorestais. Para o estudo do etnoconhecimento foram realizadas 30 entrevistas semi-estruturadas com viminicultores residentes nas comunidades típicas de cultivo do vimeiro. O estudo abordou aspectos sobre o cultivo do vimeiro e da diversidade vegetal local. Para o experimento de simulação de sombra em vimeiros, estacas com 20 cm de comprimento foram plantadas em caixas com substrato composto pela mistura de solo e esterco bovino e submetidas aos níveis de 0%, 50% e 70% de sombreamento. Aos 60 e 90 dias após o plantio foram avaliados o diâmetro e comprimento dos ramos, massa fresca e seca dos ramos e das raízes e resistência dos ramos ao enrolamento. Para a resposta de três espécies de vimeiros a diferentes condições hídricas no solo, o experimento foi conduzido em casa de vegetação, com delineamento experimental inteiramente casualisado, disposto em arranjo fatorial de 2 x 3 x 4 x 4. As parcelas eram constituídas por vasos plásticos contendo separadamente solo do tipo Cambissolo Húmico álico franco argiloso e Latossolo Vermelho argiloso nos quais foram plantadas três estacas das espécies de Salix x rubens, Salix viminalis e Salix smithiana. Os regimes hídricos do solo foram de irrigação para elevação à capacidade de retenção (CR) de água quando o solo atingia 100, 80, 60 e 40% da CR. Aos 90 dias após a implantação das estacas foi avaliado o comprimento de ramo, número de gemas, massa fresca e seca da parte aérea e das raízes de cada planta. Os viminicultores entrevistados estão dispostos à manutenção e harmonização dos vimais como sistemas agroflorestais, dando preferência a espécies nativas ou comerciais, desde que localizadas no entorno dos vimais. Em sistemas agroflorestais, para a obtenção do maior rendimento e qualidade de ramos as plantas de Salix viminalis e Salix x rubens, estas devem ser cultivadas em áreas livres de sombreamento. A produção de biomassa de Salix x rubens, Salix viminalis e Salix smithiana é maior entre 80 e 100% de capacidade de retenção de umidade no solo. Portanto, a condução de vimais fora das áreas de preservação permanente com solos de baixadas e umidos devem assegurar a disponibilidade de água aos vimeiros

Orientador: Fernando Antonio Lourenço / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências Humanas / Made available in DSpace on 2018-08-18T03:48:48Z (GMT). No. of bitstreams: 1 Portella_MarianadeOliveira_M.pdf: 40098943 bytes, checksum: b2cbbf1fdf5f51b88563bdb293980a7c (MD5) Previous issue date: 2011 / Resumo: Esta dissertação aborda o cultivo agroflorestal em cinco municípios da Zona da Mata pernambucana. Discussões teóricas são feitas no primeiro e segundo capitulo, sendo o terceiro de ordem empírica. No primeiro capítulo, uma analogia é feita entre Sistemas Agroflorestais e roças de coivara, de modo a apontar para as semelhanças e diferenças entre os dois sistemas e fazer considerações acerca do método agroecológico de construção de tecnologias. O segundo capítulo trata da Zona da Mata pernambucana e traça um histórico da agricultura na região, mostrando como o monocultivo canavieiro se implantou, homogenizou a paisagem local e determinou a estrutura fundiária da mesorregião, sendo uma de suas consequências a organização de movimentos sociais pela reforma agrária. O terceiro capitulo é composto pelos estudos de casos. Cinco agricultores foram visitados e suas experiências foram analisadas, no sentido de compreender suas vivências agroflorestais e de entendê-Ias dentro de seus contextos rurais específicos. Alguns aspectos importantes do modo de vida desses agricultores foram brevemente analisados, sendo eles a postura de resistência política, a ideologia preservacionista, a viabilidade econômica e a reprodução social. Tal análise permite a compreensão dos sistemas agroflorestais na Zona da Mata pernambucana enquanto ferramentas de resistência e de afirmação da agricultura familiar e ecológica. Os agricultores que adotam a agrofloresta como sistema produtivo não estão apenas sobrevivendo como podem, estão reproduzindo um modo de vida crítico e autônomo, bem como a idéia de um novo paradigma de desenvolvimento rural / Abstract: This research addresses the agroforestral cultivation in five municipalities of the Zona da Mata in Pernambuco. The first two chapters discuss theoretical issues. In the third chapter several empirical studies are presented. The first chapter draws an analogy between agroforestry and slash-and-bum systems in order to point out the similarities and differences amid these two systems and to further analyze the development of agroecological technologies. The second chapter elucidates the history of agriculture in the Zona da Mata of Pernambuco. It displays the implementation of the sugar cane monoculture, resulting in a homogenized local landscape and determining the land structure of this mesoregion. This transformation eventually led to the organization of social movements which advocate land reforms. The third chapter consists of case studies. Five agriculturists were visited and their way of life was analyzed in order to understand their agroforestral experiences within their specific rural contexts. Several important aspects concerning the way of life of these agriculturalists were briefly discussed; among them the attitude towards political resistance, the preservationist ideology, economic viability and social reproduction. Within this analysis, agroforestral systems in the Zona da Mata of Pernambuco can be understood as instruments of resistance and as an affirmation of ecological and family agriculture. Agriculturalists adopting agroforestry as their system of production are not merely surviving, but they are rather reproducing their critical and autonomous way of life as well as the idea of a new paradigm of rural development / Mestrado / Sociologia / Mestre em Sociologia

O presente estudo teve como objetivo avaliar a viabilidade econômica de quatro sistemas agroflorestais em área com pastagem degradada na Amazônia Ocidental. A área escolhida para o desenvolvimento desta pesquisa está localizada na Estação Experimental da EMBRAPA/CPAA (Empresa Brasileira de Pesquisas Agropecuárias - Centro de Pesquisas Agroflorestais da Amazônia Ocidental) no Distrito Agropecuário da SUFRAMA - DAS, Km 54 da BR-174 (Manaus-Boa Vista- Brasil), em áreas de terra firme. Os modelos agroflorestais analisados foram implantados seguindo delineamento experimental em blocos casualizados, com 5 tratamentos, 3 repetições e a pastagem abandonada como testemunha, em parcelas de 3.000 m 2 (60m x 50m), com uma área total de 4,5 ha. Os tratamentos foram distribuídos da seguinte forma: ASP-1 (Sistema Agrossilvipastoril – altos insumos); SP2 (Sistema Agrossilvipastoril – baixos insumos); AS1 (Sistema Agrossilvicultural – baixos insumos com palmeiras); AS2 (Sistema agrossilvicultural – baixos insumos multiestrato) e pastagem abandonada (testemunha). Houve aplicação de insumos para correção de acidez e fertilidade do solo. A avaliação econômica dos sistemas agroflorestais analisados baseou-se no cálculo do valor presente líquido dos respectivos fluxos de caixa constituídos a partir da presuposição que os mesmos podem ser repetidos perpetuamente. Os resultados obtidos, mostraram que os modelos agroflorestais utilizados são economicamente viáveis, indicando que este tipo de atividade pode contribuir para a regeneração de áreas com nível de degradação semelhante ao observado no estudo de caso e para a sobrevivência econômica dos agricultores da região. / Agroforestry systems have been considered to recover degraded areas, so as to increase the agricultural and forestry productivity and diminish the economic risk to the farmer. Four agroforestry models were introduced into a degraded pasture and abandoned areas located in one of the Experimental Station (Suframa-DAS) of the Embrapa/CPAA ( Empresa brasileira de pesquisas agropecuaria/ Centro de Pesquisas Agroflorestais da Amazônia Ocidental), at Km 54 BR-174 (Manaus-Boa Vista). This study was a randomized complete block design with 5 agroforestry models and three replicates for each model and an abandoned pasture area as the control. The parcel area measured 3,000m 2 (60m X 50m) for a total of 4.5 ha. Trataments were: ASP1 (Agrosilvipastoral systems - higt output); ASP2 (Agrosilvipastoral systems - low input); AS1 (Agrosilvicultural systems - low output with palmers tree); AS2 (Agrosilvicultural systems - low output multistrata). Fertilizers were to correct for the effects of soil acidity and soil fertility. Economic evaluations were based on the following economical criteria: Net Present Value and Land Expectation Value. Results showed that the agroforestry models were economically acceptable indicating that this kind of agroforestry activity generates income and could be used as an alternative way to recorver degraded areas in the Amazon. Agroforestry system AS2 produced the best results among the systems studied. All four systems were efficient at reestablishing the vegetative productivity. It produced agricultural benefits to the farmer and the utilized species play a important role in the land maintenance and protection against fire use and erosion. More research utilizing SAFs are required for this region to emphasize the economic benefits of the systems.

Despite of the documented impacts of the so-called green revolution, food security in the world faces new challenges in terms of population growth, increases in no-agricultural land use (urbanization), and climate change. Trends in food security show that the world community is operating within two limits of food system: (i) the quantity of food that can be produced under a given climate; and (ii) the quantity of food needed by a growing and changing population. Therefore, taking food security successfully into the future requires novel approaches to boost agricultural productivity in order to balance food supply and demand without expanding the agricultural land. To date, progress in wheat yield has been largely the result of the development of dwarf varieties through introgression of reduced height (Rht) genes. The height reductions arising from the presence of these genes increased yield by alteration of partitioning of dry matter and nitrogen in favour of the spike. However, increased partitioning through additional reductions in plant height is not likely; as comparative studies indicate that wheat yield is reduced when plants are shortened beyond a threshold, and most of the modern cultivars have reached the optimal height. Therefore, this dissertation aimed to identify the physiological attributes able to produce yield increases in the Rht genotypes with the optimal heights. Approaches based on physiological understanding of yield are necessary for developing genotypes combining high yielding potential and agronomic traits of superior adaptation, and for understanding yield limiting factors. Yet, direct measurement of physiological variables is often difficult or expensive; as an example, measuring plant water status in the field is problematic, with techniques such as psychrometry generally only being suitable for laboratory studies. Therefore, proxy such as tissue RWC may be a good alternative measure of plant water status. We aimed to address these questions with three components of experimental research :(i) proxy-based screening to increased photosynthetic rate and water use efficiency in wheat; (ii) determinants of increased HI in lines with different Rht genes (b, c) when incorporated into contrasting background wheat genomes (B, D), and the relative effect on N partitioning during grain filling; (iii) analyses of stable isotopes (δ²H, δ¹⁸O, δ¹⁵N and δ¹³C) in an agronomic perspective in alley cropping systems associated with adjacent N₂ fixing trees, in terms of hydraulic redistribution, N availability and crop yields. In this thesis, the proxy-based approach to crop selection was defined as a surrogate-based (proxy and surrogate used interchangeably) screening of cultivars for morphological, anatomical, and physiological traits of performance or crop environmental responses. The research proposed steps for conducting a proxy-based crop selection programme. A comparative screening of 23 Eps cultivars and ranking for traits of photosynthetic and water use efficiency showed the correlative relationships of SLA to An, WUEi, leaf N, Δ¹³C, Kh, leaf RWC, and IVD. Additionally, it was observed that IVD may influence WUE and Amax. It was suggested that these relationships of SLA to traits of photosynthesis possibly resulted from the association of SLA and the leaf biochemical characteristics. Attention was also given to examining the mechanistic foundations that determine the relationship between plant height and yield. The results showed the straw-shortening significantly correlated both with Amax and Kh; and SLA decreased with the level of dwarfing; and the Amax related both Kh and SLA. Therefore, it was proposed that the straw-shortening may affects Amax by exerting a controlling influence over Kh through SLA. Moreover, both the partitioning of N to spike and the flag leaf N were related to plant height and growth stage. Additionally, the increased post-anthesis partitioning of N to grain associated with high N uptake rate and high MRT of N were probably the traits behind increased NUE and NHI. The data also indicated that increased grain number per spike, kernel weight and reduced peduncle length might be the driver of the increased HI in this experiment. The test of the hypothesis that there might be practical application of the analyses of the natural abundance of stable isotopes (δ²H, δ¹⁸O, δ¹³C, and δ¹⁵N) and isotopic mixing model by IsoSource to understand plant interactions in terms of water redistribution and nitrogen transfer and uptake in agroforestry systems, indicated a consistent gradient in depletion of wheat xylem water δ²H, δ¹⁸O, and δ¹⁵N in leaf as moving further away from the tree line. The data also reflected a consistent pattern of isotopic values (δ²H, δ¹⁸O, and δ¹⁵N) in wheat in the proximity of the tree being similar to that of the tree, suggesting they were using the same source of water and N. Similarly, an isotopic mixing model data showed that the crops in the proximity of the trees accessed considerably amounts of the water and nitrogen redistributed by trees. The study also indicated the improvement in water use efficiency, chlorophyll content, grain number per spike, and grain yield for the crops nearest to the trees for a distance up to 5 m. In conclusion, selection for increased HI should shift focus from reduced plant height to include increased grain number and kernel weight, increased partitioning of N to spike, reduced peduncle length, and low SLA. Finally, the hypothesis that efflux of water and N in agroforestry system from tree roots in topsoil and influences a number of physiological functions of neighbouring crops was confirmed by isotopic and physiological data.

No description available.

A legislação atual exige adequações no sistema de produção da canade- açúcar, proibindo gradativamente a queima como método de despalha antes do corte, com o que a colheita deve ser com corte manual ou mecanizado. 37% das terras da região de Piracicaba apresentam declividade acima de 12%, o que dificulta a mecanização da colheita. Os sistemas agroflorestais (SAFs) apresentam potencial para manter a atividade agrícola na região de Piracicaba, dando maior sustentabilidade ao setor sucroalcooleiro. Através de visitas às unidades fornecedoras da região de Piracicaba, foram realizadas entrevistas com fornecedores de cana-de-açúcar, 25 em total, 7 em Rio das Pedras, 10 em Charqueada, 6 em Iracemápolis e 2 em Ipeúna, que trabalham em área própria e têm a atividade canavieira como principal, cadastrados na Associação de Fornecedores de Cana de Piracicaba (AFOCAPI), nos meses de abril e maio de 2002. Os questionários foram elaborados em base naqueles de Caron (1986) e Darolt (2000), considerando indicadores relacionados com a adoção de Sistemas Agroflorestais. Verifica-se o desconhecimento sobre SAFs. Entretanto, quando alertados das vantagens desses sistemas, os fornecedores se interessam pelas possibilidades de aproveitar melhor as áreas declivosas com SAFs. Também, não demonstra resistência natural à mudança tecnológica. Os entraves para a adoção, não são intrínsecos aos fornecedores, mas são principalmente devido às características da própria tecnologia como a adaptabilidade da tecnologia às condições locais, a segurança do mercado para os produtos e a falta de um programa oficial de assistência técnica. Os fornecedores podem investir, desde que a alternativa tecnológica seja rentável. Porém, tem uma aversão ao risco financeiro para investimentos a longo prazo. Dessa forma, o principal impedimento para a adoção de SAFs é a ausência de comprovação concreta das vantagens agronômicas e econômicas desses sistemas. / Present legislation in Brazil, by gradually preventing the sugarcane burnt, provoke adjustments on the production system, mainly by changing the harvest process from that done by labor to mechanized cutting and collection of the stalks. In the region of Piracicaba 37% of the land has an slope of 12% or above, what makes mechanization very difficult. Agroforestry systems (AFSs) have the potential to preserve the agriculture activity in the region of Piracicaba, improving the sustainability of sugarcane production chain. Sugarcane small growers, who cultivate their own land, and have the sugarcane as their main crop and were associated to the regional growers association (AFOCAPI) were visited and interviewed , 25 in total, being 7 in Rio das Pedras., 10 in Charqueada, 6 in Iracemápolis and 2 in Ipeúna sub-regions. A questionnaire, considering indicators related to the adoption of SAFs. It was observed a nonacquaintance about AFSs. However, when warned about the advantages of these systems, growers are interested about the possibilities of better utilize the undulating and steep areas with AFSs. Besides, they do not demonstrate natural opposition to technological changes. Restraint for adoption are not intrinsic to growers but mainly due to the characteristics of the technology itself, as the adaptability of technology to local conditions, the market safety for their products, and the inexistence of a official program of technical assistance. Growers may invest, since the alternative technology is profitable. Nevertheless, the have aversion to financial risk for long term investments. Thus, the major restraint for adoption of AFSs is the inexistence of concrete confirmation of the agronomical and economical advantages of these production systems.

Este estudo avaliou a evolução dos atributos físico-hídricos do solo sob diferentes sistemas de manejo (orgânico, agroflorestal e convencional), caracterizou o funcionamento físico-hídrico e avaliou o modelo Hydrus 1D em três coberturas vegetais distintas (agricultura orgânica, sistema agroflorestal - SAF e capoeira) em áreas de agricultura familiar no município de Apiaí - SP. A avaliação da evolução ao longo do tempo dos atributos físico-hídricos do solo foi realizada através do monitoramento da densidade do solo, porosidade calculada, porosidade por análise de imagens, condutividade hidráulica e do conteúdo de matéria orgânica para cada propriedade com diferentes sistemas de manejo. A caracterização do funcionamento físico-hídrico dos solos, e a obtenção dos dados de entrada para o modelo Hydrus 1D foram realizadas por meio da coleta de amostras para análises químicas, granulométricas, densidade de partículas, densidade do solo, curva de retenção, condutividade hidráulica saturada e análise de imagens. O monitoramento da umidade do solo \"in situ\" foi obtido por sensores instalados nos principais horizontes das trincheiras e associados aos dados de precipitação coletados em estação meteorológica automática instalada na área. Os resultados da evolução ao longo do tempo dos três sistemas de manejo mostraram altos valores de matéria orgânica, principalmente na profundidade de 0,0 - 0,2 m, porém não demonstraram tendência de acúmulo. Altos valores de matéria orgânica proporcionam ao solo baixa densidade e altos valores de porosidade, resultando em maior condutividade de água no solo. Todos os sistemas apresentaram atributos físicos e hídricos com boas condições para o cultivo, não sendo o solo um impedimento para a manutenção destes sistemas nesta região; além disso, o uso de sistemas de manejo agroecológicos é uma alternativa interessante para a região como forma de prática agrícola conservacionista. Em relação à caracterização físico-hídrica, os três solos sob diferentes coberturas vegetais, apresentaram, principalmente nos horizontes superficiais, altos valores de matéria orgânica e porosidade, porosidade esta representada por poros complexos grandes, que são responsáveis pela alta condutividade hidráulica e são determinantes na presença de duas regiões com propriedades hidráulicas contrastantes que confere o comportamento bimodal das curvas de retenção. Na modelagem dos dados e suas comparações, o modelo Hydrus não foi eficiente para a predição dos valores de umidade nos solos estudados, pois, no geral, apresentou valores simulados de umidade mais baixos para todos os horizontes das trincheiras nas três áreas quando comparados com os dados observados. Entretanto, apresentou bons resultados na predição dos volumes de runoff, que neste trabalho não foram medidos, mas observados no campo. Estes resultados confirmam a necessidade de mais estudos com relação à predição de movimentos da água em condições heterogêneas de culturas, visto que os dados de entrada com relação à vegetação são de difícil escolha, principalmente no SAF por apresentar alta diversidade de espécies. / This study evaluated the evolution of hydro-physical attributes of the soil under different management systems (Organic, Conventional and Agroforestry), characterized the hydro-physical functioning and assessed the Hydrus 1D model in three different cover crops (Organic agriculture, Agroforestry Systems and \"Capoeira\") in family agriculture areas , municipality of Apiaí - SP. The evaluation of the evolution over time of the hydro-physical attributes of the soil was performed by monitoring the soil bulk density, calculated porosity, porosity by image analysis, hydraulic conductivity and organic matter content for each family agriculture property with different management systems. The characterization of the hydro-physical functioning of the soil, as well as the attainment of the input data for the Hydrus 1D model, were done by collecting samples for chemical analysis, particle size distribution, particle density, bulk density, soil water retention curve, hydraulic saturated conductivity and image analysis. The monitoring of soil moisture \"in situ\" was obtained by sensors installed in the main horizons of the pits and associated with rainfall data collected from an automatic weather station installed in the area. The results of the evolution over time of the three management systems showed high levels of organic matter, especially in depth from 0.0 to 0.2 m, but showed no tendency to accumulate. These high values of organic matter provide a low soil bulk density and high porosity, resulting in a increased water conductivity of the soil. Each system had hydro-physical attributes with good conditions for cultivation and the soil was not an impediment to the maintenance of these systems in this region, moreover, the use of agroecological management systems is an interesting alternative for the region as a form of conservationist agricultural practices. Regarding the hydro-physical characterization, the three soils under different crop cover, presented, mainly in the surface horizons, high values of organic matter and porosity, being this porosity represented by large complex pores, that are responsible for the high hydraulic conductivity and are crucial in the presence of two regions with contrasting hydraulic properties conferring bimodal behavior of the soil water retention curve. In the comparisons of the modeling data, the Hydrus model was not effective for predicting the moisture values in the studied soils. This data presented simulated moisture values lower for all horizons of the pits in the three areas, when compared with the observed data. However, good results were obtained in predicting runoff volumes, which were not measured in this work, but observed in the field. These results confirm the need for further studies with respect to the prediction of water movements under conditions of heterogenous cultures, since the input data with respect to vegetation, are difficult to chose, especially in AFS, due to its high diversity of species.

O sistema de produção de café orgânico vem surgindo como uma alternativa tecnológica e economicamente rentável, que visa eliminar os impactos ambientais provocados pelo uso irracional dos recursos naturais. Muitas experiências e análises apontam a biodiversidade como precursora da estabilidade biológica encontrada nesses agroecossistemas produtivos diversificados (SAFs). No entanto, são incipientes os estudos científicos sobre o efeito da biodiversidade nos sistemas agrícolas de produção. Assim, o maior desafio da pesquisa foi identificar qual o sistema de manejo propiciava mais sinergismos biológicos, serviços ecológicos-chaves, tais como o controle biológico da principal praga do cafeeiro. E é nesse sentido que a presente pesquisa foi desenvolvida, com o objetivo de avaliar se a biodiversidade presente nos agroecossistemas está relacionada com a estabilidade ecológica, ou seja, com o equilíbrio dinâmico da população de insetos, que em determinados níveis podem causar elevados danos econômicos à cultura do café. A pesquisa foi desenvolvida na região do Pontal do Paranapanema, nos sistemas agroflorestais conduzidos pelos agricultores assentados sob responsabilidade técnica do IPÊ (Instituto de Pesquisas Ecológicas), instituição responsável pela implantação dos SAFs, por meio do projeto intitulado \"Café com Floresta\". Tal estudo possibilitou um melhor entendimento do efeito da biodiversidade sobre agroecossistemas cafeeiros diversificados que não utilizam inputs externos (fertilizantes e agrotóxicos), além de propiciar uma análise e sistematização dos sistemas de manejo agroecológicos existentes nos assentamentos rurais, bem como a caracterização do manejo e das práticas agroflorestais realizadas pelos agricultores familiares, que envolvem aspectos socioeconômicos da produção. Dessa maneira, a pesquisa tem grande relevância científica, visto que, possibilitou averiguar que os arranjos agroflorestais estudados na região possibilitaram uma menor incidência da principal praga do cafeeiro (Coffea arabica), o bicho-mineiro (Leucoptera coffeella), mostrando que os SAFS são uma alternativa ecológica e social apropriada à agricultura familiar, uma vez que confere maior resiliência aos agroecossistemas. / The system of production of organic coffee is emerging as an alternative technology and affordable, which aims to eliminate the environmental impacts caused by irrational use of natural resources. Many experiments and analyzes indicate biodiversity as a precursor of biological stability found in these diverse productive agroecosystems. However, are incipient scientific about the effect of biodiversity on agricultural production systems studies. Thus, the biggest challenge of the research was to identify which system management propitiated more synergisms biological, ecological services - keys, such as biological control of major pest of coffee. And that is what this research was developed with the aim of evaluating whether the present biodiversity in agroecosystems is related to ecological stability ,ie, the dynamic balance of the insect population , which at certain levels can cause major economic damage the coffee culture. The research was conducted in the Pontal region in agroforestry systems driven by farmers settled under the technical responsibility of IPE (Institute for Ecological Research), the institution responsible for the implementation of the SAF, through the project entitled \"Coffee with Forest\". This study allowed a better understanding of the effect of biodiversity on diversified coffee agroecosystems that do not use external (fertilizers and pesticides) inputs, as well as providing an analysis and systematization of existing agroecological management systems in rural settlements, as well as the characterization and handling of agroforestry practices carried out by farmers, involving socioeconomic aspects of production. Thus, the research has scientific importance, since possible to ascertain that the studied agroforestry arrangements in the region allowed a lower incidence of major pest of coffee (Coffea arabica ) , the leaf miner (Leucoptera coffeella) , showing that the diversified coffee agroecosystems (SAF) are an appropriate ecological and social alternative to family farming, since it gives greater resilience to agroecosystems.

L’ajout de diversité végétale est présenté comme un moyen d’améliorer la durabilité des agrosystèmes. Cependant, il y a encore des manques importants de connaissances sur l’effet de la diversité végétale sur les processus à la base de l’élaboration des rendements. Les systèmes agroforestiers tropicaux couvrent une large gamme de diversité végétale ; ce sont donc de bons modèles pour étudier la relation entre diversité et productivité. Les systèmes agroforestiers de la région de Talamanca au Costa Rica sont particulièrement intéressants car au sein de communautés végétales complexes, ils comprennent des bananiers et des cacaoyers qui sont des cultures de rente importantes et dont la production peut facilement être quantifiée et analysée. Une autre spécificité de ces systèmes est qu’ils présentent des organisations spatiales particulièrement diverses. Analyser comment la diversité des plantes et son organisation influe sur les performances de ces systèmes est particulièrement complexe et nécessite le développement de nouvelles approches. Les objectifs de cette thèse étaient d’étudier : i) quels facteurs affectent la relation entre diversité végétale et productivité ? ii) Comment la diversité végétale influence la productivité globale des systèmes agroforestiers ? et iii) Comment la structure spatiales des communautés de plantes cultivées influence leurs rendements ?Tout d’abord, une méta-analyse a été menée afin d’étudier la relation entre diversité végétale et production dans une très large gamme de systèmes naturels et cultivés. Cette analyse a notamment traité du rôle de la latitude, du climat et de la structure de la canopée sur cette relation. Elle a montré que le gain lié à la diversité végétal tend à diminuer avec la magnitude de cette diversité. Nos résultats montrent également que la réponse de la productivité à la richesse spécifique en plantes dépend énormément du type de communauté considéré, notamment si la communauté comprend des arbres.Ensuite, un réseau de 180 placettes situées dans 20 parcelles d’agriculteurs a été étudié dans la région de Talamanca. Pendant un an, la production de chaque plante a été évaluée. Cette production a ensuite été convertie en revenus en accord avec les prix du marché local. Alors qu’un effet positif de la diversité végétale cultivée a été observé sur le revenu globale (de chaque placette), cet effet était très contrasté si on le considérait séparément pour les différents groupes fonctionnels. Cet effet était positif pour les plantes des groupes appartenant aux strates hautes et négatif pour les plantes des groupes appartenant aux strates basses. Ces résultats suggèrent que la complémentarité entre plantes était plus forte pour les plantes des strates hautes et qu’inversement la compétition était plus forte dans les strates plus basses.La seconde phase de l’analyse des données de ce réseau de parcelles a visé à étudier l’effet du voisinage de chaque bananier ou cacaoyer sur leur production. Une approche d’analyse individu-centrée a été développée afin de déterminer si le nombre de voisins d’un groupe donné dans un rayon donné était un bon prédicteur de la croissance ou du rendement de chaque bananier ou cacaoyer. Les résultats montrent que la distance à laquelle la production d’un bananier ou d’un cacaoyer est affectée par ses voisins dépend de la taille de ces. De manière surprenante, les grands arbres ont eu un effet plus faible que les arbres plus petits. Cela suggère que des densités modérées de grands arbres pourraient être compatibles avec une production de bananiers et de cacaoyer avec un haut niveau de rendement. Ces résultats ont été discutés en termes de complémentarité et compétition pour la lumière. Des pistes d’organisation sont proposées et discutées au regard de la maximisation des rendements des cultures de rente et des autres cultures mais aussi dans la provision de services écosystémiques au sens large. / Adding plant diversity is increasingly presented as a mean to improve the sustainability of agrosystems. However, there is still a lack of knowledge on how plant functional diversity alters processes that support production. Because they cover a broad range of plant diversity, agroforestry systems in the tropics are a good case study to better understand the diversity-production relation. Agroforestry systems in the Talamanca region in Costa Rica are particularly interesting because among the cultivated plants they encompass, banana and cacao are two cash crops of major importance and for which production can easily be quantified and analyzed. Another specificity of these systems is that their vertical and horizontal organization is particularly diverse. Understanding how plant diversity and its organization alter the performances of these complex systems is particularly challenging and requires developing new approaches. The objectives of this thesis were to address the following questions: i) Which factors affect the relationship between plant diversity and productivity? ii) How plant diversity influences the global productivity of agroforestry systems? and iii) How the spatial structure of the plant community affects yields?First, a meta-analysis was carried out to address the diversity-production issue among a very broad range of systems world-wide. This analysis focused on how latitude, climate, and canopy structure modify the effect of plant richness on productivity of agricultural and natural ecosystems. It showed that the gain per unit of diversity added decreased as plant richness increased. Our findings also showed that the response of productivity to plant richness largely depends on the type of plants in the community, especially if the community includes trees.Then, we extensively studied the diversity and the productivity of 180 plots located within 20 fields in the Talamanca region. A global evaluation of the productivity of these systems was possible with the estimation of the production of each plant during 1 year. This production was converted into income according to local market prices. While we observed a global positive effect of plant diversity on global income, this effect was contrasted according to the functional group considered (banana, cacao, other fruits, timber, firewood. When considering the functional group separately, there was a positive effect of plant diversity for higher strata groups and a negative effect for lower strata groups. This suggested that complementarity between plants was stronger than competition for those plants occupying the higher strata of the canopy but that competition was stronger than complementarity for plants occupying the lower strata of the canopy.The second part of the analysis of the Talamanca fields dataset focused on the effect of neighbouring plants on the production of banana and cacao plants. An individual-based analysis was developed to determine whether the number of neighbouring plants of a given functional groups explained the potential yield of each banana or cacao plant. We found that the distance at which other plants alters the yield of banana or cacao plants was greater for larger functional groups (fruit or wood trees) than for smaller ones (cacao trees or banana plants). Interestingly, higher strata trees had a smaller effect than lower strata trees, suggesting that moderate densities of tall trees could be compatible with high banana and cacao production. These findings were discussed in terms of complementary and competition with respect to the availability of light at higher and lower strata of the canopy. On an applied perspective, our results suggest that productivity could be maximized by a reasonably number of plant species, and then we proposed new direction to organize fields in order to maximize the production of cash crops while providing supplementary income for farmers and ecosystem services.

A relação da palmeira-juçara com os atores sociais no Litoral Norte do Rio Grande do Sul é representada pelo conflito socioambiental entre o extrativismo ilegal e o uso sustentável da espécie. A palmeira-juçara na história da Mata Atlântica possui relevada importância ecológica, cultural e socioeconômica. Apesar das ações de corte e furto do palmito realizada por infratores ambientais ainda ser recorrente, muitos agricultores familiares manejam a palmeira-juçara em quintais agroflorestais, cultivos consorciados, áreas de ocorrência natural aliando a produção agroflorestal agroecológica e a conservação da espécie nos agroecossistemas da região. O trabalho de pesquisa teve como objetivo central compreender a dinâmica das práticas sociotécnicas dos atores sociais e a produção de novidades associadas ao manejo sustentável da palmeira-juçara. Os objetivos específicos da pesquisa consistiram em identificar os atores sociais, descrever as práticas sociotécnicas, caracterizar as novidades e a rede de novidades interligadas. O referencial teórico-metodológico mobilizado no trabalho consistiu na interface dos elementos teóricos da Perspectiva Orientada ao Ator, Perspectiva Multinível (transições sociotécnicas) e da produção de novidades. A construção da pesquisa se deu a partir de uma abordagem qualitativa de estudo de caso onde foram utilizados elementos metodológicos da pesquisa etnográfica como a observação participante, entrevistas semiestruturadas e diálogos informais com atores sociais nas comunidades rurais de Aguapés, Vale do Maquiné, Morro Azul, Arroio do Padre e Chapada do Morro Bicudo no Litoral Norte do Rio Grande do Sul. Como resultados da análise do estudo empírico nas comunidades rurais se identificou a emergência de novidades (técnico-produtivas, organizacionais e de acesso a mercados sociais) que por sua vez, geraram novidades interligadas estabelecidas a partir das práticas sociotécnicas associadas a palmeira-juçara pelos atores sociais. / The relation between the juçara palm and the social actors on the North Coast of Rio Grande do Sul is represented by the socio-environmental conflict between illegal extractivism and the sustainable use of the species. The juçara palm in the history of the Atlantic Forest has important ecological, cultural and socioeconomic importance. In spite of the fact that the palmito cutting and theft actions carried out by environmental violators are still recurrent, many family farmers manage juçara palm in agroforestry yards, intercropping, natural occurrence areas combining agro-ecological agroforestry production and species conservation in agroecosystems in the region. The main objective of the research work was to understand the dynamics of sociotechnical practices of social actors and the production of novelties associated with the sustainable management of the palm tree. The specific objectives of the research were to identify the social actors, to describe the socio-technical practices, to characterize the novelties and the network of interlinked novelties. The theoretical-methodological framework mobilized in the work consisted of the interface of the theoretical elements of the Actor-Oriented Perspective, Multilevel Perspective (sociotechnical transitions) and the production of novelties. The construction of the research was based on a qualitative approach of case study where methodological elements of the ethnographic research were used as participant observation, semi-structured interviews and informal dialogues with social actors in the rural communities of Aguapés, Vale do Maquiné, Morro Azul, Arroio do Padre and Chapada do Morro Bicudo in the North Coast of Rio Grande do Sul. As a result of the analysis of the empirical study in rural communities, the emergence of innovations (technical-productive, organizational and access to social markets) was identified, which in turn generated interconnected novelties established from the sociotechnical practices associated with the juçara palm by the social actors.