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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Video Processing for Agricultural Applications

He Liu (8735115) 24 April 2020 (has links)
Cameras are widely used as sensors for a variety of engineering applications. In a typical video-based application, spatial segmentation is a fundamental step which provides the spatial positions of different targets for further analysis. In this thesis, we focus on videos analytics applied to the agricultural industry and describe several video segmentation methods in the context of two practical projects: autonomous farming vehicles and analysis of dairy cow health. In the autonomous farming vehicle project, we propose three spatial segmentation methods based on traditional video features to isolate the regions of the video frame where critical information appears. Two applications that apply the segmentation method are presented: farming activity classification and header-height control for a combine harvester. In the project on cow health, we propose a cow structural model based on the keypoints of joints from a side-view cow video. A detection system is developed using deep learning techniques to automatically extract the structural model from the videos. Based on this model, we also present a preliminary application which estimates the cow’s weight based on video information.<div><br></div>
52

Optimizing Controlled-Release Fertilizer for Lettuce and Mizuna Grown on the International Space Station

Asmaa H Morsi (8071979) 04 December 2019 (has links)
<p>Astronaut diets on the International Space Station (ISS) depend on resupplied packaged food. However, missions to Mars of 3-5 years will not accommodate re-supply. In addition, many human macro and micronutrients degrade during long-term storage. Thus, growing nutritional plants aboard ISS is essential for providing astronauts with fresh, healthy produce. NASA is usingan experimental vegetable- production unit called VEGGIE to grow fresh salad crops aboard ISS to provide astronauts with healthy diets. VEGGIE is a small plant-growth chamber designed as a garden for astronauts that is low in mass and has a low power requirement. Veggie is equipped with light-emitting diodes (LEDs) but is exposed to the ISS cabin environment. Plants are grown with roots in a baked-ceramic substrate (arcillite) incorporating controlled-release fertilizer (Nutricote) and wicks delivering water by capillary action from a reservoir.</p><br><div>The fertilizerprills release nutrients into arcillite slowly over time. Different controlled-release types have the same amount of fertilizer but release it over different time periods. The Purdue Mitchell lab in collaboration with NASA is testing growth of salad crops within VEGGIE analogs under ISS-like environments in a growth chamber. Specifically, we are evaluating effects of different controlled-release fertilizer treatments as well as different substrate particle sizeson “cut-and-come-again” harvest scenarios, comparing productivity and quality of Lettuce as well as anAsian salad crop called Mizuna.<br></div><div><br></div><div>SS environments being mimicked include temperature: 24/21°C D/N, CO2: 2800 PPM D/N, RH: 45-50% D/N, and photoperiod: 16hours.Arcillitemedium contained one oftwo different fertilizer mixes: 7.5g18-6-8 T 70 + 7.5g 18-6-8 T100, or 7.5g18-6-8 T70 +7.5g 18-6-8 T180fertilizer/liter medium. LED Light treatment provides atotal PPFDof 330µmol m--2s-1 PAR; with 270µmol m--2s-1Red(R), 30µmol m--2s-1Blue (B), and 30µmol m--2s-1Green (G). Plants are grown under those conditions for 8 weeks, and harvested three times at 28, 42, and 56 days from planting. At each harvest, yield parameters as well as tissue mineral content have been measured for optimum fertilizer treatment selection.<br></div><div><br></div><div>Lettuce and Mizuna plants grown in a mix of 100% fine substrate particles (Profile) and fertilizer treatment of 50% T100:50%T70 had the higher yield as well as nitrogen contentcompared to those grown in 50%T180:50%T70. Growing mizuna plants in 100% profile resulted in higher shoot fresh weight; although no significant differences occurred for shoot dry weight. In addition, there was no significant interaction between substrate and fertilizer, which is reported by other research as one of the advantages of using controlled-release fertilizer<br></div>
53

LABOR MIGRATION AND AGRICULTURAL PRODUCTION IN NEPAL

Vivek Bist (10777812) 14 May 2021 (has links)
Continued migration from rural areas and the associated growth in remittance inflows are changing basic characteristics of Nepal’s agrarian economy. Using cross-sectional household survey data covering agricultural production during the 2013 growing season, this thesis investigates the linkages between migration and agricultural production in twenty districts of Nepal. This study focuses on understanding what household and farm characteristics are associated with migration decisions and destination choices using multinomial logit model. I also gauge the impact of labor migration and remittance receipts on maize yield and input levels.
54

Valoración socioeconómica del impacto de la expansión del cultivo de Quinua (Chenopodium quinoa W.) sobre la competitividad y sostenibilidad de la diversidad en las explotaciones tradicionales del Perú

Huillca Quispe, Jhon 04 March 2022 (has links)
[ES] Aunque la quinua (Chenopodium quinoa W.) se venía cultivando por los pueblos andinos desde la época preincaica, durante la segunda mitad del siglo XX, por diversas razones, fue postergado, siendo abandonado y casi olvidado en los lugares en los que se domesticó originalmente, originando así una serie de consecuencias sobre los sistemas productivos y comportamiento sociocultural de los pobladores andinos. Sin embargo, las cualidades intrínsecas de su grano como alimento, unido a cambios en los hábitos de consumo en países desarrollados, provocaron un interés creciente por su cultivo, pasando de ser un producto de autoconsumo, en un ámbito geográfico y cultural muy limitado, a ser un producto estrella de exportación; el rápido incremento de la demanda ha provocado un ajuste en los modelos productivos de la región y generando así impactos multidimensionales. En la presente investigación se ha analizado el impacto generado por el boom de quinua en los sistemas productivos agrarios de las zonas en las que su cultivo se había mantenido de forma tradicional. De acuerdo con los objetivos planteados, se ha realizado, en primer lugar, un diagnóstico y desarrollo de la importancia del cultivo sobre la población andina peruana y el papel desempeñado en los sistemas agrarios tradicionales del ande peruano. En segundo lugar, se ha realizado un análisis de la evolución de las variables que determinan la producción y distribución del grano en los últimos 70 años; se han identificado periodos de subutilización, recuperación y expansión en el contexto nacional y a nivel de los departamentos productores; hemos centrado nuestro análisis en dos escenarios extremos de superficie. Con las variables de comercialización se ha determinado la importancia económica de las zonas productoras, la penetración en nuevo mercados y su contribución sobre la economía nacional y, algunos cambios estructurales, para lo que hemos realizado un estudio de caso en las comunidades andinas de Cusco; los resultados de la encuesta nos han permitido observar la situación actual de los agricultores en el contexto del auge de quinua desde la dimensión social, tecnológica y económica; mostrando un panorama limitado y precario por las condiciones geográficas y medios productivos para el mantenimiento del cultivo en las condiciones que garanticen la sostenibilidad y el mantenimiento de la diversidad propia de los sistemas agrarios tradicionales de la zona andina del Perú. Así mismo, el indicador de sustentabilidad ambiental y social son similares y superiores al umbral, mientras que el económico es inferior, influyendo sobre el índice general de sustentabilidad. El análisis de los resultados económicos en términos absolutos de las distintas alternativas de tecnología productiva en diversos escenarios económicos muestra que, antes del boom de quinua, los agricultores prácticamente carecían de alicientes para introducir transformaciones tecnológicas importantes en sus procesos productivos tradicionales, conservando la tecnología productiva que permitía la sostenibilidad del cultivo, mientras que hoy en día los retornos de un sistema productivo basado en la productividad de variedades mejoradas genéticamente e insumos externos de las explotaciones son muy elevados y suponen un aliciente importante para el abandono de los sistemas productivos tradicionales, más o menos evolucionados, que corren el riesgo de ser abandonados, perdiéndose parte de la capacidad de estos sistemas tradicionales de ser sostenibles y adaptarse a los retos del cambio climático. El análisis de simulación efectuado sobre los resultados monetarios en diversos escenarios económicos y tecnológicos nos permite disponer de una base cuantitativa sobre la que estimar un modelo de compensación equilibrada que permita el mantenimiento de los sistemas tradicionales de producción con su demostrada capacidad para adaptarse a diversos escenarios agroclimáticos. / [CA] Encara que la quinoa (Chenopodium quinoa W.) s'havia cultivat pels pobles andins des de l'època preincaica, durant la segona meitat del segle XX, per diverses raons va ser postergat, sent abandonat i quasi oblidat als llocs en els quals es va domesticar originàriament, causant així una sèrie de conseqüències sobre els sistemes productius i comportament sociocultural dels pobladors andins. No obstant això, les qualitats intrínseques del seu gra com a aliment, unit a canvis en els hàbits de consum en països desenvolupats van provocar un interés creixent pel seu cultiu, passant de ser un producte d'autoconsum, en un àmbit geogràfic i cultural molt limitat, a ser un producte estrela d'exportació; el ràpid increment de la demanda ha provocat un ajust en els models productius de la regió i generant així impactes multidimensionals. En la present investigació s'ha analitzat l'impacte generat pel boom de quinoa en els sistemes productius agraris de les zones en les quals el seu cultiu s'havia mantingut de manera tradicional. D'acord els objectius plantejats, s'ha realitzat, en primer lloc, un diagnòstic i desenvolupament de la importància del cultiu sobre la població andina peruana i el paper exercit en els sistemes agraris tradicionals de la serralada dels Andes del Perú. En segon lloc s'ha elaborat una anàlisi de l'evolució de les variables que determinen la producció i distribució del gra en els últims 70 anys; s'han identificat períodes de subutilizació, recuperació i expansió en el context nacional i a escala dels departaments productors; hem centrat la nostra anàlisi en dos escenaris extrems de superfície. Amb les variables de comercialització s'ha determinat la importància econòmica de les zones productores, la penetració en nou mercats i la seua contribució sobre l'economia nacional i, alguns canvis estructurals, per al que hem realitzat un estudi de cas en les comunitats andines de Cusco; els resultats de l'enquesta ens han permés observar la situació actual dels agricultors en el context de l'auge de quinoa des de la dimensió social, tecnològica i econòmica; mostrant un panorama limitat i precari per les condicions geogràfiques i mitjans productius per al manteniment del cultiu en les condicions que garantisquen la sostenibilitat i el manteniment de la diversitat pròpia dels sistemes agraris tradicionals de la zona andina del Perú. Així mateix, l'indicador de sustentabilitat ambiental i social són similars i superiors al llindar, mentre que el d'econòmic és inferior, influint sobre l'índex general de sostenibilitat. L'anàlisi dels resultats econòmics en termes absoluts de les diferents alternatives de tecnologia productiva en diversos escenaris econòmics mostra que, abans del boom de quinoa, els agricultors pràcticament mancaven d'al·licients per a introduir transformacions tecnològiques importants en els seus processos productius tradicionals, conservant la tecnologia productiva que permetia la sostenibilitat del cultiu, mentre que hui dia els retorns d'un sistema productiu basat en la productivitat de varietats millorades genèticament i inputs externs de les explotacions són molt elevats i suposen un al·licient important per a l'abandó dels sistemes productius tradicionals, més o menys evolucionats, que corren el risc de ser abandonats, perdent-se part de la capacitat d'aquests sistemes tradicionals ser sostenibles i adaptar-se als reptes del canvi climàtic. L'anàlisi de simulació efectuada sobre els resultats monetaris en diversos escenaris econòmics i tecnològics ens permet disposar d'una base quantitativa sobre la qual estimar un model de compensació equilibrada que permeta el manteniment dels sistemes tradicionals de producció amb la seua demostrada capacitat per a adaptar-se a diversos escenaris agroclimàtics. / [EN] Although quinoa (Chenopodium quinoa W.) had been cultivated by the Andean Peoples since pre-Inca times, its farming was postponed during the second half of the 20th century for various reasons. In fact, it was abandoned and almost forgotten in the places where it was originally domesticated what has caused a series of consequences on the productive systems and sociocultural behaviour of the Andean inhabitants. Nevertheless, the intrinsic qualities of its grain as a food supply, together with changes in consumption habits in developed countries, has provoked a growing interest in its cultivation. From being a product of self-consumption in a very limited geographical and cultural scope to becoming a star product to export. The quick increase in its demand has caused an adjustment in the productive models of the region and that has generated multidimensional impacts. In the present research, the impact generated by the quinoa's boom on the agricultural production system of the traditionally-maintained cultivation areas has been analysed. According to the objectives considered on this work, a diagnosis and development of the importance of the crop on the Peruvian population has firstly been made, same with the role played in the traditional agrarian systems of the Peruvian Andes. Secondly, an analysis of the evolution of the variables that determine the production and distribution of the grain in the last 70 years has been carried out. The periods of underutilization, recovery and expansion have been also identified in both the national context and at the level of the producing departments. We have focused our analysis on two extreme surface scenarios. With the commercial variables, the economic importance of the producing areas has been determined, same with the penetration of new markets and their contribution to the national economy and some structural changes, for which we have conducted a case study in the Andean communities of Cusco. The results of the conducted survey have allowed us to observe the current farmers' situation in the context of the quinoa's boom. This has showed a limited and precarious panorama due to geographical conditions and productive means which keep the crop in the conditions that guarantee sustainability and maintenance of the diversity of the traditional agrarian systems of the Andes in Peru. Moreover, the environmental and social sustainability indicators are similar at the same time they both exceed the threshold whereas the economic indicator is lower influencing on the overall sustainability index. The analysis of the economic results in absolute terms of the different alternatives of productive technology in various economic scenarios shows that, before the quinoa's boom, farmers had virtually no incentive to introduce major technological transformations into their traditional production processes preserving the productive technology that allowed the sustainability of the crop whereas nowadays, the returns of a production system based on the productivity of genetically-improved varieties and external inputs from farms are really higher. They represent an important incentive for abandoning traditional production systems, more or less evolved, which run the risk of being abandoned what provokes a loss of some of the capacity of these traditional systems to be sustainable and to be adapted to the climate change. The simulation analysis carried out on the monetary results in various economic and technological scenarios allows us to have a quantitative basis on which estimate a balanced compensation model allowing the maintenance of traditional production systems with its proven ability to be adapted to various agroclimatic scenarios. / Huillca Quispe, J. (2022). Valoración socioeconómica del impacto de la expansión del cultivo de Quinua (Chenopodium quinoa W.) sobre la competitividad y sostenibilidad de la diversidad en las explotaciones tradicionales del Perú [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181509
55

Agricultores familiares pluriativos na região do Vale do Jaguari/RS : um estudo em Nova Esperança do Sul

Brasil, Claudio Raimundo de Bastos January 2016 (has links)
O mundo contemporâneo vem passando pelas mais diversas transformações e essas à medida que vem ocorrendo têm afetado diretamente as comunidades envolvidas, inclusive no meio rural. Com isso, tem–se percebido uma maior atenção à agricultura familiar, não apenas no meio acadêmico, mas, também por parte dos formuladores de políticas públicas. Nova Esperança do Sul, município pertencente à região do Vale do Jaguari, tem buscado adaptar-se às mudanças impostas pela economia, agricultura contemporâneas e as novas exigências do meio rural. Entre essas mudanças, é perceptível a crescente diversificação da produção e o aumento da ocupação da mão de obra com a pluriatividade. Neste contexto, o presente estudo busca identificar e entender a importância da pluriatividade para a agricultura familiar local. Para isso, utilizou-se os conceitos da abordagem sistêmica, uma leitura da paisagem e entrevistas com informantes chave, visando reconstituir a evolução histórica da agricultura familiar, identificar e caracterizar as UPAs pluriativas, bem como os sistemas de produção nelas adotados. Os resultados identificaram cinco tipos de UPAs que desenvolvem a pluriatividade não apenas no setor coureiro, mas também no serviço público e no turismo rural, e que implementaram os mais variados sistemas de produção. O impacto concreto e as consequências da inserção da agricultura familiar nas atividades pluriativas pode ser visto na qualidade de vida das pessoas envolvidas e na gestão e organização dessas UPAs, o que aponta uma estratégia por parte dos produtores para tornar cada UPA mais eficiente em termos econômicos, sociais e ambientais, a fim de garantir a verdadeira sustentabilidade. / The contemporary world has been going through various transformations and such as is occurring have directly affected the involved communities, including in rural areas. With this, we have observed greater attention to family farming, not only in academia but also on the part of policymakers. Nova Esperança do Sul, municipality belonging to the region Jaguari Valley, has sought to adapt to changes imposed by economics, contemporary agriculture and the new demands of rural zone. Among these changes, it is noticeable the increasing diversification of production and the increase of labor occupation with pluriactivity. In this context, the present study sought to identify and understand the importance of pluriactivity for local family farms. For this, we used the concepts of systemic approach, a landscape reading and interviews with key informants, in order to reconstruct the historical evolution of family farming, identify and characterize the pluriactive UPAs well as production systems adopted them. The results identified five types of UPAs that develop pluriactivity not only in the leather sector, but also in public service and in rural tourism, and have implemented a wide variety of production systems. The concrete impact and consequences of the inclusion of family farming in pluriactive activities can be seen in the quality of life of the people involved and the management and organization of these UPAs, which indicates a strategy by producers to make each UPA more efficient in economic terms social and environmental, thus ensuring true sustainability.
56

Relações sobre usinas hidrelétricas e alterações nos modos de produção agrícola / Relations between hydroelectric plants and changes in agricultural production methods

Praia, Amanda Salles 23 October 2017 (has links)
A instalação de empreendimentos hidrelétricos ocorreu de forma crescente no Brasil na última década. De igual modo, a importância da produção agrícola na economia nacional também cresceu. A supressão de terras e a alteração do fluxo da água causada pelo alagamento necessário à implantação de usinas hidrelétricas alteram a estrutura e a dinâmica das regiões diretamente afetadas em função de aspectos ambientais e sociais como reassentamentos, migrações, especulação imobiliária, êxodo rural etc. Estes impactos das hidrelétricas têm sido amplamente descritos pela literatura. O presente trabalho buscou analisar de forma especifica os impactos ocasionados pelos alagamentos sofridos pelos municípios brasileiros afetados por usinas hidrelétricas e seu reflexo nos modos de produção agrícola dos municípios afetados. Para tanto, realizou-se uma análise exploratória com indicadores na esfera nacional e um estudo de caso com as hidrelétricas de Jirau e Santo Antônio em Porto Velho (RO) baseado em entrevistas semiestruturadas. Os resultados na fase exploratória as correlações indicaram que quanto maior tamanho da área alagada maior é a variação de áreas plantadas e PIB agrícola dos municípios afetados. Com o estudo de caso foi possível identificar que há impactos significativos sobre os modos de produção agrícola, essa mudança pode ser explicada pela diferença entre a qualidade do solo de regiões ribeirinhas e a qualidade do solo nos reassentamentos. Tais impactos podem influenciar os indicadores que refletem a quantidade de áreas plantadas destes municípios. Identificou-se também que os impactos sobre a agricultura não são previstos nos estudos de impacto ambiental das hidrelétricas de Jirau e Santo Antônio. / The installation of hydroelectric projects has increased in Brazil in the last decade. Likewise, the importance of agricultural production in the national economy has also grown. The land suppression and the alteration of the water flow caused by the flooding necessary to the implantation of hydroelectric plants alter the structure and dynamics of the regions directly affected by environmental and social processes such as resettlement, migration, real estate speculation, rural exodus, etc. These impacts of hydroelectric plants have been widely described in the literature. The present study sought to analyze in a specific way the impacts caused by the floods suffered by the Brazilian municipalities affected by hydroelectric plants and their reflection in the modes of agricultural production of the affected municipalities. The study included an exploratory analysis of the impacts of hydroelectric dams on agriculture using selected indicators from the national scale, complemented by a case-study at the local scale, focusing on the Jirau and Santo Antônio power plants in Porto Velho, Rondônia, through semi-structured interviews.The results from correlations obtained in the exploratory phase showed that the larger the size of the flooded area, the greater the variation of planted areas and the agricultural GDP of the affected municipalities. From the case study it was possible to identify that there are significant impacts on the agricultural production methods, and that this change can be explained by the difference between the quality of the soil of riverside regions and the quality of the soil in the resettlements. Such impacts may influence the indicators that reflect the amount of planted areas of these municipalities. The study also revealed that the impacts on agriculture were not predicted in the environmental impact studies of the Jirau and Santo Antônio hydropower plants.
57

An archaeobotanical investigation into the Chalcolithic economy and social organisation of central Anatolia

Stroud, Elizabeth January 2016 (has links)
Limited knowledge about the 3000-year period between the Neolithic and the Bronze Age in central Anatolia, Turkey, prevents any understanding of change or continuity in crop production, consumption and crop husbandry techniques. This research aims to address this bias through the examination of archaeobotanical remains from the four central Anatolian Chalcolithic sites of Çatalhöyük West, Çamlıbel Tarlası, Canhasan I and Kuruçay and the consequent investigation of their crop economies. This work draws on multiple methods and techniques to understand the plant-related activities that occurred at the sites. The four chosen sites bookend the Chalcolithic period (c. 6000-3000 cal BC) and provide the opportunity for exploring the interrelationship between crop choice, crop husbandry, settlement size, surrounding environment and social organisation. Differences in crop species such as hulled barley, glume wheats and pulses, particularly lentil and bitter vetch occur at all four sites with species choice community specific. Multiple methods are used to disentangle the depositional processes, such as dung burning, that formed the assemblages, providing an indication of the origin of the archaeobotanical material and allowing inferences about the nature of weed seeds found. Crop processing activities are evident at all sites, with the dehusking of glume wheat contributing significantly to the archaeobotanical assemblage. The analysis of stable carbon and nitrogen isotopes of crops coupled with the functional ecology of arable weeds, indicate that crop husbandry techniques/regimes were site specific and were influenced by site size/population as well as environmental conditions. The identification of the crops grown and the methods used to cultivate and process them have implications for understanding the social context of such activities, and the broader socio-economic background of a period preceding the great changes in social structure seen in the Bronze Age.
58

Isolamento de bactérias de solo subtropical com capacidade de promoção de crescimento vegetal / Bacteria isolation from subtropical soil with vegetal growth capacity

Matter, Juliana Maria 28 April 2015 (has links)
Made available in DSpace on 2017-07-10T19:24:14Z (GMT). No. of bitstreams: 1 Juliana _Matter.pdf: 980208 bytes, checksum: 39b0f232a5a4474d2605637e0dc10ea5 (MD5) Previous issue date: 2015-04-28 / Chemical fertilizers management in agriculture is the main source of nutrients for crops development aiming at increasing yield. Thus, phosphorus, among other nutrients, is required by plants since it is the most limiting mineral on yield crops of commercial interest, because of its low availability and immobility in soil, as it also gets unavailable to absorption by the plants. Studies have shown that phosphate solubilization up from bacteria inoculation can improve agricultural production. Many bacteria can take part on the dissolution process through different mechanisms and promote plant growth either by dissolving phosphates or determining nitrogen (N) and indole acetic acid production (IAA). Due to the isolation of these microorganisms, they can be inoculated and make the fixed phosphorus available, reducing the use of fertilizers or readjusting excessive percentages of this element in their formulas to improve a development of sustainable agricultural yield. According to this theme, it was possible to apply a methodology for the isolation of subtropical soil bacteria with maize cropping from different soil fertilization managements. After isolating the micro-organisms, they were submitted to endurance tests after pricking, phosphatase production ability, IAA production with and without L-tryptophan and identification method by rDNA extraction technique. A greater diversity of mineralizing bacteria was found in treatment 1 soil (no fertilization). The results related to the largest percentage increase in Calcium phytate can be justified by the fact that bacterial communities can produce enzymes. The stability of the solubilizing function was greater in calcium phytate when compared to the other culture media that have been used. The study has indicated that soil microbiota keeps a similarity in which Ochrobactrum gender has prevailed and under different management situations, its diversity slightly varies, but it is able to produce metabolites promoters of plant growth; while the isolates of Treatment 2 (mineral fertilization) have kept the best acid phosphatase production. The IAA production, without L-tryptophan addition in T1, suggests that the microbiota uses metabolic pathways for different purposes, since the studied soil is poor in minerals, thus it affects the production of plant growth promoters. It differs from Treatment 3 that received fertilization with swine wastewater, and diversified IAA production for its isolates with stronger values. With this study it was possible to identify genera of bacteria with high phytate mineralization capacity. At last, according to the study results, it was possible to identify the bacteria genera with high capacity to mineralize phytate and produce IAA, indicating the promotion of vegetal growth capacity. / A utilização de fertilizantes químicos na agricultura constitui-se como a principal fonte de nutrientes para o desenvolvimento das culturas visando ao aumento da produtividade. O fósforo, dentre outros nutrientes, é o mais requerido pelas plantas e o que mais limita a produtividade nas culturas de interesse comercial em virtude da sua baixa disponibilidade e imobilização no solo, haja vista ficar indisponível para absorção pelo vegetal. Estudos comprovam que a solubilização de fosfatos a partir da inoculação de bactérias pode ajudar na melhoria da produção agrícola. Muitas bactérias realizam processos de dissolução a partir de diferentes mecanismos e promovem crescimento vegetal tanto pela dissolução de fosfatos como na fixação de nitrogênio (N) e produção de ácido indol acético (AIA). Com o isolamento desses microrganismos, é possível inoculá-los e disponibilizar o fósforo fixado, reduzir o uso de fertilizantes ou readequar as porcentagens excessivas desse elemento em suas fórmulas, visando ao desenvolvimento da produção agrícola sustentável. A partir desta temática, foi utilizada metodologia para isolamento de bactérias de solo subtropical sob cultivo de milho com diferentes históricos de adubação. Além do isolamento, os microrganismos foram submetidos a testes de resistência após repicagem, produção de fosfatases, produção de AIA com e sem L- triptofano e identificação por técnica de extração de rDNA. Uma maior diversidade de bactérias mineralizadores foi encontrada no solo Tratamento 1 (sem adubação). Os resultados relacionados à maior porcentagem de crescimento em fitato de cálcio podem ser justificados pelo fato de as comunidades bacterianas serem capazes de produzir enzimas. A estabilidade da função solubilizadora foi maior em fitato de cálcio do que nos outros meios usados. O estudo indicou que a microbiota do solo mantém similaridade onde prevalece o gênero Ochrobactrum e que, em diferentes situações de manejo, pouco varia sua diversidade, mas apresenta capacidade para produzir metabólitos promotores de crescimento de plantas. Os isolados do Tratamento 2 (adubação mineral) mantiveram a produção de fosfatase ácida mais acentuada. A produção de AIA sem a adição de L-triptofano no tratamento T1 sugere que a microbiota utiliza vias metabólicas distintas para tal, visto que o solo estudado é pobre em minerais. Isso afeta a produção de promotores de crescimento de plantas, contrapondo-se ao Tratamento 3, o qual recebeu adubação com água residuária de suinocultura e diversificou a produção de AIA por seus isolados com valores mais robustos. Finalmente, de acordo com os resultados do presente estudo, foi possível a identificação de gêneros de bactéria com elevada capacidade de solubilização de fitatos e produção de AIA, indicando capacidade de promoção de crescimento vegetal.
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Isolamento de bactérias de solo subtropical com capacidade de promoção de crescimento vegetal / Bacteria isolation from subtropical soil with vegetal growth capacity

Matter, Juliana Maria 28 April 2015 (has links)
Made available in DSpace on 2017-05-12T14:47:31Z (GMT). No. of bitstreams: 1 Juliana _Matter.pdf: 980208 bytes, checksum: 39b0f232a5a4474d2605637e0dc10ea5 (MD5) Previous issue date: 2015-04-28 / Chemical fertilizers management in agriculture is the main source of nutrients for crops development aiming at increasing yield. Thus, phosphorus, among other nutrients, is required by plants since it is the most limiting mineral on yield crops of commercial interest, because of its low availability and immobility in soil, as it also gets unavailable to absorption by the plants. Studies have shown that phosphate solubilization up from bacteria inoculation can improve agricultural production. Many bacteria can take part on the dissolution process through different mechanisms and promote plant growth either by dissolving phosphates or determining nitrogen (N) and indole acetic acid production (IAA). Due to the isolation of these microorganisms, they can be inoculated and make the fixed phosphorus available, reducing the use of fertilizers or readjusting excessive percentages of this element in their formulas to improve a development of sustainable agricultural yield. According to this theme, it was possible to apply a methodology for the isolation of subtropical soil bacteria with maize cropping from different soil fertilization managements. After isolating the micro-organisms, they were submitted to endurance tests after pricking, phosphatase production ability, IAA production with and without L-tryptophan and identification method by rDNA extraction technique. A greater diversity of mineralizing bacteria was found in treatment 1 soil (no fertilization). The results related to the largest percentage increase in Calcium phytate can be justified by the fact that bacterial communities can produce enzymes. The stability of the solubilizing function was greater in calcium phytate when compared to the other culture media that have been used. The study has indicated that soil microbiota keeps a similarity in which Ochrobactrum gender has prevailed and under different management situations, its diversity slightly varies, but it is able to produce metabolites promoters of plant growth; while the isolates of Treatment 2 (mineral fertilization) have kept the best acid phosphatase production. The IAA production, without L-tryptophan addition in T1, suggests that the microbiota uses metabolic pathways for different purposes, since the studied soil is poor in minerals, thus it affects the production of plant growth promoters. It differs from Treatment 3 that received fertilization with swine wastewater, and diversified IAA production for its isolates with stronger values. With this study it was possible to identify genera of bacteria with high phytate mineralization capacity. At last, according to the study results, it was possible to identify the bacteria genera with high capacity to mineralize phytate and produce IAA, indicating the promotion of vegetal growth capacity. / A utilização de fertilizantes químicos na agricultura constitui-se como a principal fonte de nutrientes para o desenvolvimento das culturas visando ao aumento da produtividade. O fósforo, dentre outros nutrientes, é o mais requerido pelas plantas e o que mais limita a produtividade nas culturas de interesse comercial em virtude da sua baixa disponibilidade e imobilização no solo, haja vista ficar indisponível para absorção pelo vegetal. Estudos comprovam que a solubilização de fosfatos a partir da inoculação de bactérias pode ajudar na melhoria da produção agrícola. Muitas bactérias realizam processos de dissolução a partir de diferentes mecanismos e promovem crescimento vegetal tanto pela dissolução de fosfatos como na fixação de nitrogênio (N) e produção de ácido indol acético (AIA). Com o isolamento desses microrganismos, é possível inoculá-los e disponibilizar o fósforo fixado, reduzir o uso de fertilizantes ou readequar as porcentagens excessivas desse elemento em suas fórmulas, visando ao desenvolvimento da produção agrícola sustentável. A partir desta temática, foi utilizada metodologia para isolamento de bactérias de solo subtropical sob cultivo de milho com diferentes históricos de adubação. Além do isolamento, os microrganismos foram submetidos a testes de resistência após repicagem, produção de fosfatases, produção de AIA com e sem L- triptofano e identificação por técnica de extração de rDNA. Uma maior diversidade de bactérias mineralizadores foi encontrada no solo Tratamento 1 (sem adubação). Os resultados relacionados à maior porcentagem de crescimento em fitato de cálcio podem ser justificados pelo fato de as comunidades bacterianas serem capazes de produzir enzimas. A estabilidade da função solubilizadora foi maior em fitato de cálcio do que nos outros meios usados. O estudo indicou que a microbiota do solo mantém similaridade onde prevalece o gênero Ochrobactrum e que, em diferentes situações de manejo, pouco varia sua diversidade, mas apresenta capacidade para produzir metabólitos promotores de crescimento de plantas. Os isolados do Tratamento 2 (adubação mineral) mantiveram a produção de fosfatase ácida mais acentuada. A produção de AIA sem a adição de L-triptofano no tratamento T1 sugere que a microbiota utiliza vias metabólicas distintas para tal, visto que o solo estudado é pobre em minerais. Isso afeta a produção de promotores de crescimento de plantas, contrapondo-se ao Tratamento 3, o qual recebeu adubação com água residuária de suinocultura e diversificou a produção de AIA por seus isolados com valores mais robustos. Finalmente, de acordo com os resultados do presente estudo, foi possível a identificação de gêneros de bactéria com elevada capacidade de solubilização de fitatos e produção de AIA, indicando capacidade de promoção de crescimento vegetal.
60

Sustainability Challenges for Maize and Cassava Farmers in Amankwakrom Subdistrict, Ghana

Atadja, Franklin Komla 01 January 2016 (has links)
Agricultural system in Ghana underperformed because of limited financing, which constrained some small-scale maize and cassava farmers. The purpose of this case study design was to explore the methods that some small-scale maize and cassava farmers in Amankwakrom Subdistrict used in obtaining farm financing. Two themes from the literature review were a lack of collateral for small-scale farm financing and the small-scale farmers cooperative associations' role in farm financing. Regional-scale management sustainability index formed the conceptual framework for this study. Data collection included semistructured face-to-face interviews with 8 fluent English speaking small-scale maize and cassava farmers who have obtained farm financing in the previous years. Using the Microsoft Excel and Non-numerical unstructured data indexing and theorizing software program for data analysis method, 3 major themes emerged: the farmer's membership benefits of working in cooperative associations; farmer's ability to provide the collateral requirements for the financial institutions; and farmer's good loan repayment history. The study findings indicated that some small-scale maize and cassava farmers obtained farm loans because they used the cooperative associations as their collateral assets in order to satisfy for the requirements of the financial institutions. Social implications include the potential to guide the small-scale maize and cassava farmers to access farm credits to use in expanding their farm sizes. Expansion in farm sizes may result in more maize and cassava production that can help eliminate hunger and reduce poverty in the Amankwakrom Subdistrict of Ghana.

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