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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.
1

Indicadores da qualidade do solo em Sistemas AgrÃcolas anuais e perenes na Chapada do Apodi - CE / Indicators of the quality of the soil in annual and perennial agricultural systems of the Chapada do Apodi - CearÃ.

Jamili Silva Fialho 16 March 2005 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Este trabalho se propÃs a avaliar as alteraÃÃes nas atividades microbiana, quÃmica e fÃsica em solo sob sistemas agrÃcolas anuais e perenes na regiÃo da Chapada do Apodi - CE. Procurou-se testar a hipÃtese de que o uso agrÃcola de Ãreas sob sistemas anuais e perenes causam alteraÃÃes ambientais que influenciam a biomassa e a atividade microbiana do solo, reduzindo-a em relaÃÃo a Ãreas sob vegetaÃÃo natural. Foram selecionadas duas Ãreas com respectivas testemunhas (vegetaÃÃo natural); a primeira sob cultivo de bananeiras (Fazenda Frutacor) e a outra sob cultivo de rotaÃÃo milho e soja (Fazenda Faedo). Coletaram-se amostras compostas de solo em trÃs profundidades (0-5, 5-15 e 15-25 cm) com quatro repetiÃÃes. Nas amostras coletadas foram realizadas anÃlises fÃsicas, quÃmicas e microbiolÃgicas. Fisicamente, observou-se uma elevaÃÃo no teor de argila, com o aumento da profundidade na Ãrea cultivada com banana e na mata natural pivot. Em relaÃÃo aos atributos quÃmicos do solo, os riscos potenciais de salinidade e de saturaÃÃo por sÃdio aparentemente sÃo desprezÃveis. As prÃticas de manejo reduziram o N e o carbono orgÃnico total nos solos das Ãreas sob cultivo. Quanto à microbiologia dos solos, o carbono da biomassa microbiana e a populaÃÃo de fungos micorrÃzicos arbusculares foram mais elevados na profundidade de 0-5cm do solo. A respiraÃÃo basal do solo mostrou que os solos das Ãreas avaliadas tÃm baixa atividade microbiana quando comparados a solos do Cerrado. A atividade e produÃÃo da arilsulfatase e da fosfatase Ãcida foram estimuladas possivelmente, pela competiÃÃo dos Ãnions H2PO4 - e SO4 - pelos mesmos sÃtios de adsorÃÃo nos colÃides do solo, nas Ãreas de banana e rotaÃÃo milho e soja. A maior atividade da enzima β-glucosidase ocorreu nas Ãreas cultivadas, influenciada pela quantidade e qualidade do resÃduo vegetal retornado ao solo. / This work had the proposed to evaluate the alterations in the microbial activities, chemistry and physics in soil under annual and perennial agricultural systems in the area of the Chapada do Apodi - CE. It tried to test the hypothesis that the agricultural use of areas under annual and perennial systems causes environmental alterations that they influence the biomass and the microbial activity of the soil, reducing it in relation to areas under natural vegetation. Two areas were selected with respective witness (natural vegetation); the first under cultivation of banana trees (Fazenda Frutacor) and the other under cultivation of rotation corn and soy (Fazenda Faedo). Samples composed of soil were collected in three depths (0-5, 5-15 and 15-25 cm) with four repetitions. In the collected samples physical analyses, chemistries and microbiological were accomplished. Physically, an elevation was observed in the clay text, with the increase of the depth in the area cultivated with banana and in the forest natural pivot. In relation to the chemical attributes of the soil, the potential risks of salinity and of saturation for sodium seemingly are worthless. The handling practices reduced N and the total organic carbon in the soils of the areas under cultivation. With relationship to the microbiology of the soils, the carbon of the microbial biomass and the population of arbuscular mycorrhizal fungi were more elevated in the depth of 0-5cm of the soil. The basal breathing of the soil identified that the soils of the appraised areas have microbial when compared low activity the soils of the Cerrado. The activity and production of the arylsulphatase and of the acid phosphatase were stimulated possibly, for the competition of the anions H2PO4- and SO4- for the same ranches of adsorption in the coloides of the soil, in the banana areas and rotation corn and soy. The largest activity of the enzyme β-glucosidase happened in the cultivated areas, influenced by the amount and quality of the vegetable residue come back to the soil.
2

Efeito do lÃquido do pseudocaule da bananeira combinado com soluÃÃo nutritiva na formaÃÃo de mudas de bananeira / Effect of fluid from the pseudostem of banana combined with nutrient solution in the formation of banana plantlets

Daniely dos Santos Barboza Severino 04 October 2011 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / No cultivo de bananeiras faz-se o desbaste de brotaÃÃes e o corte de plantas que jà frutificaram gerando resÃduos lignocelulÃsicos. Os pseudocaules cortados formam a maior porÃÃo desse resÃduo e servem como meio para proliferaÃÃo de pragas na cultura. Na utilizaÃÃo industrial desse resÃduo fibroso gera-se o LÃquido do Pseudocaule da Bananeira (LPCB). Este estudo teve por objetivo avaliar efeitos do LPCB combinado com soluÃÃo nutritiva nos parÃmetros fisiolÃgicos, no crescimento e na nutriÃÃo de mudas da cultivar Prata AnÃ. Mudas micropropagadas foram cultivadas em colunas de PVC de 20 cm de diÃmetro por 65 cm de altura contendo cinco camadas de Argissolo (0-10, 10-20, 20-30, 30-40 e 40-60 cm) e submetidas a cinco dosagens do LPCB (0, 288, 576, 864 e 1152 mL), representados por concentraÃÃes volumÃtricas de Ãgua e o resÃduo (100:0, 75:25, 50:50, 25:75, 0:100, v:v), combinadas com duas concentraÃÃes da soluÃÃo nutritiva de Hoagland (uma forÃa e meia forÃa), utilizando-se cinco repetiÃÃes em cada tratamento. ApÃs 60 dias de cultivo determinou-se a taxa fotossintÃtica, a condutÃncia estomÃtica e o teor de clorofila nas folhas e, na ocasiÃo da colheita, aos 68 dias, obteve-se dados de altura e diÃmetro do pseudocaule, nÃmero de folhas, peso fresco e seco das raÃzes e das partes aÃreas e analisaram-se os teores de N, K e Na das raÃzes e das partes aÃreas das bananeiras. Em camadas de solo avaliaram-se caracterÃsticas microbiolÃgicas e quÃmicas. Os resultados indicaram que LPCB afeta a dinÃmica de nutrientes no solo, favorecendo o acÃmulo de Na e K numa camada mais prÃxima da superfÃcie e reduzindo o pH do solo em camadas sub-superficiais. A aplicaÃÃo do resÃduo incrementou a biomassa microbiana e a respiraÃÃo edÃfica. Maiores doses do resÃduo resultaram no menor crescimento e acÃmulo de biomassa da parte aÃrea. A aplicaÃÃo de doses crescentes do resÃduo resultou no incremento da taxa fotossintÃtica e na reduÃÃo da condutÃncia estomÃtica, transpiraÃÃo e teor de clorofila das folhas das bananeiras. / The cultivation of banana trees generate lignoselulosic residue by cutting shoots and the plants after bunch collection. The pseudo-stem represents the largest portion of that residue and serves as a medium for the proliferation of pests in banana field. By industrial processing of that fibrous residue is also generated expressive volume of Netâs speudo-stem (LPCB). This study aimed to evaluate the effects LPCB combined with nutrient solution on physiological parameters, shot growth and nutrition of seedlings of the cultivar âPrata AnÃâ. Plantlets were grown on PVC columns of 20 cm diameter by 65 cm high filled with Ultisol from five layers (0-10, 10-20, 20-30, 30-40 and 40-60 cm) and subjected to five dosages of LPCB (0, 288, 576, 864 and 1152 mL, represented by volumetric combinations of water and LPCB (100:0, 75:25, 50:50, 25:75, 0:100, v:v), combined with two concentrations of Hoagland nutrient solution (one strength and half strength), using five replicates for each treatment. After 60 days of plant cultivation the stomata conductance, photosynthetic and chlorophyll contents in leaves were determined and, at the time of harvest, 68 days, were measured plant height and pseudo-stem diameter, counted leaves, determined fresh and dry weight of roots and aerial parts and analyzed N, K and Na contends in roots and aerial parts of banana plants. In layers of soil were evaluated microbiological and chemical characteristics. The results indicated that LPCB affects the dynamics of nutrients in the soil, favoring the accumulation of Na and K in a layer near the surface and reducing the pH in subsurface layers. The LPCB application rates increased microbial biomass and edaphic respiration. A higher dosage of that residue inhibits the plantlet growth and dry weight accumulation. The increasing of LPCB dosages promoted higher photosynthetic rate, but reduces stomata conductance, transpiration and chlorophyll content in leaves of banana plants.

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