991 resultados para Mapeamento dos solos


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Psicologia - FCLAS

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In soil surveys, several sampling systems can be used to define the most representative sites for sample collection and description of soil profiles. In recent years, the conditioned Latin hypercube sampling system has gained prominence for soil surveys. In Brazil, most of the soil maps are at small scales and in paper format, which hinders their refinement. The objectives of this work include: (i) to compare two sampling systems by conditioned Latin hypercube to map soil classes and soil properties; (II) to retrieve information from a detailed scale soil map of a pilot watershed for its refinement, comparing two data mining tools, and validation of the new soil map; and (III) to create and validate a soil map of a much larger and similar area from the extrapolation of information extracted from the existing soil map. Two sampling systems were created by conditioned Latin hypercube and by the cost-constrained conditioned Latin hypercube. At each prospection place, soil classification and measurement of the A horizon thickness were performed. Maps were generated and validated for each sampling system, comparing the efficiency of these methods. The conditioned Latin hypercube captured greater variability of soils and properties than the cost-constrained conditioned Latin hypercube, despite the former provided greater difficulty in field work. The conditioned Latin hypercube can capture greater soil variability and the cost-constrained conditioned Latin hypercube presents great potential for use in soil surveys, especially in areas of difficult access. From an existing detailed scale soil map of a pilot watershed, topographical information for each soil class was extracted from a Digital Elevation Model and its derivatives, by two data mining tools. Maps were generated using each tool. The more accurate of these tools was used for extrapolation of soil information for a much larger and similar area and the generated map was validated. It was possible to retrieve the existing soil map information and apply it on a larger area containing similar soil forming factors, at much low financial cost. The KnowledgeMiner tool for data mining, and ArcSIE, used to create the soil map, presented better results and enabled the use of existing soil map to extract soil information and its application in similar larger areas at reduced costs, which is especially important in development countries with limited financial resources for such activities, such as Brazil.

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Forestry has grown in a continuous and accelerated manner in Brazil, constituting a strategic activity for the generation of employment, income and tributes, favoring social and economic development of Brazilian agribusiness. The objectives of this study were: (1) evaluate the contents of K, Ca and Mg in the reserve compartments, non-interchangeable, interchangeable, available and the speed of its release, its correlations and its effects over productivity (annual average increment – AAI) of eucalyptus plantations, in forest sites cultivated in soils of the state of Rio Grande do Sul; (2) evaluate the initial growth, nutrition and physiological aspects of eucalyptus plants, cultivated with and without the addition of mineral sources of potassium (K), calcium (Ca) and magnesium (MG), in soils obtained from forest sites in the state of Rio Grande do Sul. In the first study, contents of K, Ca and Mg were evaluated in sulfuric digestion extract, boiling nitric acid, ammonium chloride, Mehlich-1 (only K), potassium chloride (Ca and Mg), as well as the release speed of these nutrients in the soil. In the second study, growth variables, nutritional aspects, photosynthetic rate (A) and transpiration rate of the plants (E) grown in distinct soils were evaluated under controlled conditions. The contents of K, Ca and Mg varied between compartments and depths in the studied soil classes, with the highest proportions found in the reserve compartment, indicating the importance of this compartment for the supplement of these nutrients at average and long terms. The great majority of K, Ca and Mg compartments presented significant correlations between each other, showing the dependence between them and the importance of evaluating the contents of these nutrients in the different compartments to adapt the nutritional management of the plants to each soil class, and to obtain continuous productions, minimizing the negative effects to the environment. Plants cultivated in soils that present larger reserves, availability and K, Ca and Mg release kinetics, presented similar height (H), stem diameter (SD) and shoot dry mass (SDM), with or without fertilization with K, Ca and Mg. The plants presented higher leaf content and accumulation of K in all soils fertilized with K, Ca and Mg.

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Determination of organic acids in soils and organic materials is important due to the important role they play in improving the soil's physical, chemical and microbiological conditions. This study identified and quantified low molecular weight organic acids (LMWOA) in soils (dystroferric Red Latosol, dystrophic Red-Yellow Latosol and Quartzarenic Neosol) and organic materials (cow, pig, chicken, quail and horse manures, sawdust, coconut fiber, pine bark, coffee husks, biochar, organic substrate, sewage sludges 1 and 2, garbage compost, pig slurry compost). The following acids were identified: acetic, citric, D-malic, formic, fumaric, maleic, malonic, oxalic, quinic, shikimic, succinic and tartaric.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)