1000 resultados para adsorção de fósforo
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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Pós-graduação em Ciência dos Materiais - FEIS
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Pós-graduação em Engenharia Civil - FEIS
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Pós-graduação em Agronomia (Horticultura) - FCA
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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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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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Pós-graduação em Agronomia (Ciência do Solo) - FCAV
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The enrichment of an organic compound with biofertilizers of microorganisms (solubilizing phosphorus bacteria, BSF) can improve the properties of phosphate fertilizers applied to soils to increase nutrient availability. The experimental design was randomized complete blocks with a factorial 4x2 +1 arrangement of treatments: 1) four sources of phosphorus: phosphate rock, natural phosphate, triple superphosphate (TSP) and Cuban phosphate rock; 2) two sources of bio-fertilizer prepared from filter cake (cane waste) enriched with microorganisms and no enrichment; 3) and an absolute control (no filter cake or fertilizer); repeated three times. Data was analyzed with ANOVA and treatment means were compared using Tukey (p <= 0.05). Assessments of available P (Bray-2 and Oniani methodology) and the quantification of total and solubilizing bacteria and fungi in the soil were performed 30, 60 and 90 d after starting the experiment. After 60 d, the population of BSF was lower in the control (p <= 0.05) and the content of P (Bray-2) was higher for SFT (p <= 0.01). The application of the bio-fertilizer increased the P content compared to the control. At 90 d P (Bray-2) increased with the SFT treatment, which also increased (p P in the soil at 60 and 90 d regardless of the presence of microorganism-enriched bio-fertilizer. The use of filter cake enriched with microorganisms associated with different sources of P, and applied to the soil with a high content of P, did not change the soil populations of total and solubilizing bacteria and fungi in the short term. TSP promoted the highest levels of P in the soil, irrespective of the presence of the organic compound enriched with P solubilizing microorganisms.
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Heavy metals are found naturally in soils at low concentrations, but their content may be increased by human activity, making them one of the barriers in management of tropical soils. These chemical elements can be found in the composition of organic and inorganic fertilizers, insecticides, fungicides, mine tailings, and urban waste, and may cause serious damage to the environment and human health. Thus, adsorption studies are essential in assessing the behavior of heavy metals in the soil. The objective of this study was to evaluate the influence of soil chemical, particle size, and mineralogical properties on adsorption of cadmium (Cd), evaluated by Langmuir and Freundlich models, in Latossolos (Oxisols) with or without human activity. Soil samples were collected from the surface layer, 0.00-0.20 m, and chemical, particle size, and mineralogical analyzes were performed. In the adsorption study, concentrations of 0, 5, 25, 50, 100, 200, 300, and 400 mu g L-1 of Cd were used in the form of Cd(NO3)(2). The empirical mathematical models of Langmuir and Freundlich were used for construction of adsorption isotherms. Data were analyzed by means of multivariate statistical techniques, Cluster Analysis and Principal Component Analysis. The data from the adsorption experiment showed a good fit to the Langmuir and Freundlich models. Soils with a lower goethite/hematite ratio and greater cation exchange capacity and pH, showed higher maximum adsorption capacity of Cd.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Brazil is the largest world producer of yellow passion fruit, a fruit crop which is exigent in nutrients, although little studied in relation to phosphorus fertilizing, fundamental on plant establishment. An experiment was carried out during the period of March/2010 to April/2011 in Remigio County, Paraiba State, Brazil, in order to evaluate the vegetative and productive attributes of yellow passion fruit plants under different sources and doses of phosphorus. Treatments were distributed in randomized blocks in tree replications and twelve plants by plot using the factorial design 2 x 5 referring the sources of superphosphate triple and superphosphate simple at levels P2O5 of 0, 12, 18, 24 and 30 g cave(-1). The following variables were recorded: stem diameter, number of productive branches, number of fruits per plant, fruit mass and fruit yield. The sources and doses of phosphorus affected growth and fruit production of yellow passion plants. The triple superphosphate is the most phosphorus efficient source for growth and fruit production of yellow passion fruit. The triple superphosphate dose which promoted the maximum yield of yellow passion fruit is 42.86 g.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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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)