Single-tree effects on soil organic matter properties of a xanthic Ferralsol in the central Amazon.

Studies on: a) identification soil pools which are sensitive to land-use changes on the terra firme; b) evaluation of the potential of different trees to increase soil organic matter (SOM) contents; and c) elucidation of the the mechanisms of SOM replenishment in Ferralsols of the central Amazon. Conclusions: using aggregate fractionation together with the chemical characterisation of SOM, the processes of incorporation of plant litter into stable SOM could be successfully studied in the strongly aggregated Ferralsol. Thus, it could be shown that aggregation promoted the stabilisation of SOM, but SOM did not incrase aggregate stability. The particulate organic matter was an important and valid indicator of the effects of different organic inputs on SOM properties. It could be used for assessing the effects of land-use or single trees on SOM of the studied Ferralsol. In the fraction 0.25mm-0.5mm strongly humified POM was incorporated into aggregates, being the most sensitive to land-use changes among the aggregate fractions.bitstream/item/181046/1/ID-2600-15-24.pd

Lime and gypsum applications.

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Phosphorus fertilizer placement and profitability.

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Micronutrient fertilization on a typic acrorthox at Manaus, Brazil.

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Lime requirements and downward movement of Ca and Mg.

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Nutrient dynamics.

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Caracterização química de compostos de lixo urbano de algumas usinas brasileiras.

Avaliacao das caracteristicas quimicas de compostos de lixo urbano e analise de esterco, calcario, superfosfato simples, KCl e ureia para comparacoes destes com o lixo urbano. Foram feitas determinacoes de M.O., C, N, P, K, Ca, Mg, Cu, Mn, Mo, Zn, Fe, Al, Ba, Cd, Co, Cr, Ni, Pb, Sr, Ti, e V. Houve diferencas nos teores de nutrientes entre os compostos, provavelmente devidas aos diferentes processo de compostagem, estando alguns deles acima dos niveis toleraveis em composto na Alemanha. Os demais elementos analisados, incuindo os metais pesados, estao dentro da faixa observada em lodo de esgotos na Inglaterra. De acordo com a legislacao alema, Pb, Cr, Ni e Cd estao acima dos valores toleraveis para compostos de lixo. Na maioria dos compostos analisados, os teores totais de nutrientes foram menores do que no esterco, mas a concentracao dos outros elementos, inluindo metais pesados, foi mais elevada do que no esterco. Embora os teores dos elementos avaliados nos compostaos seja os totais, e' necessario cautela para seu uso, ate que sejam obtidos resultados seguros sobre a "disponibilidade" desses elementos para as plantas