Abstract

COMBATT CABALLERO, Enrique; ALVAREZ V., Víctor Hugo  and  LIMA N., Júlio César. Comparison of Different Chemical Methods as Extrantes of Aluminum in Acid Sulphate Soils of Brazil and Colombia. Rev. Fac. Nac. Agron. Medellín [online]. 2015, vol.68, n.1, pp.7569-7579. ISSN 0304-2847.  https://doi.org/10.15446/rfnam.v68n1.47845.

The acidification of acid sulphate soil has as a result the solubilization of Al compounds, which increases the concentration of Al³⁺ in the soil solution. This study was carried out to evaluate the levels of exchangeable and active Al extracted with 12 analytical methods, in soil samples from acid sulphate soil from Brazil and Colombia. It was conducted an laboratory investigation with 12 samples soils, nine from Espirito Santo State (Brazil) and three from Colombia. The methods evaluated were: KCl 1 mol L^-1, Ca(OAc)₂ 0.5 mol L^-1 pH 7, BaCl₂ 0.1 mol L^-1, NH₄OAc 1 mol L^-1 pH 4.8, CuCl₂ 0.5 mol L^-1 pH 2.8 e LaCl₃ 0.33 mol L^-1 pH 4.0. For comparison of extraction methods, the treatments were set as a factorial 12x12 design, arranged in a randomized block with three replications. The analysis of variance, statistics descriptive and contrasts were applied to determine the capacity of Al extraction by the chemical methods. The quantitative determination showed that the method with higher extraction capacity of Al was the Na₄P₂O₇ solution. The methods that use chloride ions unbuffered, are able to extract more efficiently the Al of the acid sulphate soil than the solutions of acetates, being the CuCl₂ and LaCl₃ the ones with highest efficiency. The increase in the stirring time did not increased the extraction efficiency of Al among the non-buffered solutions.

Keywords : Chemical analyze; phytotoxicity; thiomorphic soils; acidity; organic compounds.

        · abstract in Portuguese     · text in Portuguese     · Portuguese ( pdf )