Resumo

BEHRENDS KRAEMER, Filipe et al. Efectividad de distintos pretratamientos en el análisis granulométrico de tres suelos contrastantes de la Región Pampeana. Cienc. suelo [online]. 2016, vol.34, n.1, pp.163-172. ISSN 1850-2067.

Granulometry is one of the main soil characteristics and its evaluation gives key information in the determination of its physical properties. However, there are still methodological discrepancies related to soil dispersion and organic matter elimination (OME) procedures. In this work changes in granulometry were assessed for in three soils with contrasting textures, mineralogy, and organic matter levels. Two OME procedures (calcination at 430 ºC and oxidation by H₂O₂) and two shaking velocities (90 and 150 rpm) in reciprocal agitator were evaluated. When organic matter was eliminated with H₂O₂, higher clay extraction was obtained regardless of the agitation velocities. In the sandy soil (Haplustoll), the combination of calcination and 150 rpm shaking velocity showed a similar statistical performance than H₂O₂ and 150 or 90 rpm shaking treatment. On the contrary, for the fine texture soils assessed for in this work (Argiudoll and Hapludert), calcination techniques would not be appropriate as they underestimated clay content due to a probable clay particle reorganization produced by heat. This work highlights the importance of methodological conditions on the outcome of soil granulometric distribution. The evaluation of a larger number of soils and of other soil Orders is necessary to achieve sound determination methodologies.

Palavras-chave : Granulometry; Organic matter elimination; Mechanical dispersion.

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