Naslov
Revisiting the Particle Size Distribution of Soils : Comparison of Different Methods with Regard to Sample Pretreatment Implications

Autori
Vdović, Neda ; Obhođaš, Jasmina ; Pikelj, Kristina

Izvornik
European journal of soil science (1351-0754) 61 (2010), 6; 854-864

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
clay particle; organic matter; particle size fraction; soil aggregation;

Sažetak
The choice of sample pretreatment and analytical method has significant consequences on 19 the shape of the particle size distribution (PSD) frequency curves, and therefore on the 20 evaluation of soil textural parameters and soil determination. Here, the comparison of 21 granulometric methods based on different physical principles is presented: Wet Sieving (WS) 22 – gravity and mechanical force of water, Pipette (PP) – sedimentation/settling velocity, 23 Micromeritics SediGraph (MS) – sedimentation/x-ray attenuation, Coulter Counter (CC) – 24 electroresistance particle counting and Malvern Mastersizer (MM) – laser diffraction, where 25 WS was combined with PP, MS and CC. Twelve typical soil types from temperate region, 26 determined by their mineral composition, organic matter content, conductivity and magnetic 27 susceptibility, were chosen for this study. 28 The modalities of PSD frequency curves were analyzed, showing considerably higher 29 clay fraction content measured with the sedimentation techniques, PP and MS, then those 30 measured by the CC or MM. 31 Statistical correlation and regression models were used to relate the fractions of clay, silt 32 and sand. All the regression analyses showed linear dependence, except those comparing CC 33 derived clay fractions with clay fractions obtained by other three methods - they showed 34 strong non-linear dependence. The effect was attributed to the presence of aggregates and/or 35 magnetic properties of soil particles. However, more data is needed to verify this hypothesis. 36 The implications of sample pretreatment by dispersant and H2O2 were evaluated by the 37 MS and CC techniques and inspected with the scanning electron microscope. The H2O2 was 38 proven to be efficient disaggregating agent, while the dispersant significantly contributed to 39 the clay fraction content measured by the MS method

Izvorni jezik
Engleski

Znanstvena područja
Geologija

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