Granulometric analysis of different soils by horizontal shaking

Abstract

To test the hypothesis that the particle-size analysis using slow horizontal agitation provides similar results to fast agitation, both methods, fast and slow agitation, were made at three times (6; 12 and 18 h), as well as the use of sodium hydroxide (NaOH) and sodium hexametaphosphate (NaPO₃)₆. Soil samples from different classes and depth from Ceará and Rio Grande do Sul were used in this study. The statistical analysis was done by non- orthogonal contrasts from the degrees of freedom of the treatments deriving contrasts of interest. The significance was tested by the F test at 5 and 1% of probability. The results permit to conclude that NAOH was more efficient in the chemical dispersion of soils. The slow agitation can be used to all the tested times. The additional collection of suspension showed better results for the textural analysis, dividing the experimental error within the four granulometric fractions.