Chemical dispersants and quantification textural fractions by Bouyoucos and pipette methods

Abstract

An adequate individualization of particles is required for a correct granulometric analysis in order to quantify the real percent composition of particles in the soil. The aim of this study was to compare the percent of granulometric fractions determined by two different chemical dispersion methods. For that, nine different chemically soil samples were collected from Department of Córdoba and Sucre on Colombian Caribbean region and were analyzed by Bouyoucos and pipette methods. (NaPO3)6/Na2CO3 solution (Calgon) and a mixture of 0.1 M sodium pyrophosphate solution at pH 10 and Calgon in relation 2:1 were used as chemical dispersants. Results were analyzed using Leite and Oliviera (2002) test and correlation analysis. A significant statistic difference between pipette method and Boyoucos method using the proposed chemical dispersant was found for sand and clay fractions with values of 0.97 and 0.89, respectively. The lower sand contents were obtained using the pipette method with an average value of 26%, followed by proposed dispersant with a value of 28%. Average contents of clay were 44 and 42% by proposed dispersant and the pipette method, respectively.

Keywords

• Análisis granulométrico
• dispersantes
• pruebas de correlación