The influence of soil texture on the course of volume changes of soil

Volume changes of soil associated with soil moisture changes are caused by the presence of clay minerals from illite and montmorillonite groups. Clay minerals are found in the so-called clay soil component which can be quantified by laboratory analysis of the soil particle-size distribution. Consequently, the potential for volume changes in soil can be assessed from soil texture. In our study, 172 soil samples with different textures were used to measure dependencies between volume changes in soil and changes in soil moisture under laboratory conditions. The samples were collected from 11 sites in the Eastern Slovak Lowland. On the basis of the measurements, 10 mathematical models were created to compute the correlation between volume changes of soil and soil moisture content and texture. The highest accuracy was obtained with the model which assumes the content of particles < 0.002 mm. When comparing the clay particles < 0.001 mm (colloidal clay) with the particles < 0.002 mm (colloidal + physical clay) it was also found that the particles < 0.002 mm have a larger impact on the volume changes of soil than the particles < 0.001. The inclusion of particles > 0.002 mm (silt + sand) into the models resulted in either no or only negligible refinement of the soil volume change calculations.