Comparison of Different Texture Analysis for Soil Erodibility Calculations of Loamy and Sandy-Loam Soils in Moravian Regions

The subject of this article is a comparison of results of soil texture analysis of loamy and sandy-loam soils for soil erodibilty calculation using the Casagrande areometric method and results obtained by the laser diffraction method. A comparison was made of 27 samples taken from the Větřkovice locality, and 18 samples taken from the Hustopeče locality. On the basis of laboratory analysis of the soil samples, curves of grain composition were plotted, and the soils were divided into grain-size groups according to the ratio of individual fractions. For comparison of the results, the soils' regression dependence, with linear, exponential, quadratic and polynomic trends were derived. Applying these different methods for determining soil texture may affect the determination of K factor values and the value of soil loss. The results show that the laser diffraction method provides higher values of % silt and % silty sand at both model sites. Using the K values determining from Casagrande method measuring can led to the underestimation of soil erodibility. This underestimation can be explained by a change in particle size distribution between the described methods used.