Deconvolution of Differential Particle-Size Distribution Curves for Vertisols

Abstract

The deconvolution procedure for splitting the initial particle-size distribution spectrum into constituent fractions makes it possible to refine the traditional indicators of particle-size distribution and gives us new information about the properties of individual particle-size fractions. Owing to the deconvolution, it is possible to identify fractions that remain “invisible” upon the traditional visual analysis of the initial particle-size distribution spectra. The new indicators include the average diameter of the particle-size fraction d_aver, the dispersion value D of each fraction, and the convergence index of the neighboring fractions h. Deconvolution helps us to characterize the fractions not by their size boundaries, but by the average particle diameter. Deconvolution has shown that the distribution of major particle-size fractions in Vertisols is consistent with the boundaries of the particle-size factions according to the international classification system and is not consistent with the boundaries of the particle-size classes in the classification by Kachinskii (Russia), in which the width of the classes is variable (index F is either 2 or 5). The advantage of the international classification of particle-size fractions is the same width of separate size classes with a constant F value (F = 3.2).