В. Г. Мамонтов The fractions of granulometric elements isolated by the method of roiling from the humusaccumulative horizon A of the deep typical virgin chernozem of the Kursk Region were studied using infrared spectroscopy. According to the data obtained, the fractions of granulometric elements differ significantly in their material composition. The coarse dust fractions mainly consist of quartz, feldspar, polysaccharides and a small amount of specific humus substances. The fine dust fractions, and in particular the silt fraction, differ significantly in material composition from the coarse dust fractions. They are mainly composed not only of polysaccharides, but also of clay minerals, including alternating layer formations of the mica-montmorillonite type, a much higher amount of specific humus substances, and less quartz and feldspar. The medium dust fractions occupy an intermediate position in terms of material composition and are closer to the fine fractions than to the coarse dust fractions. The method of infrared spectroscopy makes it possible to reveal fundamental differences in the material composition between individual granulometric fractions. However, a number of specific features inherent to individual components of the soil solid phase are not apparent in the infrared spectra of granulometric fractions. This is due to the active interaction between the organic and mineral components of the soil. As a result of such interactions many active centers and functional groups are blocked and do not appear in the infrared spectra.
Научная статья 
Haplic Chernozem (Loamic, Pachic)