The humus state of the soils of locally hydromorphic landscapes in the lower reaches of the don river

Abstract

The humus state of rainfed chernozems affected by local waterlogging was studied. The total humus content in the hydromorphic chernozems increases, as well as the content of fulvic acids, whereas the content of nonhydrolyzable residue (humin) decreases. A significant increase in the portions of the third frac tions of humic and fulvic acids is observed. The role of the fine silt and clay fractions in the binding of humic substances increases in the lower horizons of locally hydromorphic soils. The increase in the content of fulvic acids (fulvatization) is mainly due to their predominance in the clay fraction. The latter is specified by the sig nificant narrowing of the C ha to C fa ratio, the lower content of the nonhydrolyzable residue, and the increased content of the clay bound (3rd fraction) fulvic and humic acids. The composition of the humus in the fine silt fraction of the studied soils is characterized by an increased amount of humic acids of the second fraction with a decrease in the relative content of fulvic acids.

Current State of Haplic Chernozems in Specially Protected Natural Areas of the Steppe Zone

“…Haplic Chernozems are characterized by specific distributions of free carbonates in the form of carbonate mold along with common carbonate neoformations (beloglazka and veins) (Bezuglova and Yudina, 2006;Bezuglova and Tischenko, 2012;Gromakova et al, 2017;Minkina et al, 2008;2010). Haplic Chernozems are frequently called micellar-calcareous chernozems.…”