Chemical properties of soils in closed depressions of the northern Tambov Plain

Chemical properties of chernozem-like soils in closed depressions on different relief elements in the northern part of the Tambov Plain differ significantly. The soils with podzolic features in depressions on the watershed have a high acidity and a low degree of base saturation. The soils on the above-floodplain terrace are neutral and saturated with bases. When the degree of moistening increases, the share of magnesium in the total exchangeable bases increases to 30–35%. In the soils of surface flooding under gleyzation conditions, iron is leached from the fine earth, and iron nodules are formed. In the soils formed under the impact of groundwater, iron diffusion is observed in the surface layers. In the podzolic horizons of soils on the watershed, humus acquires a fulvic-humic character. In the soils formed under the impact of groundwater and water stagnation conditions typical for gleyed soils, the Cha: Cfa ratio is higher than 1.