Profile degradations of podzolic chernozem of the territory of Male Polissia

Abstract

The article presents the results of the study of Male Polissia podzolic chernozems profile degradation. The causes and consequences of this dangerous natural and man-made phenomenon resulting in changes in the habitus of soils, losses of soil mass and humus, deterioration of general physical properties and structural and aggregate composition, decrease in soil fertility and agriculture unprofitability on the slopes have been analysed. In the study of the profile degradation of podzolic chernozems, the following methods have been used: comparative-geographical, comparative-profile, soil-catena, analytical, and statistical. Field studies were conducted after the vegetation period. According to the study results, the thickness of the profile of weakly eroded podzolic chernozems, in comparison with non-eroded types, decreased by 17.0–35.5% as compared to the standard, which corresponds to satisfactory and pre-crisis condition, in medium eroded soils - by 32.2–63.4%, the degree of degradation is estimated as pre-crisis, crisis and catastrophic. In the highly eroded types, the thickness of the soil layer decreased by 47.8–74.9%, which indicates a high and very high (crisis) level of profile degradation. Erosion soil loss compared to the standard in weakly eroded podzolic chernozems is 1245.0-3744.6 t/ha, in medium eroded soil – 6762.4-8321.0 t/ha, and in highly-eroded soil – 8874.0-11595.0 t/ha. It has been established that chernozems as a result of water erosion from one hectare of weakly eroded podzolic, on average 39.47–118.70 tons of humus was eroded, 214.36-237.98 tons was eroded from medium eroded ones, and 240.49-267.84 tons from highly eroded soils. The average annual loss of humus is from 0.23-0.68 t/ha in weakly eroded types to 1.37-1.53 t/ha in highly eroded podzolic chernozems. Erosion processes result in deterioration of physical properties of soils. The use of dense and low-humus plumage horizons for plowing causes compaction of soils and deterioration of structure. Minimization of podzolic chernozem profile degradation in Male Polissia is possible provided that the system of anti-erosion measures, especially the conservation of highly eroded soils, the introduction of soil protection methods for soil cultivation, optimization of the structure of crop areas, ban on cultivated crops on slopes more than 3° steep, consolidation of small areas in larger arrays are applied. It is also necessary to introduce a system of basic and crisis monitoring over the condition of eroded soils. Key words: Male Polissia, podzolic chernozems, profile degradation, water erosion, humus, soil conservation.