ПРОЦЕСИ МІГРАЦІЇ ВАЖКИХ МЕТАЛІВ У ГІДРОМОРФНИХ ҐРУНТАХ ПОЛІССЯ ПІД ВПЛИВОМ ОСУШЕННЯ

Abstract

The emission of chemicals of various anthropogenic origins into the environment, including drained hydromorphic soils, is taking on alarming proportions. Therefore, the basis of our research is the ecological soil assessment on the content of heavy metals. The research is carried out by comparing the actual content of heavy metals in drained and non-drained soils and the MAC indices of regional heavy metals cliques for soils in Ukraine according to A.I. Fadeyev. Field and laboratory studies were carried out according to existing methods, applying the laboratory-chemical method for determining the main parameters of the researched soils. The authors have defined that, as a result of prolonged drainage, the elution of heavy metals moving forms from the upper genetic horizons of the humus-alluvial horizon to the lower ones in sod-medium podzolic glued sandy soils is observed. The upper genetic horizons of drained soils are revealed to undergo maximum changes as there the accumulation of the researched elements and their fixation take place. It is possible due to the largest amount of humus in these horizons, and the application of mineral fertilizers and ameliorants most of which are concentrated in the upper layer of the soil. The alluvial horizons undergo impoverishment in the moving forms of heavy metals as a result of their washing out with the descending flow of water and the transfer of the clay fractions to deeper and dense horizons. Alluvial soil profile horizons being placed at the rock edge, under the gleying and researched heavy metals elution from the upper genetic horizons, accumulate heavy metals and play the role of protective barrier to the migration of heavy metals with drainage waters. The distribution of mobile forms of heavy metals along the profile of sod-mid-podzolic gley sandy loam soils has the following character. In both drained and non-dried soils, high concentrations of the researched elements moving forms are observed in the humus-eluvial horizon. As the result of prolonged drainage, the pollutant elements are washed out from the humus-eluvial and eluvial horizons and washed and fixed in the Iluvial genetic horizon at the depth of 50-60 cm, except molybdenum and cobalt, which are also fixed in the horizon transitional to the parent rock. Moreover, copper, boron and lead are accumulated most intensively in the Iluvial horizon. To conclude, heavy metals partially migrate with the ground solution down the profile and are accumulated in the lower genetic horizons of sod-medium podzolic gley sandy loam soils, facilitated by a vertical flow of atmospheric moisture. But the accumulation of heavy metals in the lower horizons of hydromorphic soils is not a natural phenomenon: a number of heavy metals are accumulated in the lower horizons, while others are not thus requiring further research.