Report on the impact of anthropogenic factors on the properties and functions of soils from a selected area of Central European Lowland province

Abstract

Abstract Purpose The study aims to assess the impact of human activity on the content and migration of trace elements in soil profiles of various physico-chemical properties. The research hypothesis assumed that human impact related to the functioning of buildings, agriculture, industry and communication negatively affected the trace element contents and physico-chemical properties of soils in a selected urban area (the Grudziądz Basin). Materials and methods Seven soil exposures were made in areas that differed in land use and soil type over an area totalling approx. 200 ha. In the soil profiles, samples of soil of disturbed structure were taken from each genetic horizon. Selected physico-chemical properties of soils were determined: soil texture, soil pH, TOC, CaCO3 content. The total content of heavy metals in the soils was determined by AAS after digestion in hydrofluoric acid and bioavailable forms in 1 M DTPA. The sources of elements in the studied soils were assessed using the following indices: Enrichment Factor (EF), Geoaccumulation Index (Igeo) and Contamination Factor (CF). Results and discussion The sand fraction dominated the examined soil profiles, with its content ranging widely and averaging 64.7%. In general, the humus horizons had lower pH values than the deeper layers and parent rock horizons. The organic carbon content ranged from 0.07 to 4.64%. The vertical decomposition of total N was strongly related to the decomposition of organic carbon. The highest metal contents in the soil samples were for zinc, and then for nickel. Conversely, the lowest concentrations were for mercury. Most of the profiles had higher contents of the analysed elements in their upper horizons. The humus horizons were characterised by the accumulation of Cr, Hg, Zn and Fe. The samples from the soil profiles were highest in bioavailable forms of zinc and nickel. Conclusions The assessment of human impact on the concentrations and migration of trace elements in profiles of agricultural soils found the contents of heavy metals to be variable. Only in a few profiles were EF values for Cd, Pb and Ni found to indicate the effects of human activity. Likewise, CF and Igeo attest to only slight contamination in the research area.