Environmental aspects of urban soils

Physical and chemical transformation is typical for urban soils, that considerably aggravate their agroecological functions. The purpose of this work consists in ecological assessment of the current state of urban soils of Cherkasy. The city soils have a significant man-made load and contain many chemical xenobiotics. Diagnostics of the indicators of urban soils, which are crucial for assessing their ecological status and their agroecological functions, will provide an opportunity to determine the optimal and critical values for the sustainable functioning of urban landscapes and to propose the most effective and timely measures to be implemented. The urban soils analysis has shown that the humus content varies within the range of 0.033.01 %, with an average value of 0.84 %, a standard deviation of 0.67, a dispersion of 0.41, a variation coefficient of 76 %. 6.25 % of the studied soil samples have insufficient supply of humus (2-4 %), 25 % have poor supply (1-2 %) and 69 % have extremely poor supply (less than 1 %). The active acidity (pH) varies from 6.45 to 10.90 with an average value of 7.20, a standard deviation of 0.83, a dispersion of 0.69, a variation coefficient of 11 %. The soils mostly have a weakly alkaline and neutral environment. The oxidation-reducing potential varies from 252 to 287 mV, with an average value of 262 mV (standard deviation of 7.3, a dispersion of 52.6, a variation coefficient of 3 %). The ratio of Ca²⁺ and Mg²⁺cations in soil adsorption complex is not optimal. The content of Ca²⁺ ranges from 3.80 to 10.12 mg-eq./100 g of soil with an average value of 6.60, a standard deviation of 1.66, a dispersion of 2.77, a variation coefficient of 25 %. The content of Mg²⁺ varies from 0.0 to 10.40 mg-eq./100 g of soil with an average value of 3.14 (standard deviation of 2.50, a dispersion of 6.26, a variation coefficient of 80 %). The content of K⁺ ranges from 0.12 to 6.20 with an average value of 0.59 mg-eq./100 g of soil, a standard deviation of 0.67, a dispersion of 1.39, a variation coefficient of 95 %. The soils have a significant deviation from optimal values and that characterizes them as anthropogenically and technogenically urbanized. There is a need in soil gypsuming, organic fertilizers, moisture supply and reduction of moisture evaporation, improvement of aeration conditions

urban soils; chemical transformation; soil physicochemical properties; humus; plants