ASSESSMENT OF SOIL ACIDITY IN CITIES OF BELARUS

Abstract

As a result of the analysis of the pH indicator in urban soils, carried out according to the NSMOS data, it was found that in the cities of five administrative regions of Belarus, according to the average pH value, the soils are characterized as slightly alkaline, in the Gomel region – as neutral. In 74 % of the studied settlements, slightly alkaline soils predominate, in 22 % – neutral and in 4 % – close to neutral. An assessment of the acidity of urban soils over a more than twenty-year period showed that in 47 % of cities soil alkalization is observed, in 20  there is acidification, and in 33 % no changes noted. Spatial differences in minimum and maximum pH values   in soils of 55 % of cities decreased over time, 39 remained unchanged, 
and 8 % increased. The process of soil alkalization in cities can be caused by industrial emissions, the accumulation of building materials and debris in the soil during urban development of the territory, the seasonal use of deicing mixtures and a change in the mechanism of infiltration of atmospheric precipitation due to large areas of sealed territories. In the background areas studied within the framework of the NSMOS, a high pH value was also noted, which may be due to the soddy process of soil formation with a humus horizon saturated with bases, characteristic of areas with herbaceous vegetation that predominates in the background areas. The soils of agricultural lands in all rounds of their survey (1966 - 2020) belonged to groups with high acidity from moderately acidic to slightly acidic, which is the result of the natural features of the territories, as well as the systematic use of fertilizers and liming of soils in order to regulate their acid-base conditions. A change in the acidity of urban soils towards alkalization can have a number of environmental consequences, in particular, a decrease in the activity of soil enzymes and the rate of transformation of organic matter, a decrease in the mobility of heavy metals due to the formation of sparingly soluble compounds, a decrease in their availability for plants as 
microelements, and their accumulation in the upper horizons, which contributes to the pollution of urban soils.