THE EXPERIENCE OF SOCHI GYMNASIUM PUPILS IN STUDYING PHYSICO-CHEMICAL PROPERTIES AND BIOLOGICAL ACTIVITY OF SOILS UNDER RECREATION ZONES
Physical and chemical properties and "respiratory" activity of the upper horizon U of urban soils (structural and metamorphic reservoirs) (5-10 cm layer) under recreational zones were assessed in Sochi. It was found that as a result of an anthropogenic activity, the background zonal soils (yellow soils) changed according to a set of diagnostic features: color was from gray-brownish-yellow to black (due to their cultivation and application of humus horizon of chernozems to the material surface); mechanical composition was from medium to light loam; acidity of the soil solution pH varied from 5.5 to 7.9. Close to neutral pH values contributed to an increase in the "respiratory" activity of the soils under recreational zones relative to the background soils of the Dendrariy Park from 70.6 to 123.5 CO<sub>2</sub>, mg/kg PP day. The obtained data can be used in the Agrochemistry and Soil Science Laboratory of FRC SSC RAS in the framework of case studies when comparing anthropogenic-transformed urban soils with different loads (zones of recreation and pollution).