Properties of psammozems of the Kama terraces above the floodplain and assessment of their sustainability to pollution by Cu and Cd

Abstract

Pine forests growing on psammozems, found on sandy Kama terraces above the floodplain within the territory of Perm, encompass roughly 2 thousand hectares. The study was conducted on psammozems under the influence of advancing pollution caused by heavy metals, highlighting the significance of soil’s buffering capacity in preserving the ecosystem’s stability. It is of great interest to investigate the morphogenetic properties of psammozems and evaluate the risks linked to the accumulation of Cu and Cd in these soils through the analysis of changes in soil enzyme activity (catalase, urease, and invertase) and the occurrence of phytotoxicity. The psammozems found in the Kama region originated from periglacial sandy alluvium, which was deposited during glacial melting in the Mesozoic era. The variety of humus psammozems includes typical, podzolized, illuvial-ferruginous, and pseudofibrous subtypes. These soils are highly acidic, have a very low absorption capacity, low base saturation, and reduced activity of soil enzymes. The contents of Cu, Cd, Zn, and Pb in psammozems are notably lower compared to the regional soil clarks; however, in the underdeveloped humus horizons, the concentrations of these metals are slightly higher than in soil-forming sands. The experiment was conducted to determine the ecotoxicological load, where mixed soil samples from a 0–20 cm layer of humus psammozems were treated with solutions containing copper acetate and cadmium acetate. The application of solutions was done individually, with Cu and Cd ranging from 2.5 to 250 mg/kg of soil. Upon introducing Cu and Cd into the soil at the rate of 2.5–10 mg/kg, a decrease in invertase activity, deterioration of the physiological and biochemical parameters of the test crop (Lepidium sativum L.), along with the inhibition of Cd catalase activity, were observed.

Keywords

• psammozems
• heavy metals
• cu and cd pollution
• critical load
• enzymatic activity
• phytotoxicity