AGROECOLOGICAL ESTIMATION OF LOADS OF LIQUID MANURE OF CATTLE AND PIG MANURE RUNOFF ON THE CONTENT OF HEAVY METALS IN SOD-PODZOLIC SOILS IN THE ZONE OF INFLUENCE OF LIVESTOCK COMPLEXES

Abstract

The data on the effect of prolonged exposure of liquid manure of cattle and pig manure runoff on the content of heavy metals in sod-podzolic soils, identified priority pollutants (Zn, Cu, Mn, Fe). The annual application of these fertilizers in doses of 100-200 to 900-1000 t/ha increased the concentration of mobile forms of Fe in soils at 13-199 %, Cu - 11-229 %, Zn - 21-547 %, Mn - 32-175 %. Annual application of these fertilizers in doses from 100-200 to 900-1000 t/ha increased the concentration of mobile forms of Fe in soils by 13-199 %, Cu - by 11-229 %, Zn - by 21-547 %, Mn - by 32-175 %. Exceeding the established standards of maximum permissible concentrations (MPCs) and provisional permissible concentrations (PPCs) of gross and mobile forms of heavy metals was not found, the hazard ratios are below one. Agroecological condition of soils on Z_с (4,1-12,0 units) is characterized by the admissible level of pollution mobile forms of heavy metals (Z_с < 16). The observed negative trends in the increase of К_с and Z_с indicate environmental risks with the constant utilization of high doses of these organic fertilizers in a limited area.