EFFECT OF SOIL POLLUTION WITH PAHs ON THE AMOUNT OF MAIZE BIOMASS AND ACCUMULATION OF CADMIUM AND LEAD

Trace element bioavailability is of key importance for stimulation or inhibition of plant growth and development processes at later stages of their life and in result leads to changes of biomass biological value, eg limiting its use. As assessment of artificial soil pollution with benzo(a) pyrene, chrysene and fluorene effect on the quantities of biomass and accumulation in it of cadmium and lead was conducted as a pot experiment. The soil pollution with the studied aromatic hydrocarbons did not inhibit growth or development of maize shoots and roots. The greatest amount of biomass was obtained in the object where the soil revealed an elevated contents of the analyzed aromatic hydrocarbons. Value of tolerance index in the objects where the stress agent was introduced was above one, which indicates the absence of soil pollution with benzo( a) pyrene, chrysene and fluorene effect on plant biomass quantity. Value of tolerance index below one concerned only biomass from the control object. Significant increase in Cd content and its quantities taken up by maize shoots was registered on the treatments where dichloromethane and polycyclic aromatic hydrocarbons were added to the soil in comparison with the unpolluted objects. The content and amounts of absorbed lead were the lowest on the object where the soil was the most polluted. Values of maize shoot biomass Cd pollution index were apparently higher in the objects where the soil was contaminated with polycyclic aromatic hydrocarbons in comparison with the values obtained in the object where soil received only mineral nutrient solution. Values of translocation index do not point to cadmium accumulation in plant shoots. Both the values of pollution index and translocation index for lead in the objects with elevated PAHs content in soil and in the object where the soil was contaminated with these substances were below one, which did not confirm excessive lead accumulation in maize shoots.