The Effect of Applied Organic Fertilizers on the Bioavailability of Heavy Metals in Lolium Perenne, Cultivated on Fly Ash Deposits

Abstract

The study aims to monitor the capacity of certain organic fertilizers (volcanic tuff and municipal sludge), applied as such and mixed with volcanic rocks with a high content in clinoptilolite, to determine the covering with vegetation of fly ash deposits resulted from the combustion of lignite in thermal plants. Both biosolids (20 t/ha) and volcanic rock with high clinoptilolite content (5 t/ha) determined the installation of a vegetative layer and diminished the soil metal bioavailability to the Lolium prerenne plant biomass. When using the organic-zeolite mixture, a synergistic effect is recorded of the two components of the treatment agent and an increase of the biomass with 448%. Moreover, the resulted biomass shows the highest reductions of metal bioaccumulations, of 38-46% for Zn and Fe, of 62% for Cu and between 82-89% for Cr, Ni and Pb.

Keywords

• bioaccumulation
• fly ash
• lolium perenne
• organic-zeolite fertilizer