The use of natural zeolite can be a viable technique for the remediation of soils contaminated with heavy metals. This study aimed to evaluate the growth of reygrass (Lolium multiflorum L.) with different rate of zeolite in a soil contaminated with heavy metals generated by industrial activities. The rates of zeolite were as follows: 0, 1.25, 2.5, 5 and 10% (w/w), arranged in a completely randomized design with 4 replications. The plants were grown for 82 days in a greenhouse at the Agricultural University of Tirana. The results indicated that the addition of natural zeolite at all the application rates did not affect significantly (p<0.05) the germination of ryegrass seeds. However, the lowest germination performance (71.4%) was observed at the highest zeolite application rate (10%). This could be due to the effect of zeolite on electrical conductivity of the experimental soil. The plant height increased with increasing application rate of zeolite. The application of zeolite at 10% increased significantly (25.2%) the plant hight in the second cutting. Plant root and shoot dry weight was increased by increasing zeolite application, where the respective maximum increase was found at zeolite application rate of 10%. The root/shoot ratio of the plants was significantly correlated with the zeolite application rate, suggesting that the tested zeolite can functions as good plant growth regulator in heavy metal contaminated soil.
Keywords: chemical stabilization, heavy metal polluted soil, natural zeolite, reygrass