REMEDIATION OF SEVERAL CHEMICAL PROPERTIES OF SOIL THROUGH EARTHWORM ACTIVITY PUBLISHEDMădălina IORDACHE, Iacob BORZA
The great contribution of earthworms to soil quality was often demonstrated, under aspects concerning its physical and chemical properties, but numerous studies showed also the bioremediator potential of these animals living into the soil. The study consisted of laboratory experiments and was conducted at the University of Agricultural Sciences and Veterinary Medicine of Banat (UASVMBT), from Timişoara city, Romania. The experiment consisted of several plastic vats filled with soil classified as Chernozem (FAO System) purchased from the Didactic and Experimental Station of UASVMBT. There were used earthworms from species Eisenia foetida (Savigny, 1826). The experimental variants were the control variant and the variant with organic fertilisation. The organic fertiliser consisted of swine sludge which was added at once in the beginning of experiment. The analyzed factors were pH, NH 3 , NO - 3 , NO - 2 , PO + 4 , Zn 2+ , and Cu 2+ . Ulterior, in each vat were added 50 adult worms which were weighed previously. Monitoring of the chemical parameters of soil was realised after one and respectively two months since earthworms were added. The obtained results show that each analyzed chemical parameter of the soil was modified both after the first and the second month. Testing of the bioremediator potential of the earthworm species Eisenia foetida (Savigny, 1826), in laboratory conditions, led to the following conclusions: earthworms assimilated very well the swine sludge as food source, at the end of experiment no earthworm was found dead; after one month of experiment, the concentrations of the analyzed chemical factors of the soil were lower than those recorded at the beginning of experiment in the swine sludge; after two months of experiment there was found that each analyzed chemical parameter of the soil was modified, in the sense of their decrease, both after the first and the second month, being recorded decreases of their concentrations, which led to conclusion that earthworms can represent a solution to bio-remediate the polluted agricultural soils .
bioremediation, earthworms, swine sludge, pH, nitrates, ammonia, heavy metals