AZADEH ESLAMI1, ALI EFTEKHARI1, MORTEZA SIAVOSHI2*
1Department of Agronomy, Islamic Azad University of Chalus, Mazandaran, Iran.
2Department of Agricultural Science, Payame Noor University, I. R. of Iran.
A pot trial was conducted in 2016 for investigating the use of earthworm and silica element on the biological refining of heavy metal nickel in the dwarf lilyturf (Ophiopogon japonicus). The testing was designed in a factorial based on a complete randomized design. That first factor nickel was in three levels (0, 100, 200 mg per kg soil), Consume (0 and 200 mg/kg silica) as a second factor and third factor considered (0 and 5 earthworms).Some characteristics were measured like: root dry weight, shoot dry weight, soil nickel content, root nickel content, shoot nickel content and soil silica content. The results showed that with increasing of contamination, root and shoot dry weight decreased drastically. Application of earthworm resulted in increased root and shoot dry weight, This is mainly due to the effect of earthworms on increasing organic carbon and increasing the cation exchange capacity on one side, and on the other hand, increasing the absorption of heavy metals in nickel and accumulation in the tissue. Silica is also able to reduce soil toxicity and increase the nickel transfer coefficient from soil to root.
Keywords: Biological refining, Earthworm, Heavy metal, Nickel, Silica