Influence of rhizosphere on nickel phytoextraction by Ricinus communis L. (Castor)

摘要

The distribution of Ni in the rhizosphere was examined by using rhizobox system, composed of two compartments namely central and bulk soil compartments. Ricinus communis wild type plants were grown in the central compartment of the rhizobox system containing Alfisols added with 0, 50, 100, 250 and 500mg (Ni)·kg<'-1> soil. The results showed that the DTPA extractable Ni content in the rhizosphere region was two times higher compared with non-rhizosphere region. The roots decreased the soil pH significantly compared with non rhizosphere zone. Nickel accumulation by Ricinus communis increased with increasing levels of Ni in the soil.