Soil Amendments and Arbuscular Mycorrhiza Influenced the Growth and Heavy Metal Accumulation of Colosphospermum Mopane (Kirk Ex Benth.) In Heavy Metal Contaminated Soil

ABSTRACT

The potential of Colosphospermum mopane for phytoremediation of heavy metal (HM) contaminated soil was evaluated. C. mopane seedlings were planted on soils from the vicinity of Cu-Ni mine as affected by different soil amendments (Compost and fly ash-FA) and mycorrhizal inoculation in terms of growth and HM accumulation through a 2-factorial pot experiment. The survival and dry matter yield of C. mopane seedlings was enhanced by FA and compost as well as mycorrhiza. Soils with compost had high survival and dry matter yield and were enhanced by mycorrhiza. FA also enhanced the survival and dry matter yield but at lower magnitude. Except for Mn, FA and compost reduced the concentration of Cu, Ni, Pb, As, and Zn in shoots and roots of the C. mopane seedlings. Mycorrhiza reduced the Cu, Pb, Ni, and Zn concentrations in shoots but not with As. FA and compost modified the soil pH, EC, and the total and available contents of heavy metals in soil thus the difference in growth and uptake of HMs. Overall, results showed that FA or compost together with mycorrhiza can enhance the survival and growth of C. mopane seedlings in HM contaminated soils by reducing its availability and uptake by plants.

KEYWORDS:

• Compost
• fly ash
• BCL mine tailings
• heavy metal availability
• translocation factor

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Botswana International University of Science and Technology under the initiation grant DVC/RDI/2/7 IV (110) to TM and Grant no. DVC/RDI/2/1/3 XI (16) to VUU.