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.

摘要

评估了黑豆草对重金属 (HM) 污染土壤进行植物修复的潜力。C. mopane幼苗种植在铜镍矿附近的土壤上，通过 2 因子盆栽试验，在生长和 HM 积累方面受到不同土壤改良剂（堆肥和粉煤灰-FA）和菌根接种的影响。FA 和堆肥以及菌根提高了C. mopane幼苗的存活率和干物质产量。堆肥土壤具有较高的存活率和干物质产量，并通过菌根增强。FA 还提高了存活率和干物质产量，但幅度较低。除 Mn 外，FA 和堆肥降低了C. mopane的芽和根中 Cu、Ni、Pb、As 和 Zn 的浓度幼苗。菌根降低了枝条中的 Cu、Pb、Ni 和 Zn 浓度，但不降低 As。FA 和堆肥改变了土壤 pH 值、EC 以及土壤中重金属的总和有效含量，从而改变了 HMs 的生长和吸收。总体而言，结果表明，FA 或堆肥与菌根一起可以通过降低其可用性和植物吸收来提高C. mopane幼苗在 HM 污染土壤中的存活和生长。