A Preliminary Evaluation of Bamboo Tree Effect on Selected Properties of Coal Spoil Contaminated Soils of a Humid Area of Southern Nigeria

Coal exploitation produces an overburden mine spoil that overtime contaminates the soil environment. This study was conducted to evaluate the effect of Giant bamboo (Dendrocalamus giganteus) tree species on selected properties of overburden coal spoil contaminated soil. The treatment consisted of arable and agroforestry land soils contaminated with overburden coal spoil in the ratio of 1:1 (W/W) and the overburden coal spoil laid out in a completely randomized design (CRD) in five replications. Data was collected from the recombinant treatments of planted Giant bamboo cuttings in each of the treatment on the soil properties and growth response of the plants at 30, 60, 90 and 120 days respectively after shooting and were subjected to ANOVA while significant means to LSD. Results showed that the soil pH, Organic concentration, Total Nitrogen, bio available, Pb, CD, Fe, Zn, Bulk density and total porosity differed significantly ( P=0.05). There was a consistent increase in organic C content across the treatments between 30 and 120 days after shooting. Relative to the pre-bamboo planting values, bio available Pb and Cd across treatments decreased as the days after bamboo shooting increased but decreased between 30 and 120 days by Pb (31.96%) and Cd (9.90%) respectively. Similarly, the bulk density declined while the total porosity increased with increase in the number of days after shooting in the order agroforestry > arable > coal spoil soils to underpin better bamboo growth performance with the recombinant agroforestry soil, relative to the other treatments. These suggest that the bamboo did not only improve the soil physical characteristics but also removed some heavy metals (Pb and Cd) from the soil. Hence the plant could be a suitable phytoremediation plant for the restoration of coal mine degraded lands.