The effect of manure and the bioaccumulation of heavy metals Hg, Cu and Zn at ex-gold mining land on the growth of silk tree (Paraserinthes falcataria (L.) Nielsen) in Bombana, Southeast Sulawesi

One of the negative effects of gold mining activity is soil contamination by heavy metal. The aims of this study were two folds; to assess the effect of manures (cow, goat, chicken) (i) on the growth of silk tree (Paraserianthes falcataria (L.) Nielsen) and (ii) on the bioaccumulation of heavy metals (Hg, Cu, Zn) in the plant organs of the silk tree planted in the ex-gold mining land in Bombana. This is an experimental research design with a completely randomized 78 Sri Ambardini et al. design consisting of one control (without manure) and 4 treatments (cow, goat and chicken manures) with 5 repplicates. The plant growth parameters observed are plant height, stem diameter, number of leaves, leaf area, and metal content of Hg, Zn, and Cu in plant organs. ANOVA with Duncan Multiple Range Test (DMRT) were used for the analysis. The results showed that the treatment with manure has an impact on the parameter of plant growth and bioaccumulation of Hg, Cu and Zn in the plant organs. DMRT showed that the treatment with manures has a significant influence on the growth and bioaccumulation of Hg, Cu, and Zn in the plants. The manure with cows was better in supporting growth of silk tree compared to those with chicken, goat as well as control. Treatment with manure reduced bioaccumulation of Hg but increased bioaccumulation of Cu and Zn in the plant organs. The bioaccumulation of Hg, Cu and Zn was found the highest in the root than in the stem and leaves. The total bioaccumulation of Zn in plant organs was the highest compared with that of Cu and Hg. Keyword: Manure, Growth, Heavy Metals, Silk Tree, Ex-Gold Mining Land