Abstract: Chemical amendments were applied to and red ramie cultivated in multi-metal contaminated acid soil of Dabaosan mining site, and then response of the microbial community therein in biological feature was investigated. The chemical amendments significantly improved activity of the soil microbial communities in plots before the cultivation of red ramie showing an order of manure + limestone ≈fly ash > dolomite > limestone > control in  effect. Treatment manure + limestone was the most significant in improving metabolic diversity of the microbial community. However, the order altered in the presence of red ramie into the one of manure + limestone > fly ash > limestone > control > dolomite. The effect of manure + limestone was more significant with red ramie than without the crop.  In plots with red ramie, manure + limestone stimulated root exudation of L-serine, 4-hydroxy benzoic acid, L-arginine etc., enabling soil microbes to better use carbon sources of amine and amino acid types. Soil microbes in all the treatments were found to have been enhanced in ability to utilize saccharides, amino acids, amines and some others as carbon sources, which contributes to biological remediation of heavy metals contaminated soils.

Key words: metabolic characteristics of microbes, heavy metal, contaminated soil, amendment, red ramie, combined remediation