Abstract: Due to the large hardness of wall rock of iron ores in northern China, the site condition of the iron mine dumps is bad. The silty and sand contents in such iron mine dumps are about 99%. Water and nutrition holding capacity is poor. The contents of N, P and K are low. By adding artificial substrates, which were made up of municipal sewage sludge, fly ash and clay, the physicochemical properties of iron mine wasteland would be improved. The results showed that total N concentration in artificial substrate was 4.37-6.60 g·kg^-1, and the available P and K concentrations were at the high fertility level. Moreover, concentrations of heavy metals (Zn, Ni, Cr, Mn and Hg) in the substrates were low. Robinia pseudoacacia and Amorpha fruticosa were planted in fishscale pits on the slope of dump. After two years, trees grew well, many herbaceous plants appeared, and the vegetation coverage increased. Heavy metals were enriched in plant roots, which were less and less transferred to the aboveground parts over time. Soil fertility and nutrient supplementation were the key to revegetation in the iron mine dumps after 2-3 years.

Key words: biocontrol, Streptomyces, antagonistic properties