Soil microbial biomass is the living and active part of soil organic matter, which is re-established after disturbance of the land. Study of recovery time of microbial biomass is important for the development of self-sustaining ecosystem in mine degraded land. Increase in soil microbial biomass and organic carbon contents increases the functional diversity and stability of ecosystem.

The dehydrogenase activity (DHA) has been proposed as a measure of overall microbial activity and used as index of the soil microbial biomass. DHA is measured by two methods using TTC and INT as substrate, however, various authors reported poor results when TTC is used as substrate.

The mine-degraded lands initially lack viable mycorrhizal fungal population, and thus, the establishment of a vegetative community will be delayed. Mycorrhiza inoculation can enhance productivity of degraded land by increasing drought tolerance of plants and phosphorus availability, which are the main two limiting factors for plant establishment.

Metals, a major category of globally distributed pollutants, are natural elements that have been extracted from the earth and harnessed for human use. It is only when metals are present at excessive levels in bioavailable forms, they become potentially toxic to plants.