Soil microorganisms as an useful tool for assessment of soil quality and health.


Worldwide, soils are being seriously contaminated as results of different agricultural, industrial
and civil activities releasing pollutants into the environment.  In the Union European more than
37% of the soils are contaminated.  The long-term accumulation of these pollutants in the soil
environment has an important consequence for the quality of food human chain, toxicity to plant and
soil microbial processes.

Soil microorganism are considered critical in any ecosystem, by acting on the decomposition of soil
organic matter, plant nutrient cycling as well as heavy metals, degradation of pollutants and
affecting the soil chemical and physical properties, with direct effects on soil fertility and
sustainability (Cardoso et al., 2013 ). However, higher concentration of heavy metals on soils can
reduce the nutrient cycling and others functions such as mineralization of organic compounds and/or
synthesis of organic matter since soil microorganism may be affected by the presence of this
compounds (Moreno et al., 2009). Therefore, the determination and quantification of parameters like
microbial biomass, respiration rate and microbial activities can be used as potential indicators to
monitor health soil in areas contaminated with heavy metals (Smejkalova et al., 2003).