THE IMPACT OF SOIL POLLUTANTS ON SOIL MICROBIAL ACTIVITY

摘要

The functioning of the soil as a vital system and the support on its biological productivity depends to a higher extent on the soil microflora activity. That is why in the assessing of anthropogenic soil pollution it is necessary to take into account the changes in the the size, composition and activity of the soil microbial community, variation in loss of the normal bands and the appearance of new bands compared with the unpolluted soil. There is not yet a commonly accepted system of bio-indication on soil pollution. As bio-indicators are used pure cultures of microorganisms, sensitive to determined type of pollutant; the number and ratio of the main taxonomic and ecologic trophic groups of microorganisms; bacterial community tolerance; intensity of the microbiological processes - soil respiration, fixation of nitrogen, cellulose decay; soil enzyme activity and so on. With higher sensibility are distinguished the indexes, reflecting more narrowly the special processes, which are implemented by the limited number of microorganisms. The changes in soil microbial equilibrium can serve as an "early warning" for negative alterations in the soil conditions long before they could be detected by classical chemical methods and before they could become irreversible. The complex investigations on the soil biological activity should be conducted in assessing ecological risk of soil pollutants. The reliable microbiological indicator must be established and used.