POTENTIAL PENTRU BIOREMEDIEREA SOLURILOR CALCAROASe CU BACTERII RIZOSFERICE SI ACIZI HUMICI

Calcareous soils, which are typical for warm and dry areas contain minerals such as calcite and dolomite, which increase pH of the soil and worsen the conditions of plants nutrition with microelements and partly with phosphorus and nitrogen. The potential for bioremediation of such soil by rhizospheric bacteria and humic acids were studied in pot vegetation test. Test plant was Medicago sativa (Alfalfa). The strains of species �. subtilis and B. amiloliquefaciens were isolated from rhizospheres of Cichorium intybus (Common chicory), inhabiting the area with carbonate soil. The used humic acids were extracted from leonardite. There isn't significant effect of microbial cultures on physical-chemical properties of the carbonate soil. The test shows that microorganisms alone or in combination with humic acid decrease the active calcium with 5 to 20%. The composition of the soil organic carbon, after treatment with humic acids, was changed to humate type. The biomass of alfalfa, after treatment of soils with microbial culture alone or in combination with humic acid, was increased in the range of 5 to 10 times.