Since 1994 the Vokė Branch of Lithuanian institute of Agricuklture has carried out calcareous, organic, and siliceous sapropel tests on soddy-podzolic sandy loam soil. Various rates of dry sapropel together with organic fertilizers on the background of minimum rates of mineral NPK fertilizing or without it were applied. The largest amount of fungi was obtained in soil fertilized with organic and siliceous sapropel. Bacteria were spread widely in soil fertilized with organic and Streptomyces in soil fertilized with calcareous sapropel. The effect of manure on the amount of these microorganisms was positive in soil fertilized with siliceous sapropel. The action calcareous and organic sapropels were similar to the action of manure.
Keywords: sapropel, microorganisms, soil, fertilizers.