THE EFFECT OF FERTILIZATION WITH BIODEGRADABLE WASTE COMPOSTS ON FRACTIONAL COMPOSITION OF SOIL HUMUS

The investigations, conducted on the basis of two-year pot experiment, aimed at an assessment of the effect of fertilization with composts prepared of plant and mixed municipal wastes on fractional composition of humus compounds in soil. The point of reference for the analyzed features was the soil fertilized with farmyard manure and mineral salts. The composition of humus compounds was determined using Kononowa and Bielczikowa’s method. Compost admixture led to elevated organic carbon content in comparison with the concentrations assessed in soil fertilized with mineral salts. The smallest quantities of carbon were extracted by means of Na4P2O7 and NaOH mixture after the first year of the experiment from the soil fertilized with mixed municipal waste compost. After two years, the content of this humus fraction diminished most in the soil receiving plant waste compost. Value of CKH:CKF ratio was generally lower than one and compost fertilization affected this parameter more favourably than farmyard manure treatment. Values of E4:E6 of released humic acids evidences their simple structure. The content of non-hydrolyzing carbon in individual treatment soils did not differ significantly. Key words: compost, fertilization, soil, humus compound