PARAMETERS OF ORGANIC MATTER OF SOIL IN THE CULTIVATION OF Miscanthus sacchariflorus

Selected properties of organic matter in the humus horizon of soil fertilised with sludge at 10, 20 and 30 Mg . ha(-1) and with mineral fertilisers (NPK), were examined in the third year after harvesting biomass of Miscanthus sacchariflorus. The following were analysed: TOC, Nt in the soil; the following were analysed in the humic acids isolated from samples - elemental composition, atomic ratios, degree of internal oxidation, absorption coefficient, hydrophilic and hydrophobic properties, IR and C-13 NMR spectra (the latter two were used for determination of carbon species). The organic carbon content was found to increase in the pot fertilised with the largest dose of the sludge fertiliser (30 Mg . ha(-1)), while the nitrogen content increased in all the pots fertilised with the organic waste material, as compared with the control pot. Humic acids, isolated from the pots fertilised with sludge and mineral fertilisers (NPK), were found to have a higher degree of internal oxidation. The variance of the other quality parameters of those acids was not significant. Fertilisation with sludge did not significantly affect the properties of humic acids in the third year of cultivation of the test grass, which is important regarding the balance of the soil.