Abstract
The paper presents a study on the microbiological activity and the quality of organic matter of a Haplic Luvisol soil amended with selected organic and mineral materials (manure, clay, flotation lime, aluminium and iron oxides and a bark-keratin-urea preparation), during a three-year field experiment. In the soil under analysis (pH in 1M KCl pHKCl - 4.46, organic carbon Corg. - 0.465%) the following parameters of microbiological activity were assayed: numbers of microorganisms, activity of dehydrogenases, and respiration. In addition, the quality of organic matter was analysed through the determination of its susceptibility to chemical (biological) oxidation (oxidable carbon and non oxidable carbon). The components applied to the soil had a varied effect on the studied parameters of microbiological activity during the whole period of the study. The application of manure and clay caused an increase in the numbers of bacteria, in the activity of dehydrogenases, and in the intensity of the process of soil respiration. Soil respiration was stimulated also by the application of manure and clay in combination with Fe2O3 at the dose of 6 kg. Moreover, a decrease in the number of bacteria in the soil was noted after the combined application of manure, clay and Fe2O3 6 kg. The materials applied in the study caused a variation in the susceptibility of organic matter of Haplic Luvisol soil to oxidation. Soils amended with manure and clay in combination with calcium, aluminium, iron, were characterised by limited susceptibility to organic matter oxidation, while the bark-keratin-urea preparation applied caused a considerable improvement of that susceptibility