Microbiological transformations on N, S and P in degraded soil subjected to one-year remediation with various wastes

This study was conducted on the material originating from a reclamation experiment established in the area of the former Sulphur Mine “Jeziórko”, on a soil-less formation with a particle size distribution of weakly loamy sand, strongly acidified and with poor sorptive properties. In the particular treatments of the experiment, the following were applied to the soil-less formation: flotation lime and NPK; lime and sewage sludge; sewage sludge; mineral wool (5 cm 50 cm⁻¹), lime and NPK; mineral wool (5 cm 50 cm⁻¹), lime and sewage sludge; mineral wool (500 m3 ha⁻¹), lime and NPK; mineral wool (500 m3 ha⁻¹), lime and sewage sludge. Plots prepared in this manner were then sown with a mix of grasses. The control treatment in the experiment was the ground with no amendments. The analyses of the soil material comprised assays of the numbers of bacteria and fungi degrading protein, and of their enzymatic activities i.e. arylsulphatase and alkaline phosphatase. The waste materials applied to the degraded soil had a stimulating effect on the analyzed parameters. All of the wastes applied, and the sewage sludge in particular caused an increase in the numbers of proteolytic bacteria and in the activity of alkaline phosphatase and arylsulphatase. Sewage sludge applied separately or in combination with other wastes contributed also to an increase in the number of proteolytic fungi and to an intensification of the process of nitrification. The process of ammonification was also stimulated, but only under the effect of sewage sludge applied alone or together with lime. The application of mineral wool at the dose of 5 cm 50 cm⁻¹ in combination with lime caused a slight decrease in the activity of that process.