The influence of fertilization with the compost prepared from treated sewage sludge with bark additive and mulching with the fresh forest ectohumus on the soil conditions, chosen parameters of one-year old European beech seedlings growth as well as the occurrence of soil mites (Acari) with special emphasis of oribatid mites (Oribatida) was investigated in the paper. The trials were carried out in 2008 at forest nursery Białe Błota (Forest District Bydgoszcz) on the rusty soil. The whole area of the experiment was irrigated with the use of stationary sprinkling machine. The soil was characterized by the pH in H2O - 7,41 and that in 1M KCl - 6,88, as well as the low content of available potassium (6,8-7,3 mg K2O 100g-1 of soil) and available phosphorus (8,0 -8,5 mg P2O5 100g-1 of soil). European beech seedlings on plots fertilized with the compost were significantly higher than those grown on plots with mineral fertilization. Influence of mulching - conducted in September - was insignificant on both the studied parameters of one-year old European beech seedlings growth. After the measure of mulching on the adequate plots, the density of mites, especially saprophage oribatid mites. ...