The aim of this study was to determine the long-term effects of different tillage systems on some chemical and biological soil properties. The research was carried out in 2011-14 based on a static field experiment set up in 1999 at Brody Research Station of Poznań University of Life Sciences, Poland, in a temperate climate, on Albic Luvisols. Soil samples were collected from under spring barley from two layers: 0-10 cm and 10- 20 cm. The results of this experiment showed that reduced tillage (RT) and no-tillage (NT) increased total carbon, total nitrogen, the number of microorganisms (heterotrophic bacteria, oligotrophic and copiotrophic bacteria, actinobacteria and fungi) and enzymatic activity (dehydrogenases, acid and alkaline phosphatase, urease, protease, and catalase) compared with conventional tillage (CT) – especially in a 0-10 cm layer of soil. This suggests that tillage has a significant impact on soil C cycling through its effects on soil microbial activity.