Soil management systems such as conservation tillage practices and the cultivation of cover crops have various positive effects on soil environment. These practices help to increase or maintain an adequate level of soil organic matter, thus improve soil properties. The aim of the study was to determine the effects of cover crops and tillage systems on soil enzyme activity (urease, alkaline phosphatase, catalase) at different soil depths following wheat. According to the results, the cover crops affected all the enzyme activities while tillage systems affected only urease activity in the soil. The highest urease (8.09 and 6.90 μg g N soil^-1 h^-1), alkaline phosphatase (74.53 and 69.08 μg g p-nitrophenol soil^-1 h^-1) and catalase (41.56 and 48.62 ml O₂ 3 min^-1 g soil^-1) activities were observed in common vetch plots in minimum and conventional tilled plots. Another observation was that enzyme activities were decreased with the increase of soil sampling depths. These results showed that the incorporation of cover crops into rotations may increase soil enzyme activities and common vetch can be used as an alternative cover crop.