The objective of the present study was to determine the effect of tillage systems on the activities of enzymes associated with the carbon (C) and nitrogen (N) cycles (β‐glucosidase and protease) on a Typic Argiudoll (Marcos Juarez Series). The experiment was performed in a randomized complete block design with three replications under no till, conventional tillage and native pasture used as control soil. The activities of β‐glucosidase and protease, total N and oxidizable C contents were determined at depths of 0–5 and 5–15 cm. Not only the activities of both enzymes, but also C and N contents were greater in the native soil at both depths, which shows the impact of land use on this soil. The enzymatic activities in the surface of no‐till soil were significantly higher than those for conventional tillage. At the 5–15 cm depth these variables did not present significant differences between tillage systems. The enzymatic activity was more sensitive to tillage systems than oxidizable C content in the first c...