The Bashang plateau in Hebei Province has a unique ecological environment: high altitude, low temperature, and a semiarid climate, where the arable land shows serious desertification, wind erosion, and low crop productivity. The actions of the soil microbes in this region, especially those in the arable land, during crop growth seasons are still unclear. In this study, we monitored the soil microbial carbon (C), active-microbe amounts, and the soil respiration rate in the field-planted naked oats according to a 12-year permanent-location tillage experiment. We tested the treatments "no tillage" (NT), subsoiling tillage with high stubble (PT), and conventional tillage with straw returning (CT), in order to determine the effects of tillage methods on microbial activities in the meadow chestnut soil. The results showed that the soil microbial biomass C and the active-microbe amount exhibited a change pattern of the "W shape" around the heading stage. After lengthy NT and PT treatments, the soil microbial biomass C in the 0-10 cm soil layer was enriched. The difference in the active microbial amounts among various soil layers between NT and PT was decreased after longer tillage treatments. The soil respiration rate in the field displayed a change pattern of the "U shape" during various tillage treatments. NT yielded higher values in the 0-10 cm soil layer than did PT and CT. Across the whole growth stage, the respiration quotient (qCO₂) in the soil was always low during all tillage treatments and significantly increased after the harvest. Nonetheless, in comparison with NC and PC, NT increased qCO₂ in the 0-10 cm soil layer. In addition, CT was confirmed to play an important role in activation of the soil nutrient stocks and in promotion of the release of available nutrients in the cold ecological region.