Synergistic Effects of Maize Growth and Soil Respiration on Yield Under Tillage Regime Conversion

Soil respiration is a major pathway of carbon loss from agricultural soils and is substantially influenced by tillage practices. However, the short-term effects of different tillage system transitions on soil respiration and maize yield remain unclear. A field experiment was therefore conducted with five treatments: conventional tillage–conventional tillage (CK), mulching–mulching (CS), conventional tillage–rotary tillage (NR), rotary tillage–rotary tillage (RS), and mulching–rotary tillage (CRS). Soil respiration, maize growth, and yield were monitored throughout the growing season. The results showed that tillage transition significantly altered the soil respiration rate and its component structure. Higher soil respiration increased CO2 release, raised canopy CO2 concentration, and accelerated dry matter accumulation. The RS exhibited the highest soil respiration, with a peak rate of 16.83 μmol m−2 s−1, of which root respiration accounted for 64.16%, and improved soil porosity and promoted aboveground biomass accumulation. The CRS treatment achieved the highest leaf area index, dry matter accumulation, and yield, representing a 51.49% increase over the control, and had the lowest Q10 value (2.97), indicating that respiration under this treatment was more regulated by substrate availability than by temperature. The CS treatment minimized carbon loss while maintaining grain yield. Overall, tillage transitions that improve soil aeration and root activity were generally associated with higher maize yields, but different pathways created distinct trade-offs among respiration, carbon turnover, and harvestable yield. These findings suggest that conservation tillage transitions have considerable potential for balancing yield maintenance with soil respiration regulation, providing useful guidance for sustainable high-yield maize production in semi-arid regions.