Abstract

Soil respiration serves as a critical indicator of soil biological activity and ecosystem health, reflecting the metabolic processes of soil microorganisms, plant roots, and soil fauna. This study investigated the effects of different tillage practices on soil respiration rates and associated biological parameters across three agricultural systems: conventional tillage (CT), reduced tillage (RT), and no-tillage (NT). Field experiments were conducted over two growing seasons (2022-2024) on a silt loam soil under corn-soybean rotation. Soil respiration was measured using automated chambers at weekly intervals throughout the growing season. Additional parameters including soil organic carbon (SOC), microbial biomass carbon (MBC), soil temperature, and moisture content were monitored simultaneously. Results showed significantly higher soil respiration rates in NT systems (4.2 ± 0.8 μmol CO₂ m⁻² s⁻¹) compared to RT (3.1 ± 0.6 μmol CO₂ m⁻² s⁻¹) and CT (2.4 ± 0.5 μmol CO₂ m⁻² s⁻¹) treatments (p < 0.001). The enhanced soil respiration in NT was associated with increased SOC content (18.2 g kg⁻¹ vs. 14.7 g kg⁻¹ in CT), higher MBC (312 mg kg⁻¹ vs. 187 mg kg⁻¹ in CT), and improved soil aggregate stability. Correlation analysis revealed strong positive relationships between soil respiration and MBC (r = 0.87), SOC (r = 0.73), and soil moisture (r = 0.68). These findings demonstrate that soil respiration is a sensitive indicator of tillage-induced changes in soil biological activity, with conservation tillage practices promoting enhanced microbial activity and carbon cycling processes.