Temporal Dynamics of Carbon Dioxide (CO₂) Fluxes In Swamp Paddy Fields Based On Cultivation Age

Understanding the dynamics of carbon dioxide (CO₂) fluxes in lebak swamp paddy fields is important for assessing carbon cycling under different land-use histories. This study investigated CO₂ fluxes and their relationships with soil environmental properties across different land-use ages in Pelabuhan Dalam Village, Ogan Ilir, South Sumatra. Three land-use ages were evaluated, 0 years, representing uncultivated swamp as the baseline, 6 and 12 years of continuous paddy cultivation. CO₂ fluxes were measured in the field along with soil temperature, soil water content (SWC), electrical conductivity (EC), pH, soil organic carbon (SOC), bulk density, soil porosity, and soil permeability. CO₂ flux showed a nonlinear pattern, with mean values of 1.42 ± 1.29, 5.97 ± 1.29, and 4.27 ± 1.29 for (0, 6, and 12 year) land-use ages, respectively. However, differences among land-use ages were not statistically significant. Among the measured environmental variables, SOC showed a significant relationship with CO₂ flux (R² = 0.59, p = 0.015), while bulk density, soil porosity, SWC, soil permeability, pH, and EC were not significantly associated with CO₂ flux (p > 0.05). Strong correlations were observed among soil physical properties, particularly between bulk density and soil porosity (r = −1.00). These findings indicate that land-use age alone does not directly determine CO₂ flux, while changes in soil characteristics, particularly SOC, are associated with CO₂ dynamics in lebak swamp paddy fields. The findings provide a basis for evaluating soil carbon dynamics and supporting sustainable management of cultivated lebak swamp ecosystems.