The Effect of Straw Biochar Application on CO2 Emission from Farmland Soil

In this study, biochar was produced from maize straw and applied to farmland soils to investigate, through indoor simulated incubation experiments, the effects of different application rates of straw-derived biochar on CO emission characteristics at various soil depths in Baotou. The soils were incubated under controlled indoor conditions for 28 days, and CO emissions were measured using gas chromatography. The results showed that in the 010 cm surface soil, cumulative CO emissions increased significantly by 26.16% and 34.53% under 1% (BC1) and 2% (BC2) biochar treatments, respectively, compared to the control (CK). In contrast, in the 1050 cm subsoil, cumulative CO emissions under the BC1 treatment decreased by an average of 18.72% compared to the control, with a reduction of up to 24.35% observed in the 4050 cm soil layer. Doseresponse analysis indicated that the application of 1% biochar achieved the optimal emission reduction effect in the 2030 cm soil layer. This study reveals the vertical differentiation effect of straw-derived biochar on soil CO emissions, providing scientific support for the synergistic regulation of straw resource utilization and greenhouse gas emission reduction in Baotous farmland.