2025-12-01 JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE 2025 188(卷), 6(期), (1014-1026页)
BackgroundBiochar can enhance total organic carbon (TOC) stocks and reduce CO2 emissions in degraded soils.AimsThis study assessed the effects of pyrolytic biochars on TOC recovery and CO2 emissions in a greenhouse experiment.MethodsPVC columns (20 cm diameter, 50 cm height) were filled with soil and arranged in a factorial scheme (2 x 4 + 1) with four replicates. Treatments included two biochars: co-pyrolyzed sewage sludge and cashew pruning (SPB) and cashew bagasse biochar (CBB), applied at 5, 10, 20, and 40 Mg ha-1, plus a control. CO2 flux was measured in two additional gas collection events. TOC content and bulk density were analyzed, and carbon stocks (CSs) were calculated.ResultsThe application of 5 and 40 Mg ha-1 of SPB and CBB increased TOC and CSs compared to the control. CO2 flux fluctuated between samplings, as expected with corn introduction. The highest CO2 flux initially occurred in SPB40, followed by CBB20, whereas in the second sampling, CBB5 showed the highest flux and CBB20 the lowest.ConclusionThese results suggest that SPB and CBB applications improve soil CSs and mitigate CO2 fluxes, contributing to climate change mitigation and soil restoration.