Biochar as a Strategy to Mitigate Greenhouse Gases in Degraded Drylands of the Brazilian Semiarid Region: Carbon Stocks and CO2 Fluxes.

SANTOS, J. M. R. DOS; PEREIRA, A. P. de A.; MONIZ, T. da C. D.; HENRIQUE, G. da s.; BARBOSA, F. L. A.; NASCIMENTO, I. V. do; QUEIROZ, A. dos S.; ARTUR, A. G.; SILVEIRA, M. R. S. da; COSTA, M. C. G.; SOUSA, H. H. de F.; DIAS, C. T. dos S.; FERREIRA, O. P.; FREGOLENTE, L. G.; SOUZA FILHO, A. G. de; OLIVEIRA FILHO, R. L. de; MOTA, J. C. A.

Biochar as a Strategy to Mitigate Greenhouse Gases in Degraded Drylands of the Brazilian Semiarid Region: Carbon Stocks and CO2 Fluxes.

Autores

SILVEIRA, M. R. S. da

COSTA, M. C. G.

Descripción

Background: Biochar can enhance total organic carbon (TOC) stocks and reduce CO 2 emissions in degraded soils. Aims: This study assessed the effects of pyrolytic biochars on TOC recovery and CO 2 emissions in a greenhouse experiment. Methods: PVC columns (20 cm diameter, 50 cm height) were filled with soil and arranged in a factorial scheme (2 × 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. CO 2 flux was measured in two additional gas collection events. TOC content and bulk density were analyzed, and carbon stocks (CSs) were calculated. Results: The application of 5 and 40 Mg ha − 1 of SPB and CBB increased TOC and CSs compared to the control. CO 2 flux fluctuated between samplings, as expected with corn introduction. The highest CO 2 flux initially occurred in SPB40, followed by CBB20, whereas in the second sampling, CBB5 showed the highest flux and CBB20 the lowest. Conclusion: These results suggest that SPB and CBB applications improve soil CSs and mitigate CO 2 fluxes, contributing to climate change mitigation and soil restoration.