Dados do Trabalho

Título

BIOCHAR FEEDSTOCK MATERIAL INFLUENCES SOIL N2O EMISSIONS AND C STORAGE

Resumo

Currently in Brazil, agricultural and forestry residues represent the main available biomasses to be utilized as feedstock for biochar production. Thus, the present study focused on evaluating if the use of different biomasses would impact the biochar capacity to influence N2O emissions. To assess these impacts, we conducted a 60-day greenhouse pot experiment with sugarcane plants, with 6 treatments: soil only (CTR); soil + N fertilizer (NF); sugarcane straw biochar (NF+SB); sugarcane bagasse biochar (NF+BB); residue biochar of pinus (NF+PB); and residue biochar of eucalyptus (NF+EB). Our results showed that regardless of the feedstock material utilized, all evaluated biochars reduced the cumulative N2O emissions by 25-50%. The highest mitigation capacity was observed under NF+SB, whereas NF+EB had a lower ability to suppress N2O emissions than sugarcane-derived biochar. Moreover, the feedstock material also influenced the different chemical properties found in the biochar, where forestry residues biochar showed a higher C content and aromatic C functional groups on its surface. The higher C presence in those materials resulted in an increase in soil C levels above the ones registered for sugarcane-based biochars. Our findings suggest that biochar produced from eucalyptus residue is the least recommended option if the final objective of the practice is N2O suppression. At the same time, pinus biomass residue was the best option to decrease N2O emissions and increase soil C storage. Based on our findings, the relationship between feedstock material and N2O emissions and soil C levels suggests that this parameter could be used by future studies as a possible GHG response predictor under tropical environments. Hence, biochar application in tropical soils is a recommended strategy to decrease N2O emissions while increasing soil C storage, confirming that it should be considered in future projects as a nature-based solution for reducing GHG emissions by agriculture.

Palavras-chave

x-ray photoelectron spectroscopy; SEM; greenhouse gas; black carbon

Instituição financiadora

Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP)

Agradecimentos

Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)