Drivers of carbon stabilization and sequestration in Brazil's black soils

Autor(es)

Pinheiro Junior, C. Roberto ; Canisares, Lucas Pecci ; Abreu, Marcel Carvalho ; Lyra, Gustavo Bastos ; de Oliveira, Aline Pacobahyba ; Greschuk, Lucas Tadeu ; Ferreira, Tiago Osorio ; Pereira, Marcos Gervasio ; Dos Anjos, Lucia Helena Cunha ; Cherubin, Mauricio Roberto

• Tipo de documento: Artigo Científico
• Fonte: CATENA; v. 246, p. 8-pg., 2024-10-05.

Resumo

Climate and land use are recognized as two of the main drivers of changes in soil organic carbon (SOC) on a global scale. Both factors play an important role in understanding SOC sequestration and mitigation of climate change. Particularly important, black soils are mineral soils with high SOC contents and high natural fertility and play an important role in national and global food and climate security. Here, we used a database of 90 black soils in Brazil - under different climate and land use conditions across the country - to test the hypothesis that C stock is richer in wetter climate conditions and that agricultural land use reduces C stock and the percentage of carbon saturation (PCS%). Climate data were obtained from the National Oceanic Atmospheric Administration (NOAA) and used to classify Thornthwaite's climate. The land use information was obtained in the MapBiomas platform and was grouped into three major types: cropland, pasture, and native vegetation. The nonparametric Kruskal-Wallis test showed no differences for C stock, C/N ratio, and PCS% for both land use and climate. The low C/N ratio and the strong correlation between Ca2+, CEC, clay, and SOC suggest that organo-mineral interactions - which are stronger in soils with high-activity clays (e.g., Chernozems, Kastanozems, and Phaeozems) - promotes greater stabilization of the SOC and its long-term persistence and, thus being less sensitive to variations in climate and land use. Considering the total area of approximately 3.7 x 106 ha and the average value of C stock of 93.2 Mg/ha, the total SOC stored in Brazil's black soils is in the order of 0.35 Gt, and the carbon stock stabilization potential is 0.25 Gt. Our results highlight the potential of Brazil's black soils to promote carbon sequestration and climate change mitigation. (AU)

• Processo FAPESP: 21/10573-4 - Centro de Pesquisa de Carbono em Agricultura Tropical (CCARBON)
• Beneficiário: Carlos Eduardo Pellegrino Cerri
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 23/11337-8 - Efeito da mudança de uso da terra e das práticas de manejo da cana-de-açúcar no C do solo, na saúde do solo e nos serviços ecossistêmicos associados: uma síntese de evidências
• Beneficiário: Carlos Roberto Pinheiro Junior
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 23/00438-8 - Sequestro de carbono do solo em sistemas agrícolas integrados no semiárido Brasileiro
• Beneficiário: Lucas Tadeu Greschuk
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 23/08814-9 - MONS: Mecanismos de emissão de óxido nitroso em solo tropical
• Beneficiário: Lucas Pecci Canisares
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado