CARBONO E ABUNDÂNCIA NATURAL DE δ13C DO SOLO EM SISTEMAS DE CULTIVO DE CAFÉ

• Palavras-chave: carbono total do solo; enriquecimento isotópico; sistemas agroflorestais.

• Keywords: soil total carbon; isotopic enrichment; agroforestry systems.

• Abstract: The cultivation of coffee is one of the most important agricultural activities in the world. Studies have been proving the importance of agroforestry systems (AFS) for the sustainability of coffee production due to their potential to increase carbon (C) inputs into the soil. Therefore, the present study aimed to quantify the soil total C (TC) stock in different coffee cultivation systems and assess the natural abundance of 13C, up to one meter deep, in an agroforestry system (AFS) established in a pasture area. The study areas are located in the municipality of Planalto (BA). The systems studied were: Coffea arabica × Grevillea robusta (AFS); Coffea arabica intercropped with banana (CCB); Coffea arabica in monoculture (CM); Native forest (NF); and a pasture area (PA). The soil was collected at six depths (0-10, 10-20, 20-40, 40-60, 60-80, and 80-100 cm). TC was determined by dry combustion in an automated elemental analyzer system, and the natural abundance of δ13C was determined using a continuous-flow isotope ratio mass spectrometer. The highest proportion of TC stocks at one meter depth is stored at a 0-40 cm layer in the soil. The δ13C values ​​showed an isotopic increase up to um meter depth in SAF and FN and the greatest variations between systems were observed up to 60 cm depth, with a predominance of C3 in all systems.