This study investigated the effects of burnt and unburnt sugarcane harvesting systems on soil organic carbon (SOC) stocks and soil organic matter (SOM) dynamics in the north-east region of Brazil. Conversion of native vegetation to sugarcane cultivation led to SOC loss, and reduced soil quality due to losses of particulate organic matter and increased soil bulk density. The findings of this study highlight the importance of understanding the impact of land-use change on the properties of SOM.