The study investigated the effects of adding biochar to different types of soil over a 390-day period. Biochar, a product of biomass pyrolysis, was found to improve soil quality and carbon sequestration. High-temperature biochars were more resistant to decomposition, with added carbon remaining in the soil longer. The addition of 1% biochar caused changes in soil properties, especially at the beginning of the incubation period. The pyrolysis temperature and soil texture influenced the extent of these changes, with lower temperature biochar and sandy soil showing greater effects. Organic carbon compounds from biochar did not contribute as much to soil stability as those from decomposed materials.