The study conducted between 2020 and 2023 at Menofia University in Egypt aimed to convert organic wastes like sugarcane bagasse and olive mill waste into biochar. Two biochar fractions were used, regular and nano, and activated with ZnCl₂ and KOH. The study aimed to determine how these biochars affected soil chemical characteristics and nutrient content, as well as plant growth and the vital nutrients and trace elements it contained. An incubation experiment was conducted to assess the effects of biochars derived from these wastes on CO₂ efflux from soils. The results showed that nano-scale biochars have different features than bulk biochars, indicating potential differences in environmental impact. The study also clarified the chemical activation mechanism of KOH during biomass pyrolysis, providing new information about possible reactions involving KOH and oxygen-containing groups. The study suggests that sugarcane bagasse is a more viable raw material for biochar production than olive mill waste, potentially leading to more efficient and sustainable biochar use