Biochar production, a widely used biomass waste-management approach, involves pyrolysis and can serve as a soil amendment. In this study, Eucalyptus pellita bark waste obtained from a pulp and paper industry in Muara Enim, South Sumatra, Indonesia, was utilized as the feedstock. Biochar was produced by pyrolysis at 300, 400, and 500 °C for residence times of 60, 90, and 120 minutes to determine its physicochemical properties. The produced biochar was subsequently applied to loamy sand soil at rates of 2.5%, 5%, and 10% to evaluate its effects on soil physicochemical properties.The results showed that increasing pyrolysis temperature and residence time decreased biochar yield, organic carbon (OC), and organic matter (OM), while increasing macronutrient (Ca, P, K, and Mg) and micronutrient concentrations, as well as pH, particularly at 500 °C for a 120-minute residence time. Biochar application at higher rates, especially 10%, significantly increased soil OC, N, P, K, Ca, and Mg, while reducing bulk density and increasing porosity. The highest concentrations of P, K, Ca, and Mg were observed in soil amended with biochar produced at 500 °C for 120 minutes and applied at the 10% rate, reflecting the higher inorganic nutrient content of high-temperature biochar. Soil nitrogen content also increased with increasing biochar application rate and pyrolysis temperature, primarily due to enhanced nitrogen retention in the soil–biochar system.