Abstract <p>This research sought to explore how biochar influences the rhizosphere ecological conditions of soybeans, alongside its impact on the physiological growth traits and yield quality across different soil varieties. The goal is to offer both theoretical insight and practical recommendations for enhancing the characteristics of various soil types. Calcisol, Ferralsol, and Phaeozem were selected for the study, and soybean was used as the target crop with 1.0, 1.5, and 3.0% proportions of biochar, alongside a control group without biochar. Soil physicochemical properties, microbial carbon, microbial nitrogen, and enzyme activities were measured through potting experiments, as well as alterations in soybean growth traits and yield quality. The experimental results indicated that biochar positively influenced the physicochemical properties of three soil types, enhancing soil pH, organic material, and total nitrogen concentration. A 3.0% biochar application notably improved the bulk density and moisture content of Phaeozem, while Ferralsol showed significant pH changes. Biochar enhanced soil microbial carbon and nitrogen levels and boosted urease and dehydrogenase activities. Applying 1.0% biochar increased soybean yields by 26.0 and 31.1% in Calcisol and Ferralsol, respectively, with the highest quality improvements observed at 1.5% in Ferralsol. Biochar application improves soil’s physicochemical properties, increasing soybean yield and quality, especially in Ferralsol regions. This study highlights biochar’s role in sustainable agriculture and provides a scientific framework for its proper use across diverse soils.</p>