To investigate the effect of biochar in different fertilizer combinations on potato yield and soil quality in Yunnan Province, China.

The yield, soil physicochemical properties and soil microorganisms' structure under different fertilization treatments had significant difference. The highest potato production (43,095 kg/ha) was recorded in the HB treatment. HB treatment also altered the abundance and composition of the soil microbial community, resulting in more adsorbed fungi and a higher abundance of Proteobacteria and Bacteroidota. Furthermore, it was observed that biochar optimizes the rhizosphere microenvironment by specifically enriching Proteobacteria, functional bacterial genera (e.g. Advenella/Sphingobacterium), and Basidiomycota.The combination of 3,000 kg/ha of calcium-magnesium phosphate fertilizer + 1,500 kg/ha of compound fertilizer + 1,500 kg/ha of biochar optimized the balance between potato yield and fertilizer cost, reducing agricultural waste while also improving SOM levels.