The effect of combined application of biochar and phosphate fertilizers on phosphorus transformation in saline-alkali soil and its microbiological mechanism

This study investigated the effects of combining Phragmites australis-based biochar, prepared at 400 °C, with various types of phosphate fertilizers-soluble, insoluble, and organic-on the content and transformation of phosphorus fractions in saline-alkali soil. Additionally, we explored microbiological mechanisms driving these transformations. The results showed that this combination significantly increased the concentrations of dicalcium phosphate (Ca