The formation of insoluble phosphate in soils and resulting overfertilization causes a large environmental risk. Although phosphate-solubilizing bacteria (PSB) can solubilize Ca-bound phosphate well by acidification, they often have a low capacity to solubilize Fe-bound phosphate (Fe-P). In this study, a novel Mg-modified lignin biochar (MB) was prepared via the chemical impregnation method to improve the ability of PSB to dissolve FePO₄. The results show that dissolved phosphate rapidly increased to approximately 0.9 mM over 3 days in the FePO₄ + PSB + MB system. The system with MB was more effective to increase FePO₄ dissolution by 17 times and increase the amount of organic acids production by 2 times than that without the MB. The characterization results indicated that the polymerization and rearrangement of FePO₄ occurred when the FePO₄ particles attached to the surface of the MB, resulting in the formation of Fe^(III)₂Fe^(II)(P₂O₇)₂ crystals on the surface of the MB. The Mg on the surface of the MB can induce the preferential orientation of the [210] crystal plane of the Fe^(III)₂Fe^(II)(P₂O₇)₂, which can be preferentially dissolved by PSB, causing an increase in Fe-P solubility. This study provides a new method for the development of insoluble phosphate solubilization technology to limit the overfertilization of soil and offers a clear understanding of the interactions among biochar, Fe-P, and PSB.

土壤中不溶性磷酸盐的形成以及由此导致的过度施肥会导致巨大的环境风险。尽管溶磷菌 (PSB) 可以通过酸化很好地溶解 Ca 结合的磷酸盐，但它们通常溶解 Fe 结合的磷酸盐 (Fe-P) 的能力较低。本研究通过化学浸渍法制备了一种新型镁改性木质素生物炭（MB），以提高PSB溶解FePO ₄的能力。_{结果表明，在 FePO 4} + PSB + MB 系统中，溶解的磷酸盐在 3 天内迅速增加到大约 0.9 mM 。MB体系提高FePO _{4效果更佳}溶解度提高了 17 倍，有机酸产量比没有加入 MB 的情况下增加了 2 倍。表征结果表明，当FePO ₄颗粒附着在MB表面时，发生了FePO _{4的聚合和重排，导致在MB表面形成Fe} ^(III) ₂ Fe ^(II) (P ₂ O ₇ ) ₂晶体。 MB的表面。MB表面的Mg可以诱导Fe ^(III) ₂ Fe ^(II) (P ₂ O ₇ ) _{2的[210]晶面优先取向}，可以优先被 PSB 溶解，导致 Fe-P 溶解度增加。该研究为开发不溶性磷酸盐增溶技术以限制土壤过度施肥提供了一种新方法，并为生物炭、Fe-P和PSB之间的相互作用提供了清晰的认识。