The dependence on chemical fertilizers and pesticides to increase agricultural outputs owing to the demands of a growing human population creates the need for a sustainable fertilizer. Biochar is presently a promising candidate as an inoculant carrier, given its highly porous structure, with nutrients naturally derived from the biomass, high water, and nutrient retention properties, which favor microbial growth. Biochar can be produced through pyrolysis, hydrothermal carbonization, gasification, and torrefaction. The porosity and adsorption ability of biochar allows it to be effectively used as a carrier to immobilize plant growth-promoting rhizobacteria (PGPR) for enhanced crop growth. Furthermore, the physicochemical properties of biochar like surface area, pore properties, and surface functional groups can be further modified via several activation methods, such as chemical oxidation and reduction, and physical activation to optimize the PGPR immobilization. The understanding of the agronomic impacts of biochar and the possible scaling up of cell immobilization will provide insights on the mechanism of biochar as an efficient inoculant carrier. This will contribute to fewer environmental hazards with the utilization of biochar for promoting plant growth. The complex interplay of physicochemical properties of biochar as a carrier to immobilize PGPR and the potential mechanisms of biochar-based inoculants are significant to achieve agricultural sustainability.

由于不断增长的人口需求，对化肥和农药的依赖增加了农业产量，因此需要可持续的肥料。由于生物炭具有高度多孔的结构，其具有天然衍生自生物质的养分，高水分和养分保留特性，因而有利于微生物生长，目前，它是一种有希望的孕育剂载体。生物炭可以通过热解，水热碳化，气化和烘焙来生产。生物炭的孔隙率和吸附能力使其可以有效地用作载体，以固定植物促根瘤菌（PGPR）来增强农作物的生长。此外，生物炭的物理化学性质，例如表面积，孔隙性质，表面官能团可以通过几种活化方法进一步修饰，例如化学氧化和还原，以及物理活化，以优化PGPR固定化。对生物炭的农学影响以及细胞固定化可能扩大的理解将提供有关生物炭作为有效接种载体的机理的见解。利用生物炭促进植物生长，这将减少对环境的危害。生物炭作为固定化PGPR的载体的理化特性之间复杂的相互作用以及基于生物炭的孕育剂的潜在机制对于实现农业可持续性具有重要意义。对生物炭的农学影响以及细胞固定化可能扩大的理解将提供有关生物炭作为有效接种载体的机理的见解。利用生物炭促进植物生长，这将减少对环境的危害。生物炭作为固定化PGPR的载体的理化特性之间复杂的相互作用以及基于生物炭的孕育剂的潜在机制对于实现农业可持续性具有重要意义。对生物炭的农学影响以及细胞固定化的可能扩大的理解将提供关于生物炭作为有效接种载体的机理的见解。利用生物炭促进植物生长，这将减少对环境的危害。生物炭作为固定化PGPR的载体的理化特性之间复杂的相互作用以及基于生物炭的孕育剂的潜在机制对于实现农业可持续性具有重要意义。