<p>Humic acid-modified phosphate fertilizer (HP) was welcomed in China due to its high field efficiency. However, the translocation and transformation mechanisms of HP in the fertosphere soil remain poorly understood. This study aimed to clarify the phosphorus (P) dynamics and microbial responses in the fertosphere after HP application. A simulated fertosphere soil incubation experiment was conducted to obtain soil samples from distinct fertosphere layers through dense slice sampling, followed by comprehensive analysis of phosphorus dynamics and bacterial flora characteristics. The results showed that after a 28-day incubation period, HP moved 3&#xa0;mm deeper into the soil than common phosphate fertilizer (CP), suggesting a larger range of fertosphere coverage. Additionally, all available P contents (including water- and acid-soluble P, Olsen-P, and dicalcium P) were significantly higher in HP treatment than CP treatment. The efficient release percentage of the HP treatment was also at least 4.07% points higher than that of the CP treatment, regardless of the sampling times, fertosphere layers, or available P forms. Furthermore, the unavailable P contents (octacalcium, aluminium and iron P) were lower in HP treatment than CP treatment. High-throughput sequencing analysis revealed an increased abundance of eutrophic microflora and a decreased abundance of phosphorus-soluble functional microflora in the HP treatment, indicating higher storage of available P. These findings emphasize that HP enhances the availability and migration distance of P in soil fertosphere, slowing down the fixation of phosphate fertilizer, which provide a better understanding of the initial mechanisms behind HP application, facilitate the research into more efficient P fertilizers in the future.</p>