Acid and alkaline phosphatase (ACP and ALP), encoded separately by the bacterial phoC and phoD genes, participate in the mineralization of organic phosphorus (P) to inorganic P. However, the influence of chemical fertilization on soil phosphatase activities and associated bacterial communities in acidic soils remains unclear. Here, we conducted a 27 year continuous chemical fertilization experiment consisting of the no-fertilizer control (CK), N and P fertilizer (NP), N and K fertilizer (NK), P and K fertilizer (PK), and N, P and K fertilizer (NPK) treatments, in order to investigate phosphatase activities and phoC- and phoD-harboring bacterial communities. Results demonstrated that ACP and ALP activities increased significantly in the NP (198.70 and 35.46 μg pNP g⁻¹ soil h⁻¹, respectively) and NPK treatments (199.62 and 36.51 μg pNP g⁻¹ soil h⁻¹, respectively) compared to CK (143.81 and 22.49 μg pNP g⁻¹ soil h⁻¹, respectively), while ALP activity was reduced for the NK treatment (13.86 μg pNP g⁻¹ soil h⁻¹). The abundance and diversity index of phoC- and phoD-harboring bacteria differed among treatments. The two bacterial community structures exhibited similar trends in terms of the significant differences between N-free (CK and PK) and N-containing (NP, NK and NPK) treatments (Adonis, p < 0.01). Random forest model analysis revealed that the variations in ACP and ALP activities can be explained by microbial biomass P (MBP, 9.71% and 13.20%, respectively), soil total carbon (TC, 10.89% and 8.77%, respectively) and available P (AP, 9.10% and 7.15%, respectively), and microbial factors including community composition (5.94% and 4.48%, respectively) and network clustering coefficients (6.05% and 5.15%, respectively). Furthermore, the dominant genera Stenotrophomonas and Variibacter were positively correlated with ACP and ALP activities, respectively, with their members observed as keystone species in the community network. Overall, chemical N and P fertilization was generally observed to improve soil phosphatase activities in acidic soil, with soil TC and AP identified as the primary soil variables affecting phosphatase activities by altering the associated bacterial community composition and increasing MBP. These findings improve the understanding of how fertilization influences the community composition and function of phosphate-solubilizing microorganisms in acidic soils.

酸性和碱性磷酸酶（ACP和ALP），分别由细菌phoC和phoD基因编码，参与有机磷（P）到无机P的矿化作用。酸性土壤仍不清楚。在这里，我们进行了一项为期27年的连续化学施肥实验，包括不施肥对照（CK），N和P肥料（NP），N和K肥料（NK），P和K肥料（PK）以及N，P和钾肥（NPK）处理，以研究磷酸酶活性和phoC-和phoD-令人讨厌的细菌群落。结果表明，ACP和ALP活性在NP（198.70和35.46微克显著增加p NP克^-1土壤ħ ^-1，分别地）和NPK处理（199.62和36.51微克p NP克^-1土壤ħ ^-1相比分别）到CK（143.81和22.49微克p NP克^-1土壤ħ ^-1，分别地），而ALP活性降低用于治疗NK（13.86微克p NP克^-1土壤ħ ^-1）。phoC-和phoD-的丰度和多样性指数不同处理之间的细菌携带情况有所不同。就无氮（CK和PK）和含氮（NP，NK和NPK）处理之间的显着差异而言，两种细菌群落结构表现出相似的趋势（Adonis，p  <0.01）。随机森林模型分析表明，ACP和ALP活性的变化可以用微生物生物量P（分别为MBP，分别为9.71％和13.20％），土壤总碳（TC，分别为10.89％和8.77％）和可利用的P（ AP（分别为9.10％和7.15％）以及包括社区组成（分别为5.94％和4.48％）和网络聚类系数（分别为6.05％和5.15％）在内的微生物因子。此外，优势属嗜麦芽单胞菌和变异杆菌分别与ACP和ALP活动呈正相关，其成员被视为社区网络中的关键物种。总体而言，通常观察到化学氮和磷肥能改善酸性土壤中的磷酸酶活性，其中土壤TC和AP被认为是通过改变相关细菌群落组成和增加MBP来影响磷酸酶活性的主要土壤变量。这些发现使人们更加了解了施肥如何影响酸性土壤中可溶解磷酸盐的微生物的群落组成和功能。