phoD-harboring bacterial community composition
All fertilization treatments significantly increased soil AlP activity, and AlP showed significantly higher activity under the SNPK and MNPK treatments than under the NPK treatment. Partial least squares path modeling showed that AlP activity was directly and positively affected by microbial biomass carbon (MBC) and phoD-harboring bacterial community composition, and the bacterial-feeding nematode dominant genus Eucephalobus, which was affected by MBC directly, could affect AlP activity indirectly through its significant direct positive effect on phoD-harboring bacterial community composition. Among the top eleven phoD-harboring bacterial genera, only the gram-positive bacteria Massilia and Saccharothrix were significantly positively correlated with AlP, and Saccharothrix was also significantly positively correlated with Eucephalobus.