Abstract: In order to mitigate the negative impacts associated with chemical fertilizer application, an investigation was conducted to examine the effects of mushroom residue organic fertilizer on soil enzyme activities and bacterial communities. A field experiment was established with a control group of sweet potato fields that received no basal fertilizer (SPC) and an experimental group treated with mushroom residue organic fertilizer at a rate of 24 000 kg/hm² (SPE). Rhizosphere soil samples from sweet potato plants were collected at 0, 30, and 60 days post-application for subsequent analysis. The results indicated that, compared to the SPC group, the catalase activity in the SPE group significantly increased by 66.7% (P<0.01), and urease activity significantly increased by 7.7% (P<0.05), while no significant differences were observed in sucrase activities at 30 days. At 60 days, compared to the SPC group, the activities of sucrase, urease, and catalase were significantly increased by 47.8%, 50.0%, and 300.0% (P<0.01), respectively, while no significant differences were observed in three phosphatase activities. Diversity analysis revealed that, compared with the SPC group, the SPE treatment enhanced both the diversity and richness of the soil bacterial community. High-throughput sequencing results demonstrated that while no significant differences were observed in relative abundance at the phylum level, notable changes occurred at the genus level. Compared with the SPC group, the relative abundances of Massilia and Devosia in the SPE group increased by 108.7% and 214.3%, respectively, at 30 days, whereas the relative abundance of Pseudomonas decreased by 90.4%. Principal coordinate analysis (PCoA) further indicated that the application of mushroom residue organic fertilizer led to significant alterations in the bacterial community structure.

Key words: mushroom residue organic fertilizer, the rhizosphere soil of sweet potato, enzymatic activity, bacteria community, high-throughput sequencing