## 4 Conclusions  
The application of biogas slurry replenishes the soil phosphorus pool and increases the proportion of Al-P. Biogas slurry does not alter the major phyla of phosphorus-metabolizing  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Soil Indicators**} & \multicolumn{2}{c}{**Phosphorus-Metabolizing Microbial Community**} & \multirow{2}{*}{**Functional Gene Structure of Phosphorus Metabolism**} \\  & & **Structure** & & \\ \cline{2-4}  & **Mantel\_R** & \(\mathbf{p}\) & **Mantel\_R** & \(\mathbf{p}\) \\ \hline TP & \(-\)0.034 & 0.522 & \(-\)0.029 & 0.433 \\ Olsen-P & \(-\)0.068 & 0.566 & \(-\)0.055 & 0.527 \\ Org-P & 0.161 & 0.129 & 0.069 & 0.299 \\ Al-P & 0.191 & 0.147 & \(-\)0.001 & 0.424 \\ Fe-P & \(-\)0.127 & 0.805 & \(-\)0.148 & 0.86 \\ Ca-P & \(-\)0.062 & 0.678 & \(-\)0.082 & 0.767 \\ O-P & / & / & / & / \\ pH(H\({}_{2}\)O) & \(-\)0.141 & 0.722 & \(-\)0.063 & 0.523 \\ TN & \(-\)0.058 & 0.586 & \(-\)0.042 & 0.487 \\ TK & \(-\)0.040 & 0.522 & \(-\)0.001 & 0.393 \\ Org-matter & 0.219 & 0.075 & 0.023 & 0.434 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Mantel test of the relationship between environmental factors and the overall abundance of soil phosphorus metabolism genes.  
Figure 9: Heat map of the correlation analysis of environmental factors and phosphorus metabolism functional genes (\({}^{\bullet}\)_p_\(<\) 0.05, \({}^{\bullet\bullet}\)_p_\(<\) 0.01). The Spearman correlation coefficient test revealed that genes with high relative abundance, such as _pstS_, _spoT_, _phoR_, and _gcd_, were not significantly correlated, but some genes with low relative abundance in the soil reflected significant relationships with environmental factors.  
microorganisms but increases the abundances of _Chloroflexi_bacterium_ and _Acidobacteria_bacterium_ while reducing the abundances of _Actinomycteia_bacterium_ and _Streptosporrangiaceae_bacterium_. At the functional gene level, biogas slurry enhances the solubility of inorganic phosphorus and the mineralization rate of organic phosphorus in the soil, while weakening the competition between microorganisms and CO for soil phosphorus by inhibiting intercellular phosphorus transport in microorganisms. In summary, biogas slurry can replenish the total soil phosphorus pool, increase the proportion of active phosphorus forms, and promote the microbial mineralization and solubilization of phosphorus. Within the scope of this study, the best results were achieved at the highest biogas slurry application rate. However, in practical production, the biogas slurry fertilization plan should also consider the nutrient demand characteristics of CO at different growth stages and the ratio of chemical fertilizer application.  
The conceptualization, writing, editing, and finalization of the manuscript were performed by [PERSON], J.C., [PERSON], T.H., H.W., T.Z., J.H., L.D. and T.F. All authors have read and agreed to the published version of the manuscript.  
Funded by the Yuping County Agricultural and Rural Bureau, Integration and Application of Technology for the Utilization of Breeding Manure in Yuping County, Honghuagang District Agricultural and Rural Bureau, Technical Support Service for Key Watershed Agricultural Non-point Pollution Control Project in Honghuagang District, Guizhou Province in 2023, Guizhou Province Science and Technology Support Program, and Key Technology Integration and Demonstration of Efficient Utilization of Pig Breeding Manure Resources in Integrated Planting and Breeding Model (Guikehe Support [2018] 2278).  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
Author [PERSON] was employed by the company Guizhou ChuYang Ecological and Environmental Protection Technology Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.