## 3 Results
### Changes in the Abundance of Soil Phosphorus-Functional Genes Under Different Crop Cultivation  
Figure 2 shows the abundance heatmap of dominant phosphorus-functional genes (top 50 abundant genes) predicted based on the KEGG database. The high abundance of different P-functional genes revealed that soil microorganisms were metabolically diverse and active in the P cycle. The _phoU_ and _phoR_ genes were mainly involved in the regulation of inorganic phosphorus. We found that the abundance of the _phoU_ gene was the highest in Tea-oil soil (3.43%), which was 0.20% higher than that in Moso soil. In Moso soil, the _phoR_ gene abundance was the highest, 9.36% higher than that of Persimmon soil and 8.15% higher than that of Tea-oil soil. In the transport system related to phosphorus metabolism, the key genes included _ugpA_, _ugpA_, _ugpA_, _ugpA_, _ugpA_, _ugpA_, and _ugpA_ genes were the most abundant in Persimmon soil. The abundance ratios of _pstA_, _pstB_ and _pstC_ genes in Moso soil were 2.92%, 4.60% and 3.08%, respectively. The abundance of the _pstS_ gene in Tea-oil soil was the highest, reaching 7.49%. As a key gene for inorganic phosphorus solubilization, the abundance of the _gcd_ gene in the Persimmon soil was the highest, which increased by 7.14% compared with Moso soil. However, in Tea-oil soil, the abundance of the _gcd_ gene decreased by 1.50% compared with Moso soil. In addition, the _phoD_ gene, encoding organic phosphate mineralization, was the most common functional gene in the soil, with the highest abundance in Persimmon soil and the second in Tea-oil soil, and their abundance increased by 2.30% and 0.19%, respectively. In addition, genes related to polyphosphate synthesis (_ppaC_, _ppk1_) and degradation (_relA_, _surE_, _HDDC3_, _ndk_) were most abundant in Persimmon soil.  
Figure 2: Abundance heat maps of dominant phosphorus-functional genes under different crops.  
Correlation Analysis Between Soil Phosphorus-Functional Microorganisms and Basic Soil Properties Under Different Crop Cultivation  
Figure 3a reveals the dominant P-functional bacteria genera under different crops and their correlation with basic soil properties. At the genus level, the abundance of _Bradyrhizobium_ and _Camellia_ was significantly positively correlated with soil TP content, while it was significantly negatively correlated with _Sphingomonas_. In addition, the abundance of _Reyranella_, _Steroidobacter_, and _Pseudolabrys_ was significantly positively correlated with soil pH, SOM, AP, EC, TN, and MBP. These indices were significantly negatively correlated with the abundance of _Ktedonobacter_, _Amyocalatopsis_ and _Streptomyces_. Further analysis of the correlation between phosphorus-functional genes and soil (Figure 3b) showed that EC, TN and MBP were positively correlated with the _ppx-gpPA_ gene, while AP, EC and TN were positively correlated with the _phoB_ gene; TN and MBP were negatively correlated with the _phoP_ gene.  
Figure 3: Heat map of correlation analysis between (**a**) dominant phosphorus-functional bacteria and (**b**) dominant functional genes and basic soil properties under different crop cultivation. Note: SOM = soil organic matter; AP = available phosphorus; EC = electrical conductivity; TN = total nitrogen; TK = total potassium; MBP = microbial biomass phosphorus. ***\(p<0.001\). rabs = Absolabsolute value of the correlation coefficient (Pearson’s r). The block size in the figure indicates the magnitude of the absolute value (rabs) of Pearson’s correlation coefficient (Pearson’s r).