## 3 Results and Discussion
### The Relationship between Soil Physicochemical Properties and Bacterial Community  
Envisaging the intricate interplay between soil physicochemical attributes and the intricate structure of bacterial communities, represented by the prevalence of ten prominent phyla, is achieved via the visualization derived from network analysis (Figure 6). Discerning from this analysis, a notably robust positive correlation emerges between Proteobacteria, _Bacteroidota_, and soil pH while concurrently revealing a pronounced inverse relationship with soil Eh and the aggregate Cu concentration. The soil's pH, recognized as a cardinal determinant, orchestrates a profound influence on the opulence of microbial communities therein [46]. The preeminent phylum, Proteobacteria, validated as an integral facilitator of plant flourishing, adept in the decomposition of soil macro-molecules and the facilitation of elemental cycling, surfaces as a key protagonist in this correlation [47]. _Acidobacteriota_  
Figure 5: Venn diagram of soil bacteria at the OTU level (**A**) and the relative abundance of dominant bacterial communities at the phylum level (**B**) in soil under different treatments. manifests an unmistakable affirmative correlation with soil effective Cu concentration and an equally conspicuous negative association with soil EC. In stark contrast, Firmicutes, portraying a counteractive trend, exhibits a highly significant negative interrelation with soil effective Cu concentration and an inversely notable positive correlation with soil EC. This infers that the supplementation of vermicompost and steel slag serves to heighten the concentration of inorganic oxygen constituents such as Ca and Fe within the soil matrix, thereby exerting discernable effects on soil EC and effectively curtailing the bioavailability of Cu [48]. Concomitantly, soil SOM establishes a robustly affirmative correlation with _Gemmatimonadota_, juxtaposed against highly pronounced negative associations with _Actionobacteriota_ and _Patescibacteria_. Scholarly investigations underscore the pivotal role of _Gemmatimonadota_ in fostering vegetation recovery, with its abundance eliciting increasingly potent ameliorative effects on soil in tandem with rising soil fertility [49]. A thermal chart was constructed to appraise the intricate correlation existing between soil physicochemical attributes and the relative abundance of bacterial taxa, specifically the preeminent genera (Figure 7). The findings delineate a conspicuous positive correlation between _Phenylobacterium_, _Parsagegtibacter_, _Micromonospora_, and soil EC, juxtaposed with a discernible negative correlation with the concentration of effective Cu within the soil matrix. Notably, robust positive correlation surfaces between soil SOM and the genera _Lysobacter_ and _norank_f_norank_o_SBR1031_. Additionally, the genus Sphingomonas manifests a marked positive correlation with soil pH while concurrently exhibiting a markedly negative correlation with soil Eh and the aggregate concentration of total Cu. _Micromonospora_ has been validated for its efficacy in fostering the growth of vegetation in soils laden with heavy metal contaminants [50]. The genera _Lysobacter_ and _Sphingomonas_, owing to their pronounced adaptability to soil environments, exhibit notable potential in the remediation of soils subjected to heavy metal stress [51]. Ergo, the application of vermicompost and steel slag as amendments for the rectification of acidic soils hosting copper sulfide, begets alterations in the physicochemical milieu of the soil. Subsequently, this instigates a reshaping of the microbial community structure, ultimately culminating in an augmentation of soil quality. Figure 6: Co-occurrence network of soil physicochemical properties and dominant bacterial phyla in soil.