## 3 Results and Discussion  
### Metagenomic Analysis of Soil Samples with and Without Hydroinfiltrators  
A total of 39 phyla and 790 genera were detected (Table S2). The rarefaction curves obtained from these data reached an asymptote, indicating that the sequencing depth was sufficient and adequate for all samples (Figure 3). Thus, the saturation achieved suggests that the representation of microbial diversity is reliable. Sample SH40 exhibited the highest number of taxa (S) and sequences (specimens). Samples SH20 and SC40 showed intermediate values: the number of taxa (S) was similar in both samples, while the number of sequences was higher in SC40. The lowest values were observed in sample SC20. The Venn diagram shows that the four samples shared 107 genera (Figure 4). A comparative analysis reveals that the number of exclusive genera shared between hydrofinitroitro-sulfur soil samples (SH20-SH40 = 132) is considerably higher than in the control soil samples (SC20-SC40 = 7). The highest number of specific genera was found in sample SH40 (268), followed by sample SC40 (66); both samples were taken at a depth of 40 cm. In contrast, the number of unique genera was much lower in samples SC20 (10) and SH20 (2), both collected at a depth of 20 cm. The alpha diversity indices reveal a high genus-level diversity across all samples (Figure A1). According to the Shannon index (H\({}^{\prime}\)), the highest value was observed in sample SH40 (5.084) and the lowest in sample SC20 (4.517), corroborating the results obtained from the rarefaction curves (Figure 3). The complementary Simpson index (1-D) showed the highest value in sample SC40 (0.9851), although this result is not very significant because the rest of samples had similar values (\(\approx\)0.98). The beta diversity indices reflect the heterogeneity of the bacterial community among the samples (Table 2). The Jaccard index (IJ) indicates that similarity between samples ranges from moderate (\(\approx\)0.50) to low (\(\approx\)0.25). The highest value was found for the SH20-SH40 pair (0.465) and the lowest for the SC20-SH40 pair (0.253). Similarly, the Whittaker index (IW) shows that the turnover rate or dissimilarity between samples ranges from moderate (0.25-0.5) to moderately high (0.5-0.75). In this case, the highest value was also observed in the SC20-SH40 pair (0.596) and the lowest in the SH20-SH40 pair (0.366), supporting the values obtained with the Jaccard index. The most abundant phyla were _Pseudomonadota_ (29%), _Actinomycetota_ (18%), _Bacilota_ (15%), _Acidobacteriota_ (9%), and _Bacteroidota_ (6%), according to the average relative abundance across samples (Figure 5). These results are consistent with previous studies on soil microbial communities [22]. The comparative analysis of control soils and soils with a hydroinfiltrator revealed notable differences (Figure 5). The phyla _Acidobacteriota Cyanobacteria_ 4, _Pseudomonadota_ 36, and _Gemmatimonada_ 3.7 were more abundant in SC20 soils (control), while _Bacilotta_ (23.8%), _Plantomycetota_ (9.2%) and _Chloroflexota_ (4.8%) predominated in SH20 soils (hydroinfiltrator). Additionally, the phyla _Actinomycetota_ (26%), _Bacilota_ (23%) and _Acidobacteriota_ (11%) were enriched in SC40 soils (control), whereas others such as _Pseudomonad_ (33%) and _Bacteroidota_ (5.7%) were more abundant in SH40 soils (hydroinfiltrator). The bacterial community also exhibits differences according to soil depth (Figure 5). In control soils, the phylum _Pseudomonadota_ (36.6%) was more abundant in SC20 (20 cm), while other phyla such as _Actynomycetota_ (26.2%) and _Bacilotta_ (23.8%) were more prevalent in SC40 (40 cm). In soils with hydroinfiltrators, the phylum _Bacilota_ (16%) was more abundant in SH40, while other phyla such as _Plantomycetota_ (9.2%) were enriched in SH20. In general, soil microorganisms belong mainly to the phyla _Acidobacteriota_, _Actinomycetota_, _Bacteroidota_, _Bacilotta_, and _Pseudomonadata_[22].