## 3 Results and Discussion
### Dominant Bacterial Species in Different Soil Cultivation Technologies Under Horse  
_Bean Plantation_  
Our study also included an assessment of the dominance of specific bacterial species in the soil samples collected from individual cultivation systems (conventional tillage, reduced tillage, strip tillage, and no tillage) in relation to the uncultivated soil (NC--no cultivation). The percentages of OTUs of unclassified bacterial species ranged from 58.44% to 61.83% (Figure 7). The dominant species were _Arthobacter psychrochitiitiophilus_, _Cohnella soli_, and _Nocardioides islandensis_. In order to interpret the results more precisely, our analyses also included finding relative differences in the numbers of the dominant species between the samples of soil collected from different cultivation systems under the horse bean plantation and the zero-sample collected from the plantless, fallow buffer zone (Figure 7). The comparisons of all four treatments with sample \"0\" revealed an increase in the OTUs of the following species: _Aeronticrobium penti_, _Arthobacter psychrochitiitiophilus_, _Cohnella soli_, and _Gemmatomonas aurantiaca_. By contrast, the numbers of the _Candidatus Scalidomide brodae_ and _Nocardioides islandensis_ species in all four treatments was lower than in sample \"0\". The greatest increase (\(p<0.05\)) in the share of OTUs (3.90%) in relation to sample \"0\" was observed for the _Arthrobacter psychrochitinophilus_ species in the no-tillage treatment. The greatest decrease in the share of OTUs (\(-1.25\%\)) in relation to sample \"0\" was observed for the _Nocardioides islandensis_ species in the reduced tillage treatment (Figure 8). These differences were statistically significant (\(p<0.05\)) between CT vs. FA and RT vs. FA. However, comparisons of ST vs. FA and NT vs. FA did not show statistically significant differences (\(p>0.05\)) (Figure 8). Moreover, statistically significant differences were observed for _Candidatus Salindua brodae_ and _Chondromyces pediculatus_ between CT and FA; for _Candidatus Salindua brodae_ between RT and FA; as well as for _Candidatus Salindua brodae_ and _Frankia alni_ between ST and FA (Figure 8). _Aeromicrobium ponti_ is a species known for its potential to produce a variety of natural products and secondary metabolites with antimicrobial, antioxidative, and plant growth-stimulating properties [58]. It is a beneficial species for the soil environment and important for the proper functioning of the crop agroecosystem, especially in sustainable agriculture. The _Arthrobacter psychrochitinophilus_ species has oligocarbophilic properties, i.e., economical carbon management. The bacteria have low temperature requirements. According to the reference publications, the _Arthrobacter_ genus belongs to the group of plant growth-promoting bacteria (PGPB) due to its metabolic activity (the production of hormones, increasing the availability of nutrients, the production of antifungal substances, the colonization of plant roots, etc.). It offers an environment-friendly approach to improved plant production and counteracting the negative effects of abiotic stress [59; 60]. Figure 7: The percentages of operational taxonomic units (OTUs) of the dominant species of bacteria. The classifications with less than 1% numbers are gathered into the category “Other” (FA—plantless, fallow buffer zone of the field experiment—sample “0”; CT—conventional tillage; RT—reduced tillage; ST—strip tillage; NT—no tillage). _Gemmatimonas aurantiaca_ is another species with an important environmental role. In our study, the greatest percentages of OTUs of this species were observed in treatments 3 (1.05%), 4 (0.93%), and 5 (2.53%, i.e., in all no-tillage technologies (Figure 7). This species was also found in sample \"0\" and in the conventional cultivation treatment, but the shares of OTUs were much lower, i.e., 0.12% and 0.59%, respectively. Studies have shown that _Gemmatimonas aurantiaca_ can reduce nitrous oxide (N\({}_{2}\)O).