## 4 Discussion
### Soil Biological Indicators  
The production of phosphatases results from biochemical modifications at the cellular level, primarily triggered by decreased P uptake by microorganisms. This explains the increased enzyme activity in soils with low available P levels [54], indicating that there was no deficiency of this element for the soil microbiota in the present study. Approximately 30 to 50% of soil microorganism isolates exhibit phosphatase activity. For example, nitrogen-fixing bacteria, such as bean rhizobia, have a high capacity to produce phosphatases under P deficiency conditions to maintain high P concentrations in nodules, given the high demand for this nutrient in biological nitrogen fixation [55]. Regarding the activity of arylsulfatase (AS) and \(\beta\)-glucosidase (\(\beta\)G) enzymes, they were more active in non-inoculated areas. This behavior may be attributed to the higher SOM content in these plots, as previously mentioned, increasing the volume and diversity of the soil microbiota. However, there is also the hypothesis of competition between native soil microorganisms and those introduced via inoculation. Essentially, two factors are recognized as the main causes of species reduction or extinction: the loss of original habitat and the introduction of invasive species. In the first case, habitat loss, the high complexity of soil structure and composition provides considerable protection to the soil microbiota. In the second case, species introduction is more closely related to agricultural practices, as the use of organic and inorganic inputs, soil management, and the introduction of plant species can incorporate new microbial species [56]. Microorganisms in recovering soils exhibit more complex interactions than those in degraded areas, suggesting greater stability and environmental resilience in restored soils [57]. This finding indicates that lower enzymatic activity in inoculated areas may also point to the stabilization and balance of the physical, chemical, and biological components of the plots. The determination of enzymatic activities provides valuable information on soil health, as enzyme activity is influenced by soil carbon stock and changes in land use [58]. Thus, considering a scatter plot showing the relationship between enzymatic activity and total organic carbon (TOC), it is possible to define four soil health states, represented in four distinct quadrants [20]. Evaluating Figure 12, most of the experimental area fell within Quadrant 1 (Q1), representing high-quality soils. This indicates that adopting good management practices over a long period yields positive results in soil recovery, balance, and resilience. Recent studies have highlighted the crucial role of soil microbial communities in maintaining ecosystem functions and promoting plant productivity. [59] demonstrated that the interactions between microorganisms, soil properties, and plant diversity are essential drivers of soil microbial diversity in the Atlantic Forest biome. Applying this understanding to agricultural systems, the inoculation with _Azospirillum brasilense_ evaluated in our study can be seen as a management strategy that seeks to harness similar synergistic relationships. By modulating microbial community structures and functional diversity, inoculation has the potential to influence nutrient cycling, enzymatic activity, and soil health, contributing to sustainable crop production under long-term no-till systems. This perspective reinforces the importance of adopting practices that promote beneficial microbial interactions as a path to enhancing soil resilience and agricultural sustainability. Microbial respiratory activity (MRA) is defined as the total sum of all metabolic functions in which CO\({}_{2}\) is produced. Bacteria and fungi are the main organisms responsible for CO\({}_{2}\) release via soil organic matter (SOM) degradation. MRA is closely related to abiotic soil conditions, including moisture, temperature, aeration [60], and substrate availability in the soil (SOM).