## 1 Introduction  
Modern agriculture faces two major challenges. On the one hand, it must feed the growing world population. On the other hand, it must reverse its current degrading influence on soils, the natural environment, and the climate [1,2]. It is possible to achieve these goals simultaneously by following one of many parallel paths, i.e., the development of conservation and regenerative agriculture and, especially, the rational implementation of the widest possible spectrum of its principles into practices of intensive commercial agriculture. No-tillage soil cultivation technologies, which have been used for many years and are constantly being improved, are an example of such activities. They limit soil degradation and help to preserve the production, biological, environmental, and climatic potential of soils [3,4]. No-tillage technologies involve the use of simplified soil cultivation methods or even complete abandonment of tillage. As a result, it is possible to reduce input costs, including fuel consumption [5]. No-tillage systems have a positive influence on the physical, chemical, and biological properties of soils, because they limit, among other things, their drying. In consequence, the rate of mineralization of organic matter and CO\({}_{2}\) emissions is reduced. Leaving some or all of the crop residues on the surface or in the subsurface layer of soil increases its protection from drying and erosion. Apart from that, it improves the transformation of soil organic matter and carbon sequestration [6,7]. However, these technologies sometimes also have negative effects, such as excessive soil compaction and the differentiation of physical properties (especially within the surface, humus, and enriched A horizon). Also, sometimes the deterioration of the chemical properties, including acidification is being reported due to the nitrogen fertilization of the topsoil. These phenomena may negatively influence the yield of some crops [5]. Moreover, the absence of tillage usually favors the expansion of some weeds, which may cause the need to use larger amounts of herbicides [8,9]. The specific physical and chemical properties of soils cultivated in different systems also result in their characteristic biological properties, i.e., mainly the size and diversity of the adaphon, especially the population of microorganisms and the enzyme activity [10]. Individual cultivation systems significantly influence soil aeration and moisture as well as the amount and distribution of the biomass of crop residue [11]. Soil cultivation simplifications, especially the complete abandonment of tillage, usually favor greater soil bioactivity and positively affect the size and diversity of the microbial population. This applies to the total count of bacteria and fungi as well as individual taxonomic and trophic groups. At the same time, the populations of some microorganisms, e.g., bacteria of the _Azotobacter_ genus, are larger in traditionally ploughed soils [12]. The current knowledge of the influence of the cultivation system on the soil microbiome is still very general. There have been few studies covering a wide spectrum of individual taxa of soil microorganisms and their communities [13]. Detailed studies in this field became possible only with the development and greater availability of molecular and genetic research techniques. Our study assumed that the soil samples collected from a horse bean plantation would exhibit differences in the composition of bacterial communities at the phylum, order, classes, and species levels due to different tillage systems. The differences would be manifested by the pro-environmental and agricultural roles of the microorganisms in the soil cultivation system-dependent manner and would indicate the bacterial species with environmentally friendly properties.