Indicators of arable soils fatigue - Bacterial families and genera: A metagenomic approach

In the studied soils, 118 families and 305 genera were identified. Among them, 10 families were recommended as sensitive indicators of soil fatigue: Sphingomonadaceae > Chitinophagaceae > Flavobacteriaceae > Oxalobacteraceae > Acetobacteraceae > Myxococcaceae > Comamonadaceae > Pseudomonadaceae > Burkholderiaceae > Rhodanobacteraceae. Analogically, 8 bacterial genera sensitive to agricultural practices were found: Pelomonas > Ramlibacter > Flavobacterium > Rhizobacter > Steroidobacter > Cellvibrio > Halliangium > Pseudomonas. Their sensitivity was confirmed by a decrease in the number of OTUs in the agricultural soils, in comparison to the wastelands. In contrast, 5 bacterial genera that should be considered as indicators of resistance to agricultural land use were proposed: Nitrosospira > Rhodanobacter > Aquicella > Burkholderia > Mucilaginibacter. Statistical tests demonstrated that the most important factors for the abundances of bacterial families and genera included soil acidity (pH), easily degradable carbon (EDC), total carbon (TC), nitrite nitrogen (N-NO2), magnesium (Mg) and calcium (Ca) content, and soil moisture.