Comparison of bacterial communities of agricultural soils subjected to different types of tillage in the Valle del Mezquital, Mexico

Conservation tillage is a practice that positively affects the soil's physicochemical and biological characteristics. The type of tillage influences the richness and diversity of the soil microbiota since organic matter favors specific genera that, in turn, can significantly impact crop productivity. The aim was to analyze the bacterial communities in soils subjected to conservation and intensive tillage practices in two experimental platforms with more than 25 years of being subjected to this type of cultivation practices. Five composite samples of soils subjected to different tillage methods were analyzed. The treatments were Treatment 1=IT-R, Treatment 2=RT+R, Treatment 3=ZT+R, Treatment 4=IT+R and Treatment 5=ZT+R, where IT= Intensive Tillage, CT= Conservation Tillage, RT= Reduced Tillage, ZT=Zero Tillage, with (+R) and without (-R) removal of plant residues. Metagenomic DNA was extracted and sequenced using the 16s rRNA gene. CT showed higher species diversity, while IT showed higher richness. A higher beta diversity was observed in CT. IT was grouped in the same phylum range, while CT was in a different range. CT treatments improved the physicochemical properties of the soil and modified the diversity of bacterial communities. It is evident that conservation practices substantially impact the soil microbiota and favor the presence of microorganisms with a high capacity to degrade plant matter, improving the physicochemical characteristics of agricultural soils.