The Structure and Diversity of Bacterial Communities in Differently Managed Soils Studied by Molecular Fingerprinting Methods

The soil bacterial community structure is sensitive to different agricultural management practices and changes in the soil community composition can affect ecosystem sustainability and ecosystem stability. The basic idea of reduced and conservation soil tillage technologies is to preserve favorable soil parameters and also to enhance soil fertility and to reduce the negative impacts on the soil. Four soil tillage treatments—conventional, reduced, mulch-till, and no-till—were studied for their bacterial communities at a soil depth of 10 cm in September 2013 and April 2014 using the automated ribosomal intergenic spacer analysis (ARISA) and the terminal restriction fragment length polymorphism (T-RFLP) methods. The total microbial biomass was statistically higher in April 2014 than in September 2013 in all tillage treatments. On the other hand, no statistical differences were detected in the bacterial richness between the sampling dates in all tillage treatments. Only one statistical difference regarding the bacterial richness was detected between the conventional and reduced tillage in September 2013 by using ARISA. Bacterial genetic diversity measured by the Gini–Simpson, Shannon, and Pielou indices did not indicate differences among the four types of soil management systems. Additionally, no substantial variation in the composition of bacterial communities under different treatments was observed based on the principal component analysis and cluster analysis. Additionally, the changes in bacterial community composition between both sampling dates have not occurred overall or within the individual agricultural management systems