Phosphorus fertilizer application and tillage practices influence bacterial community composition: implication for soil health

Abstract

ABSTRACT Microorganisms are important in maintaining soil quality and contribute to plant nutrient uptake and pathogen resistance. However, intensive tillage and inappropriate fertilizer management distorts these important functions. This study therefore investigates the influence of tillage practices and P-fertilizer management on plant beneficial bacteria. The bacterial communities were profiled using DNA metabarcoding. Actinobacteria (40%) and Proteobacteria (21%) were the most abundant phyla in both the No-tillage (NT) and Conventional-tillage (CT) treatments. Alpha diversity analysis revealed that differences in P application influenced diversity. The bacterial community structure was significantly impacted by tillage practices. Plant beneficial bacteria including Lysobacter, Dyella, Sphingomonas and Dactylosporangium were among biomarkers in the NT treatment. Pathways for energy metabolism and the biosynthesis of siderophores were significantly influenced by both P-fertilizer application and tillage practices. Co-occurrence analysis revealed that the CT treatment reduced the efficiency of the bacterial communities while keystone species with potential for plant pathogen suppression were more in the NT treatment. Overall, this study demonstrates that tillage practices induce bacterial compositional changes, with the NT treatment exhibiting greater potential in promoting the stability and proliferation of plant beneficial bacteria, while P fertilizer influences diversity and community putative functions, regardless of tillage practice.