Agricultural tillage practice and rhizosphere selection interactively drive the improvement of soybean plant biomass.

Rhizosphere microbes play key roles in plant growth and productivity in agricultural systems. One of the critical issues is revealing the interaction of agricultural management (M) and rhizosphere selection effects (R) on soil microbial communities, root exudates and plant productivity. Through a field management experiment, we found that bacteria were more sensitive to the M × R interaction effect than fungi, and the positive effect of rhizosphere bacterial diversity on plant biomass existed in the bacterial three two‐tillage system. In addition, inoculation experiments demonstrated that the nitrogen cycle‐related isolate Stenotrophomonas could promote plant growth and alter the activities of extracellular enzymes N‐acetyl‐ d‐glucosaminidase and leucine aminopeptidase in rhizosphere soil. Microbe‐metabolites network analysis revealed that hubnodes Burkholderia‐Caballeronia‐Paraburkholderia and Pseudomonas were recruited by specific root metabolites under the M × R interaction effect, and the inoculation of 10 rhizosphere‐matched isolates further proved that these microbes could promote the growth of soybean seedlings. Kyoto Encyclopaedia of Genes and Genomes pathway analysis indicated that the growth‐promoting mechanisms of these beneficial genera were closely related to metabolic pathways such as amino acid metabolism, melatonin biosynthesis, aerobactin biosynthesis and so on. This study provides field observation and experimental evidence to reveal the close relationship between beneficial rhizosphere microbes and plant productivity under the M × R interaction effect. Summary statement: This study reveals that bacterial communities in agriculture systems are more sensitive to the interactive effects of agricultural management (M) and rhizosphere selection (R) than fungal communities, and that rhizosphere bacterial diversity drives plant biomass enhancement. Root exudates recruit beneficial genera of bacteria to colonize the root surface and promote plant growth, and the growth‐promoting mechanisms are related to pathways such as amino acid metabolism, melatonin biosynthesis and aerobactin biosynthesis. [ABSTRACT FROM AUTHOR]