Abstract: Taking the continuous cropping soil of Rehmannia glutinosa as the research object, the effect of applying bacterial manure on microbial community composition and root residual compounds in the soil of Rehmannia glutinosa was analyzed. The soil microbial count method was used to detect the number of microorganisms. Ultra high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry （UPLC-QTOF/MS） was used to profile the root residual compounds in the soil of Rehmannia glutinosa. The results showed that soil microbial community structure had significant differences under different treatments. The total number of bacteria and actinomycetes in Rehmannia glutinosa soil after 60 d of applying 0.05% bacterial manure was the highest, while the number of fungi was less. Nine unique residue compounds were screened out in the soil of Rehmannia glutinosa. The content of Compound 2 was the lowest when the concentration of bacterial manure was 0.05%. At the same time, the contents of Compound 5 and Compound 6 were the lowest when the concentration of bacterial manure was 0.10% and applied for 60 days. It was found that the application of bacterial manure could effectively change the soil microbial populations and reduce some residual compounds of continuous cropping soil. It was also beneficial to alleviate the continuous cropping obstacle of Rehmannia glutinosa.

Key words: bacterial manure, Rehmannia glutinosa, continuous cropping soil, UPLC-QTOF/MS