Effects of continuous cropping of Codonopsis pilosula on rhizosphere soil microbial community structure and metabolomics

Abstract

Codonopsis pilosula is an important medicinal plant in China. Continuous cropping of C. pilosula affects crop quality and yield. However, comprehensive research on the impacts of continuous cropping on soil properties, microbial community structures, and soil metabolites is lacking. This study involved collecting rhizosphere soil samples from C. pilosula monocropped for 1 to 4 years to analyze variations in soil properties, microbial community structure, and metabolites across different continuous-cropping years (CCYs) through metabolomic and microbiomic analyses. Significant variations in the soil properties were observed; total phosphorus (TP) and available potassium (AK) in the rhizosphere soil increased with the number of CCYs, and pH declined. The microbial community structure significantly changed with continuous cropping. Overall, the soil bacterial diversity decreased with increasing CCY. The abundances of Proteobacteria and Firmicutes significantly decreased with increasing CCY, whereas the abundance