Effects of continuous cropping on the yield, quality, and soil microbial diversity ofPseudostellaria heterophylla

To explore the changes in soil microbial diversity in continuous cropping fields of Pseudostellaria heterophylla, a field experiment was conducted to investigate the effects of continuous cropping soil and first stubble land on the yield, quality, and soil microbial diversity and structure distribution of Pseudostellaria heterophylla. The results showed that compared with first stubble land（first crop）, the yield, polysaccharide content, and saponin content of Pseudostellaria heterophylla in continuous cropping fields were all reduced, with fresh weight yield decreasing by 76.85%, polysaccharide content decreasing by 3.16%, and saponin content decreasing by 75.00%. In the analysis of rhizosphere soil microbial diversity, the number of unique or shared fungal OTUs in each sample was different in the flower plot. The unique fungi and bacteria in continuous cropping soil were lower than those in the control first stubble land. The fungal community composition in continuous cropping soil exhibited greater differences, while the bacterial community composition showed higher similarity. In contrast, the fungal community composition in the control first-crop soil treatment exhibited higher similarity, whereas the bacterial community composition showed greater differences. In the continuous cropping soil treatment, the root - zone soil fungal communities significantly enriched include Chytridiomycota, Mortierellomycota, and Mortierella, among others. In the first - cropping soil treatment, the root-zone soil fungal communities significantly enriched mainly consist of Mucoromycota, etc. In the continuous cropping soil treatment, the root - zone soil bacterial communities significantly enriched are Chloroflexi, Acidobacteria, Rhodanobacter, and so on. As for the first - cropping soil treatment, the root - zone soil bacterial communities significantly enriched involve Firmicutes, Cyanobacteria, Ochrobactrum, Acinetobacter, etc.This study preliminarily explored the differences in fungal and bacterial community diversity and distribution characteristics between continuous cropping and new rhizosphere soils, providing a reference for the continuous cropping obstacles of Pseudostellaria heterophylla.