Organic amendments derived from Chinese herb residues enhance soil ecosystem multifunctionality by enriching key microorganisms

Ecosystem multifunctionality (EMF), a key metric reflecting soil health, has been proven to be positively influenced by organic amendments. Chinese herb residues (CHR), rich in bioactive compounds and with lower ecological risks, are regarded as a promising source for organic amendments. Therefore, we conducted a greenhouse experiment with four treatments: no fertilizer (CK), chemical fertilizer (CF), single application of CHR-OA (OA), and partially replacing chemical fertilizers with CHR-OA (OA-CF), aiming to explore the regulatory mechanism of CHR-OA addition to EMF. A total of 19 ecosystem functions, covering plant growth, pathogen suppression, soil physicochemical properties, and microbial diversity, were used to calculate EMF. The results showed that most of the above ecosystem functions were improved by adding CHR-OA, with the OA-CF possessing the highest EMF, followed by OA. Additionally, Lysobacter was enriched as a key genus. Further analysis revealed that Lysobacter drove EMF by influencing bacterial Simpson index, plant height, and root length, and this conclusion was confirmed in greenhouse verification experiments. Through this study, we have gained a clearer understanding of the prominent ecosystem functions provided by CHR-OA and the regulatory mechanism of EMF.