Abstract
Chrysanthemum morifolium is widely used as a raw material in traditional Chinese medicine and in health drinks. However, continuous cropping obstacles have produced bottlenecks in C. morifolium production. Crop rotation is considered to be the cheapest and most effective method to restore soil quality. Therefore, we here studied the impact of two crop rotation models (Prunella vulgaris-C. morifolium and Brassica napus-C. morifolium) on C. morifolium productivity and soil quality. Our results showed that both rotation models led to a higher C. morifolium yield and quality advantage than monoculture model; subsequently, the main reasons for improving C. morifolium productivity by these two crop rotation modes were analyzed. Levels of soil nutrients, such as total nitrogen, available phosphorus, and available iron, showed significant augment in crop rotation; similar situation were observed for the activities of soil acid phosphatase, sucrase, and β-glucosidase. Furthermore, the reduced wilt disease incidence and the decreased Fusarium pathogen adundance under rotation could be attributed to the changes in bacterial community structure and rhizosphere metabolites. In addition, changes in the abundance of metabolites in the rhizosphere soil were key factors affecting the bacterial and fungal community structure. For instance, two rotation systems decreased the presence of Proteobacteria and increased other bacterial phyla (e.g. Actinobacteria, Acidobacteriota, Cyanobacteria), potentially influenced by rhizosphere soil metabolites. This study offers new insights into the mechanisms by which continuous cropping challenges can be overcome and provides concrete suggestions for improving yield of an economically and medicinally important plant species.