Different crop rotation systems change the rhizosphere bacterial community structure of Astragalus membranaceus (Fisch) Bge. var. mongholicus (Bge.) Hsiao

Abstract

Continuous cropping obstacles often lead to a decline in the quality and yield of traditional Chinese medicine plants. Crop rotation effectively alleviates the obstacles of continuous cropping. However, there are few studies on the rotation of traditional Chinese medicine crops. Astragalus membranaceus (Fisch) Bge. var. mongholicus (Bge.) Hsiao (A. mongholicus) is a commonly used traditional Chinese medicine. The present study investigates the growth of A. mongholicus and its associated soil microbiome and physicochemical properties under different crop rotation regimes in a field and pot experiment. The 16S rRNA gene high throughput sequencing was used to compare the composition and diversity of rhizosphere, bulk soil and endosphere bacterial communities of A. mongholicus after 5 years of crop rotation. Crop rotation with Avena sativa L, significantly increased the growth of A. mongholicus and elevated soil organic matter, total nitrogen, total phosphorus and available potassium contents. Crop rotation increased the bacterial community diversity in the rhizosphere of A. mongholicus and abundance of some beneficial bacteria, such as Clostridia, Rubrobacterales and Micromonosporales. The composition of the rhizosphere bacterial community differed between sampling times and depending on crop rotation. Briefly, crop rotation with Avena sativa L was beneficial to soil quality and A. mongholicus growth, and it is a good option to alleviate A. mongholicus continuous cropping obstacles.