Effects of crop rotation on sugar beet growth through improving soil physicochemical properties and microbiome

Soil microorganisms are critical to the sustainable development of agroecosystems. Continuous cropping obstacles refer to crop yield reduction in continuous cropping. Crop diversity can be increased through crop rotation, improving soil-plant interactions to alleviate the continuous cropping obstacles. In our study, rubber dandelion (Taraxacum kok-saghyz Rodin, TKS) and sugar beet (Beta vulgaris L.) were used for rotation. A two-year field experiment was conducted using a randomized uniform grid design to investigate the effects on soil microbial community structure and physicochemical properties, and supplemented by a pot experiment. We hypothesized that sugar beet and rubber dandelion could change soil microbiome, improve soil physicochemical properties, and ultimately promote the growth of sugar beet. The results showed that compared with continuous cropping, sugar beet and rubber dandelion rotation can enhance the soil microbiome and increase the abundances of Actinobacteria and Streptomyces. The available nitrogen, potassium and soil organic matter contents were higher in rotation soil than in continuous cropping soil. In addition, urease activity in the soil after rotation with rubber dandelion was significantly increased. In general, the rotation of sugar beet and rubber dandelion could increase the biomass of sugar beet and alleviate the continuous cropping obstacle.