The Effect of Rotational Cropping of Industrial Hemp (Cannabis sativa L.) on Rhizosphere Soil Microbial Communities

Crop rotation affects soil properties and soil microbial diversity and structure. Currently, it is not well understood how soil microbial diversity changes following different crop rotation systems of industrial hemp, an ancient and economically important crop. Therefore, these changes were analyzed in this study. Our results showed that different rotation systems significantly affected the wilt disease incidence, plant height, yield, soil physicochemical properties and soil microbial communities in the greenhouse. The rotation systems used in this study significantly reduced the plant mortality and increased the yield compared with a monoculture system. The levels of alkaline hydrolysis and available phosphorus in the soil decreased significantly compared with a monoculture cropping system. Using MiSeq high-throughput sequencing, we showed that the soil diversity and number of bacteria and fungi were significantly higher for rotation systems and controls compared to the monoculture system. The relative abundance of pathogens increased with a monoculture system. Redundancy analysis suggests that soil properties may also affect the soil microbial composition. Taken together, different rotation systems used in this study significantly decreased the disease incidence, increased plant yields and increased soil microbial diversity compared with monoculture for industrial hemp. We believe that applying these rotation systems is an efficient and eco-friendly approach to control soil borne pathogenic diseases and increase floral yields.

Automated summary

Crop rotation can significantly impact soil microbial diversity and structure. In this study, the effects of different rotation systems on industrial hemp were analyzed. The results showed that rotation systems reduced disease incidence, increased plant yields, and enhanced soil microbial diversity compared to monoculture. MiSeq sequencing revealed higher diversity and abundance of bacteria and fungi in rotation systems. These findings highlight the importance of applying rotation systems to control pathogenic diseases and improve yield.