Effects of Continuous Cropping on Bacterial Community and Diversity in Rhizosphere Soil of Industrial Hemp: A Five-Year Experiment

Abstract

Long-term continuous monoculture cultivation harms soil physicochemical and microbial communities in agricultural practices. However, little has been reported on the effect of continuous cropping of industrial hemp on bacterial community and diversity in the rhizosphere soil. Our study investigated the changes in physicochemical properties and bacterial communities of industrial hemp rhizosphere soils in different continuous cropping years. The results showed that continuous cropping would reduce soil pH and available phosphorus (AP), while electrical conductivity (EC), available nitrogen (AN), and available potassium (AK) would increase. Soil bacterial diversity and richness index decreased with continuous cropping years. At the same time, continuous cropping marked Acidobacteria, Bacteroidetes, and Gemmatimonadetes increase, and the Proteobacteria and Actinobacteria decreased. Moreover, we found that pH, AK, and AP were the critical factors associated with the changes in the abundance and structure of the bacterial community. Overall, our study first reported the effect of continuous cropping on the rhizosphere soil microflora of industrial hemp. The results can provide a theoretical basis for revealing the obstacle mechanism of continuous cropping of industrial hemp and contribute to the sustainable cultivation of industrial hemp in the future.

Keywords

• industrial hemp
• bacterial community
• continuous cropping
• rhizosphere soil