Effect of Autotoxicity and Soil Microbes in Continuous Cropping Soil on Angelica sinensis Seedling Growth and Rhizosphere Soil Microbial Population

Objective To study the effect of autotoxicity and the co-effect of autotoxicity and soil microbes from continuous cropping soil on Angelica sinensis growth, root yield and content of essential oils, and soil microbal population. Methods The pot experiments were conducted upon A. sinensis seedlings in continuous cropping soil. At the different growth stages, we determined the seedlings in growth parameters, root yield, content of essential oils, ethanol extract, and cultivable microbial populations in rhizosphere soil. Results A. sinensis seedlings were significantly inhibited in growth, root yield and quality. Compared with the control, the composition and structure of soil microbes were changed and the diversity indexes of bacteria functional groups were reduced in rhizosphere soil of A. sinensis. A. sinensis cropping problems were more seriously after the treatment with combination of autotoxicity and soil microbes than with autotoxicity alone. Conclusion The autotoxicity and soil microbes from continuous cropping soil of A. sinensis could cause the continuous cropping obstacle together.