Effects of Different Types of Rice Straw Addition on Soil Microbial Communities Under Continuous Tobacco Cropping.

In order to study the effects of adding different types of rice straw on soil bacterial communities under continuous cropping of flue-cured tobacco, fresh rice straw (FS) and rotted rice straw (RS) were added in soil, with no straw as control (CK). The community composition and diversity of soil bacteria and fungi at different times (0, 7, 30, 60 and 90 d) under 3 treatments were studied by high-throughput sequencing. The results showed that fresh rice straw and rotted rice straw could significantly improve the diversity and richness of soil microbial community. After 90 d in FS and RS treatments, the Chao 1 index, Shannon index and Simpson index of bacteria and the Chao 1 index of fungi were significantly improved. The analysis of community structure composition showed that FS and RS treatments increased the relative abundances of Proteobacteria, Spirochaetes and Verrucomicrobia. FS treatment increased the relative abundance of Basidiomycota, and decreased the relative abundances of Chytridiomycota and Rozellomycota. RS treatment increased the relative abundances of Ascomycota and Basidiomycota, and decreased the relative abundances of Zygomycota and Chytridiomycota. In summary, the addition of fresh rice straw and rotted rice straw could change the community composition of soil bacteria and fungi, improve the health status of soil with continuous cropping of flue-cured tobacco. Compared with rotted rice straw treatment, fresh rice straw treatment increased the abundance of pathogenic fungi. [ABSTRACT FROM AUTHOR]