Effect of Different Substrates on Soil Microbial Community Structure and the Mechanisms of Reductive Soil Disinfestation

Xingyan Tan; Hongkai Liao; Liangzuo Shu; Huaiying Yao

doi:10.3389/fmicb.2019.02851

Effect of Different Substrates on Soil Microbial Community Structure and the Mechanisms of Reductive Soil Disinfestation

Front Microbiol. 2019 Dec 11:10:2851. doi: 10.3389/fmicb.2019.02851. eCollection 2019.

Authors

Xingyan Tan^{1

2}, Hongkai Liao^{1

3}, Liangzuo Shu², Huaiying Yao^{1

3

4}

Affiliations

¹ Ningbo Key Lab of Urban Environment Process and Pollution Control, Ningbo Urban Environment Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Ningbo, China.
² School of Life Sciences, Huaibei Normal University, Key Laboratory of Plant Resources and Biology of Anhui Province, Huaibei, China.
³ Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
⁴ Research Center for Environmental Ecology and Engineering, Wuhan Institute of Technology, Wuhan, China.

Abstract

Reductive soil disinfestation (RSD) has recently attracted much attention owing to its effectiveness for controlling pathogens. In this study, we aimed to evaluate the effects of different C/N substrates on RSD and to explore the changes in microbial community structure during RSD treatment. The experimental set up included 10 groups, as follows: CK, without substrates; RSD treatments with alfalfa (Medicago sativa L.)[AL], maize (Zea mays Linn. Sp.) straw [MS], and rice (Oryza sativa L.) straw [RS], with three levels of addition (0.5% [L], 2% [M], and 5% [H]), yielding ALL, ALM, ALH, MSL, MSM, MSH, RSL, RSM, and RSH groups. Compared with CK, RSD treatments significantly increased the content of ${NH}_{4}^{+}$ -N, and effectively eliminated the accumulated ${NO}_{3}^{-}$ -N in the soil. The relative abundances of organic acid producers, including Clostridium, Coprococcus, and Oxobacter, in all RSD groups were significantly higher than those in the CK by day 21. Moreover, on day 21, Aspergillus and Fusarium in all RSD groups were significantly lower than those in the CK. In summary, RSD treatments clearly increased the relative abundances of organic acid generators and effectively inhibited pathogens; however, when the C/N was too low and the amount of addition too high, ammonia poisoning and rapid growth of some microorganisms (e.g., Pseudallescheria and Arthrographis) may occur.

Keywords: C/N ratio; organic matter; reductive soil disinfestation; soil microbial community; tomato.