AUTHOR=Tan Xingyan , Liao Hongkai , Shu Liangzuo , Yao Huaiying 

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

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.02851

DOI=10.3389/fmicb.2019.02851

ISSN=1664-302X

ABSTRACT=<p>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 (<italic>Medicago sativa L.</italic>)[AL], maize (<italic>Zea mays Linn. Sp.</italic>) straw [MS], and rice (<italic>Oryza sativa</italic> 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 <inline-formula><mml:math id="INEQ1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mtext>NH</mml:mtext><mml:mn>4</mml:mn><mml:mo>+</mml:mo></mml:msubsup></mml:math></inline-formula>-N, and effectively eliminated the accumulated <inline-formula><mml:math id="INEQ2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mtext>NO</mml:mtext><mml:mn>3</mml:mn><mml:mo>-</mml:mo></mml:msubsup></mml:math></inline-formula>-N in the soil. The relative abundances of organic acid producers, including <italic>Clostridium</italic>, <italic>Coprococcus</italic>, and <italic>Oxobacter</italic>, in all RSD groups were significantly higher than those in the CK by day 21. Moreover, on day 21, <italic>Aspergillus</italic> and <italic>Fusarium</italic> 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., <italic>Pseudallescheria</italic> and <italic>Arthrographis</italic>) may occur.</p>