Cross-site soil microbial communities under tillage regimes: fungistasis and microbial biomarkers

Appl Environ Microbiol. 2012 Dec;78(23):8191-201. doi: 10.1128/AEM.02005-12. Epub 2012 Sep 14.

Abstract

The exploitation of soil ecosystem services by agricultural management strategies requires knowledge of microbial communities in different management regimes. Crop cover by no-till management protects the soil surface, reducing the risk of erosion and nutrient leaching, but might increase straw residue-borne and soilborne plant-pathogenic fungi. A cross-site study of soil microbial communities and Fusarium fungistasis was conducted on six long-term agricultural fields with no-till and moldboard-plowed treatments. Microbial communities were studied at the topsoil surface (0 to 5 cm) and bottom (10 to 20 cm) by general bacterial and actinobacterial terminal restriction fragment length polymorphism (T-RFLP) and phospholipid fatty acid (PLFA) analyses. Fusarium culmorum soil fungistasis describing soil receptivity to plant-pathogenic fungi was explored by using the surface layer method. Soil depth had a significant impact on general bacterial as well as actinobacterial communities and PLFA profiles in no-till treatment, with a clear spatial distinction of communities (P < 0.05), whereas the depth-related separation of microbial communities was not observed in plowed fields. The fungal biomass was higher in no-till surface soil than in plowed soil (P < 0.07). Soil total microbial biomass and fungal biomass correlated with fungistasis (P < 0.02 for the sum of PLFAs; P < 0.001 for PLFA 18:2ω6). Our cross-site study demonstrated that agricultural management strategies can have a major impact on soil microbial community structures, indicating that it is possible to influence the soil processes with management decisions. The interactions between plant-pathogenic fungi and soil microbial communities are multifaceted, and a high level of fungistasis could be linked to the high microbial biomass in soil but not to the specific management strategy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture / methods*
  • Bacteria / genetics
  • Bacteria / growth & development
  • Bacteria / isolation & purification*
  • Bacterial Load
  • Biota*
  • Colony Count, Microbial
  • DNA Fingerprinting
  • Fusarium / genetics
  • Fusarium / growth & development
  • Fusarium / isolation & purification*
  • Phospholipids / analysis
  • Polymorphism, Restriction Fragment Length
  • Soil / chemistry*
  • Soil Microbiology*

Substances

  • Phospholipids
  • Soil