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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Agricultural Systems Laboratory » Research » Publications at this Location » Publication #286978

Title: Microbial community structure and abundance in the rhizosphere and bulk soil of a tomato cropping system that includes cover crops

Author
item Maul, Jude
item Buyer, Jeffrey
item Lehman, R - Michael
item Culman, Steve - University Of California
item Blackwood, Christopher - Kent State University
item Roberts, Daniel
item Zasada, Inga
item Teasdale, John

Submitted to: Applied Soil Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2013
Publication Date: 5/1/2014
Citation: Maul, J.E., Buyer, J.S., Lehman, R.M., Culman, S., Blackwood, C., Roberts, D.P., Zasada, I.A., Teasdale, J.R. 2014. Microbial community structure and abundance in the rhizosphere and bulk soil of a tomato cropping system that includes cover crops. Applied Soil Ecology. 77:42-50. DOI: 10.1016/j.apsoil.2014.01.002.

Interpretive Summary: Understanding plant microbe interactions in the context of crop rotation and legacy of cropping history can assist in determining how land use management and changing climatic conditions impact microbially mediated soil processes. In low input, organic and cover cropped based sustainable production systems land managers rely on microbes to process complex soil organic matter into plant available forms of nitrogen, phosphorous and most micronutrients. In the literature one finds mixed results when attempting to determine the major environmental and biological controls on soil microbial structure and functionality. The uncertainty surrounding determination of factors controlling the soil microbial community in the field is in part due to the common place of un-replicated experimental design and in part due to the scale at which researchers make determinations about the effects of any one particular factor. In this report we use Terminal Restriction Fragment Length Polymorphisms (TRFLP) in a tomato production system to “finger printing” the soil microbial community structure with Phylum specific primer sets. Factors influencing the soil microbes are a cover crop of Hairy Vetch (Vicia villosa) or Rye (Secale cereale) cover crop or a Black Polyethylene plastic mulch applied prior to planting the tomatoes. We found that during the summer month the cover crop selectively shifted the microbial community structure in a cover crop specific way, but these results were localized to the rhizosphere whereas the major driver of changes in the microbial community structure over the course of the experiment was the impact of seasonal changes. These results lay the ground work for future researchers to determine the relative effect of manageable factors on conditioning of the soil microbial community. The applied target of this research is in the future be able to recommend particular cover crop species or land cover treatments that predictively change the soil microbial community for the good of farmers and land managers.

Technical Abstract: In this report we use Terminal Restriction Fragment Length Polymorphisms (TRFLP) in a tomato production system to “finger printing” the soil microbial community structure with Phylum specific primer sets. Factors influencing the soil microbes are a cover crop of Hairy Vetch (Vicia villosa) or Rye (Secale cereale) cover crop or a Black Polyethylene plastic mulch applied prior to planting the tomatoes. We found that during the summer month the cover crop selectively shifted the microbial community structure in a cover crop specific way, but these results were localized to the rhizosphere whereas the major driver of changes in the microbial community structure over the course of the experiment was the impact of seasonal changes. Cumulatively, the factors we monitored Season, location (bulk or rhizosphere) or mulch (hairy vetch, rye or black poly) accounted for 20-30% of the observed change in microbial community structure over the course of the experiment. Individually these factors varied in the relative effects they had on the soil microbial community structure with season having the strongest effect at 5-10%, mulch at 2-4% and location at 2-3% depending on the specific phylum target. When factor analysis was isolated to just the summer month the rhizosphere was a strong influence on the soil microbial community structure followed by the mulch or soil surface treatment.