Managing Global Resources for a Secure Future

2017 Annual Meeting | Oct. 22-25 | Tampa, FL

107348 Cropping Sequence, Cover Crops, and Poultry Litter Applications Impact Soil Microbial Community Structure.

Poster Number 1200

See more from this Division: SSSA Division: Soil Biology and Biochemistry
See more from this Session: Surface Residue Management and Impacts on Soil Biology and Soil Health Poster

Tuesday, October 24, 2017
Tampa Convention Center, East Exhibit Hall

Amanda J. Ashworth, USDA - United States Department of Agriculture, Fayetteville, AR, Jennifer M. DeBruyn, University of Tennessee, University of Tennessee - Knoxville, Knoxville, TN, Fred L. Allen, Plant Sciences, University of Tennessee - Knoxville, Knoxville, TN, Mark Radosevich, Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN and Phillip R. Owens, USDA ARS Dale Bumpers Small Farms Research Center, Booneville, AR
Poster Presentation
  • ASA 2017 Microbe.pdf (627.6 kB)
  • Abstract:
    Soil microorganisms play essential roles in soil organic matter formation and nutrient cycling and are seen as soil quality indicators. The response of soil microbial communities to land management is complex and the long-term impacts of cropping systems on soil microbes is largely unknown. Therefore, changes in soil bacterial community composition were assessed in response to cropping sequences and soil amendments at long-term no-tillage sites. Main effects of four different cropping sequences of corn (Zea mays L.), cotton (Gossypium hirsutum L.), and soybean (Glycine max L.) were rotated in four year phases for 12-yrs at two Tennessee Research and Education Centers in a randomized complete block design with split-block treatments of hairy vetch (Vicia villosa L.) and wheat (Triticum aestivum L.) cover crops, poultry litter, and a fallow control. Using Illumina high-throughput sequencing of 16S rRNA genes, bacterial community composition was determined. Composition, diversity, and relative abundance of specific taxa were correlated per cropping system, soil amendment, and their interaction. We found that i) richness and diversity varied temporally and spatially, coinciding with soil carbon, pH, nutrient levels, and climatic variability; ii) community composition varied by cropping system, with continuous corn, soybean, and the corn-soybean rotation presenting a hybrid of the continuous corn and soybean communities; however, continuous cotton resulted in the most varied assemblage; iii) soil amendments asserted the greatest influence on microbial communities; specifically poultry litter treatments differed from cover crops. Consequently, microbial diversity was greatest under poultry litter and high residue producing, less pesticide-intensive cropping sequences (soybean and corn compared to cotton), suggesting a more dynamic soil ecology under these no-till cropping systems. This suggests that nutrient management (inorganic fertilizers vs. animal manure) and greater crop rotations (within 4-yr phases) may directly drive phylogenetic community structure and subsequent ecosystem services across agricultural landscapes.

    See more from this Division: SSSA Division: Soil Biology and Biochemistry
    See more from this Session: Surface Residue Management and Impacts on Soil Biology and Soil Health Poster