128-1 Soil Archaeal Communities Can Be Influenced by Land-Use History in An Australian Vertisol.

Poster Number 1213

See more from this Division: S03 Soil Biology & Biochemistry
See more from this Session: Soil Metagenomics
Monday, October 22, 2012
Duke Energy Convention Center, Exhibit Hall AB, Level 1
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Vadakattu Gupta, CSIRO, Glen Osmond, SA, AUSTRALIA, David Coleman, University of Georgia, Athens, GA, Steve Wakelin, Ag Research, Lincoln, New Zealand, Kamlesh Jangid, Department of Microbiology, University of Georgia, Athens, GA and William Whitman, Microbiology, University of Georgia, Athens, GA
Poster Presentation
  • SSSAm 2012_Archaea_Coleman_final.pdf (1.8 MB)
  • Agriculture is one of the most important human activities that exert a large impact on soils and their biota. Most research on soil microorganisms has concentrated on bacteria and fungi; only recently has the diversity and dynamics of soil archaeal communities been considered. However, there is increasing evidence to show that they are playing a significant role in the cycling or carbon, nitrogen and plant-fungal interactions. Microorganisms in Vertisols are exposed to regular disturbances due to changes in physico-chemical properties from wetting-drying and crop management practices. Such changes alter the diversity and activity of soil organisms including bacteria, fungi and microfauna. We measured the diversity of soil archaeal communities, using a PCR-DGGE profiling of archaeal 16S rRNA gene, in an Australian Vertisol under cotton-wheat-cotton (CWC) or cotton-wheat-vetch-cotton (CWVC) rotations. Surface 10cm soils collected from within the cotton crop were exposed to stubble addition and / or wetting and drying regime and incubated at 25C for 8 weeks. Previous land use history had a significant influence on the archaeal community structure (PERMANOVA CV=23.8, P<0.001) and richness and diversity was higher under the CWVC rotation. Both the exposure to repeated wetting-drying regime or incubation with stubble significantly altered community structure in soils from both field treatments; cluster analysis grouping them into distinct groups. Species richness (Margalef’s index, d) and diversity (Shannon index H’) were significantly higher in soils incubated with added stubble or exposed to wetting-drying regime (d=4.51-4.65 and H’=3.41-3.46) compared to control field soils (d=3.9 and H’=3.27).  In conclusion, the effect of land-use history and stubble addition suggest that quantity and quality of C inputs can impact soil archaeal community. In a self-mulching Vertisol the effect of wetting and drying events could be due to the changes in physico-chemical characteristics. Implications of such changes in archaeal community structure to soil functions are yet to be fully understood.
    See more from this Division: S03 Soil Biology & Biochemistry
    See more from this Session: Soil Metagenomics
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