SUSTAINABLE AGRO-ECOSYSTEMS THAT CONTROL SOIL EROSION AND ENHANCE THE ENVIRONMENT
Location: Wind Erosion and Water Conservation Research
Title: Characterization of microbes carried in dust
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 18, 2011
Publication Date: September 21, 2011
Citation: Gardner, T., Acosta Martinez, V., Zobeck, T.M., Baddock, M., Van Pelt, R.S., Senwo, Z. 2011. Characterization of microbes carried in dust[abstract]. International Symposium on Erosion and Landscape Evolution. September 18-21, 2011, Anchorage, Alaska.
There is still a lack of understanding of how soil microbial community distribution is controlled by wind erosion. This information is of international concern as eroded sediments can potentially carry away the active labile organic soil particulates containing key microorganisms involved in soil biogeochemical processes, which can have a negative impact on the quality and functional potential of the soil. Pyrosequencing techniques promises to expand our understanding of the vast microbial diversity with respect to soils that experience high rates of wind erosion; because it is able to sequence 10-100 times more DNA fragments than previous techniques (traditional cloning). Our study evaluated the bacterial distribution and diversity on different types of sediments, coarse sediment (>106µm) and fine dust (<106µm), collected from three different soils in Michigan by using a portable field wind tunnel instrument. Our results indicated that Acidobacteria was the predominant bacteria in these soils as well as the predominant bacteria carried via wind dispersion in coarse and fine dust from these soil sources. Soil 1, which had higher P levels than the other 2 soils, pH was basically 6 and it had higher organic matter (OM) content (47.3-55%), showed predominance of Acidobacter, Streptomyces, Levilinea, Patulibacter and Gemmatimonas. Although Streptomyces was the second most abundant bacteria in soil source 1, fine dust did not carry this bacteria. Levilinea was carried in fine dust from the source soil 1. Soil 2 (122-136 mg P kg-1), pH of 5.5, and an intermediate OM content (42.9%) also showed the species predominance of Acidobacter followed by Patulibacter, Conexibacter, Rhizobium and Levilinea. Three of the 5 predominant bacteria in the soil source were also predominant in the fine dust of soil source 2 except for Conexibacter and Rhizobium. Soil 3 had the lowest OM content (16.3-20.8%) of the 3 soils evaluated, had an average pH of 5.7, and P levels within a range of 123-153 P mg kg-1. This soil also showed a predominance of Acidobacter followed by Patulibacter, Rhizobium, Gemmatimonas, and Conexibacter. In addition to Acidobacter in fine dust, Conexibacter and Patulibacter were also carried in the fine dust. Generally, Actinobacteria was more associated with the soil source than with the eroded sediments. The coarse dust sediments collected from these 3 soils demonstrated some differences in bacterial distribution compared to the fine dust, revealing different locations and niches of bacteria in soil, which depending on wind erosion processes, can have important implications on the soil sustainability and functioning. Our study provides evidence that eroded sediments remove the active labile organic soil particulates containing key microorganisms involved in soil biogeochemical processes, which can have a negative impact on the quality and functioning of the parent soil.