USDA-ARS post-doctoral researcher, Matt Baddock,
stands next to a portable wind tunnel used to simulate wind erosion
Agricultural
Bacteria: Blowing in the Wind
It was all
too evident during the Dust Bowl what a disastrous impact wind can have on dry,
unprotected topsoil. Now a new study has uncovered a less obvious, but still
troubling, effect of wind: Not only can it carry away soil particles, but also
the beneficial microbes that help build soil, detoxify contaminants, and
recycle nutrients.
Using a
powerful DNA sequencing technique, called pyrosequencing, a team led by
USDA-ARS scientists Terrence Gardner and Veronica Acosta-Martínez analyzed the
bacterial diversity in three Michigan agricultural soils, and in two eroded
sediments generated from these soils during a wind tunnel experiment: coarse
particles and fine dust. Not only were the microbial assemblages on the coarse
particles distinct from those on the dust, report the scientists in the current
issue of the Journal of Environmental Quality, but the two types of eroded
sediments were each enriched in certain groups of microbes compared with the
parent soil, as well.
The
findings suggest that specific bacteria inhabit specific locations in soil—and
thus different groups and species can be carried away depending on the kinds of
particles that erode. “It’s important to know which microbes are being lost
from soil,” says Acosta-Martínez, a soil microbiologist and biochemist at the
USDA-ARS Cropping Systems Laboratory in Lubbock, TX, “because different
microbes have different roles in soil processes.”