story to find out more.
To see whether
wormholes funnel manure to drain pipes, ARS scientists trace wormhole
connections to pipes by blowing smoke through pipes and watching it pour out of
surface wormholes. Click the image for more information about
Wormholes--Yet Another Avenue for
Pollution? By Don
Comis September 14, 2005
There's no doubt that earthworms benefit agriculture by their
tunneling. But a recent study has shown that their burrows might also be
funneling liquid manure--and possibly other contaminants--to underground
drainage pipes. These, in turn, flush contaminated water onward, bypassing
normal filtering and cleansing by soil.
Agricultural Research Service
J. Shipitalo, at the
North Appalachian Experimental Watershed Laboratory in Coshocton, Ohio, and
Frank Gibbs, with USDA's Natural Resources
Conservation Service in Findlay, Ohio, did the study in no-till fields with
liquid manure applied.
They found that water moved through wormholes twice as fast when the
holes were within two feet of drainage pipes. The pipes provided outlets that
helped the water flow along, instead of slowly percolating through small
openings between soil particles.
The study suggests that the most practical solution is for farmers to
install shutoff valves so they can turn off drainage during liquid manure
application and for a short time afterwards. Some Ohio farmers already do this,
with cost-sharing from the Ohio
Department of Natural Resources. Another solution would be to install catch
basins at the edges of fields to capture water draining from pipes and hold it
for reuse. Both would help downstream water quality.
Worms--especially nightcrawlers--are especially attracted to no-till
fields in areas that require drainage. They like the combination of no-till,
drainage pipes, and the liquid manure farmers often apply to fields.
The worms eat the leftover parts of crops left on the surface by
no-till, which skips plowing before planting, and they see the manure as food,
too. The drainage pipes aerate the soil nicely, loosening it up for easy
digging, especially the soil used to cover the drainage pipes. Plus, the crop
residue offers them shelter, and with no-till there's no fear of a plow
breaking up their tunnels.
about this research in the September 2005 issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief scientific research agency.