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      Adams, Minn. (AP) - When was the last time you saw a ditch look
any different than, well, a ditch?


      A new research project in rural Adams will study how tweaks in
ditch design affect the amount of sediment and nutrients leaving
it. Known as a two-stage drainage ditch, it's said to be the first
of its kind in southeast Minnesota.


      Project leaders refer to the key change as the "benches." They
are 10-foot wide, flat areas on both sides of the water channel at
the bottom of the ditch. These are seeded with native grasses,
flowers, rye and oats. When water drains in the ditch and travels
over them, the vegetation acts as a filter, using nutrients in the
water to grow.

      The benches make the ditch wider, plus the sides of the ditch
are less steep to provide more stabilization. It's about 60 feet
wide from the top of the bank on one side to the top of the other.
It's hoped the gradually sloped banks cause less erosion and less
maintenance costs of keeping the ditch clear.


      The Nature Conservancy, a partner in this project, expects the
two-stage ditch to perform similarly to those in other states.
They're used in Indiana and Ohio.


      Rich Biske, the conservancy's southeast Minnesota conservation
coordinator, said Indiana's ditches reduced nitrogen by 20 percent
and caused the water to look significantly clearer. Eventually, the
project will also look into phosphorus reductions. It will take at
least three years of monitoring to know how much the ditch reduces
nutrients, Biske said.


      The benches will help reduce water speed in times of high flow.
Any overflow will spread over the flat space and slow down.

      Dairy farmer Randy Smith is one of three landowners involved.
His land draining to the ditch is used to grow corn and alfalfa.


      The ditch takes up more room than it used to, he said, but
that's not a problem if it works. The old ditch was prone to
erosion. He likes that the new design should be more stable and
able to hold more water.


      "I think it's a great idea," he said.


      Bruce Wilson, a professor in the U of M's bioproducts and
biosystems engineering department, said it's important to test how
the design works under Minnesota conditions.

      "We will be monitoring the stability of the two-stage ditch and
evaluating the removal of nutrients within our test reach. These
results will be compared to traditional ditches using data
collected by the Minnesota Department of Agriculture," Wilson
said.

      This project also incorporates new ideas. The researchers are
trying out a new inlet design by making surface water flow through
rocks to hopefully reduce sediment and phosphorus. They've also
incorporated a trench filled with rocks, not connected to any water
source, to see if this helps prevent seepage forces that could
otherwise make the banks less stable.


      Another tweak is they've connected some tile inlets to a small
ditch on the benches. Water runs through the small ditch, giving
vegetation more time to filter it before water enters the channel.


      The University of Minnesota, Minnesota Board of Water and Soil
Resources and the Minnesota Pollution Control Agency are involved
with evaluating, engineering and monitoring the ditch. The Mower
Soil and Water Conservation District helped get landowners
involved.

      Construction took a month and was completed the first week of
November. The project cost $200,000. Funding was provided by
Cargill, General Mills and a grant from the Natural Resources
Conservation Service.
      
      
      ---


      Information from: Agri News, http://www.agrinews.com/

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A new research project in rural Adams will study how tweaks in
ditch design affect the amount of sediment and nutrients leaving
it. Known as a two-stage drainage ditch, it's said to be the first
of its kind in southeast Minnesota.

Researchers offer a new idea for ditches

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