
Ditches--A Simple, Inexpensive
Way to Improve Surface Water QualityBy Hank Becker March 24, 2000A first-of-its-kind study of the
transport and fate of two pesticides in vegetated agricultural drainage ditches
suggests ditches are valuable tools for reducing the amount of chemicals
entering bodies of water. Drainage ditches are a common feature in the agricultural landscape. They
carry runoff water from fields following storm events or controlled water
releases in the case of rice fields. Agricultural Research Servicescientists Matt Moore, Sammie Smith and Charlie Cooper at the
National Sedimentation
Laboratory, Oxford, Miss., evaluated the role of edge-of-field best
management practices in preventing potential agricultural contaminants from
entering water bodies. They simulated storm runoff events by injecting a liquid
agri-chemical formulation into a drainage ditch in the Mississippi Delta. The drainage ditch is located in the Beasley agricultural drainage area in
Mississippi, one of three watershed/lake combinations being studied as part of
the Mississippi Delta
Management Systems Evaluation Area (MD MSEA). The MSEA project is a
national effort by the U.S. Department of Agriculture to protect America's
farmlands. It's designed to test and develop farming methods that will work
with nature, instead of damaging water quality. The scientists calculated the percentage of runoff that the ditch may be
exposed to during a small storm (0.25 inches), looking to pinpoint its role in
keeping irrigation water and pesticides from entering water bodies. They found
that the ditch trapped 60 to 90 percent of the atrazine and a commonly used
insecticide, Karate, carried in runoff water. The ARS researchers say ditches may give farmers a simple, low-tech and
inexpensive solution to improving surface water quality. Ditches can play an
important trapping and processing role. Through their vegetation and soil, ditches work like wetlands to sequester
these storm runoff materials, thereby decreasing potential harm to downstream
lakes, rivers and streams. Farmers and conservationists who want to reduce the
amounts of chemicals, nutrients and sediment leaving agricultural fields may
find that using and maintaining these ditches is vital as an alternative
management practice. ARS is the chief research agency of the USDA. Scientific contacts: Matt Moore, Sammie Smith, and Charlie Cooper,
ARS National Sedimentation Laboratory, Oxford, Miss., phone (601)
232-2955/2935; fax (601) 232-2915; [email protected],
[email protected],
[email protected]. U.S. Department of Agriculture |