COLUMBIA, Mo. Field tests by University of Missouri scientists have backed up laboratory research indicating that buffer strips of grass and other plants can reduce the amount of herbicide and veterinary antibiotics in surface runoff from farm plots.
Vegetative buffer strips have already proven effective in limiting erosion as well as reducing sediment and nutrients in runoff.
The findings come amid concerns about the potential of veterinary antibiotics in surface water leading to the emergence of antibiotic-resistant bacteria. The antibiotics can enter the environment through manure from confined animal feeding operations and from crop fields fertilized with manure.
"Vegetative buffer systems are recognized as one of the most effective approaches to mitigate surface water runoff from agroecosystems, and we think that such systems also have the utility for reducing veterinary antibiotic loss," said Bob Lerch, USDA soil scientist and MU adjunct professor.
Researchers compared the effectiveness of three grass buffer treatments in reducing the transport of herbicides and veterinary antibiotics in surface runoff. Plant species used in the three treatments included tall fescue, switchgrass and native warm-season grassesmainly eastern gamagrass. The control treatment was cultivated fallow.
The researchers applied three herbicides and three antibiotics, then generated surface water runoff using a rotating-boom rainfall simulator to create uniform soil moisture content. Water and suspended sediment samples were collected and measured.
All vegetative buffer systems significantly reduced the transport of both dissolved and sediment-bound herbicides atrazine, metolachlor and glyphosate in surface runoff by 58 to 72 percent, said Chung-Ho Lin, research assistant professor with the MU Center for Agroforestry and Department of Forestry.
In addition, the processes governing herbicide fate also applied to veterina
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University of Missouri-Columbia