Nonpoint source pollution from agricultural
areas has been recognized as a major contributor
of surface and groundwater quality problems.
Sediments, pesticide and nutrient runoffs,
and microbial pathogens from farmlands may
severely affect quality of water resources. A
majority of Kansas river basins contains high
concentrations of fecal coliforms, nitrogen,
phosphorus, and sediments. The use of vegetative
filters strips (VFS) has been identified as
one of the best management practices to reduce
pollutant concentrations in surface water
sources. Vegetation planted between pollutant
sources and receiving water accomplishes this
by filtration, deposition, infiltration, adsorption,
volatilization, plant uptake, and decomposition
processes. The effectiveness of VFS in reducing
nonpoint source pollution is being evaluated
at four Kansas watersheds. Water samples are
being collected at inlets and outlets of the VFS
and analyzed for nutrients, sediments, and fecal
coliform concentrations. Total nitrogen and
phosphorus concentrations were reduced 26
and 14%, respectively, in one watershed and by
73 and 71%, respectively, in another. On a
mass basis, total nitrogen and phosphorus
reductions were 51 and 42%, respectively, in
one and 60 and 52%, respectively, in the other.
In the third watershed, mass flow rate of fecal
coliform was reduced significantly by the VFS.
If maintained properly, VFS can be used to
improve water quality in agricultural areas.
