15. Plant Vegetative Filter Strips Or Make Critical
Area Plantings |
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Vegetative
filter strips are strips of grass, trees, and/or shrubs planted between
water and cropland. They provide four basic forms of protection.
They capture sediment, pesticides, and nutrients moving from adjoining
cropland before they reach the stream or lake. The nutrients and
pesticides are taken up by the buffer strip's grass, trees, or shrubs.
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Filter
strips increase denitrification, a process in which microbes convert
nitrate-nitrogen into a form that is lost to the atmosphere. Denitrification
reduces the amount of nitrate available to move into groundwater and
surface water supplies. |
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Filter
strips increase the infiltration of runoff into the soil. As a bonus,
vegetative filters can serve as a natural classroom for children,
a corridor for wildlife movement, and an important breeding ground
for birds and other wildlife. |
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Where
controlling the surface movement of erosion, fertilizers, and pesticides
is the goal, filter strips are most effective on slopes of 5 percent
or less. Where controlling the subsurface movement of fertilizers
and pesticides is the goal, filter strips are most effective on land
that does not have a subsurface drainage system. A subsurface drainage
system will bypass the filter. |
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While
vegetative filter strips provide protection along waterways, a critical
area planting is used to protect small, isolated areas in a field
that are being damaged by erosion. |
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