The Pelican River Watershed District has issued a pamphlet presenting its concern
over fertilizer use in the lake area. While the brochure notes that its tempting
for property owners to establish a lush green lawn down to the water, such practices
can pollute the lake. It is known, notes the district, that ingredients in fertilizers
are among the most serious of those things which can adversely impact water quality
in likes. In fact, it's pretty obvious that if fertilizer will make your lawn
or garden grow, it will also promote growth of plants in the lake.
Unfortunately, lakes respond quickly to relatively small amounts of nutrients.
The addition of the equivalent of a few bags of fertilizer to a lake, even a large
one, can cause serious damage.
Of the ingredients in fertilizer, research has shown that phosphorus is especially
important in contributing to aquatic plant growth. Excessive plant growth, including
algae blooms, results in accellerating deterioration and premature aging of our
lakes.
If you value your fishing lake as it is now, for fishing, boating, swimming or
aesthetics, then you have a stake in seeing to it that the amount of phosphorus
entering the lake is minimized.
Phosphorus from fertilizers is mainly introduced to lakes in our area by runoff.
Surplus rainfall or lawn watering dissolves phosphorus from lawn surfaces or agricultural
areas, and carries it overland to streams or storm sewers and thence to lakes.
Phosphorus also may be carried to lakes directly from shore areas, or by infiltrating
into sandy soils near lake shores, then to be carried by groundwater into the
lakes.
Occassionally phosphorus reaches the lakes as a result of poor application techniques,
as in the case in which a rotary spreader inadvertently scatters fertilizer into
a lake or stream, or by accidental dumping of fertilizer in roadways or even into
streams or lakes themselves.
It's not only from sacks that phosphorus may eventually enter a lake. It's also
carried directly from the atmosphere by rainfall and snow, and natural phosphorus
is in groundwater which enters some lakes.
Runoff from livestock operations may introduce phosphorus into rivers or streams
which drain to lakes, or directly to the lakes themselves. Phosphorus and other
nutrients can enter lakes through faulty septic system, especially in lake shore
areas where the water table is close to the surface and the soils are sandy.
How can you avoid phosphorus? Becker County soils have sufficient phosphorus to
sustain a well-groomed lawn and garden, if you wish to establish one. The use
of phosphorus-free fertilizers will provide plenty of nutrients. And consider
utilizing lake water to water your lawn and garden-lake water often contains nutrients,
including nitrogen and phosphorus.
If you do use fertilizer, control the application by using a drop spreader rather
than a rotary one. What you need to do to build good root structures and minimizer fertilizer runoff
problems is apply nitrogen fertilizers in early fall; never apply fertilizers to
frozen ground. Avoid applying fertilizers on sloping lawns, or in natural drainageways.
Pesticides may also pose a problem around lakes; if they reach the lake, they
can do great damage to aquatic plants and animals. Also helpful to minimize pollution
danger, avoid depositing grass clippings, leaves, brush or other material in wetlands,
lakes or drainageways. Such material contain nutrients which are harmful to water
bodies. They may also contain residual chemicals from herbicides and pesticides.
Oh, poop counts too: as ducks and geese produce large quantities of phosphorus
and other nutrients, avoid feeding them near the lake.