Herald Journal Herald and Journal, April 15, 2002

Fertizilers: phosphorus accumulates and doesn't go away

By Lynda Jensen

Many home owners are ready to charge out into their lawns to begin a war with weeds and lawn care that will probably last all summer.

However, few may realize ­ especially those that live inside the city and not directly along the lake shore ­ that phosphorous-laden fertilizers being sprinkled on lawns usually ends up in area lakes, feeding algae and harming marine life.

Area lake associations are making a plea for homeowners to consider what happens after the lawn treatments and fertilizer applications.

"Most people don't think about what happens past the end of their driveway," said Petie Littfin of the Winsted Lake Association.

In fact, the lake association plans to conduct a lake clean up day at the Winsted lake park 8:30 a.m. Saturday, May 4.

Hot dogs and refreshments will be served to volunteers who help clean up the lake, Littfin said.

So many beautiful lakes exist in Howard Lake, Waverly and Winsted, said Tom Hammer, a board member of the Ann Lake Watershed Association and Wright County Shoreland volunteer.

Unfortunately, these same lakes, especially Winsted and Waverly, suffer from significant urban runoff, which is partly caused from pollution related to residential lawns, he said.

But what is it?

Phosphorous is a chemical that binds itself to grass clippings, leaves, dirt, weeds, or whatever other items come in contact with the treated grass area, said Curtis Forst of the Howard Lake Lake Association

From there, the clippings or other objects are carried down the sewer drain to be routed into area lakes, where phosphorus accumulates, promoting algae growth.

It does not break down since it is a basic element, Forst said.

In turn, algae causes problems when it dies, because when it decomposes, it depletes oxygen in the water, causing fish and other aquatic life to suffer and die, according to the University of Minnesota Extension Service.

Algae is also traditionally associated with crowding out other aquatic plants, and can cause lake water to become cloudy and have an unpleasant odor and taste, according to the extension service.

One pound of phosphorus in a lake can produce 500 pounds of algae, Hammer said.

Green, green grass

The original use for phosphorus is to promote root growth for grass, however what makes grass green also makes lakes green, Hammer said.

In fact, most of the soil in Minnesota already has enough phosphorous to maintain a healthy lawn, according to the Crow River Organization of Water.

For those who are in doubt, soil samples can be brought to the county office to be tested, Littfin said.

Nevertheless, keeping phosphorus out of Minnesota's lakes is the most important thing that home owners can do to protect water quality, Hammer said.

Tips from the Extension Service:

· consider converting some lawn area into prairie grass or wildflowers. If there is no local restrictions, this would give the home owner a break from mowing.

· try making compost at home with yard waste. Gardeners know that adding compost to garden beds improves the soil.

· homeowners should measure the size of their lawns to ensure they do not buy (and use) excessive amounts of fertilizer. Use phosphorus free fertilizer.

"Finally, remember that anything you rake or throw into the street, beach or lake ­ fertilizer, leaves, sand, salt, animal wastes, or soapy water, for example ­ may end up in your lake, river or stream shortly afterward," according to the extension service April 2001 From Shore to Shore news letter.

Other residential sources for phosphorus include eroded soil, paint and paint thinner, garbage, soaps and detergents, household chemicals, gasoline, motor oil, and other greases, road dust, lawn fertilizer, pesticides, animal waste including pet droppings, and improperly maintained septic systems (among many others), Hammer said.

Phosphorus can come from all over a lake's watershed, Hammer said, which consists of all of the surrounding land where water drains into the lake. Ann Lake has a watershed that is 32 square miles, he said.

Water quality protection must occur throughout the watershed. Poorly designed developments ­ even those that are far from a lake or stream ­ can have devastating effects on water quality, he added.

Lawn care tips

The following are tips on lawn care from the Crow River Organization of Water:

· Handle chemicals carefully. Do not allow oil, paint, anti-freeze, fertilizer or other chemicals to enter a storm sewer.

· Keep streets and gutters clean.

Don't sweep grass clippings or leaves into the street or storm drains.

· Wash vehicles in the grass.

It will help water the lawn and prevent runoff into storm drains.

· Clean up animal waste.

· keep leaves and lawn clippings off streets and driveways.

· prevent gas and oil spills on driveway. Clean up if done.

· Use fertilizer sparingly.

Property owners should know the size of their lawns before they apply fertilizer.

Don't apply fertilizer within 50 feet of a lake or stream.

· protect and restore wetlands

· upgrade non-complying septic systems

· maintain an unmowed buffer strip at the lakeshore ­ at least 10 feet

A web site with additional information is www.dnr.state.mn.us/lakefind/ which contains information such as lake maps, water quality, lake levels, and secchi disc readings, if available. Another interesting web site is www.pca.state.mn.us.

Lake friendly fertilizer sale

The Big Waverly Lake Association will be selling phosphorous-free fertilizer at the park and ride lot at Waverly (near the Village Hall) from 9 a.m. to 3 p.m. Saturday, April 20.

Three different kinds of fertilizer will be available, including crab grass preventer, weed and feed, and a regular version, said Maggie Bryant of the lake association.

This is not a profit making venture for the association, Bryant said. "The only profit we're looking for is reduced phosphorus runoff into the lake," she said.

The fertilizer is being supplied by the Country Store of Howard Lake at comparable prices to other phosphorous brands, she said.

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