For many area homeowners, nothing’s quite as beautiful as a lush, green lawn.
But a lush, green lake? Not so much, Carrie Vollmer-Sanders says.
Unfortunately, Vollmer-Sanders says, misapplication of fertilizer on lawns and gardens contributes to algae overgrowth in lakes – a green monster that chokes off other aquatic life and can stifle lakes’ potential for recreation and economic benefits.
That’s why the Nature Conservancy’s Western Lake Erie Basin Project is out to educate area fertilizer users about the effect their choices have on the lake’s environment, says Vollmer-Sanders, project coordinator in the conservancy’s office in Angola.
At present, the project is concentrating on large agricultural fertilizer users by developing a fertilizer certification program for farmers. The program should be in place by next year’s growing season.
But homeowners also can help improve lake water quality by following the same principles, she says.
That means following the four R’s approach – applying fertilizer from the right source, at the right rate, at the right time and in the right place.
To determine the right source and rate for fertilizer, homeowners should first get a soil test to find out what nutrients are actually needed for particular lawn and garden activities, Vollmer-Sanders says. Such tests generally cost between $8 and $15, and should be done every three to five years.
The second step, she says, is judicious use of phosphorous. A mineral often found in fertilizer blends, phosphorous stimulates root growth. But it also promotes the growth of lake algae.
In an existing lawn, where grass plants already have strong roots, additional phosphorous likely isn’t needed, Vollmer-Sanders says.
The lush greenness homeowners prefer is actually promoted by nitrogen in fertilizer but many apply phosphorous anyway.
Alternatives are getting easier to come by. Because of concerns about algae, she says, many well-known companies now sell phosphorous-free lawn fertilizer blends.
Consumers can tell whether manufactured fertilizer has phosphorous by checking the three numbers on the side of the bag, she says. The middle number indicates phosphorous, so a 10-0-10 fertilizer would have 10 percent nitrogen, no phosphorous and 10 percent potassium and would be appropriate for an existing lawn.
If manure or compost is used instead of manufactured fertilizer, she says, those products can be tested for their components. Chicken and hog manure are much higher in phosphorous than cattle or horse manure, she says.
Whether fertilizer contains phosphorous or not, it should only be applied in recommended amounts, Vollmer-Sanders says. Formulas are usually provided on the bags.
Quite often homeowners or gardeners overfertilize because it doesn’t look like a lot of fertilizer you’re putting down, but you don’t need a lot, she says. Err on the side of less.
One of the best practices for fertilizing lawns, she adds, is allowing grass clippings to self-mulch.
As for the right time for applying fertilizer, she says it should be done only when plants need it for growth, generally the start of the growing season.
Fertilizer shouldn’t be applied when more than a half-inch of rain is predicted within 48 hours because much of it will simply run off, she adds.
And, she says, fertilizer shouldn’t be spread on walkways, driveway or other impermeable surfaces for the same reason. It should be placed only close to the roots of plants that need it and worked into the soil whenever possible.
While it might seem odd to base local actions on improving the water quality of a lake hundreds of miles away, when it comes to Lake Erie, it can’t be a matter of out of sight, out of mind, Vollmer-Sanders says. The lake’s drainage basin runs right through Fort Wayne – both the St. Joseph and St. Marys rivers drain into the Maumee River, which drains into Lake Erie.
The lake also has significant problems with algae, she says. In 2011, the largest algae bloom on record, more than 2 1/2 times larger than any previous bloom clogged the lake. The algae spread over scores of square miles and even surrounded intake pipes for Toledo’s drinking water system, causing the city to incur more than $300,000 in additional treatment costs.
Last year, because of the drought, the bloom was not so large, Vollmer-Sanders says. But this year, with an unusually wet March and April, experts are predicting another large bloom fed by fertilizer runoff by mid-July.
The science behind the blooms is that six to eight weeks after the big rains, the algae start to bloom, Vollmer-Sanders says.
It depends on how much rain we get between now and then, but there’s a lot of speculation that it’s going to be another large algae bloom because of all the rain this year.