Phosphorous- Free: Good for Lakes -- and Lawns?

Lawn care is in a revolution at its roots. Come autumn, we'll find fewer turf fertilizers with phosphorous (P). In 2012, the change will be
watershed. Most commercially manufactured lawn care products will be
absent phosphorous and have less nitrogen (N).

The handwriting is on the wall. States and communities are passing laws
that regulate use of P and N on lawns and turf (golf courses).
Virginia, Maryland, New Jersey, Minnesota, Florida, Washington,
Wisconsin, Vermont (and communities in Canada) are legislating to
dictate amounts, types, means, and times of application. Pennsylvania
is considering regulation.

Here's to an environmentally sound shift to save our bays, rivers,
oceans. P and N in runoff equals water pollution. Both have been used
excessively, often unnecessarily for decades. The excess is carried
downstream into water bodies, creating algal blooms and "dead zones"
devoid of oxygen and, as consequence, fish and other aquatic life.

Manufacturers of consumer lawn and garden products are responding.
Lance Latham, Scott's Miracle-Gro communications and environmental
stewardship representative, said that Scott's is eliminating P in lawn
care products except for starter fertilizer and organic products.
Phosphorous isn't necessary for an established lawn but is "critically
important" when starting a lawn, he explained

What About Our Lawns?
If you're already returning grass clippings to your yard, you're doing
the right thing. Grass clippings contain phosphorous (P), explained Dr.
Gary Felton, associate professor at the University of Maryland's
Department of Environmental Science and Technology. Recycling grass
clippings provides sufficient P to keep lawns healthy. Adding organic
matter (OM), such as composted leaves, supplies even more.

"All plants need phosphorous," Felton said. "Turf, when it's healthy
and growing, needs very little. But that's not zero. We often find .1
lbs. P for 1000 sq. ft. of soil is enough." Newly sown grass needs P
for cell growth.

Old established lawns on good topsoil usually have more P than needed,
Felton added. Enhanced by decades of 10-10-10 fertilizer application,
they won't show any immediate or long-term effects from
phosphorous-free lawn care products.

New lawns sown on nutrient-poor subsoil will need P. Legislation allows
for that. Manufacturers are making appropriate lawn starter fertilizer
mixes with P included.

Providing the P and OM the lawn really needs "makes the lawn healthier,
improves soil tilth, and buffers the pH (keeps it from changing too
fast)," Felton added. The ideal pH range for turf grass is 6 to 7.

Decomposing grass clippings also provide nitrogen. Felton returns his
clippings, calculating they're worth about one pound of nitrogen per
year. His is an old yard with established top soil and healthy fescue
turf. He also applies slow-release, water-soluble nitrogen twice a year
- two/thirds at 1 lb per 1000 sq. ft. in fall and another third in
spring.

The formula is not one size fits all, he cautioned. Additional P and N
will vary according with each lawn. "Fertilizing turf is
environmentally beneficial," Felton advised. "If you don't fertilize
turf, it's not a healthy plant. The benefits of grass go right out the
door -- the cooling effect, generating oxygen, preventing soil and P
erosion. Infiltration and anchoring the soil affect water quality.
Thick, healthy turf crowds out crab grass."

Surreal In Croatia

If the earth does grow inhospitable toward human presence, it is primarily because we have lost our sense of courtesy toward the earth and its inhabitants.