Campus News

UK’s No P On My Lawn Raises Awareness of Excess Fertilizer

No P On My Lawn presentation
Rick Durham speaks at a No P On My Lawn workshop. Photo by Suzette Walling.

LEXINGTON, Ky., (Sept. 8, 2017) When University of Kentucky College of Agriculture, Food and Environment specialists show up at the front door, easels and flyers in hand, it’s obvious they’re serious about their subject matter and they’re happy to share their knowledge with the neighborhood. A new UK Cooperative Extension Service program, No P On My Lawn, takes information directly to neighborhoods in Fayette County and surrounding counties to teach the risks of using too much phosphorus on lawns.

The program targets what are known as MS4 communities, those with municipal separate storm sewer systems. Those communities must meet certain requirements set by the U.S. Environmental Protection Agency, one of which is education and outreach. That’s where UK Cooperative Extension comes in. While MS4 communities are targeted, any Kentucky community would likely benefit from the program.

A pilot program in Fayette County, funded through by the Lexington-Fayette Urban County Government’s Stormwater Quality Projects Incentive Grant program, has faculty in UK’s Environmental and Natural Resource Issues Task Force responding to invitations from neighborhoods and community groups to educate people about the environmental ramifications of over-fertilization. In the 30- to 45-minute workshop, participants learn proper landscape fertilization and the benefit and method of soil testing, as well as how to interpret the results.

“A lot of these communities don’t have the resources for extensive outreach, but extension has a long history in that, so it made perfect sense to put something like this together,” said Suzette Walling, program coordinator.

UK soil and water quality specialist Brad Lee said 25 years of soil tests in Kentucky and in Fayette County in particular show that most home lawns and gardens exceed maximum recommendations for phosphorus, and the level in urban soils is rising.

“I think there’s good evidence to say that on our agricultural lands, soil phosphorus is decreasing a little bit below a level that would be critical. That is probably due to increased emphasis to farmers about fertilization,” said Rick Durham, UK horticulture specialist. “It would be really nice to have the same trend occur in our urban soils. That would be a long-term objective of this project.”

Water striking an impervious surface, such as sidewalks or driveways becomes stormwater as it runs off into the streets, storm drains and ultimately creeks, carrying with it excessive fertilizers. Standard synthetic fertilizers for lawns and gardens are labeled with three numbers to indicate the proportion of nitrogen, phosphorus and potassium, always in that order. A fertilizer labeled 10-10-10 would contain 10 percent nitrogen, 10 percent phosphorus and 10 percent potassium. However, Kentucky soils generally have quite a bit of phosphorus already in them. Adding more through lawn fertilizer raises the risk of having phosphorus be carried by stormwater or even leach out as concentrations become excessive in soil.

“Excess phosphorus in creeks supports the growth of algae and cyanobacteria,” Durham said. “While, in limited amounts, these are important to aquatic systems, too much is a bad thing. Too much algae can deprive systems of oxygen and shut out sunlight. And as cynobacteria multiplies and dies, it releases toxins that can be harmful to fish and humans.”

No P On My Lawn organizers urge neighborhood organizations and homeowner associations to contact them to arrange for a program. And they encourage people to look out for upcoming events at The Arboretum in Lexington and the Fayette County Extension office. Organizers are happy to bring the program to other counties as well, though free soil testing under the LFUCG grant is only offered to Fayette County residents. Inexpensive soil testing in other counties, however, is available through local extension offices.

Those interested in scheduling a presentation for their group or neighborhood should contact Walling at General questions about the program can be addressed to Walling or Durham at