TURF SCIENCE


Turf Nutrition for the 21st Century

By Ron Hall



Can you use the words fertilizer and technology in the same sentence? You bet you can. Just as you've adopted technology such as Smartphones and iPads, consider joining the 21st century when it comes to turfgrass fertilizers. Here's why - relatively new controlled-release products that maximize nutrient uptake and use while minimizing losses to leaching or volatilization. These products also prevent excessive turf growth.

In other words, there's an excellent economic and environmental story to tell about these "enhanced efficiency fertilizers," says researcher Dr. Eric Miltner.

Enhanced fertilizers are fertilizer products with characteristics that, when compared to an appropriate reference product, allow increased plant uptake and reduced nutrient losses to the environment, says Miltner. And that's exactly what research at Washington State University (WSU) is showing as he shared data from the first three years of a five-year study

In early December, Miltner, who spent 13 of his 17 years as a turfgrass expert at WSU, and Florida's Dr. John Cisar shared recent research on these products with 25 landscape and lawn care business owners and managers. The venue was the Green Industry Grad School at Farmlinks in central Alabama. The landcare pros were guests of Agrium Advanced Technologies (AAT), which manufactures and markets a range of newer-generation controlled-release turfgrass fertilizers.

Miltner, who now serves as agronomist and turf specialist for AAT, drilled down upon the performance of PCSCU (poly-, sulfur-coated urea) fertilizers as compared to other nitrogen fertilizers.

In the study he references, one that involved the annual application of 4 pounds of N of several quick-release, slow-release and controlled-release fertilizer products to turf plots, researchers found 80 to 85 percent N plant recovery in the PCSCU products. This was greater than any other type of fertilizer.

The performance of any turfgrass fertilizer is dependent not only on the release of N, but also upon the availability of N to plants, he says. This can made more precise through advanced coating technology that provides different release windows by different coating materials (poly, sulfur, wax) and thicknesses.

Don't discount the importance of the relation between N release and N plant uptake, warns Miltner, especially in this era of environmental activism.

He points out that since the state of Minnesota in 2003 cracked down on the use of phosphorus in turfgrass fertilizers, 12 other states have targeted phosphorus use in an effort to control algae and unwanted plant growth in their surface waters.

"I think the same thing will happen to nitrogen but it will happen faster," says Miltner. In fact, it's happening in New Jersey, Florida and elsewhere. Regulators are telling property owners and lawn care professionals how much N they can apply, when they can apply it and in what forms.

"Fertilizer technology is going to become more of an issue in the future," predicts Miltner, a point he shares with Cisar, who feels the new generation of controlled-release fertilizers may be able to bring lawn care operators and regulators closer together.

"This type of technology is the future of the [lawn care] industry," says Cisar, professor of environmental horticulture, University of Florida, who has spent more than 25 years conducting research on turfgrass and fertilizers.

Florida regulators, seeking to protect water quality in different regions of the state, have severely restricted the applicaton of turfgrass fertilizers at various times of the year. Cisar is hopeful that regulators will consider "the science" when it comes to regulations. But, even if he is a bit overly optimistic, he says that these newer controlled-release products offer lawn pros a tool in the face of "blackout" periods. It offers them the opportunity to make fewer applications and still produce quality turfgrass that their customers will appreciate.

Cisar continues to study nitrogen fertilizers, their fate, and their performance at research plots in Ft. Lauderdale and, more recently, on the grounds of the Collier County government facility in Naples, Fla., where turfgrass fertilizers are under intense scrutiny.

Cisar's research on controlled-release fertilizers, something he's been conducting since they became available, involves an incredible number of variables - soil types and the amount of organic matter in the soil, rainfall, irrigation (potable vs. non-potable). Even so, he says his research suggests there is very little, if any, leaching potential with the proper use of these products.

For that reason, and considering the extended release and enhanced nutrient efficiency they provide, he's hopeful that his research will convince regulators to reverse direction on some of their fertilizer use laws.

"I'm going to tell them, 'Don't handcuff these people,'" says Cisar referring to turfgrass pros.

"I don't know how efficient we can get, but these products are the most efficient I've worked with in my 25 years in terms of uptake by grass," he adds.

Ron Hall, who has spent the past 27 years writing about the green industry, is editor-in-chief of Turf magazine. Contact him at rhall@mooserivermedia.com.