Turf Nutrition Balancing Act

Source: www.TurfMagazine.com

Combine fertility and aesthetics

Turf Specialist Mike Goatley, with Virginia Tech, says that turf professionals can fertilizemost lawns without exceeding 3.5 pounds of nitrogen per 1,000 square feet.

Homeowners have become picky about their lawns and how they appear. They want their turf to be the best on the block.

Nelson Garner, with Gary’s Lawn Care, Inc. in Forest, Va., says some homeowners with automatic irrigation systems care less about the environment and more about how their lawns look-often setting automatic systems to run all day instead of turning them off when enough water is applied.

“We see them running in rain or any other kind of weather conditions when they do not necessarily need to be running,” Garner says, “and that’s leaching that much more of your fertilizers and phosphates out of the soil to where you’re having to go back and add that much more to keep the customer happy with that dark green. They don’t want to see that yellowing in there.”

Juggling

So, how do you balance fertility level needs to maintain turf health and meet the client’s expectations of a green lawn?

It depends on the situation. “Some turfgrasses, such as the fine fescues of the cool-season grasses and centipedegrass or zoysiagrass of the warm-season grasses, are well-adapted to minimal fertility programs that only deliver 1 to 2 pounds of nitrogen per 1,000 square feet per year,” says Mike Goatley. Goatley is turf specialist and associate professor in the crop and soil environmental sciences department at Virginia Tech in Blacksburg, Va.

Nelson Garner, of Gary’’ Lawn Care, Inc. in Forest, Va., believes lawn care professionals can balance healthy turf and the homeowner’s need for aesthetics without compromising a successful fertilization program.

He says Kentucky bluegrass and bermudagrass are examples of grasses that typically have their best aesthetics at higher management programs of 2.5 to 3.5 pounds of nitrogen per 1,000 square feet per year. Tall fescue, on the other hand, fits somewhere in between these programs, and the ultimate decision is left up to the homeowner in terms of what type of quality they expect.

“Still, I don’t find much reason to exceed 3.5 pounds of nitrogen per 1,000 square feet for most lawn applications,” he says, but “there are situations where higher levels of nitrogen might be required for specialized golf and sports turf situations. When synthetic, water-soluble nitrogen sources are used, their application rates should not exceed 1 pound of nitrogen per 1,000 square feet.”

Goatley says to pay particular attention to variety characteristics when establishing lawns. He says that opportunities exist to select grasses that inherently have genetically darker-green color than other varieties, but the color is not related to extra nitrogen fertilization.

Turf professionals can read more about genetic color information, as well as overall quality and performance data through the National Turfgrass Evaluation Program at www.ntep.org.

Using less to achieve more

When applying a fertility program, turf professionals try to use fewer chemicals, which their clients demand. Goatley recently attended a presentation by Brian Trotta of New York, who recommends responsible turf management by following what basics have been around for centuries: use “everything in moderation.” Trotta told conference attendees that the word “organics” depends on how one defines it.

Goatley says, “Misapplication of naturally occurring products [such as fertilizers and pesticides] can cause the same problems in the environment as synthetics if they are not managed properly. A well-planned program using synthetic chemicals can still be environmentally responsible.”

While a real interest exists in the more natural, organic approach, Goatley says he encourages any lawn care professional to consider offering programs that stress an “organic emphasis,” while not necessarily totally committing to only naturally occurring products. He recommends providing these products as part of an annual program or an integrated approach in combination with synthetic chemistry.

“The push for ‘organic-only’ approaches is not going to go away,” Goatley says, “but expectations of the consumer have to match the [deliverability] for organic programs that often cannot provide the highest quality, uniform turf that customers expect.”

He says many of these programs can cost more when passed along to the consumer. “It is important that everyone understands that a healthy, properly fertilized turf is one of the environment’s best friends, much more so than a non-fertilized turf over time, [which can cause] more erosion potential and movement of sediments and nutrients,” he says. “So, there is a lot of educating the customer that has to be done.”

Homeowners today want well-fertilized lawns, so the turf appears healthy and green.

Drought concerns

A drought can destroy a plan to balance a fertility program and turf health with aesthetics.

Lots of lawns in the United States were lost to the 2007 drought, “and unfortunately, reestablishment in late summer and fall has not been very successful for many because the drought continues,” Goatley says. “I hope that one outcome of the drought is that folks consider selecting improved species and varieties that have better drought tolerance.”

Many people in the transition zone areas of the United States, where warm-season grasses are adapted steadfastly, hold onto their desire to have cool-season grasses in their lawns because of their dislike for the winter dormancy period of the warm-season grasses. “Clearly, most warm-season species and varieties performed far better in the summer of 2007,” he says, “and since water is only going to become more limited in its availability for lawns and landscapes in the future, these more drought-tolerant grasses are going to have to increase in acreage.”

Good management plan

During the winter weather, and before the warm weather arrives, turf professionals may consider planning how they are going to achieve a balance in their spring fertility program. Goatley tells homeowners to “ease” their lawns into the growing season, for both warm and cool-season grasses.

“A lot of spring nitrogen can quickly produce a surge in top growth,” he says, “but it is at the expense of the root system and, ultimately, can cause problems in the lawn as the year progresses.”

The key is maintaining that balance. For cool-season grasses, he says, fertility programs that emphasize fall fertilization should remain focused.

Garner and his crew have done that and realized success with most of the homeowners they work with each year. “We’ve found the homeowner is very satisfied when we’ve done the higher nitrogen rates; to do more of what Virginia Tech recommends in line [with] the three-step application of fertilizer in the fall and early winter and not have to go in the spring with anything,” he says. “We see a good, early green-up with that program. We don’t have the problem with as much fungal diseases getting into the turfgrass and brown patch in the spring and early summer when we’ve done the fall applications like that.”

However, Goatley admits that spring fertilization offers unique advantages. He says research at the University of Maryland has shown that the most efficient fertilization programs, considering both fertilizer usage and turf response, are those where three-fourths of the seasonal nitrogen is applied in the fall and one-fourth in the spring.

“This approach supports responsible spring greening and actually enhances root growth, because the nitrogen is applied in moderation,” Goatley says.

On warm-season grasses, he recommends waiting until complete spring greening to make the first nitrogen application of the spring. However, “we all realize that from a business and economic standpoint that lawn care professionals often have to apply fertilizers in combination with the spring pre-crabgrass products,” he says. “Whenever possible, use controlled release nitrogen carriers in the spring if weed and feed programs are necessary. This strategy applies to either warm or cool-season grasses.”

Goatley says that the controlled release rates of these nitrogen sources will improve nitrogen use efficiency and not excessively promote shoot growth at the expense of the roots.

Instant results

The homeowner’s fickleness spills over into their need for speed when it comes to achieving that spectacular looking lawn. “With these new lawns, they’re coming in [and] sodding them instead of seeding them, because they want the instant gratification,” Garner says.

Garner says that the balance of a healthy lawn and aesthetics can be achieved, but the lawn care professional must play it by ear sometimes. He advises taking a soil sample, having it analyzed by an approved testing laboratory and seeing what the results are to follow the fertilizer rates that the lab recommends.

The author is a freelance writer in Danville, Va.