Concerns over lawn watering often exaggerated, experts say
By Meleah Perez
U of A System Division of Agriculture
June 14, 2017
- Turfgrass needs — including water and nutrients — are often misunderstood
- A 2015 NASA study calls turfgrass the “largest irrigated crop in the United States,” although some experts disagree with the classification
- Cooperative Extension Service offers soil testing in every county; a key first step to a healthy lawn
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FAYETTEVILLE, Ark. — The popularity of vibrant lawns, from suburban yards to rural ranches, is often cast as a primary culprit in the ongoing war to manage water and wastewater properly. But experts with the University of Arkansas Division of Agriculture caution that the public’s perception that lawns require a lot of watering isn’t always the case.
“Turfgrasses have low irrigation requirements relative to other landscape plants,” Douglas Karcher, a professor in the Horticulture Department at the University of Arkansas said. “Yes, that is the truth, and the opposite of public perception.”
Some people mistakenly assume that lawns need an abundance of irrigation water because it is common to see lawns being watered excessively, even when it is raining, Karcher said.
Karcher organizes the benefits of having a healthy, well-maintained lawn into functional, recreational and aesthetic. Functional benefits include erosion control, dust prevention and heat dissipation, among other benefits.
It also includes carbon sequestration, which removes carbon dioxide from the atmosphere and held in solid or liquid form.
“The problem here is not with the turfgrass but with the improper use of an automatic irrigation controller, which should only be in the ‘on’ position when the soil is dry, or ideally, should be fitted with a moisture sensor, which will prevent it from operating when the turfgrass does not need water,” Karcher said.
According to a study released in 2015 by NASA scientists, turfgrass is the largest irrigated crop in the United States because it covers about 2 percent of the continental U.S. surface, a claim Michael Richardson, a professor with the University of Arkansas Horticulture Department, disputes.
“Public perception is often poor, but it is based on the few bad apples,” Richardson said.
Less than 20 percent of turfgrasses are irrigated, meaning that most lawns require little to no maintenance other than mowing, he said.
“When people make statements that ‘turf is the largest irrigated crop in the U.S.,’ they are grossly incorrect,” because most turf grasses are not actually irrigated, Richardson said.
Some people do not know how to properly care for their lawns, Richardson said. One misconception is that a lawn must be watered every day. Paired with access to fertilizers and pesticides through public stores, it paves the way for an unhealthy lawn, Richardson said.
“A properly maintained lawn is not a problem,” Karcher said. “Usually when articles or books are published that are critical of lawns, the authors assume worst case scenarios such as excessive irrigation and over-application of toxic pesticides.”
There are options available that have low human and pet toxicity and are environmentally safe when label directions are followed, Karcher said.
Arkansas homeowners should know it is possible to get the lawn they want without negatively impacting the environment, he said.
The University of Arkansas has a “Turf Help” website section to determine how to take care of grass (turf.uark.edu).
The consequences of having a lawn are minimal, if it is done right, Division of Agriculture experts said.
Taking care of a lawn means knowing what has to go into it, Richardson said.
The first part is finding the best turfgrass species for a particular site, keeping it at the ideal height and researching how much fertilizer, irrigation or pesticides are needed.
The Cooperative Extension Service offers free soil testing in every Arkansas county. The test measures the soil’s nutrient levels and needs.
Maintaining a healthy, environmentally safe lawn after initial research is about continual safe application of water, fertilizer and pesticides.
Determining the best turfgrass for a particular area depends on the temperature extremes and whether the site is shaded and if irrigation is available, Karcher said.
The most common type of grass in Arkansas is bermudagrass, according to the Choosing a Grass for Arkansas Lawns University of Arkansas Division of Agriculture publication.
“To me, the bottom line is for people to consider their personal goals for their property and see if there are ways to minimize environmental impacts within the constraints of the amount of interest, time, resources and energy that they are willing to invest,” said Katie Teague, an agriculture Washington County extension agent.
Teague helped establish a rain garden at Leverett Elementary School in Fayetteville, Arkansas. A rain garden harvests rain runoff from nearby impervious areas such as roofs or driveways.
Rain gardens are examples of “low impact development practices,” said Mike Daniels, professor of Crop, Soil and Environmental Science with the Division of Agriculture.
These practices manage stormwater as part of conservation efforts, and are beneficial to turfgrasses, Daniels said.
About 30 percent of average household water goes toward outdoor water use, according to the Environmental Protection Agency. In the summer months, it can be even higher, said Colin Massey, a water quality Washington County extension agent. As much as half of irrigation water simply evaporates, if irrigation is taking place at the wrong time. Massey and Daniels said.
People should be concerned about lawns, but not because of what lawns themselves do, Massey said. Rather, people should be concerned about the homeowners who overwater their turfgrass and produce excess amounts of runoff.
“Water around the world is finite. It’s not just this endless resource,” Massey said.
If a lawn has excessive inputs or poor management practices, it could contribute to contaminants to runoff or irrigation water that is running offsite, he said.
“If it’s not usable, if it’s contaminated or you’re in a place where it’s just not available, that’s a really frightening future,” Massey said.
To learn more about water conservation and properly caring for your lawn, contact your local Cooperative Extension Service agent or visit www.uaex.edu.
About the Division of Agriculture
The University of Arkansas System Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.
The University of Arkansas System Division of Agriculture offers all its Extension and Research programs to all eligible persons without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.
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Media Contact: Mary Hightower
Dir. of Communication Services
U of A Division of Agriculture
Cooperative Extension Service