Rethinking the lawn

It may seem ironic considering Iowa’s well-earned reputation as a crucial hub in the agricultural economy, but the nation’s largest crop, in a sense, is lawns.

Yes, the humble lawn. That paragon of Americana, imbued with the cultural expectation that they all be uniform swaths of verdant vegetation, unencumbered by weed or pest.

A native prairie on the University of Northern Iowa campus.
A native prairie on the University of Northern Iowa campus.

There are 40 million acres of turf grass in the United States, according to NASA. And while lawns undoubtedly provide a social benefit in parks, school grounds and other areas, maintaining them to meet the pristine aesthetic many communities expect comes at cost.

For lawns are not naturally free of weeds. We make them that way. And we do that with pesticides and herbicides and other chemicals that studies have linked to a number of adverse health outcomes, particularly for children.

That’s where the University of Northern Iowa comes in. The college has been at the forefront of this issue, developing new research methods to quantify how much lawn-treating chemicals we use and promoting programs to either eliminate the use of these products or replace lawns entirely.

The problem with pesticides

The negative impacts of commonly used lawn chemicals are well established. They have been linked to prenatal and childhood cancers, chronic illnesses, neurodevelopmental delays and behavioral disorders. The chemicals have also been shown to pollute local water supplies, pose a danger to pets, and undermine bees and other pollinators by reducing biodiversity.

Moreover, many pesticides are unnecessary, said Audrey Tran Lam, environmental health program manager for UNI’s Center for Energy and Environmental Education.

“This paradigm that lawns must be treated with chemicals to grow or look beautiful is not true,” Tran Lam said. “Committing to managing lawns without the use of chemicals is something individuals and institutions can do to improve the environmental health of our neighborhoods.”

The question that follows is simple: How much of these chemicals do we use? And it turned out, no one knew.

So, the CEEE decided to do an observational study where they surveyed lawns in communities and, based on the presence (or absence) of weeds and other non-grass plants, determined if it was likely treated with chemicals.

The study conservatively estimated that in 2016, Cedar Falls and Waterloo applied about 37,000 pounds of weed-killers. The CEEE concluded that many of these applications were for purely cosmetic reasons, and that the chemicals were often applied near local waterways, which the labels of the products warn against.

They did the same study in Iowa City and Dubuque and found that the cities applied about 22,000 and 18,000 pounds in 2016, respectively.

The CEEE produced maps of the study, showing the neighborhoods with high application rates and the nearby waterways in danger of contamination. And while the single year of data makes comparisons difficult, it is a useful tool to help people understand and visualize the issue.

“The main reason we did the observational study was to simply make the extent and amount of weed killer use in a community visible to local residents, as a way of serving the overall goal of reducing and eliminating their unnecessary use,” said Kamyar Enshayan, director of the CEEE.

UNI tackles the problem

And if people want to address the issue, the CEEE is there to help.

One of its programs is Good Neighbor Iowa, a public education initiative that aims to reduce unnecessary pesticide use.

Almost 350 institutions across the state have joined Good Neighbor Iowa, including 56 child care centers, 188 parks and 35 schools. The program has protected an estimated 20,000 children from pesticide exposure and prevented the application of about 62,000 pounds of the active ingredients in pesticides to Iowa watersheds.

A new program the center is offering is called Turf to Prairie, which targets institutions that have to manage large tracts of turf, such as schools and parks. The idea is to replace parts of these areas with native prairie.

“There are so many ecological benefits to prairie,” Tran Lam said. “It can enhance the aesthetics of parks and schools, provide habitat, improve water quality and requires less maintenance than turf.”

The center has put together information, with the help of UNI students and research from the Tallgrass Prairie Center, to help landowners understand how replacing turf with prairie can provide environmental and economic benefits. The center can then help connect the landowner with the resources needed to establish native prairie.

Mowing and managing turf costs an estimated $350 per acre every year, according to the Tallgrass Prairie Center. After the initial cost of installing the prairie, annual maintenance on those lands shrinks to around $50 or less. And while turf’s benefits don’t extend much beyond recreation, the prairie is increasing storm water infiltration, creating habitat to support pollinators and wildlife, and improving soil retention and health, all while storing more carbon than turf and reducing carbon dioxide emissions into the atmosphere.

“Turf is great for picnics and playing on, but it’s not very functional otherwise,” said Laura Jackson, director of the Tallgrass Prairie Center. “Turf to Prairie is a good way to turn large, unused areas that are not providing any benefits into something that does provide benefits and is cheaper.”