Tea for the Turf

Assistant grounds manager Ryan Heiland developed a new way of seeding the campus with microbe-rich compost tea — to stunning effect. Now he’s helping scientists explore the roots of his success.

Ryan Heiland was waiting for a heavy rainstorm.

When the downpour came, he hopped in a golf cart and sped off for a springtime tour of campus, eyes cast downward, alert for signs of the tiny partners he knew he’d need.

“There were hardly any worms out there,” says Heiland, CU-Boulder’s assistant manager of outdoor services. “It was bad.”

It was 2002 and Heiland was new to CU. Maintaining the campus turf, including acres of lawn that cover Norlin Quad, Williams Village and Benson Field, was a big part of his job. Worms were key to the task, because they help aerate soil and produce natural fertilizer for grass roots. Their scarcity suggested the soil lacked vital nutrients and helped explain the campus’s patchy, weed-infested lawns.

“Instead of waiting for Mother Nature to increase the microbial and biological life in the soil, I wanted to add to it,” says Heiland, who comes from an agricultural family in Kansas and studied turfgrass management at Penn State.

Invigorating the soil called for something big and bold. The solution — a novel way of spreading compost tea — has led to adventures Heiland never expected, including a research collaboration with a team of CU scientists.

“It’s cool to see that a non-researcher can come up with an idea that the campus can jump behind and support,” says Heiland, who worked in golf course management for a decade. “The attention is a little weird for a guy like me — most of us turf guys like to just do our thing.”

As an initial quick fix, Heiland and his team used synthetic fertilizer to rehabilitate lawn surfaces. Then they turned to the health of the underlying soil.

In the ensuing years, they successfully integrated organic fertilizer with chemical fertilizer, ultimately leading to a campus turf management initiative that favors organic treatments. By 2011 the entire campus, except for heavily trodden sporting fields, was being treated organically.

Heiland decided the time was ripe for his big move. He proposed introducing compost tea, a liquid extract from compost used by farmers and gardeners hoping to spur plant growth. CU invested in nine large tea brewers, costing around $11,000 each, and installed them in three pump houses that run the campus irrigation systems.

A Rich Stew

The compost used in the tea mixture, vermicompost, is a rich stew of bacterial and microbial life passed through the gullets of red wiggler worms. Ten pounds of compost is steeped in a giant “tea bag” as 250 gallons of aerated ditch water jostles it in the brewer to aid absorption of the microbes, and microbial food is added to fuel the reproduction of microbial and bacterial life. The mixture is left to ferment for 27 hours before application.

Usually compost tea is administered via boom or backpack sprayers, but Heiland foresaw problems with these methods. For one, it would be difficult to spray campus evenly given trees, hand rails, benches, pedestrians and other obstacles. Second, he worried about public perception.

“We felt no matter how much signage or PR work we did, there would still be constant complaints and concerns that we were applying something toxic to the campus,” he says. “We just did not believe it was a viable option, especially at the scale I was trying to do it.”

Then he thought of the campus irrigation system, which is composed of miles of underground pipes.

He injected the tea directly into the pipes, which fed a vast system of surface sprinklers. After experimenting with various tea doses — some of which clogged hundreds of sprinkler heads — he found a mixture that flowed smoothly. The campus grew lush. The worm population rebounded.

Now Heiland applies compost tea monthly from May through October, and believes CU is the first institution in the country to use an injection technique for spreading compost tea on a large scale.

He’s savoring the success, but he’s not quite satisfied

Digging Deeper

Curious to know more about the underlying science, Heiland published his observations and other data on a CU blog about outdoor services. He posted photos of bright green lawns and flourishing trees in once sparse, dandelion-ridden areas and described the new irrigation process. Questions about his techniques flooded in. So he did what seemed only natural for a university employee: “I went after a research project to try and prove scientifically what I believe I’m seeing, so then we could make better decisions about the direct impacts and changes that tea may be having on our landscape.”

He didn’t have to go far to find partners: He connected with Noah Fierer, a microbial ecologist at CU who teaches a soil ecology class, and research assistant Xavier Rojas (EBio’14) of CU’s ecology and evolutionary biology department.

“It became clear from what Ryan was saying and from the [scientific] literature that a lot of people are using compost tea but are unclear about how it works,” says Fierer, an associate professor. “There are surprisingly few studies that have looked into it. I’d like to see if the compost tea really works as advertised and why.”

Skeptical of industry claims that compost tea is a “magic fertilizer,” Fierer says he and Rojas want to find out whether the microbes in the tea are the ones benefiting the landscape or if there are other contributing factors.

“There are a lot of really cool directions this can move in for the turf grass world and for agriculture in general,” says Rojas, who hopes their work will steer more people away from using chemical-based pest repellants or fertilizers. “A lot of our soils have been almost rendered useless because of the chemicals used on them.”

Last summer Rojas manned 30 test plots of campus grass to measure the effects of the tea on blade thickness, soil density and other characteristics. The team is preparing submissions to peer-reviewed academic journals and also will evaluate the potential for a new commercial compost tea product.

As Chancellor Philip P. DiStefano said in his most recent State of the Campus address at CU, “inventions can come from anyone.”

Photography by Glenn Asakawa (portrait); Ryan Heiland (campus)