It’s possible that pre-Colombian Amazonians worked with biochar (a.k.a. terra preta), a carbon-rich substance you might have heard about being capable of fostering healthier turf. Say what now? Dan Dinelli and Mark Hoban are not anthropologists. They are longtime superintendents who maintain excellent playability and share an enthusiasm for soil health and field trials that continue to advance the turf industry. Let’s dig deep on some of their current passions: research, phytobiomes, biochar and nanotechnology. And let’s learn why their current work can help others.

Research and shortcuts

Mark Hoban
© guy cipriano

“I love growing turf,” says Hoban, who began working in the industry during high school. Hired in part to expand the natural aspects of Rivermont Golf Club in Johns Creek, Georgia, Hoban has taken his environmental programs to a new level with the support of club owner Chris Cupit. Hoban has converted 31 acres from managed turf to native grasses; reduced 2.5 pounds of nitrogen applications down to less than half a pound annually; reduced fungicide applications; initiated the use of compost tea; and is exploring nanotechnology. “It’s not just the turf,” he says. “It’s this whole entity, this land that I’m in charge of. I can’t wait to find new ways to enhance what we’re doing.”

That enthusiasm connects Hoban and Dinelli, the superintendent at North Shore Country Club in Glenview, Illinois. Dinelli is equally eager to advance the turf industry through sustainable biological methods. “My parents always told me, ‘Dan, you ask too many questions,’” says Dinelli, a third-generation superintendent who replaced his father, Joe, at North Shore in 1995. “I’m good friends with researchers who exchange answers and questions with me. I offer them space at the course to set up trials and everyone wins. The researchers get realistic data, the club benefits from customized information, and I learn and cultivate relationships with people who study turf, soils and biology.”

Dan Dinelli
© guy cipriano

Dinelli and Hoban are close, have mutual friends and talk when time allows. Conferences and events are normally a source of conversation and a space for additional learning, but the pandemic has slowed that.

“Dan and I spurred each other on,” Hoban says. “I miss the conference education because it’s nice to expand who is in this small world. This last year kept me focused on research and I put in more time running studies.”

With the work in progress, it’s necessary to distinguish some differences. There are three basic types of research: outsourced, informal and formal.

  • Outsourced research is letting scientists come in and use the property. For instance, Loyola University Chicago is conducting studies at North Shore on water quality, pollinators, bats and more to learn about green spaces.
  • Informal research is what many superintendents are already doing: testing products and rates, evaluating machinery, observing how things happen and determining what is useful.
  • Formal research with turf requires replicated plots and testing with controls and variables. A specific question is being asked, there is an idea about what might happen and the answer is in the data. Results must be repeatable to be conclusive. That’s tricky with real-world turf because the number of variables is massive.

No two courses are identical, above ground or below, but below there are really important microbiomes that are better understood all the time. All golf courses basically function the same way just as all humans basically function the same way but we’re learning that the small differences can have a huge impact. Medical biological studies are more advanced than biological studies in turf, but they offer some good comparisons.

Before we jump ahead, you might be here for the shortcuts. There are none. Don’t be disappointed. Better than a shortcut is the opportunity to discover and optimize sustainable turf care methods that work as more than short-term solutions. Just like an antibiotic might treat an ear infection, a fungicide application might treat dollar spot, but what caused the infection and the dollar spot in the first place? Is there a way to boost the soil so that the dollar spot won’t occur again?

“There is so much that is not mainstream and trying to figure out how to create suppressive soils to pathogens vs conducive soils is the future of our industry and research efforts,” Hoban says.

Dinelli adds, “It’s not like we’re trying to convert superintendents into researchers, but every site is different and the further you drift from conventional inputs, the more important it is to explore alternatives on your site to see how they fit in with your environment and plant care program.” There are no one-size-fits-all solutions for humans or golf courses, but there is large-scale potential.

Phytobiomes, biochar and nanotechnology

A supportive ownership allows Mark Hoban to use parts of Rivermont Golf Club to research emerging turf maintenance practices.
© courtesy of Mark hoban

You’ve heard of probiotics and how important they are for digestion. Probiotics and colonizing the soil with these beneficial bacteria and fungi makes turf more resilient. Healthier turf is more pathogen resistant. The phytobiome consists of the plant and the ecological space around it, including macro- and microorganisms, sun, soil, air, water, other plants and animals, and within the phytobiome is the microbiome. Research is showing that plant health is more a product of the microbiome than previously believed. Imagine the plant as the engine (which can be influenced by probiotics such as mycorrhizae, bacillus and azospirillum) that drives much of the microbiome with its exudates.

“All these things function together,” Dinelli says. “No silver bullets. For example, turf growing in too much shade will always be weak and thin. No microbe or probiotic will ‘fix’ that.”

But there are ways to introduce more of the good stuff to the soil and that is translating to healthier turf and firmer land that is more resistant to compaction. This means less irrigation, fewer inputs, more stress-tolerant turf and more days with cart-friendly conditions.

There is always more that can be done. The short game practice area at North Shore is a site for evaluating 21 different bentgrass cultivars for putting green use and 20 rootzone cells testing various amendments. Dinelli topdresses fairways in the fall with homemade biologically-rich compost made from organic material full of nutrients the ground absorbs all winter. He treats seeds by bathing them in different bacteria and fungi to give seedlings better resistance and he also uses the irrigation system to distribute compost extracts/tea to give the course a boost. Also pre-treated with the “good guys” is the biochar that Dinelli is exploring as a soil amendment.

Biochar is created by heating organic matter in a very specific way, basically heating without oxygen (pyrolysis). The solid, carbon-rich result (biochar) is then added to the soil through topdressing and/or during construction. Biochar has the structure to retain water and water-soluble nutrients and the cavities also host healthy bacteria. The goal is to encourage healthy biologic properties in the soil to encourage plant growth and pathogen resistance. Biochar has an even greater impact on soil function if it’s low in organic matter.

“Biochar has some chemical components and the ability to hold nutrients with the water and air,” Dinelli says. “It also has protective niches for biology, bacteria and fungi so it can act as a great delivery tool when transplanting microbes.”

Additionally, biochar biodegrades more slowly than most organic matter, so it can be beneficial to the soil for a longer period of time. A soil amendment that helps retain air in the soil is one good way to increase the oxygen, but there is another way.

“The most limiting factor on turfgrass management is enough oxygen in our soils, due to poor water sources, traffic compaction, and poor soil structure,” Hoban says. “Additional oxygen in the soil should create stronger roots, turfgrass vigor and benefit microbial and soil health.”

Infusing water with oxygen nanobubbles is another potential tactic to boost oxygen in soil. Using nanotechnology to create nanobubbles in water is trending among fisheries that are seeing fish grow larger in the oxygenated water, drinking water is being infused with oxygen, nanobubble hydrotherapy is available for skin disease management and it’s also available for irrigating golf courses. These nanobubbles are so tiny they can’t be seen with the naked eye.

Think about a carbonated beverage. You see the bubbles drift to the top and effervesce but with nanobubbles, that doesn’t happen. “Nanobubbles are 800 to 1,000 times smaller than a microbubble,” Hoban says. “They are negatively charged and so tightly bound that they stay in solution. This has the value of keeping a much higher dissolved oxygen in the water for plant and microbial usage.”

Oxygenated water is absorbed more quickly than normal water and that means reduced evapotranspiration. Big benefit, but the numbers are necessary. “Working with the researchers has forced me to do more data-driven work on their level because testimonials aren’t good enough for our profession,” Hoban says, “and they shouldn’t be.”

David Warwick, of Avondale Golf Club in Pymble, Australia, has been pioneering the use of nanowater on the course he maintains for years. “I visited him one summer and saw how well his bentgrass greens were doing,” Hoban says. “I saw his research on a reduced need for wetting agents, reduced fungicide usage and his increased root system.”

Dr. Mike Richardson and the team at the University of Arkansas are working with the Australian nano unit on bentgrass trials. The Georgia GCSA has supplemented his research andafforded an additional trial grant to the University of Georgia research team under Dr. Mussie Habteselassie for Bermudagrass research in the field and inside a greenhouse, and looking at controlling cyanobacteria in ponds using nano oxygen. Hoban’s work is part of that, running nanobubble water trials on an ultradwarf Bermudagrass green. The more superintendents who are willing to work with researchers, or who are open to sharing their courses for trials, the more can be accomplished.

“All this brings us to another level,” Dinelli says. “We’re never going to be done with this, and in many ways, we’re just getting started. It boils down to the details but if you understand the principals that nature and biology follow, then you can apply them to turf.”