Back in 2013, Superintendent magazine dug into the scientific side of humic acids, explaining their complex formulations and how companies are promoting their use. This time, we asked superintendents who are using them for a real-world report on how humics are working for them.
Superintendent Ed Braunsky is using humic products in three ways at Geneva Golf Club in Batavia, Illinois. Braunsky jokes that “Cutting Edge” is his middle name, noting that, in his 35 years at the club, he’s experimented with a lot of products. And, he says, “This humic stuff seems to be a real winner.”
Braunsky began using humics on his fairways last year in the form of a 22-0-8 fertilizer that includes about 15 percent humic acid. “I don’t have a crazy budget, and I talked with my sales rep about this being something I could apply to benefit from the length of it,” he says.
Braunsky has seen results in terms of prolonging the effects of his fertilizer applications. “The middle of May was my first app, and then the middle of August. So, only two apps per season, and then you can tickle it a little bit with some microbes here and there. The longevity of the stuff is impressive,” says Braunsky. “It truly does make the effects of the fertilizer last longer.”
Braunsky says he put the fertilizer product out at about 130 pounds per acre on each application. “I’ve talked to some other superintendents who are trying to get away with just one app per year, but I prefer the two,” he explains.
Geneva Golf Club suffers from irrigation water with extremely high levels of sodium and bicarbonates, so Braunsky says he’s looking for anything to help. He amends with a gypsum/humate product that incorporates about 21 percent humic during both spring and fall aerations. Braunsky also uses a humic acid product in his spray tank when treating greens and tees, which again helps to flush the sodium, and reports encouraging results.
At Cypress Creek Golf Club in Ruskin, Florida, Superintendent Chris Threatt has been using humic products in granular form for two years. Threatt says it was trouble with one of his greens that prompted him to try the product.
“We have one green that holds moisture, and tends to have smaller, sand-size particles than the rest of the greens because it was renovated independently of the others,” he explains.
That created drainage and sulfide issues that turned into black layer. Threatt started by installing some simple in-house French drains, and then began treating the green with the humic product at a rate of 100 pounds per acre. “We went over the top and let it work into the soil,” Threatt explains. “I would put it out in the afternoon when the turf was dry and then water it in at night. It was a pretty simple treatment that didn’t require a lot of effort.”
The granular product he used had a high (more than 60 percent) humic composition. Threatt says he was “extremely happy” with the results he saw.
“We would probe the area and still see the black layer, but we would see roots running through it – it was pretty impressive,” he reports. “It was bringing life to the soil where it didn’t have life; it’s able to let the soil breathe, and it’s a great carbon source for all of our microbes.”
Threatt also had started a needle tine program, and he thinks the combination of approaches helped him to maintain the turf in an area where previously he hadn’t been successful.
Combining the granular humic product with some starter fertilizer also has shown good results, he adds. “I actually use it on thinner, weak spots, as well. I’ll just hand-fertilize and hand water it in. I just like the response it gives me; I feel like it brings life to areas that are lacking life,” he says.
Based on the initial results, Threatt has begun using humic products on all of his greens: one product that incorporates humate prilled with gypsum that is applied throughout the putting surfaces, and then a straight humate product on trouble spots.
“On my low, poor-draining areas, I double-down with a higher concentration,” he explains. Both products go out about every 30 days, usually after a needle-tining and in conjunction with microbes. “I like for the holes to be there for the oxygen pathways and to help the product move down,” Threatt notes.
Threatt says he has heard from more superintendents who are using humics as part of their maintenance program as an additive to their micronutrients and foliar nutrition plan.
“I don’t know too many who are using a granular-type humic product in high concentrations,” he says, attributing that more to a lack of information about them rather than a reluctance on the part of superintendents. Threatt says he started using humics as a curative, but now is a believer in their effectiveness as a maintenance product.
Blake Bullock had just taken over as head superintendent at Bent Creek Golf Course in Jackson, Missouri, this spring when he got word that a fungicide he had applied on his greens had been contaminated with a powerful herbicide. Other courses around the country that had used the chemical were starting to see serious turf decline, and Bullock was monitoring his greens nervously. “We were really on top of watching our greens, and we saw them turn,” he recalls. “I was consulting with agronomists here, and they suggested I use a product with humic acid in it (as well as bacteria, microbes and other organics).”
Bullock previously had used humic acid, at low rates, as a maintenance product. But this time was different.
“A quart to the acre might be a normal maintenance rate. … We went out at 10 gallons to the acre,” he says. With 3.2 acres of greens on the course, he sprayed a lot of humic acid as quickly as he could on a Monday night. And then he came back the next morning and did the same thing.
“So we put 20 gallons per acre, and then five days later we applied again at a 5-gallon rate,” Bullock explains. The goal, the agronomists told him, was that the product would eat away at the bonds of the chemical structures in the soil. “We saw some very drastic, very good results,” he says. “There were about 25 courses across the nation affected by this contamination, and we were the only one that went with the humates, and we didn’t lose a whole lot of grass. From the photos I’ve seen of some of the other courses, it really didn’t touch us.”
There was a drawback: Because the humic process broke down the bonds of all the chemicals in the soil, it also removed the effectiveness of pre-emergent herbicides he had applied earlier in the season. So there was some crabgrass and goosegrass evident. “But it also freed up a lot of tied-up nitrogen and other things in the soil that weren’t being used – we saw just a monster flush of growth after we put down the humate,” Bullock says. He acknowledges that he can’t be sure his success in keeping his greens alive is totally attributable to humates, but says firmly, “I strongly believe that it helped. It’s going to be something that I use often now.”
And that may extend beyond his greens. When treating for the chemical contamination, Bullock sprayed humates on his zoysiagrass surrounds just to be sure those areas were covered too, and he saw a dramatic difference in the health of the turf there. “There was a night-and-day difference between the zoysia that got sprayed with the humic acid and the zoysia that hadn’t. Going forward, I’m thinking about cutting granular fertilizer out of the fairways and just going out at high rates of humic acid [there],” he says.
Not surprisingly, given the chemical scare he just endured, Bullock says one of the biggest selling points for him about using humic acid is the safety of the product when it comes to putting it on his turf. “I call it ‘liquid earth,’ ” he says.
A couple of years back, Paul Carter, superintendent at The Bear Trace at Harrison Bay in Tennessee, experimented with a humate-enriched topdressing sand on his greens. “We used it for a while, but we don’t use it anymore,” he says. The goal was to increase the organic matter in the top of the soil profile beneath the greens. “We saw good results; the humates did a good job,” Carter reports. “But the problem was that they broke down off of the grass and really dulled the reels on the mowers. It would cake up on the back side of the blade and mess up the cut.”
Now, Carter sprays humates as part of his weekly foliar applications. “Visually, I feel that the greens are healthier and that the soils are better. We haven’t done any testing on the humates specifically,” he explains.
This approach is less expensive than using the humate-infused sand and also gives him greater control over the rate he is using. “It’s easier when you’re putting it down as a foliar spray to, if I want to, really bump up the rates after an aerification, for example,” he says.
Carter says he has definitely heard more about humates in recent years and feels that superintendents are more willing these days to experiment with them.
“I think superintendents now are more interested in making sure that their soil structure is healthy and properly maintained. It used to be just about just making the grass grow instead of feeding the soil and feeding the roots,” Carter says. “Now, superintendents are looking for a more balanced approach, so I think that humic acids and fulvic acids are finding a place in the industry.”