Objective Analysis

Gone are the days of cassette tapes, pagers and golf course architects shaping the land with horse-drawn equipment. Also a thing of the past ... superintendents making their best guesses at the moisture level of the soil. Thanks to today’s probes, estimation and speculation has been replaced with cold, hard numbers.

Mike Thurow, president and CEO of Spectrum Technologies, compared the historical gauging of soil moisture to an art form – often having to sense the moisture level of the soil by touch, inserting a pocket knife and feeling the moisture on the blade.

“Visually, experienced supers could see a silver sheen to the turf and know it was stressed for moisture,” Thurow says. “All of these methods are subjective. Further, this skill is not easily transferred to hand watering personnel.”

Phil Desbrow, golf course manager at Lakewood Country Club in Rockville, Md., used soil push probes before the advent of electronic devices.

“It was a feel thing that was difficult because one person could have a different opinion or different feel for the moisture,” Desbrow says. “Basically, you took a soil sample and felt it in your hand, sometimes you could squeeze the moisture out ... other end of the spectrum it came out like dust.”

Even with advances in technology, Desbrow and his team have yet to completely jettison similar probes.

“Currently, we use the moisture meters in the morning where we take our time to set the green up for the day,” he says. “Then, throughout the day, we use soil ‘push’ probes. When you are in a hurry watching greens, the last thing you want to carry around with you is an expensive moisture meter. This is where the soil probes come into play.”

As for remembering the hazards before the widespread use of probes and handhelds, Desbrow looks more at the benefits of today’s technology.

“There really are no dangers that I can think of,” he says. “What I can say, that with the use of digital moisture meters, it has trained everyone to be on the same page. We can take a moisture meter reading and correlate that to a soil probe. It is a good teaching tool to get everyone on the same page.”

Greg D’Antonio, superintendent and facilities manager at Concord Country Club in Chadds Ford, Pa., relied on early morning dew patterns to determine dry spots, as well as local knowledge of wind and shade patterns, prior to moisture meters. Consistency was the biggest issue with that method.

“It was very subjective, especially when more than one person was watering,” he says. “It was all done off feel with no backup data, especially when coming back later in the day to check on things. A dry area from earlier may not bounce back right away and thus, areas that look stressed would be overwatered.”

Thurow agrees.

“No superintendent wants to lose a green to wilt,” he says. “As a result, the tendency was to overwater greens and have a peace of mind that moisture stress would not occur. This creates a problem not visible to the eye. A saturated root zone lacks oxygen and will quickly become anaerobic. The roots become unhealthy and turf quality can decline. Black layer can occur if the condition persists. Overwatering not only wastes this important resource, but involves more labor to address this key task.”

In addition to the cost benefits, Thurow adds the use of portable soil moisture meters/probes brings objectivity to watering/irrigating golf greens and other turf areas.

“The question of when and how much to water is greatly simplified,” he says. “This benefits the superintendent in creating more consistent playability of the golf greens throughout the week. Golfers like consistent playability and supers can deliver this expectation with more consistency.

“Superintendents get a peace of mind that their folks are watering/irrigating properly and efficiently,” Thurow adds. “Their lives are less stressful knowing the task is done properly.”

D’Antonio likes concrete objectivity of today’s technology, but doesn’t rule out the importance of experience. “Intuition is still the number one factor used to decide to water, but the moisture meters allow multiple people to check greens and reduce the margin for error by having a set of numbers to help determine water needs,” he says.

Having a tangible figure to look at when testing for soil moisture has not only helped the greens at Lakewood Country Club, but also Desbrow’s bottom line.

“The benefit of physically seeing a number on a screen, this takes out the subjectivity part,” he says. “I have seen our water use go down because we use the moisture meters. Depending on your grass type, you may be able to go longer without having to put water down.”

To get the most out of his moisture meters, Desbrow starts early – before the droves of golfers inundate the course.

“In my opinion, the morning is the best time to use them,” he says. “We are located in the Transition Zone and it can get real hectic, real fast during the months of July and August in the afternoons. You just don’t have time to pick up the instrument and put it into the ground and wait for a number.”

Thurow believes portable soil moisture meters are most effective – and commonly used – when hand watering greens.

“They’re use aids in determining where and how much to water,” he says. “In addition, the meters aid in quantifying how efficiently irrigation is delivering water to a zone. Often times, the meter validates that an irrigation event may be delayed or skipped when the soil moisture levels are known.”

While Thurow says smartphones can be used to record measured values on an app and those values can be viewed on Google Earth, which aids in understanding the spatial variability of soil moisture, Desbrow is seeking additional veracity.

“I would say the units with the GPS options aren’t as accurate as they should be ... you could take a coordinate and be as much as 10 yards off the original spot,” Desbrow says. “I would think that this has a lot to do with how many satellites are being used to pinpoint the coordinate.

“To my knowledge military GPS or the expensive Trimble GPS hand held units can get as close as a centimeter,” he adds. “If you can incorporate that technology, maybe they already I have, I would look into this. Currently we do not have the GPS options at my course.”

As for the future of using these handheld devices to more accurately and efficiently water greens, D’Antonio would like the ability to sync with the irrigation system automatically and allow overheads to run based upon moisture meter readings taken that day. Thurow sees that and more.

“Performing a version of an ‘irrigation audit’ brings further value to using this technology,” Thurow says. “It may possibly validate the need to change irrigation run times, replace nozzles or even validate the need for a new irrigation system to replace the old, antiquated system. The data from the soil moisture measurement empowers turf managers to make informed decisions.”

Technology is great, but Desbrow hopes the market evens out to make the future more accessible.“More and more use of the electronic meters will be around for a while,” he says. “There are the units that you can bury in the ground, but from a cost perspective, not everyone can afford these. When cost does go down, I believe that will be more of the trend.”

Cost aside, the coming years are sure to hold impressive advancements in moisture management.

Rob Thomas is a Cleveland-based writer and frequent GCI contributor.