No more guessing games

Features - Cover Story

Magic 8-Ball Says: Moisture meters take the guesswork out of watering

February 7, 2013
Rob Thomas

Water is the lifeblood of a golf course. Without it, the turf cannot survive. Conversely, too much can be detrimental to turf health, as well as costly and environmentally unsound if coming through excessive watering practices. Many superintendents are foregoing the guessing game of when to water through the use of soil moisture meters.

Garrett Luck, has been at North Shore Country Club in Mequon, Wis., for 12 years, the last seven as head superintendent. It wasn’t until 2011 that they began using soil moisture meters, starting with the FieldScout TDR 300 from Spectrum Technologies. He says their goal was twofold – first, to more effectively hand water greens.

“During the summer, especially during periods of high temperatures and humidity, we rely predominantly on hand watering,” Luck says. “This allows us to manage our bent/Poa greens with great success by reducing the risk of overwatering. After extensive use, we have established a threshold number at which the turf requires supplemental water. Staff has been trained to monitor the moisture values and various locations throughout the green and water only the areas that fall below our threshold.

“The second goal was to provide uniformly firm putting surfaces without sacrificing the health of the turf,” he adds. “By using the meter at various locations across all putting surfaces, we are able to dial in our moisture on all putting surfaces on the entire course.”

In 2012 Luck upgraded the irrigation control system to the Toro Lynx with VP controllers, including a set of Turf Guard soil monitoring sensors.

“I have been very impressed with these sensors that can be placed within the soil profile and monitor soil moisture, soil temperature and salinity,” he says. “While salinity is not an issue at NSCC, both the moisture and temperature aspects have proven useful. Since certain pesticide applications are tied closely to soil temperature, we now properly time these applications with great certainty.”

Timing allows Luck to realize improved results and eliminates the needs for future applications, which is both good for the environment and the bottom line, he says.

“Perhaps the most important aspect of the Turf Guard system is its ability to feed real-time data back to our central irrigation computer,” Luck says. “This allows us to constantly monitor the moisture of our playing surfaces on our central computer, my iPhone, or my iPad. It is safe to say we water our greens considerably less now that we utilize this tool.

“The fact that the Turf Guard system documents all information from the sensors could prove to be valuable in communicating with the membership,” he adds. “In situations where turf loss may occur on challenging areas, the data from the sensors could be used to explain the differences from one green to another.”

Alan FitzGerald, superintendent at LedgeRock Golf Club in Mohnton, Pa., started using the TDR 300 handhelds four or five years ago to get a better idea of how his turf and, in particular, the greens were performing. Prior to that he would base watering on what he could see in the field. “I am a firm believer in deep and infrequent irrigation practices, so once I would see uniform wilting, I knew it was time to re-soak the greens,” FitzGerald says. “I thought the moisture meters would give me a little more guidance and let me know sooner than have the turf get too stressed out.

“It also helps in the days before the deep soak is due, as isolated dry spots start to appear,” he adds. “We know how much they need to be hit to carry the green through to watering with the overheads.”

FitzGerald adds the Toro Turf Guard in-ground sensors to monitor temperature, setting them to give notice once they reach a predetermined limit. Referring to them as a “snapshot” because of their placement, he installed the sensors in areas that give a good general indicator.

“I have two in a green I want to monitor – one in a known good/dry area, one in a wet/poorer area – so it gives a good average indicator of what’s happening and can alert me to something before I can see by eye,” he says. “I’ve installed them in a number of greens that are good indicators of all the greens.”

FitzGerald initially installed Turf Guard at LedgeRock as a couple of pocketed greens started thinning out from lack of air movement. They took trees out and did as much culturally as possible, but still needed more air. The greens needed fans, but he knew it was going to be a major capital outlay.

“I had demoed the Turf Guard sensors so knew what they could do and show that a fan would help,” he says. “The board approved the purchase of the sensors and a fan to see if it made a difference. I was able to show a 2-4 degree difference in temperature at a 2-inch depth, which showed the fan was working.”

Since then he’s adds fans to all the “bad” greens, which now play just like the others on the course.

Add Andy Ragsdale, superintendent at the Ritz-Carlton Golf Club in Orlando, Fla., and Mark Rawlins, CGCS at Longaberger Golf Club in Nashport, Ohio, to the list of those who use the TDR 300.

Rawlins was looking for a method to determine when areas of the greens were going to need irrigated to prevent wilt, but didn’t want to apply water if it wasn’t needed.

“[I] or the assistant superintendent will go around the course and check the high areas and the low areas of the greens and collars and record the moisture reading,” Rawlins says. “This will first be done in the morning, usually while changing the hole locations. We will know at this point if hand watering will need to be done that day. Depending on the weather, most days we will also check the areas in the afternoon just to make sure.”

Ragsdale says the process is as easy as walking across the green and checking 12-15 spots for the average reading.

From The Field // Tool of the trade

The modern soil moisture meter has revolutionized the way turf managers apply one of Mother Nature’s most important resources – water. Manufacturers have given us the flexibility to monitor not only moisture levels, but also temperature and salinity from the same unit. This data allows us to take a more objective approach to scheduling our irrigation cycles and daytime hand watering. One of my greatest concerns about the use of this technology is the rate at which it is implemented into management practices. Yes, information can be collected soon after the installation of a sub-surface unit or through the use of a portable device, but it takes time to extrapolate the information needed to get the most out of these tools.

I often hear superintendents share their positive experience with soil moisture meters in an over-simplified, rudimentary manner. Ladies and gentlemen, this is not the fuel gauge on your car. We all know that when the low-fuel indicator appears on our dashboard that we ought to make it a priority to refuel, but the presence of an arbitrary number on a graph or LCD display doesn’t necessarily mean that it is or isn’t time to add water to a green, tee or fairway.

It may take an entire growing season to combine visuals observations with the numeric data to create relationships that are most useful for your property. It’s only after this step that we may truly interpret and apply the information that is being collected by the moisture meters. For example, if the 10th green begins to exhibit drought stress at value X, we can evaluate our options and make a decision concerning the need for water. Furthermore, depending on how wide-spread the data collection is on your property, you can begin to group areas with similar characteristics. It’s unlikely that all putting greens on a golf course have the same moisture requirements. Instead of watering all greens, selectively water greens in groups. For example, Group A greens may only require deep watering every five days, whereas Group B may require watering every four days. Certainly allow for variations in this schedule as weather, chemical applications, and golfing events may require the watering schedule to be modified. In the end, this will allow for irrigating in a more predictable and efficient manner.

Nate Jordan is a superintendent at Saratoga Lake Golf Club, Saratoga Springs, N.Y., and a frequent GCI contributor.


“An irrigation flag could be used to mark areas that need to be hit with the hose, so all spots can be checked and then you can return to hit those dry spots after you put the meter away,” Ragsdale says. “Most people know their spots and will go right to them with the meter, so a flag system is not needed.”

While Ragsdale wishes more can be done with the meter’s GPS and mapping system, Luck wants even more data.

“I would like to see the ability to include mini-weather stations on irrigation controllers that could provide real-time measurements of precipitation, wind, humidity and solar radiation throughout the course,” he says. “I believe this could really lend a hand in better dealing with microclimates.”

FitzGerald believes, in time, they will provide more data, but now is finding ways to use the data already available.

“Turf Guard’s ability to read temperature is nice and saved me last spring when I was able to see my soil temperatures were still not high enough for growth, even though early in the spring we had really warm daytime temperatures for a few weeks, which was followed by another few weeks of cold,” he says.

FitzGerald was able to use that info to hold off on “waking the turf up” during the first warm spell. “Once they told me growth had started and I made my fertilizer applications, the turf jumped to life rather than shutting back down and having to rewake up.”

Based on that, FitzGerald believes once more superintendents get out to test them, the more they may be able to be used to predict pesticide application timings, such as crabgrass and grub controls.

“As more people use them, I believe more uses will pop up. Like the spring warm up, I never even thought about that until last year and I realized I had the info at my fingertips,” he adds.

FitzGerald expressed a desire for some basic soil nutrient information, too, but says he wasn’t sure how useful it would be until he actually used it.

As for tangible benefits to using soil moisture meters, Rawlins has seen plenty of advantages.

From The Field // Moisture Meter Basics

These days a golf course superintendent can only do so much with rolling and mowing and those practices are pretty consistent. Now the goal is firmness and consistency.

As such, handheld moisture meters have become a popular item with golf course superintendents. I talked with superintendents Eric Greytok, Belfair Plantation, Bluffton, S.C.; Jonathan Jennings, Shinnecock Hills Golf Club in Southampton, N.Y.; Tim O’Neill, Country Club of Darien, Darien, Conn.; and Pat Sisk, Milwaukee Country Club, River Hills, Wis.; about what portable meter they use and how they use it on their golf course. The Spectrum Technologies Field Scout TDR 300 seems to be the popular choice as all four superintendents were using it, each having two per 18 holes.

The meters come with different length probes. Sisk at Milwaukee Country Club is using 3-inch probes to manage the rootzone on his bentgrass greens, while O'Neill uses the 1-1/2-inch probes to manage on the greens at the Country Club of Darien. Greytok and Jennings were also using the 3-inch probes at Belfair and Shinnecock Hills, respectively.

While Sisk uses the meter to help fine tune his irrigation schedule, the other three superintendents are using the meter to aid in syringing their greens. Greytok, Jennings, and O'Neill use their meters to try and maintain a specific moisture range on their greens. Jennings says his "sweet spot" is between 12 percent and 17 percent moisture while O'Neill aims for 13 percent and knows that wilting will occur at 10 percent. Greytok also has specific target moisture levels he is aiming for and knows at what percentage wilt will occur.

All four of the superintendents queried take a number of readings on greens, from as little as five to as many as 20 to obtain an average moisture content.

They probe known hot spots or other trigger areas first. With time they have discovered that the moisture members provide reliable information that can be used to indicate when syringing needs to take place. For example, O'Neill and Greytok can measure moisture on the greens between 9 a.m. and 10 a.m. and know at what time they will need to syringe their greens. Sisk probes his greens mid to late afternoon and uses those readings to adjust his nightly irrigation schedule.

All four superintendents report that you do not need a lot of experience to use the moisture meters and technicians tend to catch on rather quickly. They are using the meter primarily on the greens and only occasionally will take readings on tees and fairways. They report that using the meter provides for a more consistent, dryer and firmer surface and also develops benchmarks for differences and to recognize anomalies. The meter also helps to fine the threshold so greens can be kept at the edge, not too dry and not too wet.

Monitoring soil moisture with a portable probe is a useful tool to help maintain the desired level of firmness for many superintendents.

Brian Vinchesi is president of Irrigation Consulting Inc. and authors GCI’s “Irrigation Issues” column.


“It has improved the consistency of the greens,” he says. “We try to keep water off areas of the greens that don’t need it while applying water to the areas that require water. This helps to keep the speed and the firmness more consistent from green to green. The greens are healthier now because we can keep them drier, promoting deeper rooting.”

FitzGerald, who believes a little stress is good to keep the plant strong, says his greens are healthier because of the meters and doesn’t have to look back too far to see the cost of struggling turf.

“In 2010 when the ‘bad’ greens were struggling, I believe we spent in the region of $12,000 in extra maintenance and labor nursing the greens through the summer (along with poorer playing conditions) which is now eliminated as the combination of the fans and being able to monitor moisture better has them perform as the others on the course,” he says.

Hard to find a truly conflicting view of soil moisture meters, but Luck tried.

“The only downside I can see in using these meters is to become too dependent on them,” he says. “We still get paid to manage turf during difficult conditions, which requires hard work and long hours on the course.

“During tough conditions, nothing will ever replace an afternoon tour of the course,” Luck says. “While these tools will never replace a hands-on, visual inspection, the peace of mind that comes from knowing you have adequate moisture on a Sunday afternoon is priceless.”


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

Digital extra
The use of moisture meters has grown significantly in the last few years because they allow turf managers to quickly asses soil moisture content, which provides significant long- and short-term benefits. Check out this YouTube video of USGA’s Adam Moeller presentation to the Metropolitan Golf Association on moisture meters for better turf. Enter into your web browser.

Photos courtesy of Spectrum Technologies; Garrett Luck