Sustainability and soil sensors at Sentosa

Sentosa Golf Club’s Andrew Johnston talks through his journey of taking the Singapore club toward sustainability, and the tools that have helped him achieve it.


Aerial view of Sentosa golf club
Sentosa Golf Club is home to two courses, the Serapong and the Tanjong, both of which are overseen by general manager, director of agronomy and architect Andrew Johnston. Photos courtesy of Sentosa Golf Club.

Editor’s note: The following article was supplied by Soil Scout. All product claims, research cited and other information is directly from the company.

Sentosa is one of Singapore's most established golf clubs. Over the last four years, it has gained global recognition for its sustainability initiatives and exceptional championship courses, the Serapong and the Tanjong.

Since 2005, Sentosa has hosted the Barclays Singapore Open (2005-2012), SMBC Singapore Open (2012-), HSBC Women's World Championship, Asia-Pacific Amateur Championship and the Women's Amateur Asia-Pacific. Numerous awards have joined these events, recognizing their work on sustainability, as well as the title of 'World's Best Golf Club' at the 2019 World Golf Awards.

Since 2011, this journey has taken place under the stewardship of general manager, director of agronomy and resident golf course architect Andrew Johnston. Designing over 100 golf courses around the globe while working for Arnold Palmer, Gene Bates, Fred Couples and his own company, plus a turf degree from Michigan State, molded Johnston into the perfect person to take Sentosa to the next level.

Among everything that he has achieved in Singapore, pinpointing the culture necessary to facilitate change is one Johnston clearly regards as his most significant. By working to a TR365 (tournament ready 365 days a year) mindset, Johnston, superintendent Rodney McKeown, the 75-strong agronomy department and wider Sentosa team have transformed the club.

That same drive started the Club's road to sustainability, which it is now renowned for, starting with a single-head control irrigation system.

"I knew that single head control gave you better control of your water from a golf course architect's point of view," Johnston explains. "I've built and designed enough golf courses in areas that have really struggled for water availability to know that you could reduce your water consumption by 40-60% with single head control.”

Johnston says that despite doubters, all it takes is a little ingenuity.

"People look at me and go, 'how is that possible?' A golf course with topographical contouring to it has high spots and low spots,” Johnston says. “High spots might need seven minutes, but low spots might only need 30 seconds because water runs downhill. If all heads are tied together in stations of two or three, you've got no choice but to run everything at ten minutes or whatever time you have set, so you're over watering.”

Aerial view of Sentosa golf club
The clubhouse at Sentosa Golf Club.

Another secret to the club’s sustainability success? Having hard and fast rules about water usage.

"We have the most sophisticated system in Asia right now, but I don't even let them turn it on until we have to,” Johnston says. “We drag hoses and just put them on the spot that needs it. There's a culture within the culture. It is usually the high spots that will crust off first, but the whole green doesn't need water. And too much water is what sucks the roots up and means the plant doesn’t develop that deep root system. If we can go 10 or 15 days without turning a head on, we will."

Sentosa has also made significant strides in other areas. The club introduced bee colonies, reduced fertilizer applications, product applications and is currently working with a local university and the GEO Foundation ( to develop a calculation for carbon sequestration of grasses and trees.

The aims of sustainability and TR365 are one and the same on the course. Along with GPS sprayers, biochar, and other methods, Sentosa has also been an early adopter of sensors. But, as with any new technology, they have seen it develop and are now installing Soil Scouts into every green on their two championship courses, along with selected tees, fairways and roughs.

"I'm all about tech and understanding data," Johnston begins. "Without the knowledge of this technology, then you can't improve. It is good to have hands-on intuitive skills, but you still need data.

Aerial view of Sentosa golf club
The Serapong golf course at Sentosa Golf Club.

For an example, Johnston points to an instance when the Soil Scout helped solve a mystery with a problem hole.

"I have four greens that are very close to each other. Hole 1, then hole 2, which sits down in a hole and is a par three, is right behind it. Next to it is hole 7, and then left of hole 1 is 8. So, four greens together with different elevations,” Johnston begins.

"Number 2 is in some kind of decline, and we can't figure out why. It seems like it's melting out a bit, and we're sending tissue samples and soil samples off to the lab. We've done nematode assays, and nothing adds up. Nothing points to an issue, but it is physically thinning and going downhill. We're watching it day to day, and it's been going on for about three weeks.

"I'm scratching my head, and I happened to pull up the dashboards of the soil sensors on my phone, and I see that 1, 7 and 8 are all the same temperature and 2 is ten degrees hotter. It sits in a hole and, with its axis, points at the sun as it rises and sets. So, it's got full sun all day, and it was the hottest time of year for us with little cloud cover.”<

Thanks to the data, it turned out the answer to Johnston’s problem was simple.

"Basically, it was getting too hot. So, we moved in a Turf Breeze fan and came back an hour and a half later and looked at the dashboard, and everything had levelled out. Air movement over the top provided the cooling the soil needed, so everything equaled out. In about two weeks, it had improved, its density was coming back, the plant was feeling healthy, and it didn't take a fungicide or NPK – all of it was environmental.

"We wouldn't have figured that out without a sensor that gave us the information we needed to make the right intuitive decision to change the environment. They are really valuable because they give us information that helps us, as premier turf managers, to analyze and make decisions that can put you in that ‘TR365 position’. "Now that we've gone to the Soil Scout version, which I feel is more reliable and has more background to it, I feel even more confidence in it.”

Aerial view of Sentosa golf club
Smart water usage and a reliance on data have helped Johnston ramp up sustainability efforts at Sentosa.

Providing Sentosa with the Soil Scout solution is Centaur Asia Pacific, who has built a relationship with the Club and is delighted to work with them on this project.

"Since we started distributing Soil Scout, we knew that we were partnering with a company that has something very different from other underground sensors we have seen before," explained Bryan Littlejohn, Business Manager (Sales & Services) for Centaur Asia Pacific, Singapore.

"The reliability of the product and the sensor's capabilities to send data consistently is second to none. The backup support provided by the team at Soil Scout is exceptional and gives us all the tools and resources we need to service our new and existing customers accordingly.

"We are very proud to be supplying Sentosa Golf Club with the Soil Scout solution, thus allowing their Agronomy department the real-time data required to make more informed decisions on the exact time to apply water and helping reduce their overall water consumption. Sentosa Golf Club is renowned for providing world-class playing surfaces, and it's very exciting to be associated with such a prestigious facility."

Johnston says the sensors have helped his team build a consistent understanding of the course’s turf needs day to day.

"I think they are extremely valuable to understanding all the little things. You can't come to work every day and just make decisions by the seat of your pants and expect it to look like what we look like every day."

Blair Ferguson is a freelance writer based in the UK.