Checking Moisture = Saving Money at Northland Country Club

This post was originally posted in 2010.

My name is Chris Tritabaugh and I am the Golf Course Superintendent at Northland Country Club in Duluth, MN. A few weeks ago Scott emailed and asked me if I would like to contribute to this fantastic turf management blog; I was honored and was happy to accept the invitation. For the past two and a half years I have maintained the Northland Country Club Turfgrass Management blog to update, inform and educate our membership on the day to day operations of our operation as well as efforts to create a sustainable golf course. Its an honor to contribute to and wonderful to know Northland's efforts tocreate a sustainable golf course are being noticed by people within the industry. Without further ado; my first contribution to

My brother Adam is a little more than two years younger than myself. Growing up he was a classic little brother always wanting to have what I had and do what I did. Earlier this summer Jeff Johnson, good friend and superintendent at The Minikahda Club in Minneapolis let me know he had purchased a TDR 300 soil moisture meter from Spectrum Technologies. Playing the role of little brother and not wanting to be left out, I purchased one for Northland as well. The meter, seen on the left, has two probes that when inserted into the soil give the percent water volume content in of the soil. After purchasing the meter at the beginning of August, its use was pretty much non-existent due to ample rain and at least the thought from myself that taking moisture readings when we were wet was unnecessary. This was until a couple weeks ago when  my "big-brother" in turf management made the post, linked below, on his blog.
The Minikahda Club Grounds Department: Collecting Moisture Readings on Greens

Turns out Jeff had started using his meter on a daily basis to record the average moisture readings of his greens. Just like the little brother I ran out and blew a couple months of dust off our meter and started taking our own daily moisture readings on putting surfaces.

By taking daily moisture readings from the putting surfaces we can and will learn the following:
  • Which are our driest greens and which are our wettest greens? 
    • This is something we already have a grasp of but will now have true data to tell us the real story.
  • How dry can the putting surfaces get before they need moisture?
    • The number will probably be different for each green but after a couple of weeks we will know the number for each putting surface.
    • It will take some of the "guessing" or feel out of deciding when to water, making our irrigation less subjective and more objective. Each green will have a number and when the moisture level gets to that number it will let us know an irrigation event is necessary.
    • The difference between LOOKS dry and IS dry can be very different, especially this time of year when hardening of turf plants make them look drier than they really are. Going forward we will know if a green really is dry or if the surface is dry but ample moisture remains in the soil.
  • What is the ideal moisture level to promote a balance of fine turf and ideal playing conditions?
    • How dry is too dry and how does that dryness equate to ideal firmness?
  • How does the moisture level in our putting surfaces change in the days after a rain event?
    • How much rainfall equates to our ideal amount of irrigation?
    • How much more effective is rainfall than irrigation at wetting the putting surfaces?
  • By using our irrigation central control computer we can save water by only watering the greens that need water.
Each day, or this time of year every other day, we  take 9 separate readings on each putting surface. Three across the front, middle and back of the green. If one spot shows up with a reading +/- 10% of the average then we take two more readings from that location to eliminate the affect of a mis-read. The meter keeps a running average and that number is recorded on a scorecard, then added to a spreadsheet. The ultimate goal is finding the ideal number for each green then managing the irrigation such that we keep ideal consistency and turf conditions through out the course and season.

So how do these readings help us improve our management practices? In the past we have watered the putting surfaces with two separate programs. One for the greens on the bottom of the course and one for the greens on the top of the course. This meant when the driest putting surface needed water, everything on that program would get watered. Moving forward we will be putting each putting surface on its own program so that on a daily basis we can water only the ones that show a moisture level indicating a need for irrigation. Let me give you an example. On the lower part of the course 14 green is our driest, while 18 is our wettest. Previously when 14 was dry we set the bottom green program to run and 1-3 and 14-18 would all water. Knowing that 18 was a wetter putting surface than 14 we would turn down the amount of time each head on 18 would run. Never the less watering in this manner never really allowed 18 to dry down as much as we would like. The moisture level on 18 was always on the high side and thus swinging the turf population from Poa annua to bentgrass was more difficult on 18. During the summer the necessary irrigation interval on 14 might be 4 or 5 days, whereas 18 might be 10 or 12 days. Spread this around the entire golf course and an entire season and its a lot of water being saved. It is also no coincidence that our drier putting surfaces are the same putting surfaces with higher populations of bentgrass. Using the moisture meter and being able to manage the irrigation individually on each putting surface will bring us a huge advantage.

Initially the thought having separate programs for each green seemed a bit extreme. The more I thought about it and talked to others the more I came to realize that by not having separate programs we were missing an opportunity to really fine tune the management of our putting surfaces. My goal when watering putting surfaces is to dry down the rootzone as much as possible, then re-wet with a deep irrigation cycle. This deep infrequent watering has many advantages but most of all it promotes deep rooting and gives our bentgrass a big advantage over Poa annua. In the past, having to water to the needs of our driest surfaces we were missing the opportunity to achieve this dry down on most of our surfaces. Only the driest putting surfaces were truly being managed in preferred manner. My suspicion is that by managing each green separately we not only save money but increase bentgrass populations faster on our typically more wet putting surfaces.

As I finish typing this post a Spectrum Technologies catalog is sitting on my desk. Their slogan? "To Measure Is To Know." Very true indeed.