Before 2012 I only applied fertilizer in a granular form. When I started applying fertilizer in my sprayer it was to get more precision and lower application rates using cheaper soluble fertilizer sources that I could customize the blend to exactly match what the plants needed. It also helped us reduce the chance of off target applications to areas like wetlands. I have written about the massive benefit this had on my budget and turf conditions all over this blog. From fertilizer savings of 80% or more, reduced requirement for mowing, and improved playing surfaces, I still think that applying fertilizer in a soluble form through a sprayer is the best way to go.
One of the the first negatives I noticed about this "higher precision" approach to fertilizing was that it was actually too precise. When I would go fertilize my fairways I would only fertilize my fairways! The rough would get nothing.
Back in the granular fertilizer days there was always a little overlap on the edges of the fairways into the rough. The swaths of the fairway granular fertilizer spreader were much wider and the overlap was also just as big. If you had a 20' wide pass left but the spreader only applied fertilizer 50' wide you would often have to over apply the fertilizer by 30' into the rough on one side. Or, due to the circular nature of the granular spreader application method, you would need 50% overlap on each pass (wheel to wheel) and thus, your first pass along the edge of a fairway would throw a half rate of fertilizer into the rough 25' wide.
It turns out that there was actually some benefits from a lower precision approach to fertilizing. It wasn't just the rough that was suffering. Areas like the collars around my greens were suffering. This could have been from rolling like a mad man but it was also from a lack of fertilizer overlap from granular applications on my greens and green surrounds. The collars used to get a double dose and now they weren't. The more precision that is used in an area like this, the less overlap there will be and there will be a need to make either supplemental applications or intentionally extend the boundaries of these applications to double up the fertilizer rates in these areas.
When I started spraying the fertilizer, I could control the width of these applications down to swaths as narrow as 4'. All of a sudden, the rough started to suffer in areas where there was higher amounts of traffic. I had never directly applied fertilizer to the rough as it had always indirectly got fertilizer from application overlap from my fairway, green and tee granular applications.
This wasn't a major problem with the low amounts of traffic I had at Pender. At my new course and during the Covid boom, we started wearing our rough down to the dirt. All of a sudden my higher precision approach to fertilizing, was creating issues in areas that I never used to directly fertilize. All of a sudden my higher precision approach to fertilizing was creating more work as I now had to start fertilizing these extra areas that never used to get direct fertilizer applications.
At first I thought about making a fertilizer application to my rough. The problem with this was that it would cost a lot of money, and not all the rough needed fertilizer. It was only the areas that had high traffic like around greens, where carts entered the fairways, and between cart paths and the tee decks. If I fertilized all the rough, I would also be spending more money cutting more grass which would negate most of the savings I was realizing from switching to soluble fertilizer sources.
I used a few different strategies to address the issues with a higher precision approach to fertilizing. First, I created a few extra fertilizer jobs. One was called "High Traffic Rough", another is "Tees and Tee Surrounds" and the other is "Collars". We also overspray our greens when applying fertilizer only and overlap again as we fertilize our green surrounds.
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| Boomless nozzles are great for applying fertilizer to rough areas |
High Traffic Rough is a job where we fill up the sprayer and go out and fertilize grass that is not good in the rough and on some fairways. The size and areas that we apply this vary with each application but we focus on areas in the rough along cart paths. We apply nitrogen at about 1g/m^2 (0.25#/1000) and do it as we have time or at least monthly. This job usually takes 1-2 tanks or 1-2 hours.
Tees and Tee Surrounds is a job where we use boomless nozzles to apply fertilizer to the tees and the rough between the tees and the cart paths. Boomless nozzles give our sprayer a swath of 12m (40ft) and are great for the undulating terrain around our tees. We only apply fertilizer in these applications and leave the wetting agent and any other chemicals for the precision boom applications. We start at the back tee and drive along the entire tee complex but focus the fertilizer on the side towards the cart paths. This process is very quick and takes less than an hour for 18 holes with 1 tank of spray solution.
Collars is just an application to the 2 meter wide swath around our greens. This is a very quick process and is only done when wear on the collars starts to show. Again, we apply nitrogen at about 1g/m^2 and just use the center boom. This can take as little as half an hour to apply depending on your ground speed. I often do this job while changing holes. It almost makes your time doing it free.
You could also just mix a bit more in the tank and overspray while doing the routine green tee and fairway applications. We do this too sometimes although it has the tendency to throw our routine off for the bigger application jobs especially with the uncertainty of the amount of turf that will need the extra shot of fertilizer.
The results from this approach to fertilizing the golf course have been great. We get the growth where we need it without adding a ton of work or cost to our fertilizer budget. We keep growth down in areas that have low traffic and this helps us keep our mowing costs reasonable as well. I'll discuss our fertilizer use in an upcoming blog post but needless to say, fertilizer costs continue to barely qualify as a line item in my budget. We literally spend just as much testing our water for contaminants as we do fertilizing the grass. Our soil tests on greens cost double what we spend on fertilizer for greens...
We don't use many chemicals on the fairways which is where the GPS sprayer really starts to make financial sense. The GPS can limit spray overlap from one pass to the next saving a ton of money. With our relatively low fertilizer rates, a little over or underlap from one pass to the next isn't noticeable. Is a little overspray into your rough the end of the world anyway?
With an annual fertilizer expense of about $5000CAD for an 18 hole course, there is literally no ROI for a fancy GPS sprayer on our course. Even if you factor in our wetting agent, fungicide and herbicide applications, the GPS is simply too precise for our relatively small budget.
In agriculture they are spraying MASSIVE areas. On the golf course, our largest application area is 12 hectares (30 acres). That's a joke compared to agriculture. We don't need that precision IMO. I spend $4000/yr on fertilizer for my fairways. If a GPS sprayer gets me a 10% reduction in fertilizer use through higher precision that saves me $400/yr. Over the 5 year lifespan of a sprayer that a total savings of $2000! OMG!! I have a feeling that the GPS tech will cost me more than that although I do like the idea of sleeping while I spray....
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| Self driving aerifier/fertilizer combo |
There was and still is a massive ROI for switching from granular fertilizer applications to soluble fertilizer applications using a modern sprayer. My savings continue to range about 80%. Cut 80% from your annual fertilizer budget and see how long it takes to pay off that new sprayer. There just isn't a ROI from any more precision that my low tech sprayer already provides.
Where I used to want a fancy GPS sprayer with all the latest technology, I have found that I can actually get really good results with better precision by changing the way we spray fertilizer and using my eyes to apply supplemental applications to areas that need more growth.