The Sniff of an Oily Rag

Or, the dust from an old bag of ammonium sulfate

In F1 parlance, the sniff of an oily rag references the tiny amount of fuel added for a qualifying lap. The general world of cars uses it to reference a vehicle with excellent gas mileage. ‘That car will go a hundred miles on the sniff of an oily rag.’

It’s a phrase that’s always made me laugh, and I’ve been thinking about what a similar phrase might sound like for greenkeeping. Maybe something like: I grow bentgrass from the dust off an old bag of ammonium sulfate. I’ll try and get it to catch on.

I heard the sniff of…phrase last week, and it got me thinking about what it takes to grow bentgrass for a season on our course.

On putting surfaces in 2023, we applied 0.78 pounds per 1000 ft². Taken across the entire course (150,000 ft²), this equals 117 pounds of nitrogen, in total, applied to putting surface area over the whole season. 100% of this nitrogen came from ammonium sulfate, which is 21% nitrogen, so 557 pounds of actual product was required. At $27.38 per bag, that’s $305 to supply our putting surfaces with nitrogen for the entire season.

This is a tiny amount of fertilizer required to create great greens. It’d be easy for one to think I am going to talk about the cost, but one would be wrong. If you’re using ammonium sulfate as your nitrogen source, you will know it won’t cost you much money. Even if we doubled or tripled the rate of N, we wouldn’t be looking at a dollar amount that would break the bank.

Why would anyone apply more if you can have great greens with such a small amount of N? I’m not suggesting 0.78 lbs/1000 is the right amount for everyone. I am saying to collect and analyze the data to find out exactly how much grass you need to grow. It’s not so much about wasting fertilizer as it is wasting resources. Growing any more grass than necessary will result in extra work to get the desired playing conditions.

Double the N might only cost $610 in fertilizer, but what about the extra mowing, rolling and aerifying, or topdressing that might be required? What about the unquantifiable costs of regularly disrupting golf by putting sand on the greens during the season?

It will always be good to apply the least amount of nitrogen possible, and you can only find out what the number is by collecting the proper data.