How do you collect and prepare soil samples?

I know how I do it.

As I’ve been thinking about it, and as I’ve asked a few people, I realize there may be a lot of variation in how turfgrass managers are collecting and preparing samples.

I’m curious to know how you collect, process, and prepare soil samples. By soil samples here I mean routine soil nutrient analyses. These are the kind of soil tests that measure soil pH, usually soil organic matter, phosphorus and potassium, and sometimes secondary and micronutrients too.

The standard recommendation, which I’ve written about here, is to take a minimum of 12 subsamples from each area being tested. These subsamples are then to be combined and mixed in a composite sample. Area here would refer to a single golf course putting green, for example, or a single home lawn, or a single golf course fairway, or a single sports field. That’s what I mean by area.

When I asked about this in a survey two years ago, 43% of respondents are taking 11 or more subsamples per area, 45% are taking 6 to 10, and 12% are taking from 1 to 5.

I asked a similar question on an Instagram story, and the results were similar to what I learned in that earlier survey.

According to the Instagram survey, 44% are taking 12 or more subsamples.

I’ve been thinking about that, and some of you know that I’ve been doing some research in this area. I’m going to explain how I currently recommend collecting and preparing samples. I’m going to summarize some of the research I’ve been doing in this area, and why I think it’s worth my time to do so. And I’m going to summarize the results of this survey.