OM246

OM246 organic matter total organic material topdress sand soil test

There is so much work done to manage the organic material right around the soil surface—and much of that work is disruptive. Hollow-tine cultivation (coring), scarification and verticutting, sand topdressing: sometimes these are essential, but ideally one will minimize them because they are disruptive. So how to get it right?

Measuring exactly how much organic material is present, and how it has changed over time, gives all the information you need to adjust the work, and the surfaces, to be exactly as you want them.

  • Download an abbreviated example report to see the types of charts and tables that are used to summarize your test results.
  • Use the OM246 calculator to calculate OM accumulation rate and topdressing sand requirement.
  • See all pages tagged OM246.

OM246 stands for Organic Material at a depth of 0 to 2 cm, where 0 is the soil surface; 2 to 4 cm, and 4 to 6 cm. OM246.

Would you like to do some tests?

This video goes through the four steps of OM246 testing in only 7 minutes, and I recommend watching those for those both new to, and to those experienced with, the OM246 test and reports.


You can also see the entire playlist of OM246 videos.


You can also subscribe to the ATC YouTube channel to see all the new videos.

Posts

How much organic matter is too much?
I was teaching a seminar about the distinction between soil organic matter (humus) and total organic material, and how to make use of those test results, when this question was posed:
Last updated on 2024-12-16 2 min read
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How much organic matter is too much?
All about OM246
The key thing about OM246 testing for total organic material is that the sample is handled and measured to explicitly include all the living and dead undecomposed plant material in the sample.
2023-06-16 1 min read
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All about OM246
Organic matter terminology in turfgrass soils
I have a suggestion. Turfgrass managers do a lot of work for the purpose of organic matter management. We teach seminars, or sit through seminars, about managing organic matter. When referring to organic matter, or contemplating its management, I think people in the turfgrass industry tend to lump together all the organic materials, the humus and the dead roots and the decomposing leaf sheaths and leaves and rhizomes, and the living parts of the grass plants that happen to be underground.
2023-04-29 4 min read
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Organic matter terminology in turfgrass soils
Two soil organic matter timelines
I’ve tried to explain the value of total organic material testing by comparing it to the soil organic matter. In the timelines shown below, the total organic material in the top 2 cm (0.
2022-12-04 3 min read
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Two soil organic matter timelines
My preferred method of OM246 sample collection
I’ve collected a lot of soil samples for total organic matter testing by depth. That’s what I call OM246 testing. My preferred method for this is to use a straight (no taper at the tip) cylinder to pull the core.
2022-04-14 3 min read
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My preferred method of OM246 sample collection
A Tale of Two Tests
This post takes a few minutes to read because it covers this topic in a bit of detail. The summary is, I make use of two types of soil organic matter tests for turfgrass, these tests measure two different things, both important, and I recommend turfgrass managers measure both of these, ideally once a year.
2020-12-02 10 min read
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A Tale of Two Tests
Total organic material at the surface of warm-season grass putting greens
These are the predicted distributions and percentiles of total organic matter in the surface 2 cm (0.8 inches) of warm-season grass putting greens. I include a plot for predicted organic matter of a random green of an unknown species.
Last updated on 2024-07-13 1 min read
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Total organic material at the surface of warm-season grass putting greens
Total organic material at the surface of cool-season grass putting greens
This is a time of year when there is a lot of sand going down on putting greens, and sometimes a bit of coring too. The purpose of all this work?
Last updated on 2024-07-13 2 min read
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Total organic material at the surface of cool-season grass putting greens
Soil organic matter: a bullet list
These are some key things I’ve learned after studying soil organic matter (SOM) for a few years. This is about organic matter in the context of playing conditions—how a ball reacts when it hits the surface.
2020-02-17 3 min read
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Soil organic matter: a bullet list