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. Roots, thatch, humus, mat, rhizomes, stems—that’s all part of the measurement. Soil organic matter testing, on the other hand, explicitly excludes the undecomposed living and dead plant material. Thatch, mat, roots, stems—that’s all removed from the sample before checking a 2 gram scoop of soil for the humus that remains after the big chunks of organic material are gone.
That distinction between the two tests was something I tried to make clear through words, photos, and a video in a seminar about total organic material testing. I’ve recorded a screencast of the seminar here.
You can see a highlight reel of the seminar here, on Instagram. We also went to the 9th green at HIBARI Golf to demonstrate OM246 sample collection.
You can see the seminar handout for more information and to download the slides.