organic matter


Measure exact topdressing effect, and requirement, by checking total organic matter by depth.

OM246 reports explained

I’ve made some updates to the standard OM246 report this year. The portion of the report with charts is showing four distinct things, and I showed examples and explained them in this video.

Maximum soil organic matter, not minimum, should be the goal

I like to test the total organic material at the surface of a turfgrass rootzone in autumn. Doing the testing in autumn captures the majority of the growth, accumulation, decomposition, removal, and dilution that has happened during the previous year.

Soil organic matter should be invigilated

A substantial amount of organic material accumulated at the surface of a Tifdwarf bermudagrass putting green at Rota in the Northern Mariana Islands. I don’t recall if I read this exact statement, or if it occurred to me when I read something else about invigilation.

Three things you can do right now with OM246 data

You can use OM246 test results to learn how total organic matter compares to general recommendations; better yet, you can evaluate how maintenance practices, growth, weather, and decomposition are changing total organic matter at a single site; and then there is what I call the killer feature of this testing: you can make a precise and site-specific calculation of organic matter accumulation rate and sand topdressing requirement.

Total organic material accumulation rate and sand topdressing requirement

When the total organic material is known at time A and at time B, the accumulation rate can be calculated. By accounting for the sand that was applied between time A and time B, another accumulation rate can be calculated: the organic matter accumulation rate independent of sand application.

All the organic material

Everyone understands the segmentation of OM246 samples by depth. That is in the name of the test, after all. Most people understand that OM246 testing is a mass loss on ignition of all the material.

Why I don't worry about infiltration rate

I understand there are a lot of different ways to manage grass. One way involves measuring infiltration rate. That’s not the way I do it. There are eight things1 I do like to measure.

An especially lucid abstract about core aeration

Please forgive me for mentioning hollow-tine cultivation (or core aeration, or coring) yet again, and how it might be overdone. There’s an article I want to share with you, about what happened after coring of sand-based putting greens.

Organic matter reduction by hollow-tines, solid-tines, and sand topdressing

This is an elaboration on, and an extension of, the calculations showing that hollow-tine cultivation, with removal of the cores, doesn’t reduce soil organic matter (OM) at all. That’s not an intuitive result, because OM has obviously been removed from the rootzone.