organic matter

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

If you’ve got some organic matter in the soil, then you will get some nitrogen (N) that the grass can use from it. This is called mineralization. As the organic matter decomposes, some of the N that was in the organic matter is converted into inorganic forms in the soil.

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:

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.

I got to see a lot of beautiful and interesting turfgrass around the world in 2022. I looked through my photos from the year and chose these as my favorites.

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.

This topic—carbon in turfgrass soils—was the subject of a Frankly Speaking podcast episode. One of the topics host Frank Rossi spoke about with guests Drs. Claire Phillips and Alec Kowalewski was the nitrogen mineralized from soil organic matter.

First some background information. I had shared this post that showed a number of different scenarios of organic matter change with hollow-tine cultivation (coring) and solid-tine cultivation, including examples with and without sand topdressing.

An interesting phenomenon happens when grass is planted on a golf course putting green. There’s typically not much organic material in the soil when the green is first planted. The organic material increases rapidly, to about 4% organic material in the top inch (2.

I’ve been thinking about this one a lot. It seems obvious that a sward supplied with more nitrogen fertilizer will tend to produce more organic material in the soil. It also seems obvious that a sward on which hollow-tine cultivation, or scarification, or sand topdressing, have been conducted, will need to receive more nitrogen in order to produce a surface compared with an adjacent sward that didn’t receive any of that work.