organic matter


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

N input accounting

Phil Collinson asked an interesting question: when calculating N inputs, do greenkeepers account for N added outside of fertilizer? Greenkeepers - when calculating N inputs for the year do you account for N outside of fert?

You won't believe this common maintenance practice doesn't reduce organic matter at all

Hollow-tine aerification, coring, core aeration, whatever you call it, removes organic matter from the soil. But if you measure the soil organic matter before pulling any cores, and then measure again after the cores are removed, the soil organic matter % will be exactly the same.

No core aeration, no deep verticutting, and surprise! No summer decline

Perspective. It’s funny how that works. When I first read this research report in 2011, I skimmed over some parts, and cherry-picked what I was looking for — that 15 to 20% surface area removal was required every year in order to keep soil organic matter under control.

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.

Organic matter separation from turfgrass soil samples

I collected a lot of soil samples this month. My standard procedure after collecting samples is to air dry them before sending to the lab. This is a dried sample from the top 2 cm (0.

Total organic matter 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.

Total organic matter 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?

Numerical notes from Nikanti GC

I spent a morning with Brad Revill at Nikanti GC last month. I wanted to see the course, get some measurements, see the clipping volume measurement, and talk about turf management with Brad.

Variation in rootzone organic matter (humus) from point to point on the same green

Anything resembling thatch or mat is explicitly excluded from the soil organic matter measurement made on routine soil nutrient analyses. That portion of soil organic matter is excluded because it is not measured.