Our Office Hour (actually 2.5 hours) discussion, summarized

Chris Tritabaugh and I met to review the OM246 test results from samples collected in October 2021 at Hazeltine National Golf Club. We did this as a livestream episode of ATC Office Hours, which is available for watching or listening at your leisure.

Organic matter change over time

I've been working on an explanation of what OM246 testing is. The main point I wanted to make in part 1 is that the change in total organic matter between two measuring dates shows the result of topdressing, and growth, and weather, and microbial activity, and coring, and scarification, between those two dates.

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.

Mental models, soil organic matter, and chocolate bars

I used to think of hollow-tine cultivation, with cores removed, as one of the best ways to remove organic matter from the rootzone. Maybe even as an essential way to manage organic matter.

Sand topdressing by exact depth: how to work it out

Today I explained the same calculation about sand topdressing for the third time, so I need to write a blog post on this topic. This is following the method of David Robinson, who says when you’ve written the same code 3 times, write a function; when you’ve given the same advice 3 times, write a blog post; and when you’ve done the blog post 3 times, write a book.

Updated spreadsheets for sand topdressing by GP

The PACE Turf topdressing rate spreadsheets have been updated with a new default starting value for monthly maximum topdressing sand. US units spreadsheet Metric units spreadsheet

Putting green organic matter by depth in the soil

I watched the Greenkeeper App meeting about organic matter, and I recommend you do too. The video has Doug Soldat, Bill Kreuser, and Roch Gaussoin talking about soil organic matter, rootzones, sand topdressing, and turf performance.

Sand topdressing by growth rate and clipping volume

Does this sound about right? Matching sand topdressing to the growth of the grass works out pretty good when applying 1 cm3 of sand for every 1 cm3 of clipping volume.

Three reasons why sand topdressing is best expressed as a depth

Here are three reasons I think it is best to express sand topdressing applied to turfgrass as a depth. Depth of sand standardizes the amount applied, independent of the mass of the sand or the area over which the sand was spread.

Total organic matter testing on putting greens: sample number and sample volume

Cale Bigelow asked me an important question last month. I’d suggested that measuring the total organic matter over time is a way “to simultaneously produce a putting surface with the desired characteristics while minimizing the amount of disruptive work done to the putting surface.