coring

For a few years now, when I have private discussions about the type of putting green maintenance that involves few or no holes punched in the surface and minimal sand topdressing, I often hear this response.

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.

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.

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.

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.

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.

When a measure becomes a target, it ceases to be a good measure. That’s a generalization of Goodhart’s law. I’m an advocate of measuring some surface performance, plant, and soil parameters.

A late July solid-tine spiking treatment of a creeping bentgrass green in Hokkaido, Japan. How’s this for a lede? “Hollow-tine coring and solid-tine spiking practices may not alleviate creeping bentgrass summer decline.

There was an article on the Golf Course Industry website about a course that hasn’t core aerified putting greens since the course opened 12 years ago. It’s a short article—466 words.

On a recent trip to Japan, I’d wanted to get a new video of a core sweeper in operation. Unfortunately for me, but fortunately for the greenkeeper, who had a laugh about this, the sweepers clean the greens so fast that by the time I arrived there were no more cores to sweep.