Would this work on bermuda grass?
I don't know, but..
A reader commented on yesterday's post with a great question. Paraphrasing, the reader (who identified as a non-turfgrass professional) asked if I thought this approach would work in a southern climate on bermuda grass. I don’t know the answer, but I’ll tell you what I think I would do…
I’ve never worked on bermuda grass greens, or any warm-season grass for that matter. I’ve played on bermuda greens a handful of times. Some of them have been elite, championship level surfaces, others have been of lesser quality. I know the conventional wisdom on bermuda greens is a need to perform huge amounts of cultural practices. I’m not here to say such an approach is right or wrong, but I know it's not all full-throttle all the time. I know turf managers who manage bermuda greens with varying levels of these cultural practices.
If I was to move from Minnesota to a course with warm-season putting surfaces–I’m not, but if I were–I would want to know exactly which practices are necessary to create the best possible bermuda grass putting surfaces. From such a standpoint, my approach would be no different than it is with bentgrass.
Fellow turfgrass professionals might think my approach is not to aerify, or not to fertilize, or not to do X, Y, and Z–that’s not it. My approach is to do the least amount of work required, in order to provide a membership with the least number of days disrupted by maintenance, all while maximizing the number of days with championship-level conditions. I don’t know what that cultural mix would be on warm-season surfaces, but I would track data like greenspeed, bobble test, firmness and OM246, and then decide what cultural practices needed to be employed.
So I don’t know if this approach would work on bermuda grass, but I would want to find out.
Yes, I think a general reduction in major cultural practices would still provide high quality bermudagrass putting surfaces in most cases.
The main focus would be thatch/mat and any soil layer that inhibits rooting. In USGA greens restrictive soil layering is typically rare and soil organic matter (SOM) reaches an equilibrium after a couple years. As Roch has mentioned, SOM is usually a good thing and an ideal number is not set in stone.
I did a two-year study on a seven year old ultradwarf bermudagrass putting green that had not been aerified for three years prior to initiation of hollow and solid tine aerification treatments. Plots that only received deep verticutting (1”) had the best quality and control plots did not collapse after five years with no aerification, although they were spongier due to a reduced amount of sand.
As a side note, SOM fluctuated almost a full percent over the course of a year due to changes in rooting. *This is the main knock I have against measuring Total Organic Material (TOM) because increased rooting can trigger unneeded aerification, etc. *The other knock is the lack of preciseness when measuring to a specific depth instead of separating thatch/mat from SOM at the actual depth where they meet. Thatch/mat depth in my study was 0.6”. With the 2,4,6 method an additional 0.2” of much lower OM material would be included in the sample.
Although bermudagrass greens may need more topdressing than bent or poa I believe most can be maintained at a high level with no aerification.
Regular grooming and occasional deep verticutting would likely be enough.