Technical
The 2mm debate
Agronomic Investigation
It has been three years since the infamous ‘2mm debate’ was held at Harrogate in 2010. At that time, there were many angry greenkeepers out there
shouting “he can’t sustain it” and “they will be dead in three years!” Well, three years have passed and “they” look okay to me!
The problem was that there was no scientific data to back up my shortcut method. I knew that it worked (from a player’s perspective), but was unable to point to a reliable source that explained why. However, there was also no evidence to say that it couldn’t work.
We’d all heard stories of greenkeepers who had lost their greens because they had been cutting them too short. Lots of stories, but no facts!
110 PC FEBRUARY/MARCH 2013 A
s the debate began I started some agronomic tests. By compiling the results, I hoped to produce a body of data that would go some way to proving my method. From the
start I looked at what a 2mm method could achieve from an agronomic point of view. I felt that a short cutting regime in a parkland environment could reduce organic matter levels and help in the prevention of disease attack. The other thing that intrigued me was the bad press that Poa annua has had over the years, contrary to my positive experiences of it. To investigate the results of cutting at 2mm and Poa’s performance, I looked at:
- Organic Matter levels - Soil and Tissue nutrient analysis - CEC and pH values - Percolation rates - Compaction levels - Bulk density - Sward density Ealing Golf Club’s Greens Profile
Before I go in to these areas in depth, I feel it is important to give you a true reflection of the profile of Ealing’s greens. Ealing was built in 1898 and sits in a river basin, with a sub-base of London clay. The greens’ profile consists of a 60mm USGA sand profile, sitting on top of 200mm sandy/loam and then, wham, clay! The greens are roughly 8000m² in total
and drainage on the greens is pretty non- existent, as old clay pipes form the land drainage. Some of these can be located one metre deep but, instead of pea shingle covering them, we have hard core!
Right from the start, when I was appointed Course Manager in 2006, I decided to by-pass the clay pipes and work on the rootzone percolation instead. Deep verti-draining, with heavy sand dressings, formed the backbone of my programme. It creates what I call ‘sand channels’ within the sandy/loam profile, allowing water to move from the surface and enter the sub-soil. To date, this method has worked well. Prior to my appointment, temporary greens due to wetness were common at Ealing.
The Data Programme
All of my data has been taken from our second green. It is 450m² and in a fairly open position. The back drains pretty well, but the front of the green can get quite wet. The grass species is 99% Poa annua and 1% Browntop Bent (I'm doing my best to get rid of that 1%).
Organic Matter
Although the data programme is three years old, I have organic matter (OM) data stretching back four years. I will include it here as I consider control of OM in turf maintenance to be a priority for a successful greens performance. This is the industry accepted ‘Loss on Ignition’ test, externally conducted by
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