Today 110 people attended the Thai GCSA meeting at The Vintage Club near Bangkok. I gave a presentation on Putting Green Management and Putting Green Performance. This dealt with the main reason for poor performance of sand-based putting greens – the accumulation of too much organic matter.

The presentation slides can be downloaded here.

In my talk, I first mentioned the three main problems we have with turfgrass surfaces that are wet and soft because of too much organic matter in the soil.

1. Mowing cannot be done properly and low mowing heights are impossible to obtain without scalping the turf.
2. Ballmarks are excessively large and general playability of the course is not at an optimum.
3. The probability of fungal diseases is increased.

I shared some data collected over the past year that shows an increase in soil moisture in a sand rootzone will usually lead to softer surfaces. We looked at a clip from a classic video of water movement in soils, to see what happens as water moves from a relatively fine-textured (sand + organic matter) layer down to a coarse-textured (sand without organic matter) layer, and then we discussed the four ways in which we can manage soil organic matter. Of these, I think the first two are the most important.

1. Manage the growth rate of the grass to avoid excessive accumulation of organic matter, allowing the grass to grow at a rate sufficient to recover from traffic damage, but no faster.
2. Apply sand topdressing to dilute the organic matter as it is produced. As a general rule, plan to apply at least 0.012 m³ sand/m²/year.
3. Verticut (vertical mowing down to the soil surface) and scarify (vertical mowing that goes below the soil surface) to remove organic matter.
4. Core aerify to remove organic matter, keeping in mind that tine size and tine spacing should be carefully considered to optimize the organic matter removal at each time of aerification. This will minimize disruption to golfers.

I would like to thank the TGCSA for inviting me to speak today and for all the superintendents who attended. I spoke at a TGCSA seminar at The Vintage Club when I was just starting with the Asian Turfgrass Center in 2006, and it was fun to be back six years later, with about twice as many people in the room, to be presenting about things that we have learned, based on research conducted here in Thailand and in other parts of Asia.

For more information, see these documents:

A Report on Putting Green Performance Characteristics (Woods, 2012, Asian Turfgrass Center)

Aeration and Topdressing for the 21st Century (Hartwiger and O'Brien, 2003, Green Section Record)

Cultivating to Manage Organic Matter in Sand-based Putting Greens (Landreth et al., 2007, USGA TERO)