Measuring surface hardness on greens, fairways, and approaches

I measured soil moisture and surface hardness on three fairways, approaches, and greens at a golf course in Thailand in September 2014. The fairways and approaches at this site are seashore paspalum on a sandcap. The greens are ultradwarf bermudagrass on a USGA green.

For some background info with data and charts from previous measurements, see this post: Relationship between soil water content and turfgrass surface hardness.

I do this to study a few things:

• what type of soil moisture levels are normal
• what type of surface hardness levels are normal
• what is the relationship between construction method and surface performance
• what is the relationship between grass species and surface performance
• how the surface conditions change over time 
• how the surface conditions change with different maintenance inputs

I used a TDR-300 to measure the volumetric water content of the soil to a 7.5 cm depth. At that same location, I used a Clegg Golf Course Tester with a 500 g hammer to measure the surface hardness.

For playability, I would prefer the fairways to be harder. I’m not an advocate for sandcapping of fairways in Southeast Asia. Even though the fairways at this location are sandcapped, the surface is soft. With these data, the golf course superintendent can make some changes to the fairway management and perhaps the surface hardness can be increased.

I also used the TruFirm to measure firmess at the same location. There is a bit more variability with the TruFirm, compared to the Clegg, but the result is the same—the greens are firmer, and the approaches and fairways are less firm. Note that a lower reading by the Clegg means softer, but a lower reading on the TruFirm means firmer.