We were recently visited by Steve Gingell, a turfgrass agronomist from the Sports Turf Research Institute. We use the STRI for help and advice on all agronomic matters. An agronomist would normally visit us once each year to assess the condition of the turf and suggest possible ways to make some improvements.
This year for the first time during the visit Steve undertook a series of measurements designed to objectively assess the quality of the putting surfaces. The 5th, 9th and 17th were chosen as indicator greens and five different tests were carried out to each surface.The firmness of each green was measured using a Clegg Impact Hammer
|Steve Gingell explains the Clegg Impact Hammer|
The firmness of the putting surface is critically important with regard to its receptivity/ball holding characteristics, smoothness and year-round playability. We aim to create consistently firm surfaces which are receptive to a well struck shot played from a tight lie but which do not become uneven under play. A suitably firm surface allows a ball from a well struck shot to release, check and quickly stop. Poorly struck or shots played from longer grass should be less easy to control and be prone to rolling through the green. Aeration and top dressing are two key greenkeeping practices that improve surface firmness in a green. To carry out the test the silver weight is dropped down the yellow tube and the resistance it is met with when it strikes the turf is measured giving a numerical value of firmness. The target range for our course is between 100 and 120 gravities. All our greens fell within this range.
Volumetric Moisture Content
|Andrew Ricketts measuring soil moisture|
This is measured using a Theta Probe which averages the moisture content in the top 60mm of the soil profile. The higher the reading the wetter the profile readings above 45% normally being at field capacity. The soil moisture readings were taken next to the measurement for surface firmness. There is a direct correlation between surface firmness and volumetric moisture content with wetter surfaces always tending to be softer. Our moisture readings were consistent from green to green and withing the desired range for a links course.
Core samples were taken through the soil profile to assess the organic matter (thatch) beneath the selected greens. Organic matter holds moisture resulting in soft surfaces when wet and overly hard and unresponsive when dry. It also increases the symptoms of dry patch during dry weather and can promote and contribute to the presence of superficial fairy rings which are an issue on some greens at the moment. The test results showed that our organic matter content is very marginally on the high side. This test was actually taken in the summer of 2008 and results have improved since then. Once again aeration and top dressing are key operations in the management of thatch.
|Oliver Pennington uses the Stimpmeter|
Green speeds were measured using a Stimpmeter. This method measures the roll of the ball from a standard delivery carried out in multiple areas of each green.The longer the average measurement the faster the surface is deemed to be. All the results were factored using the Bredy equation to remove the effects of slopes within the greens. Our greens showed reasonable consistency and were all within the target range of between 9 and 10 ft for mid summer.
|The trueness meter in action|
The most important aspect of any green is that it provides a smooth and true surface for as long a period possible throughout the year. We try to create a surface which does not deflect a ball from its intended path causing snaking and does not cause bobbling due to unevenness. Smoothness and trueness was measured using a newly developed trueness and smoothness meter which gives a reading in millimeter deviation in each direction per linear meter. The measuring device, which resembles a pimped trolley jack, was pushed across a 10 meter green section at a steady pace in two directions. In the photo above PGA professional Mike Deeley tries out the device under the watchful eye of Steve. The readings showed the 5th green to be the smoothest and 17 the least smooth. Greenkeeping practices that improve smoothness include top dressing, rolling using lightweight turf irons and the promotion of healthy, dense grass plants through adequate nutrition. Golfers can play a big role in maintaining surface smoothness by choosing to diligently repair pitchmarks.