Throughout the year we will take many samples, readings and measurements of the greens in order to assess their condition.
These can be from visual tests- looking to see any obvious signs of change in the greens performance ie a change in turf colour, signs of disease occurrence. pest activity etc etc - to sending off nutrient samples to assess how much nutrient has been retained in the rootzone.
Regularly we check the greens soil water content. During the summer we use this to assess our irrigation needs and during the winter to assess how the greens are draining.
We took these two readings from the 18th green 5 days apart. During the summer we will keep the greens at a moisture content of 15-25%. At 8% the surface will dry out (this is our 'wilt point'). During the 5 days of the readings we had very little rain so this shows how the thatch layer retains moisture and acts like a sponge making the surface soft and leading to a poorer surface with increased footprinting and open to increased disease incidence.
This photo shows a soil profile sample from the 18th green taken from a high spot. The thatch layer is about 25mm thick.
This photo, again from the 18th green, but from a low spot (where water accumulates) shows the thatch layer at about 60mm thick and notice the darker layering. This is where the soil is becoming anerobic, a condition called 'black layer'.
This photo, again from the 18th, but taken from a level area shows the thatch layer at 40mm but you can also see the profile is lighter in colour and you can also see where we have recently cored and the sand infill present. Compared to the previous photo a much more healthier situation but still the need for thatch removal.
What these samples clearly present is how important thatch removal and topdressing is to the health of the plant and to the soil and how water content is also one of the controlling factors of how quickly organic matter (thatch) is decomposed in the soil.
"The measurement of soil water content is a critical part of good greenkeeping practice and groundsmanship. Monitoring soil water content can alert turf managers to potential problems before visual symptoms can become evident. It can also enable managers to assess the efficacy of turf maintenance operations."