Superlatives abound following the recent spell of hot weather with temperatures sitting at record levels for a number of days and a lack of rainfall leading to drought being declared across large parts of the south of England.
July rainfall was 12mm, less than 20% of the July average. Couple this with the preceding dry spring and dry, hot June we have effectively been under drought stress for most of the season barring a few days after rainfall.
In addition to lack of rainfall we have seen temperatures well above average with two days reaching 36 degrees before “cooling down” to around 30 degrees. Mid August saw a run of 8 consecutive days above 28 degrees.
Conditions such as these present us with two distinct problems. First, as temperatures rise we see a rapid increase in evaporation both from the soil and through transpiration from plants. Peak days when we had both hot and windy conditions saw evaporation rates of more than 5mm per day which accumulated to a total in excess of 110mm of evaporation here at Bowood for the month of July. When we take our rainfall figure of 12mm and apply this to evaporation we were left with a deficit of roughly 100mm, certainly a situation that most golf course irrigation systems would have had trouble keeping up with.
The second problem we have in conditions such as these is simply that turf plants will not grow once temperatures become hot, particularly after a prolonged spell of heat where the soil has been absorbing and retaining heat. Turf plants will become dormant and therefore will not respond to irrigation and feeding and in turn will not be able to recover from traffic.
So the big question is what are we going to do to come back from these conditions and the impact they have had on the course. We have already begun a series of work that will continue over the coming weeks and months and will entail the following:
Running through this programme and addressing areas hole by hole will see good recovery as soil temperatures are in the range to encourage good growth.
The focus of summer renovation on greens this year was maximum aeration effect while looking for recovery as quickly as possible. Our strategy was using solid tines and aerating to a very tight pattern to maximise aeration opportunity, aiding irrigation infiltration and also creating an environment for strong root development throughout the resulting soil cavities.
We slowed the machine down so that our tine spacing was only about 30mm between rows and, as I know some of you like numbers, this resulted in over 11 million holes being punched into the greens and collars. Recovery from here involved sand topdressing, brushing and rolling to firm the green surface back down. Irrigation and fertiliser aided growth and integration of the sand.
Trialing something new for us here, we hollow-cored the eighth and eleventh fairways before topdressing and brushing in 60 tonnes of sand to each fairway. This is a substantial amount of sand and spending a couple of afternoons once the sand had dried brushing into the hollow core holes we will see an improvement in rainfall infiltration through winter and a improved irrigation efficiency through summer. It did take quite a while after the operation for the sand to settle down enough to mow but the finish now is very good after a couple of cuts and worth the wait and effort.
That’s all for this month, I’ll take a look at our recovery progress next month and discuss where we are relative to now.
Yours in sport.
Jaey Goodchild
Head Greenkeeper
