Friday, 12 July 2013

Water Management At Ealing Golf Club

Miro hand watering any dry areas on the 5th green
At last we seem to have a summer that isn't raining and we have long glorious days, with some heat included too:) This is great for the golf course as it is busy with golfers but puts huge pressure on the water management side of things and especially greens moisture. Over the last decade we have invested in water management tools at Ealing. In 2006 the club invested nearly £300k on a new fully automatic watering system. Playing surfaces such as greens, tees and fairways had a system installed that would allow the greenstaff to maintain good playing surfaces during dry, hot periods. However, an irrigation system is a tool and needs to be managed correctly as misuse will have the opposite affect on playing surfaces. Along with this we have invested in scientific tools such as a weather station and portable moisture probe. These tools along with the irrigation system allows us to set up a water balance sheet so that when we have to use the automatic sprinklers, we water correctly so that plant uptake is maximised and wastage reduced.

If you look at the image above you will see our current water balance sheet. It is basically a profit and loss spreadsheet with ET (evpotranspiration) as the loss and irrigation/precipitation as the profit.You will notice two things. The first is the high moisture loss that we are currently experiencing and second, the amount (or lack of) rainfall for the month. You will also probably gauge that that when we irrigate we don't replace by 100% of the loss on that day. It is roughly around a 60% figure. The reason for this is that it can take around 16 hours to lose say 4.2mm of moisture that we lost yesterday, but to add back just 2mm, roughly 4 minutes by the pop up sprinklers. Completely different rates. So to get the moisture levels right it is where hand watering and a new technology called 'VWC' or volumetric water content (last column on the right) comes in to allow us to be in complete control.

VWC is a fairly new technology which came out around 10 years ago for the turf market. It measures electrical resistance between two probes and converts it in to a percentage reading giving you the water content for that area. Two years ago we invested in a portable soil moisture probe, which along with our water balance sheet allows us to be in total control of our moisture levels on the greens. When it doesn't rain of course!. During hot periods such as this, we go out and measure the VWC for each green and then adjusted the run times for the sprinklers accordantly. So today we measured all the greens and found some such as the 11th green were too wet and that green will not be watered tonight. Our bench mark figure for these clay based push up greens is around 30%. We find when we go below that figure the water repels and they can become hydrophobic. So with the current weather, when we are losing between 4 and 5mm of moisture per day, we set the default VWC at around 35% first thing in the morning. So by the end of the day they will lose around 4 to 5% VWC and come down to around that 30% mark. This means that during the afternoon (when historically they have dried out and crusted up), playability is not affected and they play as good then as they do first thing.

Modern valving head sprinklers

They have around a 20m throw and apply evenly across the surface

Weather station giving daily ET and rainfall figures
Soil moisture probe giving instant readings

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