A common question is “How much does it cost to water a bowling green for a season?”
Answer: a lot less for a performance bowling green than one in the throes of a traditional maintenance program.
It surprises me that clubs are surprised at the little surprises they get when the water bill comes in.
How can you be surprised that you used more water this year when you added 5 or 10 tonnes of sand to the green last autumn?
Many greens are already unmanageable in a normal (UK) summer due to excessive water requirements, localised dry patch and impermeable thatch; in a drought scenario its unlikely that there is any amount of water that would suffice.
This is because most of the water applied to poorly maintained greens is wasted to evaporation, run off and/or leaching.
Thick thatch holds water at the surface like a sponge, until of course LDP sets in, then it becomes akin to concrete and most water is lost to run off.
LDP causes soil particles to become hydrophobic, shedding any water that gets through the thatch to the macro-pores in the soil and away to the drains.
Performance greens can be watered cheaply and effectively because they only need enough to keep them alive during prolonged dry periods and can mostly take care of themselves in the normal course of a British Summer.
In many cases there is no need for anything more sophisticated than a large holding tank (the bigger the better) a simple pump and a 19mm hose to hand water hot spots on the green. This is much more effective than pop up sprinklers.
Water requirements and routines are given in more detail here.
Already the relatively dry April and start to May has seen bowling greens suffering from Localised Dry Patch (LDP).
As we have discussed many times on this site before, this condition is a major problem for bowling clubs throughout the UK and if your bowling green is aready showing the tell tale signs then you need to take rapid and relentless action to avoid major disruption to your bowling green surface this season.
Meantime for greens already showing signs of the problem here is my Read more
Localised Dry Patch (LDP) is a condition that causes turf to become hydrophobic (water repellent).
Once LDP has taken hold, irrigation simply causes the unaffected areas to get lusher while the LDP affected areas get drier. This exacerbates the problem making the green increasingly frustrating to play on.
Soil sampling will reveal powder dry soil. Unsightly brown patches of turf start to spread over most of the green. The turf on these areas recedes causing a bumpy surface and in most cases the weakened grass will be taken over by moss. But what can be done to cure the problem?
Research shows that fungi can contribute to the onset of this problem. Fungal mycelium may coat individual soil particles making it impossible for water to adhere to them.
Thatch control and irrigation management are the two most critical factors in the management of this problem.
By the time the problem is visually evident it is already too late to achieve an effective cure. This is because the problem is inherent in the green and usually only becomes visible at the height of the season.
Infrared photo of green showing LDP
Irrigation management requires an understanding of Water Balance in the soil and this is detailed in Performance Bowling Greens. Just look at the infra-red thermographic image on the left, it shows an infrared image of a bowling green. The red areas show the extra heat that is being kicked out by the LDP affected areas, and that is directly related to the lack of moisture retained in the soil in these areas. In the standard photo, the LDP is barely noticeable at this stage, but will get steadily worse.
…but there is still no real sign on the surface
Frequently we are now seeing that areas affected by dry patch disorders have suffered a complete depletion of moisture and that the soil structure has failed, turning to powder. Traditional wetting agents have sought to address dry patch from a very limited viewpoint, namely the reduction of water surface tension making it easier for water to be attracted and held around individual soil particles.
Although Wetting Agents can be used to good effect on LDP once dry patch has progressed to what we call breaking point, no amount of simple surfactant wetting agent will help it re-wet sufficiently to ensure a full recovery of the turf with full grass cover. Typically the manager has to wait for the turf to over-winter before full grass cover is returned.
This makes it all the more critical that we ensure that the products we use are effective in both results and cost.
As LDP is a disorder within the soil it is important to keep one eye on re-wetting and one on re-building the soil’s health. This can best be achieved by ensuring that you use a wetting agent product which can supply carbohydrates to the soil in addition to their soil re-wetting properties. The addition of a high volume of Carbohydrates ensures that the products also contribute to the maintenance of soil structure while helping stressed grass plants hang on to life for longer while the soil is re-wetting.
Excessive use of sand on bowling greens over the years has been the single biggest influence on the occurrence of LDP.
Previously we talked about some of the reasons commonly put forward for not watering bowling greens. I also shared with you, my amusement that so many clubs fail to mention irrigation or lack of it when looking for an explanation for the poor quality or condition of their greens; even though it’s very obvious. They will use just about every other aspect of bowling green maintenance as a reason for poor performance.
Now we come to the cost of irrigation; and I am not talking about the cost of installing a system, but merely the cost of the water being applied on any given night.
This is another big reason or excuse that I hear a lot about:
“we can’t water any more because it costs a fortune”
Now of course there will be variations (slight) around the country and also from system to system, but here is my 10 second rundown on the cost of water for irrigation:
As we saw previously a typical system will put out 1mm of irrigation water for every 2 minutes of system run time.
A typical system will also put out 150 litres per minute; so to calculate the cost per mm of irrigation we do this:
2 (minutes) X 150 (litres) X 4 (sprinkler heads) = 1200 litres/mm
That’s to achieve 1mm over the whole green.
As 1200 litres is 1.2 m3 you simply have to multiply the irrigation requirement in millimetres by your cost per m3 and then by 1.2
Example:
Water balance sheet shows we need to replace 15mm of moisture loss.
Multiply 15 (mm) X 1.2 (m3) X £/m3
1.2 (m3) X £0.90 = £1.08/mm of irrigation over entire green.
I’ve used 90p as an average cost, but you can find your own local charge on your water bill or by phoning the water company.
The question is whether you see irrigation as a cost or an investment in the future of your green.
Bowling green irrigation or watering is often mis-understood and as a result is often managed insufficiently to ensure that the green performs to its highest standards.
The first thing is to make sure of, is that you are applying enough water every week and that means trying as best you can to keep a record of any rainfall and irrigation that is going onto the green.
Making irrigation management a priority in your bowling green maintenance program is crucial because in a typical dry week your green will lose the equivalent of 25mm of moisture through evaporation from the soil and transpiration from the grass plants ; please remember that this varies considerably around the country and will depend on things like temperature, relative humidity, wind speed and direction, precipitation and of course your bowling green maintenance program.
This means that you should be aiming to get at least that amount back on.
In Performance Bowling Greens, a practical guide I go into detail about Soil Moisture Deficit and how to keep a water balance sheet for the most accurate and efficient way to manage irrigation and that is a really good method to use to get this right.
However, bowling green maintenance at the height of the summer relies a lot on feel for the soil as well and although I would always try to maintain a manageable Soil Moisture Deficit to encourage deeper rooting etc, it is more important right now to get on sufficient water to ensure your green plays consistently and to keep localised dry patch under control or hopefully at bay.
This means you should be aiming to get 25mm of water on in any dry week, making allowances for any rainfall you have had by reducing that amount accordingly.
The most common pump and sprinkler set ups for bowling green maintenance from most of the major irrigation manufacturers will put out approximately 1mm of water for each 2 minutes of system run time.
This means that you need to run the system for 2 minutes per head to replace 1mm of water lost. Remember that is “per head”.
So for a 25mm watering you need to run the system for 50 minutes per head during a 7 day period.
The most effective way to do this is to get this water on in as few applications as possible. Try to aim for 25mm over 3 nights. This is much more effective and makes much better use of precious water than 7 light applications where much of the water is lost to evaporation in the morning.
In my Bowling Green Maintenance book: Performance Greens, a practical guide I go into this subject in quite a bit of detail and lay out a plan that you can use to manage irrigation more effectively.
