0 Irrigation 2010 and beyond...

Irrigation-JohnDeere1.jpgWater Management in uncertain times. Budgets stretched to breaking point. The spectre of climate change. The developing culture of retrospective blame; that degree in foresight you put off doing when you were in your 20s might have been a good idea.

One thing, however, is one hundred percent certain - water is essential for plant survival. I use the term survival, and not growth, intentionally. As we are not farmers, we do not look for yield in our grass harvest, but a delicate balance between growth and playing quality. Over 90% of plant tissue is made up from the life giving liquid. It also contributes to cooling the plant, keeping it turgid, and acts as a vital transport system for nutrients and chemicals around the plant.
It is my endeavour, in this article, to look at 'water conservation and usage in the future' in the short, medium and long term.

In the short term, follow the principles of 'Best Practice' and the development of exemplary cultural practices. Perhaps, you might say, it is not within my remit to discuss cultural operations, but I would be failing in my duty if I were not to mention such considerations.

It goes without saying that aeration is, arguably, top of the list. Deep aeration, by whatever means, will increase the root biomass, encourage deep rooting and present the sward with a greater opportunity to search for available water. Surface aeration, on the other hand, and the constant strive to control thatch, will encourage greater infiltration and allow vital dew to penetrate the rootzone before it is burned off and evaporated as the sun rises. The use of wetting agents and the benefits of switching will assist in the harvest of this small, but vital, free supply of water.

Raising the height of cut, and even leaving the clippings on certain playing surfaces to act as mulch, will play yet another small but significant part in moisture conservation, but this may not sit too well with some of the membership, whilst clean sharp cylinders will minimise leaf wounding.

Irrigation-JohnDeere2.jpgThe use of growth regulating chemicals are now increasingly common in turf management regimes, reducing the internodal length of grasses, producing denser swards and greater root biomass; seaweed extracts and soil ameliorants playing their part in the general awareness of rootzone quality. Gone are the days when quantities of unmentionable chemicals raped the soil fauna and microorganisms, leaving the rootzone inert.

Changing and influencing the composition of the sward, towards a greater tolerance to drought and salt, could be achieved by gradual over-seeding with new and developing cultivars.

A look at all these factors, and more, can have a small, but significant, influence on the conservation of water supplies.

Turning our attention to the application of water and the irrigation system itself. Much can still be achieved by checking the system thoroughly during the off, or at the start of, the season.

Do the pop-up sprinklers actually pop-up, are they rotating, have any been damaged by winter aeration procedures, is the spacing of the sprinkler heads correct, are the arcs set correctly, and do the pop-ups have the correct nozzles to provide adequate head to head coverage? Simple measures, but you would be amazed how often these common problems occur.

Poor spacing of sprinkler heads is, perhaps, the commonest problem. Without head to head contact, accurate distribution of water is not possible. Poor spacing may be the fault of the initial installation or may be the fact that the green shape has changed over time.

Arc settings should be studied and checked annually, as should the actual water pressure at the sprinkler heads. This information can lead to the discovery of leaks within the system or the change of nozzles to achieve the desired outcome.

When the system is a block design, as experienced often with the traditional design of tees and greens, then each pair of sprinklers will deliver water for the same length of time. Where there has been an on-site modification to allow, for example, aprons to be irrigated, both sprinkler arcs must be the same for, if one is full circle and the other part circle, the full circle will be delivering 50% less water than the part circle, per unit area, in any given time.

Irrigation-TyrrellsWood2.jpgIn the medium term, and each of the rather arbitrary terms will overlap, we must look at 'Education and Training'. As irrigation is often said to be 'out of sight and out of mind', at least one member of staff should be fully trained in its management. After all, a new system will possibly be the most costly piece of maintenance equipment in which a club will invest.

When a new system is installed, ensure a full training course is offered on the operation and management of the hardware. This is essential as, so often, the system is set up in the way it was on the first day, with little regard for current environmental conditions. Trained staff should be able to calculate sprinkler precipitation rates and run times to coincide with the desired application rate, and operate the system to its full potential.

But, it is not just the greenstaff who should appreciate the need for knowledge regarding the use of water. The membership of the club should also be aware of the dangers of over irrigating. With the intervention of CAMS (Catchment Abstraction Management Strategies) and the Water Framework Directive, water usage in the future is fast becoming a political issue, and indiscriminative water usage will be a thing of the past.

Water and irrigation audits, and the justification for the continued use of potable water, will become yet another chore for the Course Manager. Proper accountability, the maintenance of detailed records of water usage, and the justification for that usage, is unquestionably on the way.

In the long term, modern technology must be employed to save the day. Club committees should decide on which areas of the golf course are to be irrigated - modern design can be area specific, whether that be simply tees and green or to encompass fairways, approaches and walkways.

Irrigation-Sprinkler-head.jpgGood design, using sprinkler densograms for example, can save water and take into account the need for the conservation of the peripheral landscape. It may not be necessary to sell off the family silver to plan and put into operation a new irrigation system. Provided the overall plan is discussed and approved by all concerned, the grand plan should incorporate all future requirements. A phased development can then be put into operation, for example, installing initially greens and tees but with adequate pipework, cabling infrastructure and pumping capacity to allow for future expansion to encompass aprons, fairways and walkways.

Balancing the infiltration rate with the sprinkler precipitation/application rate and the incorporation of a correctly positioned weather station and soil moisture sensors, along with traditional ways of observing soil moisture deficit, can be demonstrated to be effective in managing water, some estimates suggesting as much as a 20% saving.

However, we should also take into consideration, when planning and designing any system, the complex issues of water resourcing. On the Continent, some countries are already restricting the annual quantity of water which it is permissible to use. In Denmark, for instance, some courses are restricted to as little as 5,000m3 per year.

Borehole usage will be, and in many areas already is, controlled under the local CAMS, and restrictions may apply in the future. Water collection and the provision of water storage facilities will be essential in future planning and, depending upon the quantities of water required, continued use of potable water from the public water system will undoubtedly, at the very least, become prohibitively expensive, if not denied.

Climate change is another complex issue. Speculation varies widely. However, over the past few years, few will disagree that the pattern of our climate has tended to be more extreme, in particular heavier, but less frequent rainfall.

We must look to the long term to secure our water resourcing and install some form of water storage facility. For a relatively simple green and tees system in the UK, a storage capacity of some 10,000-15,000m3 should be adequate but, if expansion is planned for the future, then 25,000-40,000m3 may be required.

We also need to explore the sourcing of that water. Water farming and collection of water from the golf course, via drainage and hard standing areas, such as car parks, should be considered. Recycling non-soiled clubhouse water through reed beds and ultra violet filters is another option. Winter abstraction from boreholes, rivers and streams is yet another possibility. This really is long term planning and to discuss it should not be deferred. Remember that degree in foresight I spoke of earlier.

On a global scale, away from the needs of the golf course, water resourcing, or the lack of it, is a very real issue which has already led to inter-border issues and violence; it yet may be a far bigger problem than oil.

In conclusion. Yes, there are some relatively simple measures which can be implemented to conserve water and improve our irrigation procedures, but there are also some difficult choices ahead.

STRI Irrigation Services are available to help in many of the areas covered in this article, from irrigation system audits and feasibility studies for a new irrigation system, through to detailed irrigation design and the production of scaled plans and tender documentation (specifications and bills of quantities). For further information please contact Helen Waite on 01274 518918, email helen.waite@stri.co.uk or visit www.stri.co.uk

Images © John Deere Ltd

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