Irrigation faces numerous challenges; from new tougher regulations and climate change to public pressures for greater accountability and environmental sustainability, any way to re-use, recycle and utilise water is good news, says Toro distributor Reesink Turfcare's irrigation manager, Robert Jackson
Optimised efficiency in water usage is one of the greatest challenges in the sustainability of sport surfaces. Therefore, optimising water consumption by increasing usage efficiency and utilising innovative technologies needs to be high up on the agendas of greenkeepers and groundsmen.
Estimates vary but, according to the US Geological Survey's Water Science School, about seventy percent of all the world's freshwater withdrawals go towards irrigation use and only half of that is reusable. The rest is lost through evaporation into the air, evapotranspiration from plants or is lost in transit by a leaking pipe, for example. Compared to the ninety percent of water for domestic and industrial use that can be used again, it is clear to see why it's so important golf and sports venues, landscaping, green spaces and other amenities look at ways of managing water use.
Essentially, this is a two-pronged attack. It starts with the level to which irrigation is applied. That is a skill and one that can be greatly assisted by technology.
Every green, fairway, sports pitch, training ground or estate parkland is different and trying to measure these differences and come up with a 'one size fits all' irrigation solution will rarely be successful. It's critical that applied water is fully utilised by the sward with minimal wastage, therefore delivery of the water and its penetration is vital - how much or how little should be applied?
It sounds obvious, but basically we should only apply the amount needed. Applying the right amount on fewer occasions is far more effective for maintaining moisture levels. This allows the water to get deeper into the soil, encourages deeper root growth and will help reduce the amount lost due to evaporation and transpiration of the grass. Timing is important, too, and water should be applied in the late evening or overnight to prevent immediate water loss through evaporation in the sun, allowing more to be absorbed deeper into the soil.
Golf courses and sports venues tend to get lots of attention when it comes to water-saving efforts, especially during prolonged spells of warm weather. However, in general, many sites in the UK are already great examples of efficient water use and later I provide two examples where a golf course and rugby club are doing this well.
Efficient water application involves inside knowledge and a good level of up to date technology. Knowing how well your current irrigation system is performing is essential; as I've said in previous articles, it all starts here. It goes without saying that using the latest irrigation technology and innovation enables turfcare professionals to significantly cut their water use and maintain optimal playing conditions. Having an old system can mean water losses of up to twenty-five percent which, long-term, is simply not financially acceptable or sustainable. A thorough check of your irrigation system is a process that should be carried out every five years or so, to see what's in place, how it's performing and if improvements can be made to save money and resources.
Having a fully functional control system will ensure only the required amount of water is applied, whilst the information that can be taken from a soil monitoring system will also cut back on over-watering. Modern sprinklers have become key contributors to water use reduction. As irrigation control systems have advanced over the years, so have the sprinklers they control. Use sprinklers that have nozzle options and adjustment capabilities to apply water precisely where it is needed. By simply upgrading older sprinklers to today's models, it will significantly reduce water use, without affecting play.
Irrigation application is not just about pressing the button on the automatic system though, no matter how good the system is; for that, nothing beats the knowledge of the man working the turf, whether that's the greenkeeper, groundsman, grounds manager, gardener, landscaper or estate manager.
Turfcare professionals are best placed to know when to employ maintenance practices such as aeration and spiking, vital to ensure the water can penetrate the ground, and checking compaction; all of which contribute to ensuring optimum penetration and being efficient with water usage.
They are also best placed to check equipment is leak, blockage and scale free, to check uniformity of the sprinkler radius, and look out for signs of water hydrophobicity, which is common on dried-out sandy or thatch soils. Plus, they can advise on the best mix of grass to use, considering finish and quality with drought-resistance.
Step two is diversifying away from the mains water supply through the use of abstracted surface and groundwater and rainwater harvesting. Like it or not, we will eventually reach a cut-off point when the water companies say 'no more'. At that point, those clubs that have been storing water will be at a distinct advantage; they'll be partly sustainable and have a head start.
Water management covers lakes, reservoirs, ponds, water courses and boreholes. It is possible to extract up to 20m2 a day from a watercourse or borehole without a licence, and working with the Environmental Agency will bring plenty more options on how to extract water, create a water resource or alter the existing banks of a watercourse to make it usable.
A great case in hand of this is Oxfordshire's Frilford Heath Golf Club and its 6m, 10 million gallon reservoir.
In an effort to become sustainable, Head Greenkeeper Sid Arrowsmith wanted to use the reservoir water to irrigate the course but, because the water is piped from a brook downstream through farming fields, it brings pollutants such as waste and silt with it and the water started to smell, turn black in colour and was simply too unhealthy to apply to turf.
Working closely with the Environmental Agency, Sid had a diffused aeration system installed to pump air to the bed of the reservoir, releasing oxygen and creating mass circulation to the bottom and top water layers. This process allows the aerobic bacteria to metabolise the nutrients and, within twelve weeks, he had water ready to use.
This is a fantastic situation to be in; within three months, Sid and the club were a massive step closer to becoming self-sufficient with the reservoir holding good quality water, ready to use.
I'm often making recommendations of professionals, such as independent irrigation consultants and geologists, directing clubs to the best people to talk about their irrigation concerns or plans and helping them start the process to achieve a good level of water sustainability. As mentioned, Sid worked closely with the Environmental Agency throughout this process and I know he found that to be a great benefit.
Football and rugby clubs are, of course, more limited with regards to the options available to them in terms of water sustainability, simply down to the lack of space and the fact that they are usually situated in urban areas - not many have a ten million gallon reservoir at their disposal, or the space to create one! But there are ways.
Leeds Rhinos, for example, has plans to put in place water holding tanks underneath the stands to harvest water from the stand roofs. Head Groundsman Ryan Golding says the surface area there will collect a good amount of water to reuse.
Similarly to Sid, the important thing for Ryan will be ensuring the water is thoroughly cleaned as, in order for the collected water to be used for pitch irrigation, the salt content of the water, which can be high in rainwater, will have to be low enough to not damage and depreciate the club's irrigation system. Ryan will test the nutritional value of the water every four weeks and, from the results, will be able to decide whether to irrigate the pitch or use it in the washrooms and showers.
Three years ago, Leeds Rhinos invested in a new irrigation system, believing the benefits of having a high spec irrigation system could contribute towards water sustainability, save money and improve grass-growing conditions. Ryan says the efficient head-to-head sprinklers, soil sensing equipment, weather station system and integrated pump stations they opted for have had a big impact on how much water they use and on the club's bottom line - water off the mains is not cheap and it's sensible, not only for the environment but also your budget, to use the resource effectively.
Interesting stats on water usage in the world of cricket were identified in the Sport England Sustainable Cricket Project, which highlighted that eighty-four percent of clubs use mains water for irrigation and that a typical twenty minute watering during pitch preparation uses 500-800l (0.5-0.8m3) of water. With water rates changing every three months, as they do, it's easy to see why, for budgetary planning purposes, it would be a great help to know water usage and spend can be controlled to a degree by the club itself, just like Leeds Rhinos is planning.
If I had just one minute with you on this subject, I would stress the importance of how the simple fact of reducing water consumption will bring long-term benefits, and how reducing run-off and selecting drought-tolerant grasses are all steps in the right direction. Because, the fact is, water costs will rise and tighter regulations on usage will become more of an issue. Acting decisively now will bring long-term cost savings and prepare you well for achieving full sustainability - a head start you might be grateful for!
For a chat with Robert about your irrigation needs, call him on 07776 187243
A diffused aeration system provides a calm and serene water surface (right) thanks to quiet onshore compressors which pump air to diffusers on the lake or pond bed. The diffusers release oxygen, creating mass circulation to the bottom and top water layers without affecting the water's surface. This creates a perfect water feature for the golfing environment where peace and tranquillity is important to players.
What is hydrophobic soil?
Soil that is hydrophobic causes water to collect on the soil's surface rather than infiltrating into the ground. Soil hydrophobicity is thought to be caused primarily by a coating of long-chained hydrophobic organic molecules on individual soil particles. These substances may be released from a range of plants, decaying organic matter, soil fauna and microorganisms and last from as little as a few seconds to in excess of weeks. Hydrophobicity is often most prominent after prolonged dry spells and usually disappears after prolonged contact with water.
What is evapotranspiration?
Evapotranspiration is the sum of evaporation and plant transpiration from the earth's land and ocean surface to the atmosphere. It is an important part of the water cycle, bringing significant water losses from drainage basins. Types of vegetation and land use significantly affect evapotranspiration and the amount of water leaving a drainage basin.
Fine turf is dominated by two fine-leaved, slow-growing, deep-rooted, drought resistant grasses namely festuca rubra and the bents (agrostis). Whereas, for amenity turf, mixing up some tall and tufted fescues (festuca arundinacea) with some dwarf ryegrass will tolerate long periods of drought thanks to a deep (up to five feet) root system.