Irrigation

Squeeze every last drop

Climatologists are suggesting that hot summers are to become an annual event, so good practice is needed across the irrigation industry to adapt to the changing climate suggests Peter Longman of Rain Bird Europe

With the 2022 heatwaves and meteorologists suggesting that such events may well occur annually, the irrigation industry needs to adapt to the changing climate. This applies both to those whose job it is to keep landscapes

Peter Longman and gardens in prime condition, whatever the weather, as well as the manufacturers of irrigation products. With efficient and improved irrigation technology and practices, plants, shrubs, trees and landscapes can be kept healthy while also reducing water consumption by as much as 25 per cent.

Generally, a landscaped area needs to receive approximately 25 millimetres of rainfall per week to thrive. Therefore any irrigation that is in use needs to provide or make up to this amount of water during drought or drier spells. During wetter periods, when there is a risk of overwatering, irrigation should not be used so much or at all. Yet it is not unusual for landscapes to receive twice as much water as needed and therefore result in unnecessary wastage.

Efficient irrigation

Manual irrigation of course makes it more difficult to be precise in the amount of water that is applied by any form of sprinkler or rotary spray and in this respect, investment in an automatic irrigation system will bring much closer control over water application. Different types of emitter apply water at different rates, so it is essential to know the precipitation rates of the products being used in order to apply close to the correct amount of water to maintain the health of the landscape.

For example, a rotary spray head nozzle with a typical precipitation rate of 16mm/hour would need to be in operation for approximately 1.5 hours per week within a given irrigation zone to achieve and match the required 25 mm of precipitation. Information is readily available for all modern irrigation products to assist users in making these calculations.

The most important element of good irrigation practice is to follow the principle that irrigation should only be carried out when and where it is needed. Over or underwatering simply does not use water to maximum efficiency and also results in barren or saturated landscapes.

It is wiser to spray irrigate during the morning or evening to help prevent water evaporation during the warmer hours of the day and when wind drift can cause water to be wasted as it fails to hit the target zone. Pressure regulating sprays and rotors combined with thick streamed nozzles, such as R-VAN, can help reduce the effects, keeping water where it is needed. Using sprays and rotors with matched precipitation rates are available and designed to be used together in the same zone.

Drip irrigation

Drip irrigation, on the other hand, presents none of these issues. Well mulched beds help drainage, encourage root development and improve the soil. Combined with surface dripline irrigation, or by using sub-surface dripline, this will ensure plants and shrubs receive the correct amount of moisture exactly where it is needed – around the plant and at root areas. Furthermore, this highly efficient form of irrigation can be applied throughout the day.

There is additional information that can be used to make irrigation more effective during hotter weather. Various types of soil have differing rates of water intake and hold moisture for varying amounts of time. This will influence the precipitation rate and choice of irrigation product. Different varieties of plants will have different watering requirements. Therefore

Dripline with valve technology eliminates low point drainage.

dividing a landscape into separate zones so that ground cover, shrubs and trees can be watered separately and less frequently is worth considering during the planning stage.

Whilst automatic irrigation systems will not suit everyone, their primary aim is to help ensure that water is used as efficiently as possible, squeezing out every last drop, and this will become an increasigly important consideration in hotter summers. Irrigation schedules can be set automatically in accordance with real-time and predicted weather conditions. With a weather station based system, a smart controller that can use Wifi will automatically adjust a watering schedule and prevent under or over watering by taking into account current and predicted weather. Additional rain sensors provide a physical switch off of the irrigation system.

Real time irrigation

On-going evaluation of an irrigation system's performance is also essential and an automatic irrigation controller will monitor continuously and use real-time alerts to indicate problems. Small leaks in a system which may be caused by animals, garden tools or just general wear and tear can go unnoticed and result in wastage. However, a Flow Meter, such as the latest FG 100, will spot any changes in waterflow, send an alert to the controller or user's mobile device and remedial action can be taken.

Manufacturers are more aware than ever of the need for water conservation and the impact of our changing weather patterns. This has resulted in the introduction of simple yet innovative technology that the landscaping industry can use now to help achieve its own water efficiency goals. For example, users can now specify dripline irrigation with check valves which retain water within the system, whether within a flat or sloped landscape, prevent run-off, pooling and wastage so that the system does not have to be recharged before the following day's irrigation cycle.

If water pressure is high when using spray heads to deliver water across an irrigation zone, the result is misting, wastage and inefficiency. Spray heads with Pressure Regulating Stems and Spray Heads (PRS) on the other hand, which are available now, feature built-in pressure regulation to reduce excess water pressure, manage nozzle water flow, droplet size control and maximise performance.

There is no question that hot summers, drought conditions and more frequent hose pipe bans will set unprecedented challenges not just for irrigation but for society as a whole. Water is the most precious resource and everyone in the irrigation industry and beyond has a role to play in its conservation. Good management and maintenance practice combined with the continuing development of innovative irrigation technology can make a major contribution to the preservation of our landscapes.

ESP- LXIVM irrigation controller provides real-time, highly efficient irrigation with immediate diagnostic feedback.

Green-tech provides irrigation bags for Kensington roof terrace

Hunter is first-class for Bromley CC

127 Kensington High Street was once the site of the original, highly regarded Pontings department store. Demolished in the 1970s, the store was replaced with two office blocks. Later, to provide much improved mixed-use space, these structures were part removed leaving 30% remaining, and added to with extended areas and an additional two floors, as well as three levels of outdoor terracing.

The £53M project will finally provide primarily commercial space, with retail space on the ground floor and basement, as well as a new arcade entrance to Kensington High Street underground station. It has an environmental BREEAM rating target of excellent.

The western side has been realigned to recreate the original street line of Wrights Lane, and the upper levels have been set back to create three terraces offering much needed outdoor amenity space. Green-tech were contacted by Elite Landscapes Ltd working on the development to quote for the tree planting in soft beds on the terraces, including anchoring systems, underground root ball irrigation and for the larger trees, slow-release tree irrigator bags. Green-tech launched the tree irrigator bag in 2020 in response to Tree irrigator bags requests for a surface fed but slowrelease irrigation system. When using direct irrigation, either from above or using perforated rings around the rootball, there is always the risk of

Artists impression of the terraces at 127 Kensington High Street. significant water wastage, whereby a lot of the water soaks straight down to the subsoil when delivered in one go, bypassing the root system that needs it.

Made from green PVC mesh cloth, with a permeable membrane in the base, the tree irrigator bag can hold up to 60 litres in a single bag (95 when doubled up), which it slowly releases over a period of 5-9 hours depending on the conditions. It is very easy to fit post-planting, and simply wraps around the tree trunk and is zipped up, then filled via a filler opening at the neck.

On open terraces where the beds are exposed to the effects of high winds, the bags also help by keeping the soil surface around the rootball covered, which prevents drying out.

“We have worked with Elite for many years, and it is always nice to help out on such prestigious projects. The tree irrigators are a fantastic addition to our irrigation offering, and they will help the newly planted trees establish quickly and make keeping them well-watered an easy task,” says Mark Browne, Green-tech key account manager.

Bromley Cricket Club recently raised enough funds to purchase a much-needed new Hunter Irrigation system from KAR UK.

Founded in 1820, Bromley Cricket Club is one of the leading cricket clubs in Kent, with a long, successful, and proud tradition. As well as boasting four senior sides, the club is focused on promoting youth cricket and has approximately 500 youth players ranging from 4 – 18 years old.

As you can imagine, a lot of cricket is played at the club’s ground and David Wilson, cricket committee member and director of the main sports club, explained exactly why an irrigation system was needed.

“We have a very low, shallow, subbase of soil. The consequence of that is in particularly hot periods without any rain, the pitch would turn into a desert. It would turn to straw, become very hard and any undulations would become quite dangerous.

“Rainfall is becoming less and less reliable,” continues David. “We felt that we were getting to a point where a period of say six weeks would make the outfield non-playable.”

Bromley Cricket club commissioned a topographical survey and a feasibility study, which stressed the importance of an irrigation system. The board began to raise funds in various ways, and it eventually reached its target at Bromley Cricket Club’s bi-centenary dinner celebrations which took place at The Oval.

The project went to tender, and Prime Irrigation was selected as the chosen contractor to install a Hunter

Irrigation system from KAR UK. The system included 25 of the most technologically advanced commercial rotors on the market – the I-80’s.

Engineered for sports turf, the I-80 is built with a robust, dirt-tolerant gear drive that offers the highest torque output of any rotor in the commercial sphere, and extends a radius range from 11.3 to 29.6 meters. The I-80 features a wide range of highly efficient, dual-trajectory, wind-fighting nozzles for highly efficient performance in a range of applications. It also provides total top serviceability (TTS) via its integrated, surfacemounted snap-ring for no-dig easy maintenance.

The I-80’s were installed strategically around the outfield while 6 TTS-885’s were installed on the square.

The Hunter TTS-800 rotors provide maximum uniformity and longevity as they use the same gear drive and nozzles as the I-80’s. The high-torque gear drives are the strongest in the industry, so the challenges of reclaimed water use or poor water quality are mitigated. An extra-large, fastaccess flange compartment comfortably accommodates wire connections and other components.

Bromley Cricket Club also purchased the Roam remote which means operators never have to walk back and forth to stop and start irrigation. Furthermore, the club will soon be benefiting from the mobile-friendly Centralus irrigation management platform. This provides highly secure, comprehensive cloud-based control and monitoring features which allows users to view a controller’s status, change settings, view forecasts, save Bromley Cricket Club raises funds to water, and receive purchase a Hunter Irrigation system instant notification from KAR UK. of important system alarms — all without costly and time-consuming travel and site visits.

“I like the fact that Trevor, our groundsman, will soon be able to wake up in the morning, if needed, and operate the system from his phone all the way from his house in Whitstable!” adds David.

Commenting on the project, Alan Williams, sales director for Prime Irrigation, says: “It has been great to be a part of this project and the system is going to make a big difference. The Roam remote is incredibly easy to use, and the operator can select various programmes; they now have the flexibility to water certain areas and can have different run times.

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