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The right way to water

Features - 2012 Irrigation Update

Irrigation product suppliers give some tips on how to best apply technologies in the field.

Peter Chakerian | June 14, 2012

Irrigation contractors have a lot of hardware at their disposal – everything from far-reaching rotors, spray heads to more miserly and unassuming dripline systems.

With a robust battery of irrigation controllers, rotary sprinklers, pop-up spray heads, nozzles, bubblers, irrigation valves and more available to contractors, it can be hard to figure out where to begin, let alone which items will maximize your bang for the buck.

All this would be challenging enough if there wasn’t a compliment of 21st century water-saving technologies to couple them with. Below is a round-up of the latest in irrigation technology.


Spray for me. Spray heads are fairly common within the context of an irrigation plan, but outside of watering a range of perennials, ferns, garden greens and beds, they’re also a good way to add moisture to the air and cool off your plants.

The problem with misters (also known in some parts of the country as “foggers”) lies in evaporation – a problem that uses up a critical natural resource and often leaves the very plants they’re watering somewhat parched in the process.

With fairly low precipitation rates and petite diameters for better control, spray heads are best for humidifying and watering of tropical potted planters and baskets, indoors and out.

Jeff Miller, product manager for The Toro Cos.’ irrigation division, says that a lot of that decision-making process on irrigation technology for contractors comes down to the plant material you’re planning to water, and the distance with which the water needs to be thrown.

That is, of course, if moisture needs to be thrown around at all. Contractors also have other options.

“Misters have a limited range and use, but suit that job well,” Miller says.

“Generally, drip irrigation systems are more popular for concentrated watering – they’re very popular – but they are for watering on a larger scale and should be used for shrubs, flowers and anything that has a small, tight watering space of five feet below.”


Dripping below. Rain Bird’s director of corporate marketing, Dave Johnson, adds that subsurface irrigation in a grid design or pattern” is becoming a popular option for public green spaces with turf.

Drip irrigation systems are well-liked for their water conservation talents but also for what Johnson calls “design flexibility” – that ability to adapt to any landscape layout during installation, whether it is above or below grade.

What’s more, watering may take place during prime use hours without much notice being taken by users.

Miller and Johnson add that for the vast majority of landscaping contractors, traditional pop-up spray heads (regular spray heads and rotors) are probably the most universal for watering turf.


The ever-popular pop-up. “There are ranges to all of them. After you get to a certain point with them, with some crossover past 15 feet, you would want to move to a pop-up spray head that would throw a quarter, half or full circle further,” Miller says, adding that larger spaces “generally require products with rotating nozzles” to be effective.

Fixed spray heads generally spray in a fan-shaped pattern (think your bathroom shower head) with small heads, while rotors tend to provide better coverage with rotating streams of water.

Many of the former use “interchangeable nozzles,” while the latter have a multitude of different steams, arcs and patterns.

“We have one with an adjustable arc, which offers multi-stream, multi-trajectory patterns,” Miller says, adding that each manufacturer creates these differently, “with outflow of as many as 21 different water streams at once.”

When it comes to irrigation technology, Miller also sees a big picture scenario which identifies the whole as greater than the sum of its parts. “But when you need range accompanied by specialized watering technique … a whole arsenal is necessary if you’re truly serious about irrigation.”


Green thumb technology. Johnson and Miller also agree on electronic technology for irrigation for larger, more complex jobs where everything from proper watering variations to conservation are taken into account.

“Having several components on a site, pulled together with the underground plumbing and a smart irrigation controller to turn things on and off really is the future we’re headed towards,” Johnson says. In the past, a closed control loop operation identified a watering strategy on timing.

Today, much more detailed decisions about when to apply water and how much water to apply are handled by controllers supported by weather stations connections (with data powered on-site or by uplink) and moisture sensors.

“There really is no need for turning things on and off in that traditional sense anymore,” Johnson says.

“The underground plumbing and valves are told by (the technology) when watering is necessary. And that takes a lot of the guesswork out of what would normally be determined by a person.”

Smart controllers can obtain up-to-the-minute weather data, including critical humidity and precipitation information – all of which helps the controller set up its own watering system.


Outside the box. Being green and the motto “make every day Earth Day” have permeated most peoples’ thinking when it comes to their line of work – and it’s no different with landscape contractors.

Outside of new electronics and the three watering technologies mentioned, clients and contractors alike are considering new green spaces and uses for the tools to help them stay that way.

“I think some people are thinking about green roofs now,” says Miller, “where top-of-building plantings help keep the energy costs of a building down.
 

Get the facts on three types of watering technologies.

ROTORS
Range of dispersal: Rotors usually work best at 25-35 feet.

Angle of spray: Varies based on product, though generally rotors are adjustable within an arc between 40 and 360 degrees. Above or below those levels could cause the assembly to inadequately operate.

Plant materials suited for: Rotors are best suited for turf and some generalized plant bed watering applications, depending on their composition.

Distance and size of area covered: Areas that are between 15-28 feet wide are ideal places for rotary sprays, and can, depending on the product, effectively water areas that are up 30 x 25 feet in size.


SPRAY HEADS
Range of dispersal:
Spray heads can deliver a lot of water to a very small area quickly, but the finely atomized water is subject to drift and evaporation. Application rates can vary widely, from 0.05 inches/hour up to 6 inches/hour.

Angle of spray: Depending on the product, angle of spray can range from 80-110 degrees.

Plant materials suited for: Flower beds are among the most sought uses for misters, but care with them is important. Overwatering foliage with them can lead to black spots, fungal diseases and powdery mildew occurrence. Some micro-sized spray heads are even good for containers, while others are sought for greenhouse applications as well.

Distance and size of areas covered: Diameters of up to 4 feet.


DRIPLINE
Range of dispersal:
Varies. Most dripline products have a dripper line with 6- 24 inches on emitter spacings, in lengths of up to 1,000 feet. Analysis of the location would be necessary to determine how much ground (literally) the dripline would need to cover.

Angle of spray: Below-ground lines drip down, leaching a slow trickle into the root system. Above ground lines spray up and out.

Plant materials suited for: Most below-ground dripline irrigation systems are used in turf applications, while above ground lines and some drip tapes are used in beds and row plantings.

Distance and area covered: Varies depending on length and installation.

 

“Those might benefit from larger rotary heads with smart technology to help redistribute that collected rain water and gray water.”

He says that “generally (contractors) are using irrigation technology for the intended traditional applications” but that there’s “potential for an upsurge” in future use for drip and sprinkler head technology in that regard, especially when paired with a smart controller, in markets where rainfall can be minimal.

Johnson says that he’s sees a lot of “green walls” and shallow plantings on walls being used for cooling and other effects.

In addition, smart irrigation options can make some sense for those as well – and will only continue to be a smarter option as the technology gets, well, smarter. And some of it doesn’t even need to be smart,” Johnson says.

“It can be (not smart,) if it makes sense for the growing area, because the efficiency of technologies like drip irrigation is already safe, environmentally friendly and viable for low volume applications of water.

“With all the options available for gray water usage – that non-potable, yet really clean water like sink and dish water – we’re likely to see an increase in usage in say the next five years. Here in Tuscon, any new house has to be plumbed for collection of gray water, which is an indicator that pretty soon gray water is going to be a much more viable source of water for irrigation. There’s little doubt that trend will continue.”

 


The author is a freelance writer in Bay Village, Ohio.


For more on irrigation technology, as well as videos explaining the latest products in the world of irrigation visit www.lawnandlandscape.com and search “irrigation.”