Irrigation boot camp

How to stretch every last drop of irrigation water is a topic nearly all superintendents wrestle with in some fashion. Drought and restrictions, escalating costs, and a public sensitive to how water is being used around them are all factors coming into play throughout the golf industry.

As superintendents, you’re not only being asked to maintain a certain level of playing conditions at your facility, but many times you’re forced to do it with water limitations.

Distribution uniformity is an important part of the overall equation. Here’s a bit of irrigation boot camp to help you use water and your system most efficiently.
 

An H, two OS and what else?

The first step to proper water management is making sure you’re familiar with the water and all the tools you have.

“Know what your water is,” says Erik Christiansen, president of EC Design Group. “Sample it at least once a year, in some areas, twice.”

Many factors can impact how the water affects turf growth. If the pH is off or the salinity is high, your turf is going to be affected. Your system may be working perfectly, but the water could be causing problems.

“The majority of superintendents are on top of this, but it is so important it has to be at the top of the list,” Christiansen says,
 

Maintain what you have

You’ve tested the water, made the necessary adjustments and know what you are working with. Now review and maintain your system.

Are all components working properly? Make sure all heads are level and set to their optimum height. Machinery and top dressing can tilt heads or cause them to be too deep. Tilted or too deep heads are not going to distribute the water uniformly. Make sure the heads are spaced properly, the pressures are correct and any pressure regulators are working as designed. Check if the flow meter in your pump station is calibrated.

“You can’t manage your water if you don’t measure your water,” says Brian Vinchesi, design engineer, Irrigation Consulting. He recommends testing flow meters at least once every two to three years. Some states require annual testing and some require no testing at all.

Lastly, make sure your computer system is up-to-date with what you’re using in the field. Did you add a head in a dry spot, but not put it into the computer? Did you change out a full circle head to a part circle due to a change in the landscape? Did you add new components that will affect the overall operation?

If your computer and the components in the field are not current with each other, you are not going to get accurate data. And without accurate data, it is impossible to know if you are using too much or too little water.

If a weather station is a part of your system, check it at least every four or five years to make sure it is working accurately. Update as needed, and collect accurate data.

If you do not have a weather station, consider adding one. They can be used to automatically turn water off due to rain events. They can also turn irrigation off if wind conditions are at a level that too much water is wasted when water is run at those times.

If you know what you have and know if it is working as designed you can then determine if adjustments need to be made to use water more efficiently.

Vinchesi suggests having an irrigation technician or someone dedicated to irrigation. “One person dedicated to irrigation can provide preventative rather than reactive solutions,” he says. “That is not only good for the course, but for the irrigation system.”
 

Audits and other tests

Now you need to see how the water is being distributed. Is it hitting the areas you want hit? Are you watering areas that no longer need it? Is your system putting out the amount of water you want over the areas you want covered? Is the water distributed uniformly over the area? Distribution uniformity is a measure of irrigation efficiency defined as the ratio of dry areas to average areas. The best way to determine your distribution uniformity is to perform a water audit.

“Some level of audit is important, otherwise you are guessing,” says Dr. Grady Miller, professor of crop science at North Carolina State University. “Do an audit to get a baseline.”

While you may have been watering the greens for 20 minutes each, you may find through an audit that some greens need 22 or 23 minutes and others need only 18 or 19 minutes. You need to know the amount of water for optimum turf growth, but any irrigation beyond that amount is a cost you don’t want. While you may not want to do it during your prime season, you can gradually cut back your runtimes to find your minimum.
 

Options to auditing

You can do the auditing yourself. Courses are available from The Irrigation Association and the GCSAA. There are also numerous online articles that provide the details. If you can’t audit the whole course, start with three greens. Audit your best green, your worst green and an average green. Then work with the averages for your overall schedule. At the very least, start with the worst areas and determine how the water is being distributed and what is needed to obtain the best efficiency.

If you don’t have the time or inclination to perform the audit in-house and if you can budget for it, there are experienced irrigation consultants who are registered to perform audits to get the most efficient performance from your system.

Distribution uniformity is especially critical if you are using fertigation or applying other products through your irrigation system. It is not the only important factor. He recently completed research and is in the process of publishing the paper on the results. “The nature of the soil and the canopy will affect the water distribution as much as the irrigation distribution affects water availability,” Miller says.

Moisture meters and sensors are excellent tools to determine how the moisture is being distributed in the soil. While soil probes have been used for years and many superintendents are very proficient at pulling a core and feeling the soil, they don’t provide reference numbers. It’s difficult to convey how much an area should be watered based on how the soil feels.

Entry-level analog meters cost around $375. Digital meters start at around $600 and adjust to soil types. For $1,100 you can get a long-handled meter with dual handles that adjusts for soil types, but also can be connected to a GPS receiver stores 3,200 readings, and is compatible with online web-mapping software. Probes of different lengths provide readings at the depth you need. These meters offer real-time accurate measurements of what moisture is present in the soil.

Collect readings before and after watering to determine if what you are putting down is adequate. John Mascaro of Turf-Tec Technology recommends to use the irrigation system to saturate an area and get your wet reading. Go to another area that needs watering to obtain your dry reading. Then you can determine how much water you need to apply to get to the best range between the two. Stationary soil moisture sensors are another great tool that can help you make decisions.

There are all kinds tools, including handheld radios and smart phone apps to manually run your system as you visually observe specific areas. None of these are going to give you the results you really need without knowing what you have, maintaining it properly, and auditing your system to measure what it is doing. Apply just the amount of water you need, in the needed areas, to prevent damage to your turf and overuse of water.

Steve Trusty is a writer based in Council Bluffs, Iowa, and is a frequent GCI contributor.