Next Stop Long Beach: Previewing Irrigation Show 2018

By Michael Gutierrez

The irrigation industry is gathering next week in Long Beach, CA, for the 2018 Irrigation Show and Education Conference. Easily the largest industry event of the calendar year, the Irrigation Show features trainings and certification exams, technical programs presenting new research in both landscape and agricultural irrigation, and a massive product expo showcasing the latest wares from new and established manufacturers.

Gators Presente

UF-ABE will be present at Irrigation Show 2018. Tuesday morning’s technical program includes two presentations from the Dukes research team’s Bernard Cardenas. “The rain sensor study compares field results of rain sensor performance to modeled results of turfgrass dry out and reinforces the results from our experiments across simulated different soil types,” said Dr. Michael Dukes. The other talk is an update on the long-running work studying smart irrigation technology in residential sites in Orange County, FL.

E3

Another exciting aspect of the Irrigation Show is the annual Irrigation E3 Program. E3 invites students from across the country for a week of exposure, experience and education at the event. 2018 includes students from 19 schools in 14 different states! Two UF Horticulture Science graduate students will be making the journey to Long Beach. Watch this space from more about their show experience, and if you see an E3 learner in the crowd during show week do say hello.

Exam Week

Since the focus of my work has shifted from research to practice this year, the Irrigation Show is more relevant than ever for me. I’ll be there next week excited to see familiar faces and learn about new products. I’ll also be taking me first ever certification exam. If you are attending Irrigation Show 2018 make sure to get on Twitter and add your POV using the #irrigationshow tag. You'll find me there as well. See you in Long Beach!

Third Time's a Charm: An Urban Landscape Summit Report Back

By Michael Gutierrez

March 2018 marked year number three for the UF/IFAS Center for Landscape Conservation and Ecology Urban Landscape Summit. Arguably the best summit to date, this year’s event included informative and sometimes surprising insight from experts actively involved in developing solutions for urban landscape issues in Florida. UF/IFAS Miami-Dade Florida Yards and Neighborhoods (FYN) Coordinator Laura Vasquez traveled from South Florida to Gainesville to attend the event and agreed to share her summit experience with IrriGator.

Outdoor water-use all-stars: Jesus Lomeli, Bernard Cardenas, Michael Dukes & Laura Vasquez @ Urban Landscape Summit! pic.twitter.com/tyOVjMUMnB

— UF/IFAS Miami U.C.U. (@MiamiUCU) March 14, 2018

Can you tell us about the work you do as Miami-Dade's FYN Coordinator?

LV: Our program encompasses three different sections: the Florida-Friendly Landscape portion of FYN, the irrigation portion (which is the Urban Conservation Unit) and also the rain barrels in schools program. I coordinate different events with the staff and work in each of the sections to help achieve program goals and teach landscape sustainability.

What was your primary motivation behind attending Urban Landscape Summit 2018?

LV: My primary motivation is learning about all these issues and solutions affecting urban landscapes and trying to apply them to our program in South Florida.

Was there any presentation(s) that really surprised you this year with new/original information?

LV: The presentation that stood out for me was the soil and tissue testing for Florida turfgrasses talk by Dr. Travis Shaddox from Fort Lauderdale REC. He talked about how much of the tissue testing for turfgrass is void. When someone does a tissue test, they receive a report that offers recommendations on how much fertilizer should be applied. He explained how there hasn’t been much research for establishing ranges for fertilizer application. So now Dr. Shaddox is working on establishing ranges of what should be applied based on tissue test results.

The fact that this is just now being addressed was surprising to me. This new insight suggests that recommending any kind of fertilizer use based on test results is not something we should continue to do.

Thank you @mddukes for leading such a quality event! https://t.co/O2vd8pYND6

— Travis Shaddox (@TravisShaddox) March 15, 2018

Did you learn anything that you feel you can immediately apply to your work in Miami-Dade?

LV: With respect to the previous question definitely. Don’t be so quick to recommend soil/tissue testing since the usefulness of results are in question. In addition, researcher Bernard Cardenas presented a study on how quickly rain sensors dry out. According to his work, on average rain sensors dry out within 24 hours. For me this indicates that rain sensors are not the best option.

Miami-Dade Extension's Laura Vasquez conducts an FFL certification 

That’s fascinating, given that rain sensors are often the simplest/most practical option for preventing unnecessary irrigation. So what’s the alternative?
LV: For now, we’ll continue to push weather-based irrigation controllers/cloud-based controllers and shy away from rain sensors. Many homeowners depend on rain sensors but having this confirmation that they dry much faster than moisture in the soil was kind of surprising.

Your team has been consistent about attending the summit every year. What would you say to anyone working in your field that has been thinking about attending but hasn't yet?

LV: The best advice I would give is that if you really want to expand your knowledge of landscape sustainability, irrigation technology and on-going research that’s happening at the University - not only by professors but also students, so many students presenting posters with new ideas - this summit is one you should attend. There are opportunities as well to network with the people that are initiating all this work - one-on-one contact with top researchers in landscape sustainability and irrigation.

One Water Saving Sensor Too Many? - A Dialogue

By Michael Gutierrez

Over the summer an area utility came to us with a technology problem. Due to an incentive-based program, soil moisture sensors were being installed on new housing development irrigation systems. This is just the kind of best practice we love to hear about. In this instance, however, the installers elected to add rain sensors as well. Wiring issues ensued.

This month the Dukes research group is conducting its 3^rd smart water technology workshop of 2016. To mark the occasion, water-use expert Dr. Michael Dukes agreed to a discussion on the above “two sensors” situation so we can all better understand the installers’ intentions and what went wrong. This is also a preview of some of the topics that will be addressed in next week’s training.  

Dr. Michael Dukes instructs during a smart water technology training earlier this year

MG: Rain sensors v. soil moisture sensors – which is more effective?

MD: Soil moisture sensors are definitely more effective than rain sensors. We’ve shown that time and time again. They’ll reduce irrigation two to three times more under the same conditions. And longevity is better in soil moisture sensors. Despite this, rain sensors have been around for a long time and they are in everyone’s way of thinking – everyone being contractors, practitioners, utility people. To us, being close to the research it makes sense just to use a soil moisture sensor. “Why would you consider a rain sensor based on all this research?” Well, for practitioners one of the things that is on top of their mind is seeing an irrigation system run when it’s raining. A rain sensor would stop that. Their next thought is “why not add a soil moisture sensor. Wouldn’t my results be even better?”

A soil moisture sensor properly installed in an undisturbed soil profile

MG: As people that specialize in encouraging best practices, we like seeing practitioners install water saving devices. In reality, one well-installed, functioning device on a system is a rare thing. Two devices is something I’m still trying to wrap my mind around.

MD: In this instance, the only reason is to get the instant shut-off that a rain sensor would provide during a rainfall event. But think about it this way: we only have a limited amount of research on testing a soil moisture sensor with a rain sensor together and in that limited study there was a benefit. It wasn’t a great deal, but there was a benefit. But think about the conditions where you get a benefit: there has to be irrigation during a rain event and if you only have several irrigation events scheduled per week that means everything has to line up perfectly. I’m not sure how likely that is. The benefits to adding a rain sensor is probably marginal because we already know they require more maintenance. You’re adding something that needs more maintenance for some perceived benefit which is not all that great.

Rain sensor: going the extra mile and getting it right

MG: This is what I was thinking. Installers may not be so familiar with the research, but they know rain sensors. What it’s like to work with these devices. Why…

MD: There’s another angle on this though: the soil sensor technology we’re discussing in this instance is slower in reacting to moisture. So the addition of a rain sensor may actually help address this. It’s not a terrible idea.

MG: So intentionally or not, installers in this instance may have compensated for a short-coming of one device by adding another.

MD: That’s exactly right.

MG: I just stumble on the idea of willingly pairing two devices, when you know one will deteriorate before the other.

MD: Perception is reality. Perception is a big deal. We’re in the process of publishing a paper on the OCU research. And surveying homeowners participating in that study, their perception of water savings was more important than the actual water savings in their attitude of whether they were going to continue using smart irrigation technology in the future.

The Orange County Utilities (OCU) study also includes weather-based irrigation controllers (WBICs)

MD: The important part here is: having a rain sensor to prevent a system from running when it’s raining, that goes a lot toward perception. Having a system with only a soil moisture sensor is probably not a real problem in the long run, day in and day out over the year. But let’s say a developer sees a system watering in the rain one time. That may mean the difference between these new homes continuing to get this technology or not getting it.

MG: The only reason we’re actually aware of this "two sensors on one timer" practice is that something went wrong. Can you talk about this?

MD: What happened was the timers in this instance have a rain sensor port and the installers wired both sensors to that port. They intended an either/or scenario to interrupt irrigation. But when both are wired in this way they are in parallel, so both have to trigger to interrupt irrigation. They needed to be wired in series, so either/or would break the circuit.

When the soil moisture sensor can wire into the rain sensor port, a series connection is necessary (courtesy: Francis Galdo)

MG: In summary, if you insist on using two devices – rain sensor and soil moisture sensor – with your timer….

MD: Know your wiring.

Catch the Dukes research group in Tarpon Springs next week for more in depth insight

Saving Water with Manatee County’s Mobile Irrigation Lab

On one of my many field adventures this summer I was able coordinate an impromptu visit with some of the team that comprises UF/IFAS Manatee County’s Mobile Irrigation Lab (MIL). I was working near their next residential irrigation evaluation, and they were kind enough to let me stop by to shoot video and pepper them with questions.

Your mobile irrigation lab's mobile irrigation lab

Statewide 

Rebate and cost-share programs that encourage outdoor water conservation are widespread in Florida. Many programs promote the use of smart irrigation technology (soil moisture sensors and weather-based irrigation controllers), rain sensors, or replacing irrigated turf with non-irrigated Florida-Friendly Landscaping.

L to R: irrigation rebate program examples from Miami-Dade County and Orange County 

The idea is to improve overall system efficiency (often among especially extravagant water users) and save water.

Kind of a Big Deal

Manatee County Utilities Department funds such a program as well, and lore has it that it’s the best in the state – offering sizable incentives for practical system upgrades, and cementing the save water ethic with mandatory educational classes for participants.

So I had to see it for myself and the MIL, who evaluate the irrigation systems and make the rebate-worthy recommendations, were just the people to talk to.

Screen the video below. Learn more about Manatee County’s rebate programs here.

Water-Saving Sensors Go Toe-to-Toe? The Winner Will Surprise You

By Bernard Cardenas

Ever suspect that some of your neighbors apply too much water to their lawns? In some cases you might be right. To remediate this issue, the irrigation industry has developed products to reduce the amount of water wasted during landscape irrigation. 

Water waste adds up (via EPA WaterSense)

Among these technologies are rain sensors and soil moisture sensors (SMS). Rain sensors detect when sufficient rain has fallen and then bypass the irrigation timer’s schedule. Likewise, SMS can detect if the soil is moist enough (so that the lawn can withstand some extra days without watering) and then prevent scheduled irrigation events. 

Sensor vs. Sensor

In a recently published study researchers at UF evaluated the water savings potential of rain sensors and SMS in homes for more than two years. They compared their results to homes only equipped with irrigation timers. They also compared those results to homes that were provided both a rain sensor and educational materials. 

To evaluate if the homes in the study were applying the right amount of water, the researchers also estimated the water applied by the different technologies compared to a theoretical requirement (calculated using a daily soil water balance).

Palm Harbor, FL - where we lay our scene

The Location

In the vicinity of Palm Harbor, FL, a total of 64 homes supplied with reclaimed water for irrigation were selected for this study. Dedicated irrigation flowmeters were installed in every home to measure the amount of water applied. The 64 homes were divided in 4 treatments with 16 homes each. Treatments were: MO (monitored only), SMS, rain sensor, and rain sensor plus educational materials. 

The Results

By the end of the study, SMS-equipped homes were the only group significantly different to the MO homes. This means that the homes equipped with a rain sensor, or a rain sensor plus educational materials, did not save a significant amount of water compared to the MO homes.

Further, the homes equipped with a SMS reduced the average number of irrigation events per week, compared to the MO homes (1.7 vs. 2.7 events/week, respectively), decreased the depth of the weekly irrigation (22 vs. 42 mm, respectively), and applied 44% less water, over the 32 months of data collection. These savings were achieved with no adverse effects to turf quality.

These results indicate that the tested SMS can save a significant amount of reclaimed water, compared to the other methods/technologies investigated.

This paper is part of a series. Read part one here. And if you are attending the ASABE International Meeting in Orlando this month, the studies will be presented in session 138 on 7/18, 2:30pm - 5pm. Follow all our Orlando coverage on Twitter.