A Full Slate for Summer 2018

By Michael Gutierrez

Summer is always an exciting time for ag and bio engineering in general

and water-use work in particular. The next two months include both the

Florida Section ASABE Annual Conference and the

ASABE Annual International Meeting. July also ushers in

Smart Irrigation Month, a national effort to educate everyone about how

to water smartly just as outdoor water-use ramps up across the country.

Expect coverage of all of the above here on irriGator.

Tampa Bay Water HQ in April

Our first summer entry is a brief report back from the recent Landscape Irrigation Water Conservation Technologies Training which took place in

Clearwater, FL. This event was a joint effort by Tampa Bay Water,

Florida Irrigation Society (FIS) and UF/IFAS - bringing together regional

practitioners, a variety of vendors showcasing their latest devices, and

IFAS researchers training on best practices. This is a rare treat in

Florida in the spring, so much so that I made the trek from South Florida

to attend.

“Why go all that way?” you may ask. Well, Dr. Michael Dukes had promised an expansive agenda that would not only include water-saving devices like weather-based controllers and soil moisture sensors, but also pressure regulating sprinkler spray bodies (now a EPA WaterSense certified product). And that’s exactly what the training delivered. We covered water-saving technology best practices, why rain sensors are not the best choice for preventing unnecessary irrigation, and the work that went into testing how and why pressure regulating spray heads save water. Further, this year’s training featured a new lab portion requiring attendees to engage with a vendor to learn some basics about a specific technology, making for a lively vendor area with great exchanges about attendees.

Training lab session underway

The combination of Tampa Bay Water and Florida Irrigation Society (offering CEUs) helped attract a broad spectrum of practitioners to the training. I took every opportunity to speak to attendees to learn what area of the green industry they worked in and what they were interested in learning about. I spoke landscape architects, irrigation technicians, and a residential system contractor. Some attended to learn more about a specific technology (soil moisture sensors), others learned the most during the vendor lab session, and the residential contractor had plenty to share about the limitations of adopting new technology with homeowners when/where there are no incentives (rebates, etc.).

There will not be a more worthwhile irrigation-focused event until fall when

FIS and the Irrigation Association have trainings and certification exams. I

certainly journeyed back to South Florida eager to build on what I learned in

the auditing work that I do. Smart Irrigation Month is just a few weeks away.

Look for more information on water-saving technology and irrigation best

practices on here on irriGator.

Plot Study Comparing Different Irrigation Technologies For Turfgrass

By Kati Migliaccio

From 2015 to 2017, a plot study was conducted in Gainesville, FL, during the growing season. A weather station at the plot site collected weather data and water meters recorded the amount of water applied to each plot. Plots contained established Bermudagrass and were irrigated with four quarter-circle pop-up spray heads.

Figure 1. Picture of turfgrass plots at University of Florida.

Treatments
Eleven different irrigation technologies were used to schedule irrigation: time-based treatment without a rain sensor (WOS), time-based with a rain sensor (WRS), time-based with a rain sensor and a 60% deficit (DWRS), Smartirrigation turf app (APP), Smartirrigation turf app with seasonal water conservation (APPSWC), Baseline soil water sensor (BAS), Rain Bird soil water sensor (RBD), Toro soil water sensor (TOR), Hunter Solar Sync ET (ETH), Rainbird ESP SMTe (ETR), and Weathermatic ET (ETW).

Figure 2. Data collection at the turf plots at the University of Florida Agricultural and Biological Engineering Department (Bernard Cardenas-Laihacar and Ian Hahus pictured)

Results

Results showed that all irrigation scheduling method tested produced water savings as compared to WOS treatment. Average water savings for the soil water sensors ranged from 50 to 61%, for the ET controllers ranged from 19 to 62%, and for the Smartirrigation apps 51 to 64%.

In this plot study, we investigated the use of the seasonal water conservation feature in the Smartirrigation Turf app (APPSWC) where irrigation schedules were provided at a 25% deficit if rainfall exceeded evapotranspiration (ET) the five previous days. This strategy helps reduce irrigation when rainfall is expected to occur and to contribute to plant water needs. During the three years of the study, adding the seasonal water conservation component to the APP schedule resulted in additional water savings. The average water savings over the three years as compared to the WOR treatments for the APP and APPSWC were 51% and 64%, respectively.

During year 2017, a modification was made to the soil water sensor treatments where irrigation was split between two events, a morning and afternoon event. Interestingly, this strategy resulted in only 20% or less events of full irrigation for the three treatments (Fig. 3)

Figure 3. The percent of irrigation events that were full irrigation (pink), percent of irrigation events that were half (green), and percent of irrigation events that were interrupted (gray) for 2017 soil water based sensor treatments

Useful Add-ons
Our results suggest that coupling an irrigation technology with another scheduling feature, such as split irrigation events or irrigation deficits, provide for additional water savings without impacting turf quality. These two add-on features would be useful to implement in locations where rainfall significantly contributes to plant water needs.

For more information on using technology for scheduling irrigation - contact Dr. Kati Migliaccio or Dr. Michael Dukes from the Agricultural and Biological Engineering Department. Additional information is also available in the UF/IFAS EDIS system.

Three Questions About Smart Irrigation Technology

By Michael Gutierrez

April is Water Conservation Month in Florida. A large part of using water efficiently day to day includes outdoor water-use. Next week UF-ABE Professor and Extension Specialist Dr. Michael Dukes is participating in an irrigation technology training in collaboration with Tampa Bay Water and Florida Irrigation Society. Dr. Dukes’ team is usually involved in several of these technology trainings every year. To mark the initial event of 2018, he agreed to answer three preview questions for IrriGator.

Register

What is exciting right now in the world of smart irrigation technology?

MD: There are many options. There are over 800 models of weather-based (evapotranspiration, ET) controllers that have the EPA WaterSense label. Soil moisture sensor (SMS) based controllers don’t yet have a label but there are several of those on the market as well. Exciting new developments are that many ET controllers have remote connectivity. Some are completely controlled by your smartphone. These devices offer many features. Unfortunately, most haven’t been tested in Florida and I understand from field reports that not all are adapted to our climate with intense local rainfall. We always recommend some sort of on-site rain sensor such as an expanding disk rain sensor.

I often find practicioners view weather-based and soil sensor-based irrigation technology as rival options. How do you address this perspective?   

MD: They can be seen this way, but each have their place. I believe the advantage of the SMS is that it integrates rainfall to control the system. Not all ET systems do this well (see previous comment). On the other hand for a one sensor SMS system, the location of the SMS is critical since it controls whether the system irrigates or not.

Your group does several trainings like this during the year, what can an attendee expect at the April event?
MD: We’ll review how smart controllers work, both ET and SMS, and why water conservation is important, and some things to be aware of on how to properly install these devices. We’ll also introduce other types of conservation devices such as pressure regulating spray heads, check valves and flow reduction - technologies such as pressure regulation that aren’t new but in the case of pressure regulation a new EPA WaterSense label is available. We are relying on vendors to present hands-on for their particular products.

Click to register for the Landscape Irrigation Water Conservation Technologies training.

Another One: A Look Back At 2015

By Michael Gutierrez

The end of the year affords a great opportunity to reflect on and assess the work of the past twelve months. For me and the Dukes research group, 2015 was all about initiating new projects and watching others come to fruition. Follow along as I review our year in water research.

#Landscapechat
When you receive an invitation to discuss your work and agenda for the year before a national audience, you take it. That's what Miami-Dade's Urban Conservation Unit (UCU) and I did in January, collaborating on national twitter discussion #landscapechat - explaining the water challenges we face in Florida and highlighting the work we do to promote sustainability. Relive the discussion here.

A January 2015 promotional short 

Water Quality to the Fore

The SVAEC project (named after the Suwannee Valley County research center where it is based) started early in 2015 and continued throughout the year. SVAEC is a three year nutrient management study in corn and peanut cultivation that encompasses water sampling from drainage lysimeters, soil core sampling and plant tissue sampling to determine how nutrients from fertilizer move in the growing area. 

Installing a drainage lysimeter in Live Oak: like this, but 72 times!

We tested lysimeter designs on campus in early spring and by May were installing 72 drainage lysimeters in the ground in Live Oak. Planning for the second year of SVAEC begins in January, you can learn more about the project through the short video below.

Monday: new tech for nutrient management in corn & peanut at the BMP field day. http://t.co/REiNe8EQA1 pic.twitter.com/cBZPInw6Pm

— UF/IFAS IrriGator (@IrriGatorUF) August 14, 2015

Celebrating Rain

As a content creator, I never miss an opportunity to showcase people in the world of water that I admire. Cynthia Barnett is one of those people. In January, Ms. Barnett returned to UF as a Hearst Visiting Professional to teach Environmental Journalism and was kind enough to let me sit in on the lecture portion of the course. 

Cynthia Barnett at the Gainesville release event for Rain: A Natural and Cultural History

Ms. Barnett was also game to sit down with graduate student Mackenzie Boyer and discuss teaching as well as a new book set to release in April. For me, listening to and learning from an author like Cynthia Barnett, who is doing some of the finest water writing around, was a highlight of 2015. You can listen to the IrriGator interview here, as well as an extended public radio interview on Rain: A Natural and Cultural History here.

From Homestead to Gainesville

The renowned team of UF water researchers based in Gainesville grew in 2015 with the addition of Dr. Kati Migliccio. Previously based at UF’s Tropical REC, this summer Dr. Migliaccio relocated to Gainesville and soon began work on North Florida trials for the successful smart irrigation turf app. Located at research plots on campus, the tests are comparing smart turf app water savings with that of many widely available weather-based timers and soil moisture sensors. 

A proven water-saver, the smart turf app is currently under additional testing by @hydroKati http://t.co/Co3Hp4PPfl pic.twitter.com/zM3D0inH2P

— UF/IFAS IrriGator (@IrriGatorUF) October 16, 2015

Dr. Migliaccio has helped develop a number of irrigation apps for smart devices. Learn more about current testing in the short video above and check back with IrriGator in 2016 as these app products continue to improve and the focus of Dr. Migliaccio’s North Florida water research expands.

#UFSIM15
July is smart irrigation month. This year I helped push the message of wise outdoor water use on two fronts: showcasing experts locally and nationally. For IrriGator I produced videos with UF experts about four aspects of water-efficient irrigation. For the UCU I collaborated on a longer production collecting insights from industry professionals across the country defining the smart irrigation concept. See the four micro-videos here and the longer piece below.

July also marked an important milestone in the Orange County Smart Irrigation Study that the Dukes group helps manage. Following three years of research and data collection, the county began the process of developing policy around the water saving potential of smart irrigation devices. Learn more about how UF research helps promote water saving through technology here.

Faculty Fellow Award

This fall Dr. Michael Dukes was awarded the UF Water Institute’s Faculty Fellow Award for achievements in interdisciplinary water research and education. 

Congratulations Dr. Dukes!

Listen to a portion of Dr. Dukes’ acceptance speech here, and if you’re in Gainesville in January, be sure to attend his Water Institute Distinguished Scholar Presentation: Using Research to Inform Extension for Real World Water Conservation.

Next week: @MDDukes & others will be recognized at the Faculty Fellow Awards Celebration http://t.co/Xe0IgHYWAN pic.twitter.com/pqDJnuE8Qy

— UF/IFAS IrriGator (@IrriGatorUF) October 12, 2015

The Oklahoma/Miami-Dade Connection

Much of the irrigation technology and maintenance fundamentals that I know I learned while working in South Florida, and the group I’ve worked the closest with while there has been Miami-Dade’s UCU team. So few were more pleased than I this fall when they finally filled their long vacant team leader position with Extension Agent Morgan Hopkins.

Meet @MorganH2O, Miami-Dade Extension's new FL Yards & Neighborhoods Agent http://t.co/jbAyNMDC8h pic.twitter.com/Ggiy6rcnbo

— UF/IFAS IrriGator (@IrriGatorUF) September 16, 2015

At the time of this writing, Ms. Hopkins is four months on the job and doing very well. In fact, look for her to showcase some of the tangible water savings the UCU generates in Miami-Dade this spring at UF’s Water Institute Symposium.

Closing Big

Late fall is conference season for us and this year we were able to attend and present at both WaterSmart Innovations and the Irrigation Show and Education Conference.

Do irrigation water restrictions work? @UF ABE's Mackenzie Boyer will present this week at @WSIConfExpo #WSI2015 pic.twitter.com/gx0XdQaQSx

— UF/IFAS IrriGator (@IrriGatorUF) October 6, 2015

I was especially honored to have been invited to collaborate with IA/ASABE during the conference in November on content highlighting the good work of extraordinary researcher Dr. Terry Howell and the E3 Irrigation Program, which annually sponsors students and instructors to attend the event.

Looking Ahead

We’re starting 2016 at full speed. For the Dukes team, SVAEC planning begins in early January, followed by a contractor training on soil moisture sensor use and installation with Tampa Bay Water in February, and the Water Institute Symposium soon after. Check this space for on-going developments! 

In West Kendall shooting video about @MiamiDadeWater incentives for smart irrigation & sustainable landscapes! pic.twitter.com/WK338Z78MT

— UF/IFAS Miami U.C.U. (@MiamiUCU) December 29, 2015

In Miami-Dade, the UCU and I already have a slate of three videos in the can awaiting release, and as the work of promoting and educating about conservation and sustainability continues, there will certainly be plans for more. Follow them on Twitter, FaceBook or Instagram and stay tuned!

Make it work: Methodologies for successfully implementing smart irrigation controllers

Encouraging the use of smart technologies for residential landscapes has become a popular trend in water conservation and rebate programs by water utilities and agencies looking for ways to decrease waste due to inefficient irrigation.  Generally, these technologies can be separated into two categories (Figure 1):

•  evapotranspiration-based irrigation controllers (ET) The ET controller uses weather data, inputs chosen by the user based on landscape characteristics, and proprietary algorithms to determine when to irrigate and how much to apply. 
• soil moisture sensors (SMS). The SMS measures the amount of moisture in the soil and skips irrigation if the soil is too wet.  

Figure 1. Examples of ET controllers and SMS systems (clockwise from top left): Rain Bird ESP-SMT, Weathermatic SL1600, Rain Bird SMRT-Y, Toro Precision Wireless, Toro Intelli-Sense, and Baseline WaterTec S100.

If at once you don’t succeed

A recent ET controller study was planned and implemented in Hillsborough County, FL.  A community-wide analysis of water billing data was completed for the county and the three communities that showed the highest estimated irrigation were Apollo Beach, Riverview, and Valrico.  A total of 36 volunteers were selected across the three communities with 21 of them receiving Toro Intelli-sense ET controllers.  All ET controllers were programmed with UF/IFAS-recommended program settings (ET+Edu).  The remaining volunteers were monitored, but did not receive an ET controller (comparison).

Unfortunately, results were not as positive as anticipated.  Though the ET controllers decreased irrigation application by 23% to 41%, irrigation increased by 14% for homes in Valrico and 54% for homes in Riverview when compared to the respective volunteers without technologies. Irrigation was high within these two communities, but the volunteers were not necessarily over-irrigators.  It was clear that there must be a better way to identify the utility customers that would benefit from smart technologies. 

More technology, bigger canvas

A new study was planned for Orange County, FL, that would evaluate the water conservation potential of both types of smart technologies when installed on homes with excessive irrigation habits.  Instead of focusing on communities, all customers in the Orange County Utilities service area were evaluated individually for trends in over-irrigation.  The UF/IFAS recommendation for irrigation is based on a soil water balance approach where the change in soil moisture depends on evaporation, transpiration, rainfall, and irrigation (Figure 2).  

Figure 2. The soil water balance is used to estimate the amount of irrigation needed to account for evaporation and transpiration losses when rainfall is not sufficient.

Landscape Irrigation Ratios (LIR) were calculated for every month over a five year span for each utility customer.  The LIR is a ratio of measured irrigation to UF/IFAS recommendations for the same month.  An LIR greater than 1 indicates over-irrigation whereas an LIR less than 1 indicates conservative irrigation practices.  Customers were considered for the study when a minimum of three months in three consecutive years had ratios greater than 1.5.  Out of 140,000 accounts analyzed, there were only 7,408 accounts that exhibited this behavior and out of these accounts, there were 843 volunteers willing to learn more about the study. 

After a detailed evaluation of many of the volunteering homes, the study included 139 participants located in seven communities across the county.  There were 28 that did not receive a technology (comparison), 55 that received a Rain Bird ESP-SMT (ET), and 56 that received a Baseline WaterTec S100 (SMS).  There were 28 homes of each technology that received additional educational opportunities and UF/IFAS recommended program settings (+Edu). 

Figure 3. Average landscape irrigation ratios from before the Orange County smart controller study began.  Irrigation trends were high with 6-8.3 times the recommendation.

The average historical LIRs (five years of monthly irrigation application to monthly UF/IFAS recommended irrigation) for Orange County study subjects ranged from 6.0 to 8.3, meaning that these volunteers were applying 6 to 8.3 times the amount of irrigation needed (Figure 3).  When considering historical LIRs in the aforementioned Hillsborough County study, they ranged from 1.5 to 2.4 indicating that they were also over-irrigating but were already much more conservative than the Orange County participants (Figure 4).

Figure 4. Average landscape irrigation ratios from before the Hillsborough County ET controller study began.  These volunteers had some over-irrigation, but did not exhibit signs of excessive water use.

Diving into the numbers

Irrigation by the comparisons in Orange County decreased from historical trends (6.9 before the study, 4.3 during the study).  Though the real reason is unknown, possibilities for the behavior adjustment include highly publicized droughts encouraging water conservation, awareness of being monitored for the study, or even repairing leaks discovered during their initial system evaluation.  Implementing the technologies had a larger effect, reducing the LIRs to 2-3.3 (Figure 5).  The additional education and programming was important for the SMS, reducing the ratio significantly from 2.9 (SMS) to 2.0 (SMS+Edu).  However, all of these treatments are still well above a value of 1, which is the goal, so more savings are possible.

Figure 5. Average landscape irrigation ratios that occurred during the smart controller study in Orange County.  The technologies were effective at reducing water use, but there’s room for improvement.

The takeaway

Smart technologies should be focused on homes that exhibit habitual excessive irrigation.  In situations where marginal water savings are possible, such as in the Hillsborough County ET controller study, a soil moisture sensor with UF/IFAS recommended installation and programming is recommended.  These sensors can be used in situations of deficit irrigation schedules whereas ET controllers can increase water use to maintain a well-watered landscape.  Both technologies were effective when used in the right situations.

Thanks to Hillsborough County Water Resource Services, Tampa Bay Water, Orange County Utilities, Water Research Foundation, St. Johns River Water Management District, and South Florida Water Management District for providing the support to complete these projects.  These studies were co-authored by Michael D. Dukes.

About the author:

Stacia L. Davis, Ph.D. is an assistant professor of irrigation engineering with the Louisiana State University Agricultural Center located at the Red River Research Station, Bossier City, LA.  She studied the water conservation potential of smart technologies at the University of Florida prior to moving to Louisiana.

Applying science to water savings: smart irrigation month 2014

In late June I had the opportunity to join Miami-Dade’s Urban Conservation Unit (U.C.U.) for a day in the field visiting properties participating in Miami-Dade County’s Irrigation Rebate Program.

Front yard turf zone, circa 2011

Playing the classics

The final visit for the day was a home in Coral Gables, the City Beautiful. In 2011, this residence had rehabilitated its potable water irrigation system and installed a weather-based irrigation controller (WBIC). With a landscape that features mostly palms, shrubs and decorative stones, a seven zone irrigation system has no business at this location. In any case, the controller installation was rebated in 2011 and the homeowner asked the team to stop by to see if things were still on the up and up.

No longer on the up and up: Jesus Lomeli and a riser nozzle gone missing

A bit about WBICs

Once we realized where we were, U.C.U. tech Jesus and I had eyes big as saucers. Why? Two words: applied science. Weather-based irrigation controllers require very specific programming for each zone:

• soil type
• plant type
• shade factor
• sprinkler head type, etc.

All those factors are churning away in this little guy right here

The WBIC model at this location uses these factors along with weather data from an on-site weather sensor/tipping bucket rain gauge to calculate evapotranspiration (or ET). This ET value is then used to generate run times for each zone. When a landscape is designed with hydrozones in mind, much like this one with one turf zone and six tree or shrub zones, a weather-based controller can really work its magic.

Weather sensor: perfectly located and busy doing science 

So after a quick zone by zone wet-check to look for breaks or other problems, we dove into the controller’s “history” feature to track the watering events by date starting from January of this year.

#SIM2014

Smart irrigation month is an industry-fostered construct that promotes outdoor water-use efficiency during the month of July, the outdoor water-use peak in the calendar year. The Irrigation Association recommends a plethora of practices from design to technology that, if implemented, can reduce water-use while still maintaining a healthy landscape.

Tree canopy shade is real: front yard turf zone in 2014

Better living through tech

In the best of all possible worlds the property I'm discussing here would have no (or temporary) irrigation. There would be a colorful Florida-friendly groundcover in the shady front area, and all the remaining ornamental areas would continue to live off rain alone. 

Back yard rocky expanse: wait, what...

In this world, however, the weather-based controller was expertly managing water-use for this landscape – irrigating the lone turf zone regularly, and watering the other zones once a month, or once every few months. During especially rainy stretches, the system would not run for weeks. 

Some water-wise options from Ewing Irrigation

The takeaway
There is definitely room for improvement at this location - namely low-volume irrigation in the six tree/shrub zones - but the best decision this homeowner ever made for the landscape (and water bill) was installing a WBIC three years ago. This wasn't the first time Jesus and I had seen a weather-based controller save water this way, but it's the most recent, and on the cusp of smart irrigation month 2014, all the sweeter.

About the author: 

Michael Gutierrez is a water resources 
technician with UF/IFAS in the Ag & Bio 
Engineering Dept. He tweets, blogs and 
also shoots still and video media in South 
Florida, Gainesville and anywhere else a 
camera is handy. (image: Martha Golea)