Making Sense of Landscape Fertilizer Ordinances in Florida

Water quality is a hot topic in Florida. If you follow water media you’ll know that in the wake of 2016’s algal blooms along some of the state’s finest coastlines, putting policy in place to lessen the possibility of future recurrences was a top priority during the Legislative Session. During debates therein everything from Ag, to septic tanks to landscape fertilizer were mentioned as factors contributing to poor water quality. While IFAS research suggests landscape fertilizer does not play as significant a role as its often assigned, the reality is that much of the state has crafted ordinances on when it should/should not be applied (some vigorously contested).

What part of Florida has enacted which landscape fertilizer ordinance? Good question! Enter turfgrass specialist Dr. J. Bryan Unruh. Earlier this year Dr. Unruh tweeted a preview of a mobile website/app he is developing about landscape fertilizer ordinances throughout Florida. IrriGator caught up with Dr. Unruh during the recent Urban Landscape Summit and he was kind enough to answer a few questions about this exciting project (a collaborative effort in conjunction with the Florida-Friendly Landscaping Program and IFAS-IT).

New map showing FL fertilizer ordinances. Two months from launching app that will allow you to know what's in place where you are standing! pic.twitter.com/ACC7B9vqqb

— Bryan Unruh (@jbunruh) March 9, 2017

How did the idea for the fertilizer ordinance app come about?

JBU: Working with the landscape industry in Florida – with now over 100 landscape ordinances, there’s a lot of confusion, especially in the larger urban areas (Orlando and Tampa) where you have multiple counties. So the idea was conceived that if you have a GPS-enabled smart phone you can hit a button and it will tell you exactly what ordinance is in place at that particular point. Nobody has really kept a very accurate compilation of all of these ordinances. My masters student, Christopher Ryan, through some of his work had created ArcGIS maps that show where all these ordinances are. So we’re merging this information into a handy app.

A screenshot preview of app interface (via Dr. Unruh)

Who is the intended audience for this product?

JBU: The primary audience would be the landscape industry. There’s an estimated 70,000 fertilizer applicators out there. Extension faculty as well might find it useful. I don’t presume to think an average homeowner would purchase this app, but they might.

Is this a stand-alone app or is it web-based?

JBU: We’re using app and mobile-website interchangeably. A mobile-website links into the database that is housed on a server. Whereas an app, your updates are tied to app stores. If they don’t push down an update as soon as we would like, then we have a problem.

There is a functional component, too. As we’ve compiled these databases, a lot of it is reactive. You’ll hear about an ordinance and then you have to go vet it out. But with 70,000 landscapers out there, this app has functionality in it where an industry person may hear about something happening in their municipality or their county, they can actually upload information into the tool that then comes back to us and then we can vet for accuracy. They won’t be able to change the database or maps, but they can provide us their ears on the ground.

Will this be a free service?

JBU: The app is a for sale product. You pay a fee for access. We have partial funding from Center for Landscape Conservation and Ecology, FNGLA, and internal program funds. It may not have thousands and thousands of users, but I think that those users that do have it will find it to be very helpful.

Detailed ordinance info at your fingertips (via Dr. Unruh)

The Florida Fertilizer Ordinances web app is now available for use on mobile devices. Access it here.

Water Need and Water Use in Landscape Irrigation

By Michael Dukes

“Turf grasses need irrigation systems. Some grasses listed as Florida-Friendly need tremendous volumes of water. The homeowner also needs to fertilize and quickly address diseases and pests that will be present. Despite the homeowner's best efforts, all or part of the turf will need to be replaced every 4 to 5 years.”

- email from master gardener

A Need Benchmark

People often work under the assumption that turfgrass needs a lot of water. What is the definition of a lot? Normally, turfgrass is irrigated far more than it needs to be and this reinforces the perception that it needs a lot. There are lots of misconceptions about how much is used and how much is needed. If people knew how much is really needed, there would be a benchmark and you would have an idea of where you are relative to what is needed.

Michael Dukes and Bernard Cardenas in the research plots

An example is the comparison homes treatment (no technology, monitor-only) used in our Orange County smart irrigation study. We’re in our 6^th year of data collection. Over that whole time period, the average application for those homes has been more than an inch per week – that’s over 52 inches a year, no matter how much rainfall. And we’re getting about 40+ inches of rainfall in a year. That’s 90 inches of water being applied to the landscape. But ET (evapotranspiration) of turfgrass is only maybe 30 inches in Orlando.

A properly installed weather-based irrigation controller

Timing is everything - for turfgrass in particular, with shallow root zones. In theory, if we get 40 inches of rainfall and ET is 30 inches, the amount of rainfall far exceeds the amount of water that plant needs. But it’s not timed perfectly. There are dry times and there are times when you get excess water. That’s where irrigation comes in. If you time that irrigation perfectly you’re in the mid-20 inches of water needed.

Ideally if you’re applying at the right time at the right amount, which a smart irrigation controller allows you to do automatically, you should be in that mid-20 inches of water applied. The comparison home treatments are applying over 50 inches. That’s why smart technology is a viable way of getting irrigation in the right ball park. They are not perfect, but when the problem is 2x and you have a solution that gets you to 1.3x or 1.5x you’ve made a huge dramatic improvement by doing one thing.

A Use Percentage

Image via Ewing

I often am asked how much water is used for irrigation, usually referring to single family homes. Often we see a mysteriously even number of 50% cited. The truth is that irrigation water use varies in time and space. In areas with more irrigation systems, there will necessarily be more irrigation water use. In drier years, irrigation water use will be higher. I believe the 50% number is a very convenient number to cite but here’s what we know based on data from Florida.

The reality is that in a given utility there will be a spectrum of users with most not over irrigating or perhaps irrigating at all. In Mackenzie Boyer’s recent work in Southwest FL we showed this for the Tampa Bay region, (Mining for water: Using billing data to characterize residential irrigation demand). That said, other utilities in the east and southeast part of the state have higher irrigation demand since their conservation programs typically aren’t as developed as in the SW region.

Additional research informing on water-use estimates:
Romero & Dukes (2016): A Method to Estimate Residential Irrigation from Potable Meter Data – Metered data from Orlando (1,781 homes) showed that irrigation accounted for 64% of total use.  The first paragraph also gives a good summary of several other studies that reported Florida residential irrigation use (ranging from 25-75% of total use).

Boyer et. al (2014): Irrigation Conservation of Florida-Friendly Landscaping Based on Water Billing Data – Again, the introduction summarizes key statistics from Florida studies.  For example, Haley et al. (2007) estimated 64% in central Florida, and Romero and Dukes (2014) estimated 32-63% in central Florida.

A good resource for how much to water your landscape depending on region in Florida, time of year and irrigation system can be found here.

Charles Barrett and Understanding the Importance of Water in Florida

This month marks a year for Dr. Charles Barrett as water regional specialized agent (RSA) for UF/IFAS Northeast District. This district spans Jacksonville, the Suwannee River Valley and the Nature Coast. I caught up with him during Urban Landscape Summit 2017 and he was kind enough to speak with IrriGator about his RSA experience thus far.

Dr. Charles Barrett - Regional Specialized Agent, water resources

What attracted you to the Water RSA position?

CB: I did my PhD research in agriculture (ag) irrigation and best management practices for water and nutrient management. That’s what got me interested in it. And being a Florida resident my whole life I understand the importance of water to Florida. If there’s something I can do to help out I’m excited to do that.

What are the most critical water issues in your district?

CB: We have some new basin management action plans coming into place. My role with IFAS extension is education about what this means for our residents in the district. It’s a very rural area, so I'm getting the message out to farmers and small communities so that they understand what the implication of a basin management action plan is and how they can get prepared for it.

Dr. Barrett (middle) presents at an irrigation demo

Also, out of the 31 listed Outstanding Florida Springs (OFS), we have 17 of them in my district. That’s a large majority. OFS in the new water bill got special attention so if you have an OFS in your basin management action plan you have even more stuff you have to pay attention to. There’s a lot coming down the pike and I feel there’s not a whole lot of education going on about that. This is where we step in and give the science and information. I feel we have to do a much better job of getting information out to people.

Being almost a year into this position are you satisfied with how the work is coming along?

CB: I feel like I’m starting to get the lay of the land which is the most critical part in any job. There was nobody before me to tell me what I needed to do - which is exciting but sometimes a challenge because you’re kind of making up your own road map as you go. You’ve got to do a needs assessment and figure out where the big fires are and start working on putting those fires out first. In my area, being that it’s predominantly ag, a lot of the identification of the nutrient loads in the rivers and in the springs has been identified as ag-related. That’s the big fire right now, to get those guys to understand how important best management practices are. How it’s not only important to enroll, but the rule has now changed that you have to verify your implementation of it. That means good record-keeping. It’s a lot of education on that.

Read Dr. Barrett's article on soil sensors & irrigation scheduling

If I can say anything is a success, it’s just making relationships right now – working with the water management district, working with FDACS, working with DEP and the Suwannee River Partnership has been huge up there. We meet regularly and we talk about these issues. We have a really tight-knit group. So I think the biggest success so far is that I’ve been able to get on board with those guys and to work hand-in-hand with the guys that are trying to get this information out. We’re all working together. I’d like to see more success on the side of getting things done, but that comes with time.

Before I met you I knew you from Twitter. Can you talk about why you joined Twitter and some benefits of maintaining a digital presence?

CB: I created an account on Twitter right when I first started as a water RSA. I went through the professional development academy, or new agent training, and it was brought to my attention how that media stream could be useful in your career. I figured like-minded people might find some of the stuff that I find interesting interesting to them. That’s why I got on it. I didn’t think anybody was looking at it! I see you on there with IrriGator and you’re always picking up stuff that I miss so it’s awesome. If I find something, or you guys find something, we can all share it along. I thought I’d never be on Twitter, I’m not a social media type of person. But it’s kind of cool.

Read profiles on Water RSAs James Fletcher and Dr. Lisa Krimsky.