Zack Burns - How Hydroponics Feeds Giraffes and Cuts Emissions at the Zoo

[00:00:10] Dominique: Hello. Welcome to another episode of Green Champions.

[00:00:13] Adam: Thanks for joining us in a conversation with real people sharing sustainability success stories.

[00:00:18] Dominique: From entrepreneurs to artists, scientists to activists, this podcast is a platform for green champions to share their stories and plant new ideas. I'm Dominique.

[00:00:27] Adam: And I'm Adam. This episode is part of a mini-series in partnership with the Midwest Regional Sustainability Summit, which celebrates collaborative climate solutions in the Midwest region of the United States.

[00:00:37] Dominique: In this mini-series, you're joining us in virtually attending the annual summit and meeting a few of the over 100 speakers and key storytellers from this year's event. 

Today, we are joined by Zack Burns. He is the hydroponics technician at the Cincinnati Zoo and Botanical Garden. He is a passionate innovator in sustainable food systems.

Zach has played a key role in launching and managing the zoo's pilot hydroponics program, basically it's exploring how small-scale, closed-loop agriculture can reduce food miles, conserve water, and engage the community. So many amazing things all tied into one. today we're talking about the outcomes from the first year of this initiative and what that means for the future of urban agriculture, and a little bit about what Zack is bringing to the summit as well. So thanks for joining us today, Zack.

[00:01:22] Zack: Yeah, thanks for having me. Excited to talk to you guys.

[00:01:24] Adam: Well, let's dive in with the basics, like what inspired the Cincinnati Zoo to explore hydroponics as part of the sustainability effort?

[00:01:30] Zack: Yeah, So we we're working with a consulting group and they kind of found out that one of the biggest impacts of our carbon footprint was on our animal food supply, which if you can imagine with having hundreds, maybe thousands of animals we have at the zoo can be pretty large, especially when you're talking , the elephants that eat a ton of produce, eat a lot of hay. Our manatees, our rehab Manatee program, they can eat about seven and a half percent of their body weight in a single day. So lots of animals, lots of produce that we need to procure. And the goal is, again, just to try to figure out how we could reduce that, just on a small scale to start with where that goes from in the future or if we plan on expanding.

[00:02:07] Dominique: Ca

n you explain kind of a 101 on hydroponics?

[00:02:11] Zack: Hydroponics basically means, hydro, water. We think we all probably know that one. And then ponic means work. So essentially the water is doing the work to help us grow the plants.

And in short term, basically you're growing plants without using any soil. So, the water that we feed our plants every single day is gonna have a nutrient rich solution in it from a large breakdown of all the different macro and micronutrients that they need. Obviously, the big ones are gonna be nitrogen, phosphorus and potassium. But it can go down to anywhere from 20 different individual elements and compounds that could be fed into the water to feed to our plants. So, most of the time with hydroponics, you're gonna use an inert media. So media that's not gonna have basically anything in it.

So for us here, we use coco coir and peat moss grow plugs. But there's, hundreds of different types of media that can be used in hydroponics. That's just the one that we found that's worked the best for us. 

[00:03:02] Adam: So how does that actually work? Like you have a layer of the peat moss and then you're planting the plants inside of that? What does that look like? 

[00:03:08] Zack: So, our plugs, they actually hold together pretty well. They're like little plugs. when you go to the garden store and you pull your flowers out of, and the dirt that's attached to 'em, it's almost like the exact same shape as that. So we start them off in a large tray. We keep 'em in there for two weeks of anywhere from 250 to 300 individual plants in a tray. And then we grow 'em in the small tray for, like I said, about two weeks. And then once they get big enough and they start touching each other, we need to space them out a little bit. So we take 'em from our nursery station and we put them on our cultivation wall, which typically for us.

So, if you can imagine, our walls that our plants are hanging on are actually like vertically hanging from the ceiling, which is a little bit different. When I think when a lot of people think of like hydroponics and vertical farming, they think of stacked stables. Ours are almost like on the side and perpendicular to what a normal growth system would be. And then they hang there. We have panels in each one of our rows that we plant the plants into. The water drips down from pipes close to the ceiling, drips down through channel. It'll go through those plugs, and then the roots will absorb it and it'll help us feed and grow our plants.

[00:04:12] Adam: Very cool.

[00:04:12] Dominique: I think I've read that the Cincinnati Zoo is 75 acres worth of land But when I'm picturing your hydroponic system, I'm picturing like walking into the size of your average greenhouse. How wrong is that?

[00:04:27] Zack: Yeah, so there's varying different systems that you can grow plants in hydroponically, but specifically for us, we actually have two 40 foot long shipping containers that we're growing them in.

[00:04:35] Dominique: super cool. 

[00:04:36] Zack: And they're right next to each other. So a little small footprint and actually because the zoo is so landlocked and we want to give all of our space inside the zoo to our animals and our guests that come in and enjoy the zoo, we're actually a little bit off the property, like I'm talking a quarter mile in another property that the zoo owns.

[00:04:53] Dominique: Okay. So I was gonna ask, is this an experience that visitors get to engage with? 

[00:04:57] Zack: For the most part, no, you can't see the farms. We just didn't really have the space to put 'em on zoo grounds right now as different expansions and constructions can happen and we're making more space inside the zoo, that could be a possibility.

but part of our giraffe feeding program so people can come to the zoo. And they can actually purchase a direct feeding experience. And through that feeding experience, our hydroponics program supplies all of the lettuce that goes into that. So we have a sign up there that talks about it, and then the people that are facilitating the feeding, if they have a nice little moment, they'll be able to talk about it. but long story short, no, they're not technically in the public sphere.

[00:05:30] Dominique: If I do that feeding program, who exactly am I feeding?

[00:05:33] Zack: So you're gonna feed one of our five giraffes. I think their names are Tessa, Zeke. I can't remember all of them off the top of my head. I should know that. I should know that answer. 

[00:05:42] Dominique: Somewhere, a giraffe heart just broke.

[00:05:44] Zack: Yeah, yeah, I know specifically Tessa because Tessa is the one from what I've been hearing from the folks that are working up there, that she's been loving our lettuce recently, so I love to see that. But we got five of 'em, so you can choose any five. They kind of come and go as they want, and each one can eat up to 10 pounds in a day, so we're talking 50 pounds of lettuce that's going up there every single day that our guests get to feed them.

[00:06:07] Adam: So what does your day look like day to day? 

[00:06:09] Zack: Yeah, so the first thing you do is obviously to check on your plants. For the most part, come in, look at the plants, that's obviously the number one way you're gonna tell that they're looking and making sure there's not any welting or anything else that can happen.

Check our parameters. So, typically we're gonna be growing our plants between about 70 to 73 degrees Fahrenheit, and then 65-70% humidity is kind of that sweet spot that the crops that we're growing grow the best. And then we will check to see, maybe we need to refill our fertilizer tanks. And then kind of once all that stuff is settled, depending on the day. So some days we come in and we seat everything by hand. 

So some days we'll seed and then twice a week we harvest each container. So one day in a week we'll harvest half the container, and then that same day we'll harvest the other half of the container. And then two days later we'll do the same thing. And then kind of after we're done harvesting, we transplant our new crops into them. 

And that's one of the advantages of hydroponics is that you can go directly from the crop you just harvested to the next one growing right behind it. Because we're not dependent on our soil conditions because we know the media, we know our nutrient rich solution that we're giving them. and we can grow 365 days a year.

[00:07:17] Adam: That's fantastic. How do the different seasons kind of affect that? 

It kind of depends. So like during the winter, it sounds weird, but our HVAC is actually working harder in the winter when it's colder outside because it's trying to expel hot air from inside the container. So our lights that we're growing the plants with, they put off a ton of heat. So most of the time we're focused on cooling our containers down even when it's 10 degrees here in Cincinnati. In the winter, they're gonna have to work a little bit harder. Now, what were some of the key takeaways in learnings from the first pilot year of doing this?

[00:07:49] Zack: Yeah, so we experimented with different crops. So, romaine lettuce, that's what we feed during the giraffe feeding program. So that was always gonna be like our number one need that we had was romaine lettuce.

 we tried some different things like, turnips and turnip greens, mustard greens, collard greens, different types of lettuce as well too. So, we experimented with all those. But really what we found is that we grow the romaine lettuce very successfully.

Some of the biggest eaters at the zoo, the hippos, the elephants, the primates, of course, the giraffes and the manatees, they all remain with us. So we're always gonna have a need for that. 

you've learned a lot in this process and obviously had a lot of like good key drivers and persevering through all of those things and had good reason to drop two storage containers and fill them with plants and monitor all that you're monitoring. 

[00:08:36] Dominique: And I know we alluded this at the beginning of this is really important 'cause it's reducing food miles, it's conserving water, it's engaging the community.

Can you say more about what the benefits have also been and maybe even the response?

[00:08:45] Zack: So when plants and food, they come into the zoo, they're coming all the way from the west coast. 

So, when they get to the zoo, they're shipped on a refrigerated truck all the way from the other side of the country, and that can obviously have a large amount of emissions associated with that. So one of the things we've been tracking is comparing basically for every 30 pounds will kind of equate to a certain emissions rating essentially or a certain metric tons of CO2 produced. So trying to reduce that, and I think over the last year it was about 15 metric tons of CO2, just from transportation emissions. So, that's not specifically even focusing on the emissions associated with actually farming the crops. So you're talking, fertilizer off gassing, running all the machinery that it takes to run a big outdoor farm and all those other things. 

Addition to the emissions, we obviously wanted to increase our resiliency, and then also just know where a portion of our food is coming from. So, knowing that we can rely on a certain amount of lettuce that we're growing every single week, that's something that we always know that we're gonna be able to have.

[00:09:46] Adam: Just out of curiosity, do you know how much you were spending on lettuce per year before the hydroponics?

[00:09:51] Zack: 36% of our operating budget goes into just food for the animals.

[00:09:55] Adam: Oh wow. 

[00:09:56] Dominique: Which makes a lot of sense,

Just a great point, I think around resiliency and frankly leaning into the fact that you are a zoo and you have so much knowledge around nature. So being able to bring that in-house, reduce your emissions, but also rely on your own systems and your own experts. It just feels so sensible.

[00:10:14] Zack: Yeah, and we're the, the Cincinnati Zoo and we always make sure that we say and Botanical Garden 'cause we're the, one of the only zoos that is a botanical garden. so our department, we're actually the sustainability department, so that's really what we're focusing on.

And this is just one small part of it. So, in addition to that, we have solar projects that we work on. We have in our parking lots, we have a solar canopy. From what we know, we actually believe we have the largest urban solar canopy anywhere in the US which is really awesome. And then we also work on some other zero waste. We had a goal to be completely net zero by 2025. We've done a lot of work to get there. We still have some ways to go, but our team has really done a great job of advancing that and getting us to a point where we think we know we can get there within the next couple years, hopefully.

[00:10:58] Dominique: And I'm sure that connects to the work that you're doing too. You're not shipping in as many packaged materials than having to dispose of those materials that have arrived at your site and are now your responsibility.

[00:11:09] Zack: Exactly. I think going through our data, we saved roughly about 800 pounds of cardboard just from our lettuce. Again, when we harvest, we put 'em in reusable containers, we take 'em up, we get our old ones that are empty, we clean 'em, we reuse them. And then every single package that we're getting in is a cardboard box with a plastic bag inside. So significantly reducing our waste.We have an on onsite bio digester, so we can actually take our plant waste, our plugs and the occasional trimmings And we can take those up to our composter and use that as compost that we'll eventually use hopefully in like our beds, for our horticulture team. So it's kind of like a full circle zero waste. 

[00:11:48] Dominique: you really are demonstrating like a circular closed loop system in every way. I love the ways that it's also benefiting the animals and benefiting your bottom line. That is just like sustainability doing its magic. That's awesome.

[00:12:00] Zack: Yeah. And that's the goal. Spearheaded by our director of facilities, he's done amazing work since he's been here at the zoo. I think at one point the zoo was the largest source of using water in the city of Cincinnati. And that was one of the things that he focused really early on and significantly reduced the amount of water that we're using here at the zoo. Pretty much every time we do a construction, we're also retaining water. All of our new exhibits, we have retention pools underneath that will store rainwater to keep it out from going into our sewers, and then eventually overflowing our sewers and the sewage ends up out in our waterways and all that exciting stuff.

And also being a good community steward because water is gonna run off the zoo just from the amount of pavement that we have and end up in our neighbor's basement. So we don't wanna do that. We wanna be a part of the community that we're in and not add more headaches to the people that are around here. 

[00:12:50] Adam: Y

ou've also touched on the data that you're collecting multiple times. I'm just curious, are there different challenges that you've had in putting those data collections in place, and how does that play into the sustainability efforts?

[00:13:02] Zack: So we've been collecting our harvest data and all of our purchasing data and all those things from the very beginning dumping it into a spreadsheet.

 it was really good that we kinda had that foresight at the very beginning to at least collect this data and then figure out what we can do with it. And then, kind of towards the end of December, looking in January is really when we started to dig into that data and look at the emissions. And basically now we have our spreadsheet set up to when we put in how much weight that we harvested, we can almost get a transportation emission saved. So put a lot of work into it. I know it's not just me. Our whole team has put a lot of work into getting that spreadsheet nice and organized. 

We hope we can eventually look at some of the data and get a full kind of lifecycle assessment on our animal food program. And starting from when a seed goes into the ground in California, until it gets into an animal's mouth.

[00:13:53] Dominique: You've clearly painted why this is hard to navigate. There's a lot of components to keep track of because you're being so intentional about every piece. But I'm sitting here also being like, "This is genius. This works so well." You have found so many wonderful benefits from this. Like arguably it just makes sense initiative. Why don't we just create what we need right on site? But I'm wondering like, why aren't other zoos not doing this? Do you have context, at least from like how you're comparing with initiatives, try to other zoos or what's held them back or things that you've also learned from other zoos that were inspirational?

[00:14:31] Zack: I think luckily we kind of have the bandwidth to do it. We have the support of our management team, which has been really beneficial. We also have a very large donor network that maybe we don't have some of the limitations that unfortunately some others zoo have. Cincinnati loves their zoo and that's something that everybody knows in the city, that it's like one of our shining jewels. And yeah, so that's the luxury that we have that unfortunately a lot of zoos maybe don't have.

They also maybe don't even have the space, especially like some urban zoos. There's no room for them to expand. And luckily, with the foresight of our team, we have some different vacant properties around the zoo that we own, that we can do some of these things in 

So, our director and some of our management team actually went out to the Cheyenne Mountain Zoo in Colorado Springs, and they were actually the kind of like the first ones that spearheaded this. So, we meet and we talk with them pretty regularly. We share data, kind of like that science, right?

We can do more together in sharing our data than we can trying to compete against each other. So we're both really busy and we don't have a lot of time, so we try to meet every month or so and just kind of talk about how things are going. Even then, we've also had some other zoos reach out to us about how can we do this? What are the things that you've learned? What are the downsides to doing what we did? If you can do it all over again, how would you change different things?

So we hope that by doing that we can keep building on our network and spreading our learnings and our knowledge to some of these other zoos, and they can hopefully start to do something similar.

[00:15:59] Dominique: Yeah. That collaborative energy also feels very true to the world of sustainability, but especially to this summit, I think that's really the mission of the Midwest Regional Sustainability Summit is trying to story tell so we're not all making the same mistakes. So I'm excited for other folks to hear you and learn about what you've already learned. I think also a successful component of your project is having a Zack and I think we've now had a chance to ask you, why you're doing this work.

what was your personal journey to being the hydroponics guy and what makes you love this work day to day?

[00:16:33] Zack: I started working at the zoo in 2015. I was doing different public animal interactions, so like animal encounters on zoo grounds, doing some chats, doing the giraffe feeding, which is kind of full circle a little bit now. And until I was kind of, finishing my undergrad and I was like unsure what I really wanted to do.

I loved it here, but it just was one of those things that like, I think I need to branch out a little bit more. And kind of when I started thinking about that, I actually had somebody reach out to me about a company that was starting up here in Cincinnati called 80 Acres Farms that was back in 2018, when there was only one farm there and started working there. 

I learned a lot from some very experienced growers and learned how the systems run and different things like that. And ended up working my way up through 80 Acres and went from a farm tech, to a grower, to a supervisor, to managing my own farm. So I kind of got to see the whole steps of it, which I think really helped me in the project management side of the position here and kind of getting us there. So that was like my journey and how I got here, the zoo. I heard through the grapevine a little bit that the zoo is talking about possibly doing a hydroponic. So I reached out to the people that they told me were gonna be running it. I applied for it and interviewed and I got the position. And yeah, really been hitting the ground running since then.

Growing plants can be challenging. But also it's rewarding too, especially when you're constantly improving.

I can do my little experiments here and there and get immediate results, which is really awesome because a field crop farmer, if they're gonna change something, they gotta wait maybe till the next year to see the results. And for us in here, our full cycle is only roughly about 42 to 45 days. So I can do multiple replications. I can run a trial for six weeks and get a good amount of data and we can evaluate that data. And maybe we found it didn't work. Maybe we found that we did. Yeah so, it's really it's like science and action, right? That you can analyze our data and make informed decisions based on the data. So that's a fun part to me.

[00:18:29] Adam: I love it. Now if you scale that to a bigger picture, what role do you see hydroponics playing in addressing food security or climate resilience in urban spaces?

[00:18:38] Zack: The great part about hydroponics is that really you can put it anywhere. You can put it in a blighted areas. I've heard of some hydroponic farmers moving into brownfield buildings and different things like that. And you can put them right next to where people live. and this isn't obviously talking bad about local farming 'cause local organic farming is great. It's awesome. There's always gonna be a need for that. But you can only do so much.

So, that's the benefit, is you can put your farms right next to people, and by doing that, you're reducing those emissions associated with transporting the food. And then also it's gonna be a lot fresher. When you harvest something on the west coast, it's gonna take at least a couple weeks to get from those farms to the grocery store or to the supplier for restaurants and things like that. For here, for us, we'll harvest on a Tuesday morning and that could potentially be start being fed out Wednesday morning. So it's like a 24 hours from a live living plant on our wall growing to being in an animal's mouth. Which there's different studies that show that during that transportation process that plants can lose a little bit of their nutritional value through that and just kind of degrading a little bit. So, it's closer, it's fresher and it can be more nutrient dense as well, so.

[00:19:52] Dominique: Really win-win across the board.

[00:19:53] Zack: Absolutely. 

[00:19:54] Dominique: I'm curious also, Not everyone grows food that isn't eaten by humans. Is there anything like extra rewarding or more fun about like growing food for animals?

[00:20:05] Zack: Yeah, absolutely. And I think we get so busy sometimes here in our little area that we kind of forget that we work at the zoo because we don't get to see the animals every day. And that's a really big thing that like our team has tried to be better about is going into the zoo, seeing the animals, and then knowing that you're feeding them really good, really fresh high quality produce. And then too, like the, the fun part too is you get to see kids go up there and feed the giraffes and kind of have that cool little moment that they'll remember. I started coming to the zoo when I was a little kid and I always thought that would be an awesome place to work. And inspiring the next generation of sustainably minded people and kind of fostering that and seeing those moments is really cool. 

[00:20:45] Dominique: I was gonna joke about something along the lines of they don't complain. There's no, imperfect produce when 

you're giving it to an animal, which I, as a grower who's put a lot of time and effort in, the idea imperfect produce is like the most frustrating thing.

[00:20:58] Zack: Yeah. Oh no, definitely. And maybe it would be a lettuce that like is a little bit yellow that personally if that's in my salad, I don't know if I would've want to eat it. But you know, a giraffe sees that and they don't even think second of it. we're also sending food up to our manatees So that's something on the endangered species list. And actually our manatees here are all rescue animals. And we will beef 'em up, get 'em nice and heavy before we take 'em back out to the wild.

So they're here for a year. So that's really cool too, that you're helping endangered species, not only here at the zoo, but eventually that's gonna go back out to the wild and live and hopefully help build up their populations too eventually, that it'll be a stable number and continue their species on.

[00:21:38] Adam: So if somebody is listening and inspired to get involved in sustainable agriculture, where do you think they should start?

[00:21:43] Zack: Yeah, so there's a lot of different that you can do. the number one thing I'm always gonna say is support your local farmers. Go to your farmer's markets, go to all those different things and support your local farmers. Really wanna get your hands dirty and you want to start farming. There's a Community Sponsored Agriculture or CSAs, all over urban areas that you can actively go in and help people farm.

There's also organizations and obviously speaking specifically in Cincinnati, but I'm sure there's other cities in the Midwest as well that are going in and doing gardening and urban farming in blighted areas. So you can check on the old Google and CSAs and community gardens and things like that. Those are things that are all really important. And you might not be able to work in hydroponics. Maybe you can find a place that you could. But there's, like I said, all of these different organizations, they're always looking for volunteers and they're always needing help because farming, it's a labor intensive initiative. So, always needs some extra hands.

[00:22:37] Dominique: Do you recommend any hydroponics resources? I'm curious if you have any book recommendations or places to learn more about like hydroponic specifically?

[00:22:46] Zack: There's a couple of universities that really specialize in hydroponics. So Ohio State University has a great hydroponics in a controlled environment program. There's a lot of different resources they have on their website. I know I've learned a lot from them. And then the other one I'll think of is like University of Arizona as well, has really great hydroponics program and they publish a lot of things.

[00:23:06] Dominique: Maybe you don't wanna start with the scientific papers and that side of it. But there's all different books that you can read. And, YouTube's a great resource, I learned from YouTube all the time. Well, thank you so much for chatting with us. I think the full circle ecosystem that you've been building and finding benefits like time and time again from is just brilliant. But also I think it's just an amazing way to lean into having experts like yourself, building resiliency in spaces that I think are just so important like a zoo that's, also a botanical garden, and has to run as a nonprofit. All those things lead good reason to wanna have resiliency right now. And then, for our listeners, if they want to connect with you or support the work that you're doing, do you have any resources or websites, or socials?

[00:23:49] Zack: Yeah, you can reach out to me on LinkedIn. You also can get on our website and you can fill out the contact desk form if you really wanna learn some more and you can get my information from that. Or you can send me an email at zack.burns@cincinnatizoo.org and I'm happy to answer any questions, cincinnatizoo.org. in the contact us section and they can get that forwarded over to me.

[00:24:11] Adam: Well, thank you again for joining us. As always, our guests have found a unique way to champion sustainability. We are here to put real names and stories behind the idea that no matter your background, career, or interests, you really can contribute in the fight against climate change.

[00:24:24] Dominique: You can find our episodes and reach us at thegreenchampions.com. If you wanna stay in the loop, give us a review and follow us in your favorite podcast platform.

[00:24:32] Adam: Our music is by Zayn Dweik. And special thanks to Green Umbrella, hosts of the annual Midwest Regional Sustainability Summit. Thanks for listening to Green Champions. We'll dig to another sustainability success story in our next episode.

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