Fish and Lettuce

Mageau with lettuce

Mike Mageau hefts a polystyrene float full of lettuce plants in the Victus Farms greenhouse.

You can raise tropical fish in Minnesota. But why would you want to? To feed the lettuce, of course. It’s called aquaponics. The veggies filter the water, and the fish fertilize the veggies.

A couple of guys working on a university-funded fish and veggie operation in Minnesota have come to think that small, backyard fish and vegetable farms might be the wave of the future.

 

Tony Beran’s standing in the kitchen at the Lake Avenue Restaurant in Duluth with a head of romaine lettuce in one hand and a clump of curly lettuce in the other.

“They’re beautiful,” he says.

He’s the executive chef, and one thing he likes about these bunches of lettuce is how clean they are.

“They’re grown aquaponically instead of in dirt,” he says. “Which is wonderful in the kitchen. It’s less labor for us.”

Another thing he likes about this lettuce is that it was grown just up the road. The restaurant features local ingredients, and Beran serves locally grown lettuce all year, which is a bit of a trick in a place like Duluth. Last winter, the temperature was below zero 23 days in a row.

But it’s always warm in the greenhouse at Victus Farms. That’s where Beran’s lettuce came from. It’s about an hour’s drive from Duluth in a little mining town called Silver Bay.

Mike Mageau (right) and Baylor Radtke with their floating lettuce in the Victus Farms greenhouse.

Mike Mageau (right) and Baylor Radtke with their floating lettuce in the Victus Farms greenhouse.

“These are all our babies,” says Mike Mageau, as he shows off his latest lettuce crop.

He runs the place, and he’s an unlikely looking farmer. He’s wearing cargo shorts and a backwards ball cap and he’s barefoot. He’s an unlikely looking professor, too, but that’s his job: professor of geography at the University of Minnesota Duluth. He runs a program in environment and sustainability, and this indoor farm is a research project.

Universities and private businesses across the country are experimenting with aquaponics.

“It’s kind of fun,” Mageau says. “It’s like the electric car. It’s almost a race to come up with the method or the model that really works well.”

Most of Mageau’s lettuce is floating. Each plant is stuck into a hole in an inch-and-a-half thick sheet of polystyrene foam. The foam rafts float in pools in the greenhouse, and the lettuce roots dangle through the foam into the water.

The fish live in a neighboring room. They’re tilapia, and they swim in nine, round plastic tanks, each one about six feet tall. Waste from the fish gets pumped over to fertilize the plants in the greenhouse, and some of the pools in the greenhouse grow algae and duckweed that come back into this room to feed the fish.

“Which means you grow fish and plants sort of in concert, one living off the other,” Mageau says.

Two years into the project, Victus Farms sells all the fish and vegetables it can produce to local restaurants and stores. Now the goal is to get more efficient.

Here’s an idea Mageau and his crew got online and then spent six months refining.

They built floor to ceiling racks made of PVC pipe. Each rack looks sort of like a ladder. On the horizontal pipes, they drill holes in the top and stick a plant in each hole. Then they run nutrient-rich water from the fish tanks through the pipes, bathing the roots of the plants.

“It’s all trial and error,” Mageau says. “You know, ‘I wonder if we can grow tomatoes in four-inch pipe?’ Yes! You try it and it works! I mean look at these tomatoes, there’s millions of them.”

Mike Mageau picks a strawberry from a plant growing in PVC pipe

Mike Mageau picks a strawberry from a plant growing in PVC pipe

One wall of the greenhouse is covered with ripening tomatoes and strawberries growing out of white, plastic pipes. And the fruit looks good.

Mageau’s banking on this vertical gardening scheme for the future. It will let them make use of some of the empty vertical space, and it will allow them to move the fish into the ponds in the greenhouse, making the second room for fish unnecessary.

“Then we can grow probably 10 times the plants per unit surface area, which means our greenhouse needs to be one tenth the size, “ Mageau says.

He wants to pilot a small, hyper-efficient version of Victus.

“Every small town could have one or two or three of them,” he says. “And the food could literally be produced in the backyard of the restaurants or whatever.”

Mageau says aquaponic operations will never replace farming in dirt, but they could give a big boost to the amount of local food that’s available, especially in places with short growing seasons.

The Victus building cost about $2 million, but Mageau thinks a self-sustaining version could be built for a small fraction of that. And it really could be built in someone’s yard.

So that’s what he’s doing next.

Mageau and Radtke are building new, much smaller fish and vegetable operation in Radtke's yard with their own money.

Mageau and Radtke are building a new, much smaller fish and vegetable operation in Radtke’s yard with their own money.

Mageau’s right-hand man at Victus is Balyor Radtke, a former student. The two of them pooled their money and on their own they’re building a much smaller and simpler fish and vegetable operation in Radtke’s yard in Duluth.

“The whole point of it is to allow people to grow as much as we did in that $2 million facility in a facility that costs under $100,000,” Radtke says.

Way under. Radtke and Mageau say the new operation will cost only $20,000 to build because they’re doing all the labor. The annual energy costs will be comparable to single-family house, and they’re cutting those even further with solar panels on the roof of the greenhouse.

They figure they’ll bring in $50,000 in the first year. And that’s from a building the size of a four-car garage, about 24 feet by 52 feet. They plan to be completely up and running by this fall.

If it works in northern Minnesota, they say, imagine how well it could work someplace warm. Like Iowa.

-Chris Julin

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From Rice to Shrimp

By Christopher Johnson

It’s the rainy season here in Tran De. About a dozen field workers have squished out into a green paddy that goes on for more than two and a half football fields.

They chatter in Khmer as they bend low and pull young rice plants from their monsoon-soaked beds, and toss them into piles for replanting.

“I was born in this area, I’m from this area,” says a 64-year-old farmer named Minh. “I learned from my father and my grandfather, from the time I was a kid, how to grow rice.”

Minh is renting the land to grow his crop. “Rice is good,” he says, “you can always eat it. It’s reliable.”

At least right now it is.

Some of Hai Thach’s usually green fields are starting to yellow. He says that's a sign of saline intrusion. (Photo: Christopher Johnson)

Some of Hai Thach’s usually green fields are starting to yellow. He says that’s a sign of saline intrusion. (Photo: Christopher Johnson)

Things will change when the dry season starts in January. That’s when farmers here usually start raising a rice crop, typically relying on fresh water they pump or channel in from some branch of the Mekong River.

But the dry season has been getting dryer. And the South China Sea – less than a mile away – is rising and pushing up into empty river and stream beds.

What little fresh water there is goes salty. So does the soil.

Once that happens, rice farmers like Minh know their crops are history.

“This village is affected by saline intrusion,” he explains. “During the dry season, people here can’t do anything with the land. They just leave it, go somewhere else and work, or try to find some work locally.”

If Minh risked planting a dry season crop, he could earn more than $2,000.

But he won’t take that chance. Instead of fighting saline intrusion, he’s found a way to hedge his bets and make some money off climate change.

Many rice farmers are switching to saltwater shrimp as a crop, to eliminate risk from salinization. Paddles aerate a shrimp pond, adding oxygen to the water. (Photo: Christopher Johnson)

Many rice farmers are switching to saltwater shrimp as a crop, to eliminate risk from salinization. Paddles aerate a shrimp pond, adding oxygen to the water. (Photo: Christopher Johnson)

He’s gone and bought himself a shrimp farm.

So has another farmer, named Sung. Standing beside two shrimp ponds out behind his house, Sung fires up what looks like a system of small spinning steamboat paddles.

They’re adding oxygen to an opaque brown pool.

This salty water is killing off the region’s rice, while the shrimp, somewhere down at the bottom, are loving it.

They can earn Sung in a year more than four times what an average rice farmer brings home.

“In a good year,” Sung says, “I do two crops. If it hits, I get $4,720 from these two ponds. This is the only thing I can do. Growing rice is not very profitable.”

With very few choices, explains Tim Gorman, a Cornell grad student researching how peoples’ lives in the Mekong Delta are being changed by global warming, some farmers are turning away from rice.

“The biggest option to people here in these areas affected by saline intrusion,” Gorman explains, “is to abandon rice altogether and switch to saltwater shrimp.”

This has been a “winning strategy” for many people in the area, Gorman observes. “Just driving around here you can see that there are big new houses, you see some nice new cars. And so you have some people who really have made a lot of money from growing shrimp, which is primarily exported to markets in Europe, Asia, and the US.”

A shrimp farmer named Sung pulls a basket loaded with shrimp from the bottom of one of his ponds. (Photo: Christopher Johnson)

A shrimp farmer named Sung pulls a basket loaded with shrimp from the bottom of one of his ponds. (Photo: Christopher Johnson)

Shrimp farmer Sung isn’t doing quite that well. He’s helping his daughter pay for college, but there’s no fat new Mercedes in the driveway.

That kind of money goes mostly to big-time farmers. Some people earn tens of thousands of dollars a year in the shrimp trade. With the lure of five and six-figure profits, plus faltering rice crops killed off by rising seas, Gorman says some folks are even taking hammers to the very gates and dykes set up to protect the area from the ocean.

“People are actively manipulating the infrastructure,” he says, “sabotaging the infrastructure, to allow salt water to come in. Not just during the dry season, but all year, so they can switch from freshwater rice farming to saltwater shrimp farming.”

Shrimp is no sure bet, either. Seeds, antibiotics, aeration systems, start-up costs – kilo for kilo, it’s way more expensive to raise than rice. A few sick ones can take out a whole pond.

Sung says he’s gone bust before. “In a bad year, all I have left are the whites of my hands!”

That’s the risk for most farmers here – rice, shrimp, or anything else.

But more and more, those who can afford it are moving away from rice and putting their money down on a changing climate.

Christopher Johnson is a freelance journalist who has worked in public radio as a producer, reporter, editor, commentator, and manager.

This story appeared on Marketplace.

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