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Harvest Public Media is a reporting collaboration focused on issues of food, fuel and field. Based at KCUR in Kansas City, Harvest covers these agriculture-related topics through an expanding network of reporters and partner stations throughout the Midwest.Most Harvest Public Media stories begin with radio- regular reports are aired on member stations in the Midwest. But Harvest also explores issues through online analyses, television documentaries and features, podcasts, photography, video, blogs and social networking. They are committed to the highest journalistic standards. Click here to read their ethics standards.Harvest Public Media was launched in 2010 with the support of a grant from the Corporation for Public Broadcasting. Today, the collaboration is supported by CPB, the partner stations, and contributions from underwriters and individuals.Tri States Public Radio is an associate partner of Harvest Public Media. You can play an important role in helping Harvest Public Media and Tri States Public Radio improve our coverage of food, field and fuel issues by joining the Harvest Network.

Tapping in to the Earth's Energy to Grow Local Food

Grant Gerlock/Harvest Public Media
Russ Finch holds up half of a Cara Cara orange that grew in his geothermal greenhouse.

The middle of winter is when the stream of locally grown fruits and vegetables in the Midwest begins to freeze up.  Nicole Saville knows first-hand. Saville is the produce manager at the grocery co-op Open Harvest.

The store -- in Lincoln, Neb. -- promotes food grown by local farmers, but this time of year there just isn’t much available.

“We can get kale and some culinary herbs this time of year,” Saville said. “Otherwise the only other local option is a soil mix in our garden center.”

That means the bunches of carrots, bags of onions, and piles of pears on shelves from Lincoln, Neb., to Ames, Iowa, to Columbia, Mo., made a long trip to get there.

Credit Grant Gerlock/Harvest Public Media
Nicole Saville is produce manager at Open Harvest grocery coop in Lincoln, Neb. Whenever possible she orders from local farms, but in the winter few farmers are able to keep producing fresh fruits and vegetables.

“This time of year we are sourcing globally almost,” Saville said. “It hurts me to say because the fossil fuels it takes to get things here are astronomical. But we try to source from within the United States when we can. Florida and California are going to be the two biggest options.”

In the Midwest, it’s possible to stretch the growing season for nine months or more with unheated hoophouses or high tunnels, metal frames stretched over with plastic coverings. But even a well-insulated high tunnel is likely to have to go dormant at some point.

Greenhouses can produce year round, but they are typically heated by burning fossil fuels. That’s why growing in local greenhouses isn’t always best for energy consumption, says Dawn Thilmany, who studies the local food system at Colorado State University. .

“It might actually, energy-wise, make more sense to ship from far away distances because we do have a lot of energy efficient ways to ship including trains, barges and such,” Thilmany said.

But some creative locally-focused growers are working on ideas that could change that equation.

“In the case where people are being innovative, where some of that energy is in alternative forms, it might make sense to produce locally year-round,” Thilmany said.

Credit Grant Gerlock/Harvest Public Media
Russ Finch of Alliance, Nebraska designed his first geothermal greenhouse around 20 years ago. He sells new designs which have been built in six states.

One alternative is up-and-running in western Nebraska, created by an amateur engineer. Former mail carrier and farmer Russ Finch built a greenhouse near Alliance, which he calls the Greenhouse in the Snow. Though it looks ordinary from the outside, inside it’s a citrus grove with lemons the size of oranges and oranges the size of grapefruits. In Nebraska.

“We can grow the best citrus in the world here on the High Plains,” Finch said one afternoon as he was walking me through the original greenhouse design he built 20 years ago.

And it doesn’t break the bank or suck too much energy because the other unique aspect about his greenhouse is that it’s geothermal. It harnesses the earth’s heat by pumping air through underground tubes to heat and cool the plants.

“All we try to do is keep it above 28 degrees in the winter,” Finch said. “We have no backup system for heat. The only heat source is the earth’s heat at 52 degrees at 8-foot deep.”

Credit Grant Gerlock/Harvest Public Media
Generally, locally grown fruits and vegetables have a lower carbon footprint because it travels a shorter distance to consumers. But if it's grown in a greenhouse heated with fossil fuels, that carbon advantage is likely lost.

The idea behind Finch’s design is that you can grow a variety of crops year-round in a low-energy, low-carbon system. If that were to work on a large scale, Nebraska stores could sell local lettuce in the dead of winter. Maybe even local oranges.

Designs for low energy greenhouses vary; some move air or water underground, while others heat water in solar cells and store it in tanks to heat the greenhouse at night. Stacy Adams, a horticulture and greenhouse management instructor at the University of Nebraska Lincoln, says whatever the method it’s aimed at the same goal: to find a sustainable ways to get through cold winter nights.

“We could use fossil fuels, but if we can make the environment better by using sustainable options why not do it?” Adams said. “It’s basically free energy that we can capture.”

And that’s better for a farmer’s bottom line because energy is one of the biggest costs for Midwest greenhouses.

Adams says geothermal greenhouses can work, but there are limitations to such a low-energy system. For instance, Adams says they are best suited for cold crops like kale, cabbage, or lettuce.

“But when we start getting to the warm-loving crops like tomatoes, which everyone loves, or cucumbers and squash, then we’re talking about greenhouses that need to be much warmer,” Adams said.

It’s actually easier to grow oranges in a cold greenhouse than tomatoes, Adams says.

Also a low-energy greenhouse is most efficient if it’s relatively small. It might supply a farmers market, but probably not a supermarket.

To grow more, you’ll need more energy. Perhaps fossil fuels. But that’s where Adams says people should think outside of the box. Imagine using heat from the wastewater at a factory like a slaughterhouse or an ethanol plant. He says manure from dairy barns or beef feedlots could generate methane to heat a greenhouse.

Any method that incorporates renewable energy sources would improve the footprint of local food grown in a greenhouse when compared to the shipments brought in from California or Mexico.

That could give winter a local flavor, even in Nebraska.

Harvest Public Media's reporter at NET News, where he started as Morning Edition host in 2008. He joined Harvest Public Media in July 2012. Grant has visited coal plants, dairy farms, horse tracks and hospitals to cover a variety of stories. Before going to Nebraska, Grant studied mass communication as a grad student at Miami University in Oxford, Ohio, and completed his undergrad at Buena Vista University in Storm Lake, Iowa. He grew up on a farm in southwestern Iowa where he listened to public radio in the tractor, but has taken up city life in Lincoln, Neb.