Sitting down to eat a salad you may think your greens traveled in a shipping container, but it might not occur to you they were grown in one. Yet this will soon be the case for people eating at MDining’s cafés and halls.
The Freight Farm is a 320-square-foot recycled shipping container outfitted with 256 columns that can grow plants ranging from veggies to flowers. Automated humidity and temperature controls, a hydroponic system and hot pink LED lighting control the plants’ growing conditions.
The farm sits on the U-M Campus Farm at the Matthaei Botanical Gardens. While a Freight Farm typically costs around $75,000, this one is being lent to U-M by LaGrasso Bros. Produce.
While the greens produced there will be sold to MDining, the farm also serves a larger purpose as a research project conducted within the Center for Sustainable Systems.
“The project, funded as a catalyst grant by the Graham Sustainability Institute, initially sought to provide evidence-based decision support for institutional buyers (like MDining) who are faced with a barrage of options that may be seen as ‘sustainable,’” says Martin Heller, senior research specialist at CSS.
Yet the researchers had difficulty procuring data on existing Freight Farms, so they decided to generate their own. The energy needed to operate U-M’s Freight Farm — for lights, air conditioning and circulation pumps — will be monitored along with other inputs like water and nutrients. In August, East Carolina University began using the same data collection tool on its Freight Farm to provide more data.
A life-cycle assessment — or LCA — that considers the environmental impact of all stages of a product’s life cycle will be used to compare greens grown in the Freight Farm with those produced by other methods, such as hoophouses at the Campus Farm or those shipped in from states like Arizona or California. The environmental impact of the Freight Farm structure will be factored in as well.
Greens grown close to home may seem like they’re the most sustainable, but Heller said that isn’t always the case.
“It’s easy to assume that the locally grown greens would fare better, but we know from experience with LCAs of food products that, relative to the inputs required for production, transportation may not be a dominant driver of environmental indicators such as energy use and greenhouse gas emissions,” he said.
While the results aren’t in on the environmental impact of the Freight Farm, it offers a unique way to grow produce in small spaces.
Jocelyn Marchyok, a recent U-M graduate now pursuing her master’s degree at the School for Environment and Sustainability, is working as an MDining sustainability intern to manage the Freight Farm.
Marchyok is filling up one-quarter of the Freight Farm at a time, allowing her to grow around 3,200 heads of lettuce in two months. As seedlings, batches of plants will rest in trays for two weeks before they’re transferred to the vertical columns.
From a sustainability standpoint, one way the farm is unique is in its limited water usage.
“This is a completely hydroponic system, so in terms of water, we’re going to be using a lot less,” Marchyok said.
“The tank by the columns has 135 gallons and the one with the seedlings uses about 35 gallons of water. The water is continuously recycled through so there’s not really any input of water unless I’m cleaning it out, which should be every two or three weeks.”
Marchyok is interested to see the energy usage, as the LED lights are on about 18 hours a day. The lights generate heat, which in turn requires an air conditioning system and dehumidifier. In the winter, a heater may be needed. The LEDs are supposed to be enough to heat the farm, but Marchyok isn’t convinced this will hold true with Michigan winters.
The end goal of the project is to determine the associated energy use per kilogram of salad greens produced and delivered to MDining. While the duration of the project is uncertain, Heller would like to get data from all four seasons to capture seasonal variation.
In the meantime, people eating with MDining can know that their greens are not only coming from less than five miles away, but are contributing to research as well.