U-M Looking to Grow Research Data — and Lettuce — with Addition of Freight Farm to Campus Farm
By Caroline Skiver
Sitting down to eat a salad you may think that your greens traveled in a shipping container, but it might not occur to you that they were grown in one. Yet this will soon be the case for people eating at MDining’s cafés and halls.
The Freight Farm, which typically costs around $75,000 but is being lent by LaGrasso Bros. Produce, is a 320-square foot recycled shipping container outfitted with 256 columns that can grow plants ranging from veggies to flowers. A mix of automated humidity and temperature control, a hydroponic system, and hot pink LEDs control the plants’ growing conditions. The farm sits on the U-M Campus Farm located at the Matthaei Botanical Gardens.
While the greens produced will be sold to MDining, the farm also serves a larger purpose as a research project conducted within the Center for Sustainable Systems (CSS).
“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, like lights, air conditioning, and circulation pumps, will be monitored along with other inputs like water and nutrients. Beginning in August, East Carolina University will use the same data collection tool on their Freight Farm to provide more data.
A life cycle assessment (LCA), which considers the environmental impact of all stages of a product’s life cycle, will be used to compare greens grown in the Freight Farm through those produced with other methods. This includes hoophouses at the Campus Farm or those shipped in from states like Arizona or California. The environmental impact of the Freight Farm structure itself will be factored in as well.
Greens grown close to home may seem like they’re the most sustainable, but according to Heller, this 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.”
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 graduate of U-M who will be entering her master’s at the School for Environment and Sustainability in the fall, 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. 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 very little input of water unless I’m cleaning it out, which should be every two or three weeks,” explains Marchyok.
Yet Marchyok is interested to see the energy usage, as the LEDs are on around 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.