Cadets create indoor farm inside shipping containers

January 11, 2019January 14, 2019last updated on January 14, 2019 at 12:27 Science & Mathematics Students

Cadets look at lettuce in the sustainable farm container on The Citadel campus

Inside three shipping containers on the campus of The Citadel, a military college in South Carolina, cadets are learning how to grow lettuce crops in a controlled indoor “farm” setting, producing organic produce in an environment that can withstand unpredictable weather conditions and disease. The cadets’ hands-on education comes from The Citadel Sustainability Project, in which the first shipping container functions as a hydroponic cultivation system for lettuce crops, the second container is a testing ground for various growing systems, and the third container will be outfitted by cadets who design and build the growing equipment as part of a corresponding independent study.

The Citadel STEM Center of Excellence initiated the project in 2016 as an interdisciplinary collaboration. Of the 20 or so students who are members of the Sustainability Club, several are STEM Scholars. We also have electrical engineers who are completing a design project on hydroponics. We’ve had students from almost every campus department — engineering, biology, business — who have worked with the project.

Prior to their graduation, Alex Richardson, who studied engineering, and Cameron Brown, who studied business, managed the growing container with the help of other students motivated by a passion for the environment.

“Cadets are excited about The Citadel Sustainability Project because it incorporates biology, chemistry, computer science, business, engineering, and community outreach. It gives us the opportunity to collaborate with students outside of our own programs on a project focused on global population needs,” Richardson says. “And seeing people on campus eat and enjoy our crops is gratifying.”

A sustainable food source

We’re currently growing more than 4,400 plants in the shipping containers, including collards, lettuce, spinach, and herbs. The nutrients used to grow the crops are recycled within the system’s 100-gallon reservoir and are managed through a smartphone application. The app tracks the metallic minerals in the water and sends nutrients to the plants every 10 minutes. It also displays the water’s temperature and the container’s carbon dioxide and pH levels.

Cadets walk down the middle of the sustainable farm container — More than 4,400 plants, including collards, lettuce, spinach, and herbs, grow in the container. Photo by Stefanie Swackhammer.

The transformation from seed to harvest inside the shipping container farm occurs in five weeks, compared with the 10 weeks the crops would need in an outdoor environment. Thanks to high-density crop production, the cadets harvest more than 800 heads of lettuce per week for the campus restaurant’s salad bar as well as events. Additionally, cadets get to eat the fresh lettuce in the student mess hall. If the growing container is running at full capacity, the 320-square-foot space can yield about 40,000 heads of lettuce per year.

Each container is valued at $115,000 after it’s outfitted. The cadets intend to make the project sustainable by putting profits from the crops toward the purchase of more containers.

“Our self-propagating irrigation system uses up to 98 percent less water than conventional industrial farming does,” says Brown, who wrote the project’s business plan. “We want to expand, grow more, and sustain this Earth-friendly initiative, making our healthy produce available to more members of our community.

In addition to providing a sustainable food source, the goal of the project is to help young entrepreneurs and members of other disciplines gain hands-on experience.

We also try to bring in high school students. Last spring, students from Burke High School, which is next door to our campus, incorporated the indoor farm into one of their projects. Then, a 10th grade economics class wrote business plans for the container with data we provided, and followed up with two field trips to the container.

One of two containers is installed on The Citadel's campus — The container farm is installed in a corner of campus, leaving room for expansion. Photo by The Citadel.

The shipping container farm is located in a back corner of campus near the marsh, with plenty of room for expansion. We’ve submitted a National Science Foundation grant application with The GEL Group, AmplifiedAg, and SuperGreen Solutions to design a system that would filter excess nutrients out of treated wastewater and incorporate sustainable energy so the system could be viable anywhere. Ultimately, we’d like to expand the project to be able to produce more fresh food for the South Carolina Corps of Cadets, which comprises the college’s undergraduate population.

Our advice for other schools thinking about starting a small, sustainable farm like ours: Have a faculty member who’s invested in the success of the project and understands that student interest will wax and wane depending on schedules. It’s also important to have a succession and mentoring plan for students. Seniors mentor juniors; juniors work with underclassmen. That will keep the farm going strong.

Jennifer Albert is the director of The Citadel STEM Center of Excellence. Dalia Martinez graduated from The Citadel in May 2018, and is now a researcher at The Medical University of South Carolina.