LEXINGTON, Va., June 21, 2022—With recent grocery store shortages and rising food costs, many people are considering growing their own fruits and vegetables. But what do people do who live in urban areas, with little or no garden space available? Anne C. Townsend ’24, a civil and environmental engineering major, studied that problem in her Summer Undergraduate Research Institute (SURI) project titled, “A Study in Hydroponics: Comparing Vertical and Horizontal Nutrient Film Technique Systems for Maximum Yield and Feasibility.”

Townsend, who grew up on a small farm in Crozier, Virginia, where her family works to produce their own food, pointed out that agricultural practices need to adapt for several reasons: due to pollution and land overuse in the last 40 years, one-third of the world’s cultivatable land has been lost; small family farms have largely faded into history, being taken over by massive, large-scale mechanized farms that use high-tech equipment; and the growth of the human population.

One sustainable food production method is the use of hydroponics and urban farming. Hydroponics is a one-crop oriented system, cycling nutrient-enhanced water through a series of pipes for the growth of plants. “Hydroponic start-up costs are higher than traditional agriculture, but due to year-round harvesting and significantly less water, land, and pesticide usage, (since hydroponics can be placed in an indoor, controlled environment,) in the long-term, hydroponic crops earn ten-times that of traditional cultivation methods,” said Townsend.

She wanted to compare two different hydroponic systems: vertical and horizontal, to discern if there is a difference in crop yield, and to discover which is more environmentally and economically feasible for dining services on a college campus, specifically for use in growing lettuce at Virginia Military Institute. “According to Parkhurst Dining, VMI’s food services vendor, the Corps of Cadets consume, on average, 40-50 pounds of lettuce per day – that’s up to 350 pounds per week,” noted Townsend, who hopes her experiment will result in a permanent supply of lettuce, microgreens, tomatoes, and even strawberries for Crozet Hall (dining hall at VMI), in the time frame of five weeks, while maintaining a high standard of efficiency and sustainability.

Townsend’s first step was to construct the vertical system, consisting of two units, which took her several days to complete. She built the system out of five-gallon buckets, a pump system, and PVC pipes, which she was able to purchase at local retail stores. The total cost of the system was under $500. Each unit is approximately six-feet tall by three-feet wide. It holds 144 cultivating cups for seedlings and constantly cycles through 25 gallons of water.

The two horizontal systems used by Townsend, were cultivated by her friend and roommate, Grace Rader ’24, who is also working on a SURI project regarding vegetable growth and hydroponics. Each horizontal unit stands 41” high by 37” wide by 19” deep, and holds 108 cultivating cups. Each one costs $144 to construct, and constantly cycles through 5 gallons of water.

Both systems are located in the VMI greenhouse, where Townsend carefully inspects the growth of each seedling daily, monitors the water trickling through the systems, and records her findings. After one week of growth, Townsend will add two different plant food nutrients to the water to supplement seedling growth, and will compare the growth of the seedlings from the two different plant foods.

Dr. Tanjina Afrin, assistant professor in civil and environmental engineering and one of Townsend’s advisors for the project, said, “I think the best thing I will remember from this SURI project is Anne's excitement, her long-term vision, and self-motivation.”

Another of Townsend’s advisors, Maj. Rebekah Martin, assistant professor in civil and environmental engineering, shared Afrin’s praise of Townsend. “Anne has worked hard to build and design these systems on her own. She knew what tools she needed and knew or learned how to use them during week one. It will be very interesting to see how her vertical design compares to the horizontal designs,” said Martin.

Townsend plans to pursue a master’s degree in architecture after graduating from VMI. She is interested in incorporating hydroponics in architectural designs to help feed future populations.

Marianne Hause
Communications & Marketing
VIRGINIA MILITARY INSTITUTE