A group of Penn State students huddles over a wooden worktable in Headhouse II. Their hands move in unison as they clip the leaves and clean a harvest of microgreens, which were planted in the greenhouse in early spring. In a few days, the gardeners-in-training will dine on the tiny leaves (that look more like shamrocks than lettuce) during an end-of-semester potluck.
Alongside their microgreens, the students grew organic tomatoes, cucumbers, eggplants, peppers and herbs as part of a hydroponics and aquaponics class, which taught the ins-and-outs of using soilless processes to grow plants. The students’ efforts — which on a weekly basis yielded up to 80 pounds of cucumbers alone — were a success, in part, due to new technology added to the nearly 60-year-old greenhouse.
Headhouse II, which was built in 1960, and eight other College of Agricultural Sciences greenhouses were updated last year with climate-control computer systems, LED lighting, a rooftop weather station and other automated tools.
Like plants in any ecosystem, those in greenhouses need a well-calibrated mixture of light, water, air and nutrients to thrive. However, creating ideal climate conditions and growing habitats can be expensive in older buildings, according to Scott DiLoreto, greenhouse operations manager at Penn State. He says adding the modern climate-control technologies has helped him to not only grow healthy plants, but to reduce energy costs and outputs as well.
“The technology we added has made it possible for teaching, learning and research to happen in the greenhouses at a scale that wasn’t possible before,” DiLoreto said. “Prior to the upgrades, a number of the greenhouses weren’t particularly useful in summer or winter, because temperatures would be too high or low to grow plants. Now that we can efficiently control the internal climate, there’s more usable space and it’s more functional for a range of activities.”
Using a new Wadsworth climate-control system, DiLoreto is able to manage the mechanical systems (including air circulation fans, misters and heat pumps) that determine temperature, light and humidity in every compartment of each greenhouse — about 50,000 total square feet. While he can pre-program or change each setting manually from his computer or smartphone, he can also set the system to auto adjust based on outside weather conditions.
“We installed a rooftop weather station on Headhouse I that measures wind speed, wind direction, temperature and light intensity from the sun,” DiLoreto said. “The information from the weather station communicates with each greenhouse compartment computer, so I can program the mechanical systems to automatically adjust based on the weather outside.”
When sunlight goes above or below a pre-programmed value, new supplemental LED lighting, which replaced the older high-intensity discharge lights, will kick on or off.
“If the sun gets really bright, you don’t need the LED lights,” DiLoreto said. “Conversely, I can program it so that if the lights are off in the greenhouse and it all of a sudden gets really cloudy outside, the weather station will detect that and tell the computer to turn on the lights. And since LEDs only produce the red and blue wavelengths that drive photosynthesis, no energy is wasted producing light that doesn’t support growth.”
Helping plants grow is also something Robert Berghage, associate professor of horticulture and extension specialist in greenhouse crop production, has been teaching and doing for decades.
This spring, Berghage set up shop in Headhouse II to teach the University’s first course about hydroponics and aquaponics, which use nutrient solutions and fish waste to fertilize plants instead of soil. Berghage says student demand for the course (which he co-taught with Elsa Sanchez, an associate professor of horticulture systems management) has been on the rise for years, in part due to the “buy fresh, buy local” movement and a growing interest in understanding where food comes from and how it’s produced.
“I think the sustainability element of these processes is also intriguing for students. Hydroponics yields are much, much higher than they are for an equivalent crop out in the field, and water use tends to be more efficient as well since we’re watering in a closed-loop system where very little water is wasted,” Berghage said. “The new greenhouse climate controls helped us a lot this semester, and the LED lights enabled us to produce vegetables during a portion of the year when we wouldn’t have been able to otherwise — and now each student is harvesting and taking home five heads of lettuce each week.”
As a group, the 21-student class was responsible for building the hydroponics and aquaponics systems (including the fish tanks), choosing climate settings, and fertilizing, watering, caring for and harvesting their plants. They also learned business skills and the economics of operating a Community Supported Agriculture (CSA) program and greenhouse for profit.
“By setting up a CSA and learning business and food safety procedures, the students are now in a position where they could start a small hydroponics or aquaponics business if they wanted,” Berghage said. “If not, just having the experience of growing their own food is incredibly useful. Learning how to produce food in an environment with this kind of technology helps reinforce a lot of other scientific and educational goals.”
In addition to teaching and learning, there’s also more research happening in the greenhouses, according to DiLoreto.
“We’ve had an influx of new faculty and researchers from plant science, plant pathology, environmental biology, entomology, ecosystem science and management and other departments,” DiLoreto said. “I’m now able to provide them with much better data — such as detailed logs of temperatures, weather and watering schedules over a period of time — to use in their analyses and journal articles.”
DiLoreto says the IT is also helping him keep up with the needs of thousands of varieties of vegetables, fruits, flowers and succulents in his care.
“The first thing I do when I get to work in the morning is turn on my computer and scroll through the settings for each greenhouse to see if everything is okay,” DiLoreto said. “I can manage 50,000 square feet from my desk — and so far, the computers have only made my days easier. But, I still think there’s something about going into the greenhouse to feel the air and see the plants that you can’t learn from looking at a screen. Maybe I’m just old school.”