Hydroponics
Using a controlled environment to grow soilless crops
Students carefully move through towering green tomato vines, methodically removing excess leaves. The plants, grown hydroponically in a campus greenhouse at the college’s horticulture unit, have grown from seedlings to more than 8 feet tall in less than 10 weeks. Soon, they will fruit.
The greenhouse vegetable production class, offered in the fall quarter, teaches students how to grow crops hydroponically – the practice of using nutrient-rich water and no soil in a controlled environment to grow the plants. The 15 students in class start with an empty greenhouse and quickly learn hands-on how to cultivate vegetables such as tomatoes, peppers, cucumbers and leafy greens.
Sarah Grizzle, a third-year agricultural and environmental plant sciences major, grew up in the Imperial Valley, surrounded by agriculture. She took the enterprise course because she was interested in learning a new aspect of growing vegetables. “We have been a part of the process from preparing the greenhouse, to transplanting the plants, to learning to control the nutrients for optimal growth,” she said. “I have definitely learned a lot in just a few weeks.”
For many students, this is the first time they have been introduced to growing hydroponically in greenhouses. They quickly learn that in a controlled environment with heat, good light and irrigation, we are able to grow vegetables year-round.— Susan Snyder
Vertical agriculture continues to grow in the U.S. and is being used as a tool in meeting increased demands for food production as the world’s population is projected to surpass 9 billion by 2050. The practice allows growers to produce desired vegetables year-round. “For many students, this is the first time they have been introduced to growing hydroponically in greenhouses,” said Susan Snyder, a lecturer in the Horticulture and Crop Science Department. “They quickly learn that in a controlled environment with heat, good light and irrigation, we are able to grow vegetables year-round.”
Students take shifts managing the greenhouse, measuring fertilizer levels, checking on the irrigation system and the temperature and health of the plants daily. The class also visits 168-acre Windset Farms in nearby Santa Maria – getting a first-hand look at a commercial scale hydroponic farm.
A state-of-the-art fertilizer injection system,which is used to pump the water and nutrients to the plants, was recently upgraded by Innovative Control Systems – giving students direct experience using similar technology found in commercial operations. “We work directly with industry to ensure that our students are fully immersed in understanding hydroponic growing,” Snyder said. “By visiting farms, they get a true sense of how big the industry is and the opportunities that are available to them.”
During winter quarter a successive class is offered that teaches students how to harvest, market and sell the produce at farmers markets, both on campus and in downtown San Luis Obispo. The courses take the students through the full cycle of production, Snyder said.
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