Continuing Education: Urban Agriculture
Vertical Harvest intends to build up to 15 farms in the next five years, with agreements already in place for projects in Philadelphia and Harrisburg, Pennsylvania, and Chicago, and discussion is under way for five other locations.
Katharine Logan
Architectural Record
Apr 1, 2021
Excerpt:
“Controlled environments have been used for many years,” says Chieri Kubota, a professor of controlled environment agriculture (CEA) in the Department of Horticulture and Crop Science at Ohio State University. “Now that multiple issues are making conventional production outdoors more difficult, putting controlled environments in and near cities brings food production closer to potential markets—and also to younger generations of potential farmers who want to live in urban centers.”
Vertical agriculture is a type of CEA that—like high-rise buildings—stacks layers to provide usable area many times the footprint of the site. Instead of growing in soil, which is a heavy way to deliver nutrients, plants in vertical farms are grown hydroponically, aquaponically, or aeroponically. In hydroponics, plants are cultivated in nutrient-enriched water, which is captured and reused so that the system uses as little as a tenth of the water conventional agriculture needs. An aquaponic system pairs hydroponics with fish production, circulating the nutrients in the fish waste to feed the vegetables, and using the plants as a biofiltration system that returns clean water to the fish. Reducing water consumption even further—by as much as 98 percent, compared to field growing—aeroponic systems deliver nutrients in a fine mist to plant roots that are just hanging in the air. And because controlled environments exclude the weeds and pests that trouble field-grown produce, the use of herbicides and pesticides is all but eliminated.
