What would happen if we grew wheat not on acres of land but in multistory structures that look like office buildings? The answer: yields as much as 600 times greater than those of traditional farming methods, according to a study just published by researchers at the University of Florida Institute of Food and Agricultural Sciences. Growing food in stacked layers is called vertical farming.
“This is the first study to simulate growing wheat with vertical farming,” said Senthold Asseng, professor of crop systems modeling in the department of agricultural and biological engineering, and the lead author of the study. “Wheat is the most important food crop in the world. But, this study can also be a ‘model’ for exploring the potential yield for any other crops for vertical farming.”
Unlike outdoor farms, vertical farms are a controlled growing environment. This controlled environment shields crops from the elements, eliminates the need for pesticides and herbicides, recycles water and fertilizer, optimizes the amount of light plants receive and allows for several harvests per year rather than just one.
Furthermore, vertical farms require far less land and can be built in places usually inhospitable to agriculture. For example, vertical farms could grow wheat in the deserts of the Middle East, where farms could be powered by solar energy, the study’s authors say. These advantages allow vertical farms to produce more food with fewer resources.
While vertical farming has been practiced commercially for about a decade, today it is mainly used to grow high-value crops, such as leafy greens and herbs, said Asseng, who is also the director of the Florida Climate Institute. “Vertical farming became possible with the invention of light-emitting diodes (LEDs) in the 60s. But the breakthrough came in the last 10 years when LEDs became affordable and so efficient that they are redefining the economics of indoor farming,” Asseng said.
He and his collaborators wanted to simulate how vertical farming would affect the production of wheat, which provides 20% of the world population’s calories and protein. Producing more food with less is a critical challenge as the world’s population rises, Asseng said. “Today, one in nine people face hunger. By 2050, we will have close to 10 billion people on earth, and we will need to produce more food, without more land, with less water and without polluting our environment. On top of this we have climate change threatening agriculture worldwide,” he said.
To simulate how various farming methods affect yields, scientists like Asseng use computer models to game out how factors such as a crop’s genetics or available water will impact crop production. In this study, researchers compared yields of wheat grown on one hectare of land — approximately the size of two football fields — to wheat grown on the same area but in ten stacked layers, where the plants would be grown hydroponically.
These simulations help pave the way for real world experiments and the development of crop varieties suited to that method. However, farming wheat vertically still has a long way to go, Asseng said.“Since wheat is cheap, currently about $180 per ton, the equipment, the LEDs and the energy for the lights are too expensive to make vertical farming economically viable in the near future for wheat. The price of LEDs and energy would need to drop drastically for it to be profitable,” he explained. “Having said that, there might be nations that want to use vertical farming to invest in their food security without aiming for a profit.”
Asseng hopes this study creates new opportunities for interdisciplinary research into vertical farming for critical world crops on which future populations will depend. Such studies could investigate ways to make vertical farms more energy efficient, as well as breed plants that are adapted to vertical farms and are more nutritious.
This study came out of such an interdisciplinary team, which includes Jose Guarin, a postdoctoral researcher with the UF/IFAS department of agricultural and biological engineering; Mahadev Raman, director of the engineering firm Arup; Oscar Monje with the Kennedy Space Center Air Revitalization Lab; Gregory Kiss with the Kiss + Partners architectural firm; Dickson Despommier, professor emeritus at Columbia University; Forrest Meggers, assistant professor of architecture, and Paul Gauthier, associate research scholar of geosciences, both at Princeton University.
The study, “Wheat yield potential in controlled-environment vertical farms,” is published in PNAS.