Picture this: a downtown greenhouse skyscraper. On each floor are rooms filled with LED lights used to grow leafy greens, tomatoes, cucumbers and even watermelons year round. Sound like a scene out of a science fiction movie? If Columbia University professor Dickson Despommier is right, this type of vertical farming could be part of agriculture’s future.
Despommier envisions the world’s food system will increasingly turn to vertical farms to help feed a hungry planet. By the year 2050, the world’s population is expected to be 9.1 billion, up from about 7 billion today. That translates into a 60 percent increase needed in global food production, according to the United Nations. Despommier estimates that the amount of new farmland needed to grow the amount of food needed in 2050 is larger than Brazil. Unfortunately, more than 80 percent of the world’s land that is suitable to grow those crops is already being used.
That’s where vertical farming comes into play, says Despommier, author of “The Vertical Farm.” He defines vertical farming as growing food inside a building that is at least two stories high often with the use of hydroponics (submerging plants’ roots in nutrient-fortified water), aeroponics (spraying roots with a similar solution) and LED technology.
“In many places, indoor farming is a real solution to a growing problem,” he said on Town Hall Ohio, Ohio Farm Bureau’s public affairs radio show that is broadcast statewide. Despommier noted, however, that vertical farming is a supplement, not substitute, for the current farming system.
Southeast Asia is one area where the idea has taken off. Japanese businesses started investing in vertical farms after the 2011 earthquake, tsunami and nuclear reactor meltdown. Those three events contaminated part of Japan’s farmland and created distrust among consumers about their food supply, Despommier said.
“The people of Japan did not trust their food anymore because of fear of radioactivity getting into their food. Over the next three years, over 200 vertical farms were created when there were almost none before that,” he said.
The type of indoor farming in Japan ranges from large-scale leafy green production in a warehouse to hydroponic lettuce grown in some stores of the Subway sandwich chain. In a 4-story-high greenhouse-like building in Singapore, conveyer belts move potted vegetables along windows so every plant has the same amount of sunlight, Despommier said. Singapore’s abundant sunlight, frequent rainfall and warm temperatures are ideal for vertical farms in the small island country, which produces only a fraction of the amount of vegetables residents consume yearly.
Ohio State University Extension Educator Mike Hogan said research on vertical farms is in the “budding stage” in the United States. Increasingly, urban farmers have been asking Ohio State officials what the most profitable and economically sustainable ways are to grow plants and vegetables indoors. Zoning and the high cost of land in cities often are barriers with urban agriculture, he noted.
Despommier and Hogan each said vertical farming has both advantages and disadvantages. The advantages include growing food year round and close to consumers, which cuts down on transportation costs and pollution; preserving rural land; having a controlled climate with little impact from severe weather or climate change, and little need for pesticides.
The biggest challenges are energy and infrastructure costs, but those costs are starting to come down. Five years ago, the LED lighting efficiency was 20 percent, which means that of the 100 percent electricity that goes into a lightbulb, only 20 percent comes out as light with the rest as heat. A 50 percent LED efficiency is needed to be economical, Despommier said. Lighting manufacturer Philips recently announced a 68 percent LED efficiency.
“When that lighting efficiency gets installed, their profit margins will go up,” he said.
For Despommier, the future is bright for vertical farms around the world with the potential for the United States to lead the way with new technology.
“Even if the technology isn’t applicable today, why can’t we be an exporter of technologies that empowers many other areas of the world to (grow food) in a different way. Let’s show them how to grow their food,” he said.
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