Vertical Farming: Feeding the Cities of the Future?

The future of urban farming is no more outdoor, but indoor and vertical. (Image source: Sky Greens)

The vertical farming concept took birth in 1999, as an idea in Dr. Dickson Despommier class on medical ecology, in Columbia University. Despommier defines a vertical farm as any building, which grows food inside of it and, which is taller than a single storey. Employing closed-loop agricultural technology, all the water and nutrients are recycled and the only thing that actually leaves the building is the produce.

The concept of vertical farming did not arise as another fanciful way of growing food, but as a practical solution to meet the impending food crisis facing humanity. Out of the present 7 billion world population, 50 percent of them are living in cities, and it is estimated that by the year 2050, the human population will reach 10 billion with more than 80 percent living in urban centers. As of now, 80 percent of the earth’s land suitable for farming is already in use and this land mass will not be sufficient to meet humanity’s food needs in the next 35 years.

Looking at these statistics, the need of the hour is an efficient local food growing system that has low demands on energy and water, is not susceptible to climatic changes, and occupies less land space than traditional farms. Vertical farming fits these expectations, and many entrepreneurs and innovators around the world have successfully converted this concept into reality.

Food is now been grown in such unlikely places as old factories, abandoned warehouse and industrial buildings. Technological advances in vertical farming methods and indoor lighting is enabling to grow food alongside existing commercial and residential structures and making local food available for city dwellers.

Source: Sky Greens
Source: Sky Greens

Jack Ng started one of the world’s first commercial vertical farms in Singapore. Known as Sky Greens, this vertical farm, makes use of a patented technology called ‘A-Go-Gro’ to grow lettuce, spinach and many other leafy greens. In this system, vegetables grow on nine meters tall A -shaped towers, each hosting 38 tiers of growing troughs. The troughs rotate around the aluminum tower at a speed of one millimeter per second, which ensures uniform distribution of sunlight, proper air circulation and irrigation for all plants.

Source: Sky Greens
Source: Sky Greens

Powered by a unique gravity aided water-pulley system, each tower uses only one liter of water, which is collected in a rainwater-fed overhead reservoir. Costing 3$ per month to run each tower, this hydraulic system has a very low carbon foot print, needing energy only the energy equivalent to illuminating a 40-watt light bulb. In accordance with the principles of three R’s- reduce, reuse and recycle – the water powering the frames is recycled and filtered before circulating them back to the plants and all the organic wastes are also composted and reused.

Housed in translucent structures nearly four storey’s tall, the plants growing in a soil based medium receive natural sunlight all year round. Producing one ton of vegetables every other day, the farm boasts a yield which is 10 times more per unit land area than a conventional farm, while consuming less water, energy and natural resources.

Source: Green Spirit Farms
Source: Green Spirit Farms

While SkyGreens makes use of natural sunlight to grow vegetables in translucent structures, Green Spirit Farms in New Buffalo, Michigan, grows greens in a closed indoor facility under pink-tinted LEDs. In this vertical farm started by father and son duo of Milan and Daniel Kluko, plants are raised on a soil-less growing system called hydroponics, using mineral nutrient solution in water. With a growing cycle of just 21 days for most crops, Green Spirit Farms has 17 harvests yearly, with a yield as much as 10 tons of lettuce in 500 square feet of space.

Compared to conventional induction lamps, Illumitex LEDs consume less energy and provide correct light intensity and spectrum. In addition, because of reduced heat and spread, LEDs allow less distance between plants and the light source, allowing more produce to be grown.

Daniel Kluko says the LEDs, providing the appropriate blue and red wavelengths for photosynthesis, have enabled to reduce the power consumption by 10-12 % per system while increasing the yield by about 15-20 %. This has helped to make the business more profitable and more sustainable.

Lead by Daniel, the research team in Green Spirit Farms is developing a smart phone/tablet app which will remotely monitor and control nutrient levels and soil pH balance, and even sound an alarm when a water pump is not functioning. This will give them the ability to look after multiple farms from afar.

Source: FarmedHere
Source: FarmedHere

Seventy -odd miles to the West of Green Spirit Farms is another vertical farm called FarmedHere in Bedford Park, Chicago. What was once an old corrugated-box facility has now been re-purposed into an urban farm. Just like Green Spirit Farms, this indoor vertical farm grows vegetables under the pink light of LEDs, but makes use of a food growing system called aquaponics, where plants and fish are grown together in one integrated system.

Tilapia fish, free of hormones, are cultivated in specialized tanks. The water with fish effluents – the source of nutrients for plant growth – is circulated among the plant beds. The plants, growing in a soil-less medium, absorb the nutrients and clean the water. The water is then circulated back to the fish tanks, which keeps the tilapia flourishing. Both the greens and fish are sold as food. This system, which grows 100% organic produce while generating no waste, has made FarmedHere become the first USDA organic certified vertical indoor farm in the country.

Source: FarmedHere
Source: FarmedHere

With six layers of vertically stacked grow-beds, covering an area of 90,000 square feet, the facility produces vegetables equivalent to that of a five-acre farm. With crops reaching maturity in about 30 days, half of what traditional farms experience, FarmedHere is able to meet the demands for salad greens, herbs, and decorative dressing, from 79 grocery stores and vendors in and around Chicago.

Vertical farming is bringing fresh food to remote places that have been previously considered unsuitable for growing plants. Residents of the town of Jackson, Wyoming, beneath the snow capped Tetons, no longer have to be dependent on food trucked from far-off Mexico and California. Instead, Vertical Harvest, a vertical farm now under construction, will soon be providing tomatoes, greens, and herbs year-round. Three stories high, 13,500 square foot urban farm will produce an estimated 100,000 pounds of vegetables annually.

Source: FarmedHere
Source: FarmedHere

Along with the weather and climatic factors, circumstances arising from manmade disasters are also prompting entrepreneurs to start vertical farms. The nuclear disaster in Fukushima, in the wake of the 2011 earthquake and tsunami in Japan, irradiated much of the region’s farmland, leaving many people doubting the safety of their country’s food supply. To meet the ensuing food shortage, Shigeharu Shimamura, a plant physiologist, converted an abandoned semiconductor factory into an indoor farm. And today, encouraged by the government, there are more than hundred vertical farms in Japan.

Vertical farms are not just restricted to growing leafy greens for immediate human consumption. Caliber Biotherapeutics, a pharmaceutical company in Bryan, Texas, grow 2.2 million expensive tobacco-like plants in 18 storeys high structure. Lit with LEDs, this plant production platform with a growing area of 150,000 square foot is been used to make new drugs and vaccines. In addition to providing an ideal environment to closely monitor and control plant growth, this indoor closed facility provides a protective barrier against possible diseases and contamination from the outside world.

At present most vertical farms are limited to growing leafy vegetables such as basil, micro-greens, lettuce, arugula, kale and spinach, though have been successful in growing carrots, radishes, strawberries and peppers on a commercial scale. Further research is needed to find suitable techniques to grow staple crops like rice, wheat and maize, or tubers, like potatoes.

Mankind is at the door step of yet another green revolution. The strides made in vertical farming – from a class room idea to a commercially viable technology in the last 15-16 years are quite remarkable, but are just the beginning of a new world in farming.

Ravindra Krishnamurthy

Ravindra Krishnamurthy is a freelance science writer covering science, tech, the environment, health, food, and culture.

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