VERTICAL FARMING - How “Locally Grown” Will Soon Mean Grown High Above You
By the year 2050, the global population is projected to increase by some 2.5 billion people, with at least 80% of them residing in urban centers. Feeding them via traditional farming practices will require an estimated 109 hectares of new land – that’s 20% larger than Brazil – and 80% of the land suitable for raising crops is already in use. The math spells disaster. To meet this urgent challenge, agriculturalists and designers are developing plans for vertical farms as a productive and environmentally friendly way to feed swelling populations. Green skyscrapers are already sprouting up worldwide, and we’re on the brink of seeing more of these that serve as farms. Some will be hybrid buildings that also function as offices, while others will be entirely dedicated to farming.
Vertical farms can potentially avoid food crops problems such as drought, overuse of fields, and transporting food far from the population centers they are consumed in. Columbia University ecologist Dickson Despommier, who has been championing vertical farms since 1999, stresses that growing food year-round in urban high-rises reduces carbon-emitting transport of fruit and vegetables. Production can continue even during extreme weather, making food supplies more secure. Vertical farms can recycle, thus conserve water. What’s more, they can potentially thrive without herbicides or insecticides.
As of now, most vertical farms rely largely on natural light, notably in sunny, equatorial regions. The SkyGreens vertical farm in Singapore, for example, requires no artificial lighting. This four-story glass-sided farm comprises mobile racks of cabbage and lettuce that rotate slowly up towards the sun. The sun’s not the limit, however. More innovative developments include specialized LED lighting that mimic sunlight. Plant racks in a vertical farm can be fed nutrients by water-conserving, soil-free hydroponic systems. Software can control rotating racks of plants, ensuring each gets equal amounts of light, as well as evenly distribute water and nutrients. All this can be monitored right from a farmer's smartphone.
The world's largest existing vertical farm is currently in Scranton, PA. Though it’s only a single-story structure, it covers 3.25 hectares, with crop racks stacked six high – that’s enough to house 17 million plants, including lettuces, spinach, kale, tomatoes, peppers, basil and strawberries. In Japan, Kyoto-based “Nuvege” is a windowless indoor farm with LED lighting tuned to two types of chlorophyll, so that any plant can grow anywhere. In this way, Nuvege is able to produce 6 million lettuces a year. The fact is that plants do not need artificial sunlight that’s consistently bright, but as in the outdoor world, can suffice with light that varies in intensity through the day – another big energy saver.
Japan also boats the world's largest indoor farm, which produces 100 times more vegetables per square foot than any comparable farm and cuts food waste by 30 to 40 percent. Indiana’s Green Sense Farms grows microgreens, leafy greens and herbs in 25-foot-tall carousels. In Linkoping, Sweden, a 177-foot vertical farm grows crops on spirals that move downward over the course of two to three months to be harvested when they reach bottom. Vancouver’s VertiCrop grows 50 varieties of leafy green vegetables on plastic trays, producing as much food in its 50' x 75' area as a 16-acre farm, but requiring only 8 percent of the water consumption used to irrigate field crops. Meanwhile, the city of Paris has devised a plan for vertical green buildings that would reduce the city’s greenhouse gas emissions by 75 percent. The project envisions a “smart city” of vegetation towers that act as “farmscrapers,” cleaning smog and filtering the air while keeping food production local. Who wouldn’t want to live and eat in a city that smart? Here’s a video on the basics of vertical farming from leading proponent Dickson Despommie. https://www.youtube.com/watch?v=yIXYHk0A0gM#t=92