New Scientist: Vertical farms sprouting all over the world
The US Defense Advanced Research Projects Agency is using an 18-storey vertical farm in College Station, Texas, to produce genetically modified plants that make proteins useful in vaccines.
By Paul Marks
16 January 2014
The plant racks in a vertical farm can be fed nutrients by water-conserving, soil-free hydroponic systems and lit by LEDs that mimic sunlight. And they need not be difficult to manage: control software can choreograph rotating racks of plants so each gets the same amount of light, and direct water pumps to ensure nutrients are evenly distributed.
The whole apparatus can be monitored from a farmer’s smartphone, says GSF’s R&D manager, Daniel Kluko. He says the new farm in Scranton will grow 14 lettuce crops per year, as well as spinach, kale, tomatoes, peppers, basil and strawberries. Its output will be almost 10 times greater than the firm’s first vertical farm, which opened in New Buffalo in 2011.
Proponents see vertical farming as a way to feed a global population that is urbanising fast: 86 per cent of the people in the developed world will live in cities by 2050, the United Nations predicts. It could make food supplies more secure as well, because production can continue even when extreme weather strikes. And as long as farmers are careful to protect their indoor “fields” from pests, vertical farming needs no herbicides or insecticides. They also conserve water far better than earthbound farming.
GSF’s first farm was inspired by the long-term drought that has been afflicting many parts of the US. “Water is a big issue,” says Kluko. “We have designed our vertical farms to recycle it, and they use 98 per cent less water per item of produce than traditional farming.” That’s done in part by scavenging water from the grow room’s atmosphere with a dehumidifier. It’s a machine with a dual role, as excess humidity can lead to problems like leaf mould.