Kalinga Seneviratne's Inter Press Service about high-rise agriculture in Singapore highlights ideas about urban agriculture I've not heard of in a while. While costs need to come down to make the system competitive with traditional agriculture--or, less happily, costs associated with traditional agriculture need to come up--might this be a widespread phenomenon in the near future?
With a robust economy that boasts a gross domestic product of 239.7 billion dollars, Singapore has plenty of money. “But money (is) worthless without food,” according to Sky Green Director Jack Ng.
“That’s why I wanted to use my engineering skills to help Singapore farmers to produce more food,” Ng told IPS.
An engineer by training, Ng created the vertical farming system, which he nicknamed ‘A Go-Grow’. It consists of a series of aluminium towers, some of them up to nine metres high, each containing 38 tiers equipped with troughs for the vegetables.
In keeping with Sky Green’s focus on environmental sustainability, the water used to power the rotating towers is recycled within the system and eventually used to water the vegetables. Each tower consumes only 60 watts of power daily – about the same amount as a single light bulb.
Ng knew that if the system was too expensive or complicated, urban farmers would not be able to survive. And given that he designed the project with retirees and other housebound farmers in mind, he tried to create a situation in which “the plant comes to you, rather than you going to the plant.”
The multi-layered vegetable tower rotates very slowly, taking some eight hours to complete a full circle. As the plant travels to the top it absorbs ample sunlight and when it comes back down it is watered from a tray that is fed by the hydraulic system that drives the rotation of the tower.
This closed cycle system is easy to maintain and doesn’t release any exhaust.
Ng says that such towers, if set up on roofs of the many multi-storey residential blocs that house most of Singapore’s population, could provide livelihoods for retirees and housewives, who would only need to spend a few hours up on the roof to attend to the system.
Sky Green towers currently produce three vegetables popular with locals – nai bai, xiao bai cai and Chinese cabbage, which can be harvested every 28 days.
They already supply NTUC FairPrice, Singapore’s largest grocery retailer that has a network of over 230 outlets and supermarkets. The urban-grown vegetables cost roughly 20 cents more per kilogramme than the imported varieties.'