Farming in the sky in
Singapore By Kalinga
Seneviratne
SINGAPORE - With a population
of five million crammed on a landmass of just 715
square kilometers, the tiny republic of Singapore
has been forced to expand upwards, building
high-rise residential complexes to house the
country's many inhabitants.
Now, Singapore
is applying the vertical model to urban
agriculture, experimenting with rooftop gardens
and vertical farms in order to feed its many
residents.
Currently only 7% of
Singapore's food is grown locally. The country
imports most of its fresh vegetables and fruits
daily from
neighboring countries such as
Malaysia, Thailand and the Philippines, as well as
from more distant trading partners like Australia,
New Zealand, Israel and Chile.
An influx
of immigrants has resulted in a rapid crowding of
Singapore's skyline, as more and more towering
apartment buildings shoot up. And meanwhile, what
little land was available for farming is
disappearing fast.
The solution to the
problem came in the form of a public-private
partnership, with the launch of what has been
hailed as the "world's first low carbon,
water-driven rotating vertical farm" for growing
tropical vegetables in an urban environment.
The result of a collaborative agreement
between the Agri-Food and Veterinary Authority of
Singapore (AVA) and a local firm, Sky Green, this
venture aims to popularize urban farming
techniques that are also environmentally friendly.
With a robust economy that boasts a gross
domestic product of US$239.7 billion, 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 aluminum towers, some of
them up to nine meters 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-story 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 kilogram than the
imported varieties.
The group's purchasing
manager, Tng Ah Yiam, recently told a Straits
Times reporter that these "sky farms" are now able
to offer their customers quality, locally-grown
vegetables "that are fresher because they travel a
shorter distance from farm to shelf".
Sky
Green plans to supply two tons a day to NTUC by
the middle of next year when they expand their
farm towers.
Coordinated
efforts The Sky Green project feeds into a
trend that has been underway in Singapore for
several decades.
Since the urban expansion
of the 1990s Singapore has attempted to respond to
the scarcity of land available for traditional
cultivation by promoting rooftop vegetable
gardens.
A number of local institutions
developed hydroponic and aeroponic cultivation
systems but none ever took off. "There was always
concern over whether or not the rooftops could
take the weight of these structures," Shih Yong
Goh, former head of public affairs at AVA, told
IPS.
Experts like Lee Sing Kong, director
of the National Institute of Education and a
long-time advocate of the use of 'sky farms',
believe there is an urgent need for Singapore to
become less dependent on food imports.
Given the increasing frequency of extreme
weather events, including "natural disasters such
as flooding, which could impact food production,
it may be necessary for Singapore to look at
producing some of its own vegetables from the food
security point of view", he told IPS.
Kong
said that he is currently involved in the
development of 'vegetable factories', whole
buildings designed to grow fresh produce.
"We have (begun) developing a six-tiered
aeroponic system to grow vegetables with the help
of LED lights," he said, adding, "this is in the
experimental stage. If the model proves to be
successful, then the multi-tiered system can be
installed within enclosed buildings for producing
vegetables. This will certainly enhance the
opportunities for urban agriculture."
Since 2005, the government has shed some
of its reservations about rooftop production. The
National Parks Board recently converted the
rooftop of a multi-story residential building in
the densely populated Upper Serangoon Road into an
educational farm to promote urban agriculture
among school children.
Meanwhile, Sky
Green has signed an MOU with Singapore's Temasek
Polytechnic technical college. Dr Lee Chee Wee,
director of the School of Applied Science,
believes that partnering with Sky Green will
expose his students to how technology is used in
vegetable farming and make "modern farming so much
more attractive as a career choice for our
graduates".
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