March 2, 2011
Our food crops may be grown on vertical farms in skyscrapers in the near future.
Imagine a swanky skyscraper in Chicago growing nothing but rich-green lettuce on all its floors and a giant barge floating in New York’s Hudson River housing lush paddy fields. Both make for picturesque, yet unusual, cityscapes. Nonetheless, such scenic beauty in the middle of a bustling megalopolis might no longer be unusual in the days to come, thanks to the world of urban farming.
Large-scale urban farming that includes growing a variety of food crops in tall rises and free spaces of today’s cities may hold the key to solving the challenge of rising food demand. It is estimated that by the year 2050, our planet will be the home to 9.5 billion human beings, far more than the current 6.9 billion. The earth will also be more urban, as 70% of its inhabitants are predicted to live in cities. These facts not only demand that our agriculture be more productive, but also be more urban. And this is what urban farming seeks to address.
To the organic-food seeking urban consumer, farming in the city might be nothing new. Presently, a daily salad might be grown in a small corner of an apartment. And anyone who has eaten a hot-house tomato knows that food has been grown inside glass greenhouses for many decades now. However, to wake up in front of giant towers harvesting entire fields of produce would indeed be a novelty!
Although in the initial stages, the idea of growing food crops in multi-storied, glass-house towers is drawing increasing attention. Vertical farming is based on the principle of hydroponics, a technique in which plants are grown out of water, containing dissolved minerals but no soil. The plants are grown inside a multi-storied, glass tower on many layers of conveyors that are capable of rotating. The conveyors rotate in such a way that plants inside the tower get uniform light from the sun. In places with no sunlight, artificial light is used to ensure proper growth of the plant.
Enthusiasts of vertical farming list out its many advantages over conventional farming. Dickson Despommier, an American ecologist considered the pioneer of urban farming, points out that plants in vertical farms are not susceptible to the vagaries of the weather as in conventional agriculture. In his book, ‘The Vertical Farm’, Mr. Despommier also argues that plants in skyscrapers require much less pesticides and insecticides, as they are grown in a controlled atmosphere. Further, growing food crops in urban areas, where a majority of the population in the future will reside, could result in lower transportation costs and reduced spoilage of foodstuff.
The UN estimates that earth’s population will touch nearly 9.5 billion
in 2050 from around 6.9 billion in 2009. And around 70% of its
inhabitants will live in cities forcing agriculture to move closer to cities
Land-starved nations such as Singapore have already started experimenting with vertical farms (though the height of the farming tower, at six meters tall, is much shorter than what enthusiasts envision). The tower, developed through a joint effort between the Singapore government’s Agri-Food and Veterinary Authority and a private firm DJ Engineering, is designed to rotate one millimeter per second to ensure uniform sunlight for plants. Authorities say that the system is a success, capable of producing five times the output over a normal farm of the same size. A few more pilot projects in Europe and the Middle East have also been set up, and early results are encouraging as well. A number of start-ups engaged in the design of towers and hydroponic conveyors have sprouted across North America, indicating that vertical farming is generating interest.
So, will vertical farming lead the technologies that seek to solve our food deficiency? Critics of vertical farming argue that sunlight required to grow plants inside stacks of glass towers is not always a given. In that case, artificial lighting could be needed and that will make vertical farming an energy-intensive activity, which raises the carbon footprint of the technique. Naysayers also point out that buying or developing expensive real estate to grow plants will be economically impractical in the near future.
Rather, they suggest that greenhouses on giant barges floating on water-bodies such as rivers or lakes could help address the problem of space constraint for cultivation in urban areas. Here too, food crops are grown hydroponically. However, unlike vertical farming, barges do not have towers, so the problem of non-uniform distribution of light to plants does not arise. Still, running the hothouses will require power, and to be environment-friendly, this technique would have to be executed with the help of huge renewable sources of energy such as solar power.
Whatever the method, urban farming promises a viable solution for our food needs in the 21st century. And with that, this eco-minded alternative ensures a healthy dose of greenery to eyes normally used to concrete sprawls.
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