Many original ideas seem impossible when first proposed. See how people react when told about agriculture in multi-storied buildings, and without soil either. It could be a scientific curiosity, but can it supply a large proportion of the world’s demand for food? The idea of vertical farming was first proposed 10 years ago by Dickson Despommier, professor of public health at Columbia University. Big vertical farms do not yet exist, but could be a reality soon.
A vertical farm, as proposed by Despommier, is a building about 30 storeys tall and used to grow plants — vegetables to begin with — using minimal inputs and no soil. Despommier is now conceptualising several projects with administrators around the world. He does not quite divulge the details, but says that administrators from the cities of Chicago and New York are interested, and that he is working with people in other countries as well. “I can tell you that a vertical farm is going to come up in some places soon,” says Despommier.
Up In The Air
As Despommier works on his grand scheme, other companies are trying their own variations of the idea in smaller scales, some with proprietary technology. At Cornwall in the UK, the subsidiary of the Canadian firm Valcent Products is beginning to sell equipment for farming without soil.
GROWING CRISIS |
|
In Ithaca in New York State, a company called AeroFarms is now selling equipment to make your own farm without soil. AeroFarms began as a company that practised aeroponics (growing plants in the air), but was persuaded by investors into becoming a company that sells aeroponics equipment.
Singapore is nurturing a commercial soil-less farm and has several grand plans. Aero-Green Technology, a private company, is using aeroponics to grow salad vegetables that do not grow in the tropics. Small experiments are taking place in several places in the world on technologies that will be useful in vertical farms. Says Lee Sing Kong, aeroponics expert and director of the National Institute of Education in Singapore: “We are trying to see how we can develop farming along with housing.”
Other projects include the Eden Project in Cornwall (Despommier’s prime exhibit), which has built giant domes with different controlled climates that can grow plants from anywhere in the world. The domes — called biomes — use a material called ethylene tetrafluoroethylene. Despommier says it is ideal for large-scale vertical farming. It is light, mostly transparent, tough and recyclable. In Chicago, the Illinois Institute of Technology is converting an old warehouse into a vertical farm.
Shrinking Lands
In normal circumstances, humanity would never have thought of using buildings for farming. However, the 21st century is creating circumstances that make people stretch their imaginations. The world population, currently at 6.5 billion, is expected to be 9 billion by 2050.
DECODING THE EARTH’S FUTURE |
Many things look easy till science tries to understand them. Look at the earth, for example. We are so intimately involved with its daily workings, but we understand less about it than we do about the moon or even about Venus or Mars. Understanding how the earth’s complex systems work and interact with one another is one of science’s greatest challenges. Many scientists think the ability to do so quickly is vital to our existence beyond this century. Consider a seemingly simple thing like the carbon cycle, through which carbon is exchanged between the earth’s various ‘spheres’. For example, the biosphere (living beings) contains 42,000 gigatonnes of carbon and the hydrosphere (water bodies) 36,000 gigatonnes. The atmosphere contains only 750 gigatonnes, and human beings pump in only 6.5 gigatonnes into the atmosphere every year. This would seem negligible when compared with the total carbon in the world, but it is changing the world’s climate. We would understand the role of carbon dioxide on things vital to us only if we understand it in relation to the full carbon cycle. And we do not understand it well enough. For example, consider this question: how would plants behave when carbon dioxide levels in the atmosphere go up? We do not know clearly, and yet this answer is important to predict our future climate. It is important to predict our future food needs as well. In the near future, we would need to understand how many systems — the climate, soil health, population growth, societal changes and future economies — will interact together. Science is far from able to understand these interactions. “We would need a new science to understand how the world will behave in 40 years,” says Stephen Emmott, head of computation at Microsoft Research. Our existing methods of science are not good enough to model the interaction of several complex phenomena. Five years ago, Emmott had chaired a meeting of internationally distinguished scientists from several fields to look at how science will be in 2020. This group foresaw a central role for computational science. This rapidly developing discipline is becoming important in all areas of biology. Tomorrow’s computers may have to decode the future of our earth. |
The world’s agricultural land is rapidly eroding. About 40 per cent of it is already degraded, and a substantial portion of the rest will be gone by 2050. So in 40 years, the earth may not have enough land to feed its large population.
Agriculture, as it is practised today, is known to destroy the soil quality rapidly. Any kind of monoculture does so, as it reduces biodiversity. Modern intensive farming rapidly destroys the soil because of excessive use of irrigation and fertiliser, not to speak of creating pollution through fertiliser run off.
If the earth is to survive as a habitat for human beings and other animals, farming practices need to change considerably. If agriculture does not use soil at all, we could restore a large portion of the earth to its former state. It would reduce carbon dioxide buildup in the atmosphere and thus help combat climate change (see ‘Decoding The Earth’s Future’).
Scientists have shown that plants actually do not need the soil to flourish, as long as they have an anchor and a source of water and nutrients. In fact, it turns out that plants anchored in the air — as in aeroponics — need only 10 per cent of the water used by those in farms.
AeroFarms use aeroponics in their equipment. They live just as well in water, and this method is called hydroponics. Vertical farms can use both hydroponics and aeroponics, but some researchers question the technical viability of aeroponics at the moment.
There are considerable variations in the methods being practiced and promoted by various companies and organisations. For example, AeroFarms, which has been funded by angel investors and is now looking for its first venture capital funding, takes the idea of soil-less agriculture to its extreme form: it uses artificial lighting.
Says Ed Harwood, chief executive officer and founder of AeroFarms: “Natural lighting inside a building has its costs. With artificial lighting we can produce anything anywhere in the world.” AeroFarms uses LED lighting, and has collaborations with Cornell University and the Rensselaer Polytechnic in New York State.
Freeing Up Farmlands
Despommier, on the other hand, favours the use of parabolic mirrors and optic fibres to get sunlight into the building. A mixed approach could also work. “We use a mixture of natural and artificial light,” says Tom Bentley, director of business development of Valcent. Among other things, the company sells systems for high-density hydroponics that can purportedly produce 20 times more yield than conventional methods of farming. Neither hydroponics nor aeroponics systems would need to use pesticides in large measure.
Despommier and vertical farming enthusiasts have now got several designers and architects interested in the concept. For example, architects such as SOA in Paris, Weber Thompson Design in Seattle and Vincent Callebaut in Brussels have come up with preliminary designs for vertical farms, many of which are aesthetically pleasing structures that blend into cityscapes. Despommier himself is advocating a completely self-contained system that uses municipal waste to produce energy for the farm. Energy is the most critical input for the vertical farm, and its cost can ultimately determine the economic viability of the farm.
Modern agriculture is practised away from the cities. Transport of food uses up a considerable portion of the world’s energy production. By situating farms inside cities, we may reduce the need to transport food long distances. This trade-off may contribute to the economic viability of vertical farms. In Singapore, for example, aeroponics is commercially viable now for temperate climate salad greens, but not for tropical plants (Singapore imports most of its salad greens). By 2050, 80 per cent of the world’s population might be living in cities. Vertical farms could produce food all year around, day and night. However, the cost of production using this method is not known yet as it is still in infancy. But they give hope for freeing up the world’s farm lands for nature to work its magic again.
p dot hari at abp dot in
Del.ici.ous
Digg
reddit
Stumbleupon
Even as we run out of space to produce food, technology is creating new forms of farming that will cut emissions and reduce the use of fertilisers