Saturday, April 30, 2011

Twenty-First Century Farming

Vertical Farm designed by Chris Jacobs and Dean Fowler 

Demand for food resources is increasing as the global population increases. Economists, agriculturists, aquaculturists are finding new ways to meet this need of increase in food production in the twenty-first Century. Over the next 40 years, U.N. predicts that global population will increase by 2.5 billion people. Among those 2.5 billion people approximately 80% of whom will live in urban cities. This poses two problems: 1) land scarcity and 2) food scarcity. Dr. Dickson Despommier, a professor of microbiology at Columbia University, came up with the idea of the Vertical Farm Project, as a solution to the future pressure on land and resources and as a way of reducing the carbon footprint of our cities. His argues that “vertical farming” is legitimate due to environmental reasons. He claims that cultivating plants and animals in skyscrapers requires less energy and water, and it even produces less toxicity to the environment.

Traditional agriculture and aquaculture were both practiced unsustainably for several reasons: croplands destroying forests and natural habitats, fish farms polluting water, and long “food miles” of transporting from suburban farms to urban cities leading to carbon dioxide exhaust. Cities which heavily rely on other “food-producing” cities (such as China) are now researching on new ways to sustain themselves. Dr. Dickson Despommier and his advocates of environmentalists, scientist, and aquaculturists, claim that the solution is “vertical farming.”

Vertical Farming” is “a concept that argues that it is economically and environmentally viable to cultivate plant or animal life within skyscrapers.” Some conceptual proposals of vertical farming that have been usually designed with integration of systems such as hydroponics and aquaponics.

Hydroponics is “a method of growing plants using mineral nutrients, in water, without soil.” This allows plants to grow in a tube, tank, anywhere--even in indoor space of high-rise buildings. This solution allows avoiding the usage of land around our cities; the old farm lands, which were reducing soil quality and unnecessarily damaging to our environment, can even return to an unspoiled ecosystem of forests and grasslands. By placing our food source right around the corner in the center of the city, we can now shorten the food miles, relieving the pollution from CO2 emission of delivery trucks and ships exhausting fumes.

However, one of the disadvantages of hydroponics is that the system recirculates the same water that filtered through the plants, which means that it requires additional nutrients in order for the plants to be full of nutrients and flavor. (Hydroponic tomatoes are claimed to have no flavor.)

This problem is solved by system called aquaponics. Aquaponics is system that combines a traditional aquaculture with hydroponics in a symbiotic environment. If run correctly, aquaponics systems can be extremely efficient, since the only major input needed is food for the fish. Their waste then provides nutrients for plants, and the plants filter out nitrates and ammonia that can harm the fish as the water returns to the tank. Only a little bit of water to account for transpiration is needed.

Because the cycle of these systems are closed loop, the orientation of farming can be vertical--the water travels down the system from the top (providing nutrients for plants) and the water on the bottom of the system is pumped back up to the top. According the Dr. Despommier, the benefit to the environment of producing food in vertical greenhouse-like farms in the heart of urban cities would be multiple. By farming in completely controlled environment allows consistency of food production--no soil borne diseases or pests, no drought, no flood. What is even better is that vertical farming allows all this optimal condition in verticality. Also, hydroponics claims that the system only uses one-twentieth of the water used in traditional farming for irrigation.

Many developers, investors, mayors, and city planners have become advocates of “vertical farming” and are looking into making it reality in the future. Time magazine wrote an article on “Vertical Farming” and have commented positively by saying this proposal can possibly feed the world. Oliver Foster, an Australian architect, currently works on a design to build the first full-scale vertical farm for about five years and is about to be built in China. The new concept of “vertical farming” provided opportunities for architectural students and competitions to conceptually visualize futuristic scenarios of the vertical farming in our cities without holding practical potential for providing food. Currently, AWR Competition “Loft London Farm Tower” is calling for entries for innovative “design of a vertical farm with a residential use.” The competition advocates Dr. Despommier’s proposal and is asking designers to further explore the idea of “vertical farming” in the heart of London.

Although the idea is providing opportunities for architecture students and designers to create innovative, sometimes beautiful building designs, it holds little practical potential for providing food.

Despite the benefits of “vertical farming” which Dr. Despommier claims, “vertical farming” does not calculate its ecological and environmental costs of extracting materials to build skyscrapers for the simple purpose of agricultural production. The costs of the additional energy needed for “consistent conditions” such as artificial lighting, heating, and other vertical farming operations, would outweigh the benefit of the building’s proximity to the areas of consumption.

Most importantly, major downfall of “vertical farming” is that it does not expose plants to “the most plentiful and ecologically benign energy source of all: sunlight.” Stan Cox and David Van Tassel writes and investigates the feasibility of “vertical farming.” The authors argue that “vertical farming” does not expose plants to “the most plentiful and ecologically benign energy source of all: sunlight,” unlike the traditional farming, which are horizontal. They further elaborate the argument that “for obvious reasons, no one has ever proposed stacking solar photovoltaic panels one above the other. For the same reasons, crop fields cannot be layered one above the other without providing a substitute for the sunlight that has been cut off...As a result, the lion’s share of a vertical farm’s lighting would have to be supplied artificially, consuming resource-intensive electricity rather than free sunlight.” The authors calculated the efficiency of converting sunlight to plant matter, and found that the vertical farming’s lighting alone will require “eight times as much electricity as all U.S. utilities generate in the entire year.” (See calculations here.)

After disclaiming the idea of “vertical farming,” the authors conclude by stating that we don’t have to farm vertically, but we do have to change the way we do it horizontally: “it will mean a reliance on natural processes and cohesive rural communities, not technological fantasies.” Knowing the downfalls of vertical farming and suburban farming (long food miles), we must seek alternative solutions. The growth of population and urban centralization will inevitably lead to increased demand for food in the urban cities.

One possibility is “floating farm.” “Floating farm” is a concept of farming on river or on ocean to be close to urban coastal cities and provide food without using spaces on land. While this can be hard to visualize, similar concept can be seen in a competition entry from the “South Street Seaport: Re-envisioning the Urban Edge.” N.E.E.D., whose entry was awarded First Place, proposed “an aquaculture-driven floating park” called “Fish Works.” Looking at its site plan on the left, we can imagine vegetation farms spread out on New York’s riverfront horizontally, utilizing sunlight (which was one of criticism of “vertical farming” by Cox and Tassel). If proposed as urban farm, this proposal not only can fully use the free source of sunlight but also the resource of water. Because the project is situated on the surface of the water, it can easily “borrow” the water the river by bio-filtering the water to irrigate vegetations instead of using waters from aqueducts and reservoirs (which are valuable for human consumption). “Floating farm” not only can provide energy-and-resource efficiency, but also can provide variety of food production. For example, “Fish Works” proposes fish farms on New York’s riverfront. When the water is filtered, the river can be home to fish farms.

Fish is becoming one of the most important food resource for human consumption as it is known as healthiest food choice. Unfortunately, wild fisheries are overfished and ocean is in danger to be depleted because of human consumption. CBS news further predicts that the world marine ecology will be depleted by 2048. By providing floating fish farms, there is opportunity for urban aquaculture to sustain fish consumptions in the future.

The major potential problem of “floating farm” will be recycling. The dirty water and fish waste must not be released to surrounding environment to not harm the natural ecologies. This can be easily solved as hydroponics and aquaponics systems, which already solved the issue by providing closed-loop system. Although the “floating farm” also needs to be further investigated for its feasibility, it brings hope for our urban cities to become environmentally responsive cities--marrying environment and human usage, while using residual spaces which our minds do not perceive as occupiable spaces.

1 comment:

  1. It seems that solving the world's problems revolve around having sufficient renewable (and hopefully clean) energy. If we could develop such technology, then the artificial lighting costs would be nullified and the vertical farming concept would actually be feasible; the world could feed itself. However, like the many other benefits that humanity would have from abundant renewable power, vertical farming is still impractical.

    ReplyDelete