Vertikale Landwirtschaft

Ersin Kacapor

Vertical farming is a proposal to conduct large-scale agriculture in urban high-rises or "farmscrapers". Using recycled resources and greenhouse methods such as hydroponics, these buildings would produce fruit, vegetables, edible mushrooms and algae year-round. Their proponents argue that, by allowing traditional outdoor farms to revert to a natural state and reducing the energy costs needed to transport foods to consumers, vertical farms could significantly alleviate climate change produced by excess atmospheric carbon.

Dickson Despommier, a professor of environmental health sciences and microbiology at Columbia University in New York City, developed the idea of vertical farming in 1999 with graduate students in a medical ecology class. In an interview with Miller-McCune.com, Despommier described how vertical farms would function:

"Each floor will have its own watering and nutrient monitoring systems. There'll be sensors for every single plant that tracks how much and what kinds of nutrients the plant has absorbed. You'll even have systems to monitor plant diseases by employing DNA chip technologies that detect the presence of plant pathogens by simply sampling the air and using snippets from various viral and bacterial infections. It's very easy to do.

Moreover, a gas chromatograph will tell us when to pick the plant by analyzing which flavenoids the produce contains. These flavenoids are what gives the food the flavors you're so fond of, particularly for more aromatic produce like tomatoes and peppers. These are all right-off-the-shelf technologies. The ability to construct a vertical farm exists now. We don't have to make anything new. "

Architectural designs have been produced by Chris Jacobs of United Future, Andrew Kranis at Columbia University and Gordon Graff at the University of Waterloo.

Mass media attention began with an article by Lisa Chamberlain in New York magazine. Since 2007, articles have appeared in The New York Times, U.S. News & World Report, Popular Science, Scientific American and Maxim (magazine), among others, as well as radio and television features.

Economic analysis

The detailed analytical work needed to establish the feasibility of vertical farming has not yet been done. Nevertheless, Despommier has argued that the idea is plausible. He estimates that, using currently available technologies, one vertical farm occupying one square city block and rising 30 stories would feed 10,000 people. In other sources he claims this number to be up to 50,000. Because the stacked growing surfaces of a vertical farm would receive far less sunlight than the equivalent land area in a rural farm, the vertical farm would require a significant level of artificial lighting and heating to operate in all seasons. Proponents of vertical farming have yet to demonstrate that the cost of producing and transporting energy from renewable sources which are mainly located in rural areas to an urban vertical farm can compete with the energy costs of directly growing food under sunlight in rural areas and then transporting it to cities.

The economic and environmental benefits of vertical farming rest partly on the concept of minimizing food miles, the distance that food travels from farm to consumer. However, a recent analysis suggests that transportation is only a minor contributor to the economic and environmental costs of supplying food to urban populations. The author of the report, University of Toronto professor Pierre Desrochers, concluded that "food miles are, at best, a marketing fad."

Advantages

Several potential advantages of vertical farming have been discussed by Despommier. Many of these benefits are obtained from scaling up hydroponic or aeroponic growing methods. Others relate to vertical farming building designs that would allow the use of renewable energy sources (wind and solar) and the recycling of materials of production such as water.

Increased crop production

Unlike traditional farming, indoor farming can produce crops year-round. All-season farming multiplies the productivity of the farmed surface by a factor of 4 to 6 depending on the crop. With some crops, such as strawberries, the factor may be as high as 30.

Furthermore, as the crops would be sold in the same infrastructures as it will be made, and as a consequence of not needing to be transported or refrigerated between production and sale, there will be far less spoilages and infestations than conventional farming. Research has shown that 30% of harvested crops are wasted due to spoilage and infestations.

Despommier suggests that, if dwarf versions of certain crops are used (e.g. dwarf wheat developed by NASA, which is smaller in size but richer in nutrients), year-round crops, and "stacker" plant holders are accounted for, a 30-story building with a base of a building block (5 acres) would yield a yearly crop analogous to that of 2,400 acres of traditional farming.

Protection from weather-related problems

Crops grown in traditional outdoor farming suffer from the often suboptimal, and sometimes extreme, nature of geological and meteorological events such as being too hot or cold, dry or wet, earthquakes, monsoons, hailstorms, tornadoes, flooding, wildfires, and severe droughts. These always reduce crop yields and sometimes cause crop failures.

Because it provides a controlled environment, the productivity of vertical farms would be mostly independent of weather and protected from extreme weather events. Protection from extreme weather may become a crucial feature as climate change increases the occurrence of such events. Although the controlled environment of vertical farming negates most of these factors, earthquakes and tornadoes still pose threats to the proposed infrastructure, although this again depends on the location of the vertical farms.

Conservation of resources

Each acre in a vertical farm could allow between 10 and 20 outdoor acres of farmland to return to its natural state, and recover farmlands due to development from original flat farmlands.

Vertical farming would reduce the need for new farmland due to overpopulation, thus saving many natural resources, currently threatened by deforestation or pollution. Deforestation, desertification, and other consequences of agricultural encroachment on natural biomes would be avoided. Because vertical farming lets crops be grown closer to consumers, it would substantially reduce the amount of fossil fuels currently used to transport and refrigerate farm produce. Producing food indoors reduces or eliminates conventional plowing, planting, and harvesting by farm machinery, also powered by fossil fuels. Burning less fossil fuel would reduce air pollution and the carbon dioxide emissions that cause climate change, as well as create healthier environments for humans and animals alike.

Furthermore, vertical farms would make maximal use of the locally most efficient sources of renewable energy: farms in Iceland, Italy and New Zealand would benefit from geothermal energy, desert environments such as in the Middle East would make use of abundant solar energy (in which case the structures would have to be wider than they are tall, to maximize solar energy input), and coastal areas would benefit from wind, wave or tidal energies.

Organic crops

The controlled growing environment and recycling reduces the need for pesticides, herbicides, and fertilizers. Advocates claim that producing organic crops in vertical farms is practical and the most likely production and marketing strategy.

Water recycling

Because water recycling is more practical and economic in a controlled agricultural environment, vertical farming would use much less water than traditional farming. New York City dumps 1.4 billion gallons of “treated waste water” into its rivers daily. However, a system of water recycling is already in use in the Solaire building in Battery Park. Vertical farming would convert black and gray water into potable water by collecting the water released into the air by evapotranspiration. Today, over 70% of the liquid fresh water on Earth is used for conventional agriculture. The agriculture often pollutes the water with fertilizers and pesticides. Vertical farms will use far less water (with drip irrigation techniques, for example), and recycle it. Recycling water involves condensing transpired water from the plants. This recycled water is pure, and can be used for crops or drinking. Furthermore, by using waste-water for irrigation, vertical farming would contribute to ameliorating problems with ocean dead zones, caused by algae blooms which are in turn enhanced by runoff fertilizers.

Halting mass extinction

Withdrawing human activity from large areas of the Earth's land surface may be necessary to slow and eventually halt the current anthropogenic mass extinction of land animals. Because most of the Earth's human-occupied land is used for agriculture, vertical farming may be the only way to restore enough land for animal habitat to prevent extinction while continuing to sustain large human populations.Vorlage:Citation needed

Traditional agriculture is highly disruptive to wild animal populations that live in and around farmland and may become unethical when there is a viable alternative. One study showed that wood mouse populations dropped from 25 per hectare to 5 per hectare after harvest, estimating 10 animals killed per hectare each year with conventional farming. In comparison, vertical farming would cause very little destruction of insects and other wildlife deaths.Vorlage:Citation needed

Impact on human health

Traditional farming is a hazardous occupation with particular risks that often take their toll on the health of human laborers. Such risks include: exposure to infectious diseases such as malaria and schistosomes, exposure to toxic chemicals commonly used as pesticides and fungicides, confrontations with dangerous wildlife such as poisonous snakes, and the severe injuries that can occur when using large industrial farming equipment. Whereas the traditional farming environment inevitably contains these risks (particularly in the farming practice known as “slash and burn”), vertical farming – because the environment is strictly controlled and predictable – eliminates them altogether.

Urban growth

Vertical farming, used in conjunction with other technologies and socioeconomic practices, could allow cities to expand while remaining largely self sufficient. This would allow for large urban centers that could grow without destroying considerably larger areas of forest to provide food for their people. Moreover, the industry of vertical farming will provide employment to these expanding urban centers. This may help displace the unemployment created by the dismantling of traditional farms, as more farm laborers move to cities in search of work. It is unlikely that traditional farms will become obsolete, as there are many crops that are not suited for vertical farming.

Energy production

Proponents claim that vertical farms could generate power. Methane digesters could be built on site to transform the organic waste generated at the farm into biogas which is generally composed of 65% methane along with other gasses. This biogas could then be burned to generate electricity that can either be consumed at the farm or added to the grid.

The claim that vertical farms could contribute surplus power to the electric grid assumes that most light used by the plants is obtained from sunlight. In high density vertical farming, use of sunlight is problematic because natural light could only nourish plants near the surface of the building. Plants in the interior would need artificial lighting. If artificial light is used for most lighting needs, the building would not be capable of net power gain.

Technologies and devices

Vertical farming relies on the use of various physical methods to become effective. Combining these technologies and devices in an integrated whole is what a vertical farm consists of. Various types are proposed and under research. The most common technologies used are:

• Solar greenhouse (technical) / Greenhouse
• Aeroponics / Hydroponics
• Composting
• Grow light
• Phytoremediation
• Skyscraper

Plans

Professor Despommier argues that the technology to construct vertical farms currently exists. He also states that the system can be profitable and effective, a claim evidenced by some preliminary research posted on the project's website. Developers and local governments in the following cities have expressed serious interest in establishing a vertical farm: Inchon (South Korea), Abu Dhabi (United Arab Emirates), and Dongtan (China).

Criticisms

Critics have noted that the energy needed for artificial lighting and other vertical farming operations might outweigh the benefit of the building’s close proximity to the areas of consumption. Artificial lighting would be needed for crops growing in areas of the building unexposed to sunlight. Bruce Bugbee, a crop physiologist at Utah State University, believes that the huge power demands of vertical farming would be too expensive and uncompetitive with traditional farms using only free natural light. He notes that the levels of light needed by growing crops is about 100 times the amount used by people working in offices.

See also

• Arcology
• Hydroponics
• Aeroponics
• Aquaculture
• Folkewall
• Hanging Gardens of Babylon
• Horticulture
• Terrace (agriculture), Terrace (gardening), and Terrace (building)
• Rooftop farming
• Development Supported Agriculture

External links

• The Vertical Farm Project
• Various Vertical Farm Designs
• Dickson Despommier's Ideas
• Vertical Farming: For the Greener Good
• Rewilding Canada
• Meet Farming’s Future
• The Farmer in the High-Rise, Plenty Magazine
• Vertical Farming, Time Magazine
• Vertical Farms & Large Scale Urban Agriculture Research - Except Consulting
• Animation of large Vertical Farm in city - Chris Jacobs and Dean Fowler
• Chris Jacobs Vertical Farm Blog
• CNN Vertical Farming; Sky Farming Video
• "Professor sees vertical farms on horizon," Columbia Tribune, 8/30/2005, accessed 9/3/06
• "La Tour Vivante de l'agence soa architectes" (French and English)
• "Comment on article "Urbanism and the environment" - Gar Lipow coins the term "farmscraper" 4/23/2007
• "Vertical farming in the big Apple" BBC article from June 19, 2007
• Howstuffworks - "Will there be farms in New York City's skyscrapers?"
• "Grow Up" Pullquote: "If designer Gordon Graff gets his way, a new skyscraper in Toronto's Theatre District could be the unlikely source of food for 35,000 residents."

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