Victoria Boustani April 28, 2017
Real Estate Sustainability
Homework 2 Final Memo
Urban Agriculture – An Oxymoron or a Growing Continuum?
By the year 2050, nearly 80% of the earth’s population will reside in urban centers. Applying the most conservative estimates to current demographic trends, the human population will increase by about 3 billion people during the interim.
An estimated 109 hectares of new land (about 20% more land than is represented by the country of Brazil) will be needed to grow enough food to feed them–if traditional farming practices continue as they are practiced today. Urban Agriculture has been a pioneering alternative to traditional methods. In this evaluation of potential ventures into urban agriculture, we will be focusing on vertical farming, specifically two types: aeroponics and aquaponics.
Vertical farming is the practice of producing food in vertically stacked layers, such as in a skyscraper, used warehouse, or shipping container. The modern ideas of vertical farming use indoor farming techniques and controlled-environment agriculture (CEA) technology, where all environmental factors can be controlled. Aerofarm is working on the largest vertical farm in the nation right now in New Jersey.
NASA developed the indoor growing approach in the 1990s when they were interested in looking for efficient ways to grow plants in space. An aeroponic system is the most efficient system for vertical farms. It uses up to 90% less water than even the most efficient hydroponic systems. Plants grown in these aeroponic systems have also been shown to uptake more minerals and vitamins, making the plants healthier and potentially more nutritious.
The aquaponics system combines plants and fish in the same ecosystem. Fish are grown in indoor ponds, which produces waste filled with nutrients that is later used as a feeding source for the plants. The plants, in turn, filter and purify the wastewater, which is recycled to the fish ponds. Aquaponics is used in smaller-scale vertical farming systems. Most commercial vertical farm systems focus on producing only a few fast-growing vegetable crops, therefore don’t include an aquaponics component. This simplifies the economics and production issues and maximizes efficiency.
Now we face the question of value and efficiency. There are several pros and cons to the vertical farming practice. The pros are as follows:
• Continuous Crop Production—Vertical farming can ensure crop production year-round in non-tropical regions. Additionally, Production is much more efficient than land-based farming. According to Dickson D. Despommier–an emeritus professor of microbiology and Public Health at Columbia University–one acre of a vertical farm may produce yield equivalent to more than 30 acres of farmland, when the number of crops produced per season is considered.
• Elimination of Herbicides and Pesticides—In the discussions of urban agriculture two very big concerns come up and one of them is the danger of large populations being exposed to large amounts of herbicides and pesticides in close approximation. In 2015, in the small city of Bordeaux–which relies heavily on the wine industry and vineyards for local jobs–the NGO Générations Futures carried out tests in homes located nearby vineyards, cornfields, and industrial orchards. The results showed that on average, 20 different chemicals were detected in each dwelling. Vertical Farms eliminate a large portion of these risks. The controlled growing conditions in a vertical farm allow for a reduction or total elimination of chemical pesticides.
• Protection from Weather-Related Variations in Crop Production—Being in a controlled environment, crops are safe from extreme weather occurrences such as droughts, hail, and floods, which are becoming increasingly frequent due to climate change and global warming.
• Water Conservation and Recycling—On average over all techniques, vertical farms use about 70% less water than normal agriculture.
• Climate Friendly—Growing crops indoors reduces the use of large farm equipment commonly used on outdoor industrial farms, which reduces the burning of fossil fuel. According to Despommier, deploying vertical farms on a large scale could result in a significant reduction in air pollution and in CO2 emissions. Furthermore, because crops from a vertical farm usually sell to local markets, they reduce the emissions of shipping product hundreds or thousands of miles to further markets. Still requires a lot of electricity and their produce is limited so still shipping a lot.
The cons are as follows:
• Land and Building Costs—Urban locations for vertical farms are expensive. As expressed above a 1 acre vertical farm can produce the same yield as 30 acres of farmland, however impressive that seems, we need to view it subjectively to what 30 acres of farmland produces in number of plates. Susan Gudeman, a contributor and mechanical design engineer wrote for the Green-buildings blog estimating the cost of a vertical farm that could feed 50,000 people. She estimated the appropriate size of the building to be 5 acres and 30 stories high at 6.5 million square feet. With the land costs and technological costs, basing off a NYC market, she concluded the project would cost roughly 1.9 billion dollars. In perspective, it seems quite steep although the land saving sounds appealing. Some existing vertical farms are based in abandoned warehouses, run-down areas, which can be more economical for construction, but not enough. Another counter to this obstacle would be the idea that we are saving land for other uses but it then comes to question how much land would be saved if we still need farms for livestock and other produce like grains that are less perishable and would not grow well in vertical farms.
• Energy Use—Although transportation costs and burning of fossil fuel may be significantly less than in conventional farming, the energy consumption for artificial lighting and climate control in a vertical farm can add significantly to operations costs and be harmful to the environment. But in Lauren Hepler’s interview with co-founders of Association for Vertical Farming, Andrew Blume notes “LED lights are getting more efficient. The renewable energy sources are going to also continue to get more efficient, whether it’s solar or wind or these renewable sources.” (GreenBiz, 2016)
• Limited Number of Crop Species—The current practice for vertical farms focuses on high-value, rapid-growing, small-footprint, and quick-turnover crops, such as lettuce, basil, and other salad items. This makes the vertical farm project more feasible and profitable. Co-founder of Association for Vertical Farming, Henry Gordon-Smith says “Right now, the diversity is, let’s say, relatively limited. It’s leafy greens, microgreens. But it’s getting more interesting over time. I think the new crops that are going to be coming onboard from an economics perspective are probably going to be strawberries and other berries.” (GreenBiz, 2016)
• Pollination Needs—Crops requiring insect pollination are at a disadvantage in a vertical farm, since insects are usually excluded from the growing environment. Plants requiring pollination may need to be pollinated by hand, requiring staff time and labor.
The opposing arguments are both credible and there is still not enough case study data to set a finite answer on whether we as an urban society will be able to move to a heavily reliant vertical farming produce model. The costs are high, and the produce is limited. However, we do have to consider that the technology is still evolving. Just as solar panels were once a costly appliance; they have now become a very viable option for individual homeowners. There is also the ecological/ethical responsibility as stakeholders in cities and of inhabitants of this planet. One major argument to this is the idea of additional, consistent, and reliable produce production. Texas A&M AgriLife Communications released an article in 2014 saying that by 2050 our world food shortage will be as destabilizing as energy issues are today. (Science Daily, 2014) Aside from this, the impact of climate change on our natural storms and disasters puts our food production at high risk and the concept of having consistent food that withstands these disasters is an important idea to consider, especially in major cities like New York that imports a lot of food and can only hold enough food in their markets for 2 day’s worth of feeding for the city’s population.
The recommendation is circumstantial and complicated. Simply, the idea is to move forward with the support and development of more vertical farms. Long-term, these projects are extremely important, not so much for now, but for the future. With more development of vertical farms, the costs of the technologies and other needs of production will decline making projects more feasible and consequently preparing vertical farms with the appropriate tools it requires to be dependable when the population needs it most. The current costs make the projects virtually impossible in major cities like New York–although there are some–to support the large population. However, as said before, there are nearby locations in failing cities that would have a cheaper land and building cost as well as bring jobs to the area which can be a great ground to introduce vertical farms.
Works Cited
Hepler, Lauren. “LEED for Vertical Farms? Defining High-tech Sustainable Food.” GreenBiz. GreenBiz Group Inc., 15 Aug. 2016. Web. 02 May 2017.
Mancebo, Francois. “Is There Any Type of Urban Greenspace That Addresses the Urban-Rural Continuum? Urban Agriculture – The Nature of Cities.” The Nature of Cities. The Nature of Cities, 08 Jan. 2015. Web. 02 May 2017.
Photograph by LYNN JOHNSON, National Geographic Creative, and Photograph By Lynn Johnson. “Opinion: Why Cities Are the Future for Farming.” National Geographic. N.p., 02 May 2017. Web. 02 May 2017.
ScienceDaily. ScienceDaily, n.d. Web. 02 May 2017.
“Vertical Farming.” Vertical Farming | ATTRA | National Sustainable Agriculture Information Service. N.p., n.d. Web. 02 May 2017.