Available via license: CC BY-NC-ND
Content may be subject to copyright.
10.1515/jlecol-2017-0016 Journal of Landscape Ecology
OPPORTUNITIES AND CHALLENGES IN SUSTAINABILITY
OF VERTICAL FARMING: A REVIEW
FATEMEH KALANTARI*, OSMAN MOHD TAHIR, RAHELEH AKBARI JONI
AND EZAZ FATEMI
Faculty of Design and Architecture, University Putra Malaysia, Kuala Lumpur, Malaysia,
*Corresponded author - e -mail: Fatimah.Kalantari@gmail.com
Received: 4th April 2017, Accepted: 20th June 2017
ABSTRACT
As the world population continues to grow at a rapid rate, accompanied by a substantial
growth in food demand which is expected to transpire in the next 50 years, 80 % of the
population will be living in urban areas. In order to feed this growing population, there is
a need for sustainable urban food. Producing sustainable urban food requires considering all
factors of sustainability collectively including, environmental, social and economic
advancement. A new method that has been proposed to address the issue of sustainability and
to meet the growing food demand is, designing and implementing vertical farms. Vertical
farming is a concept that involves cultivating plants with livestock on vertically inclined
surfaces such as in skyscrapers in urban areas, where there is a lack of available land and
space. However, there is a paucity of information and a limited number of published critical
reviews on Vertical farming in urban areas. This study, in an attempt to review the major
opportunities and challenges of Vertical Farming, uses the framework of sustainability to
examine the role of it in prospective food provision in cities. This study is a critical review of
60 documents from related published papers from relevant journals and scientific online
databases. Vertical Farming can be potentially beneficial in increasing food production,
maintaining high quality and safety and contributing to sustainable urban farming.
Well-known advantages of growing food within the urban territory can be beneficial
environmentally, socially and economically. Vertical farms can also provide solutions for
increasing food security worldwide.
Keyword: Vertical Farming (VF), Food Security, Urban Agriculture, Sustainable Urban
Food
INTRODUCTION
Fundamental changes are predicted to occur in the upcoming 50 years accompanied by
higher demand for food, all across the world as the world population continues to grow
exponentially (Banerjee & Adenaeuer, 2014). The world population is predicted to reach an
estimated 9 billion by 2050 (Despommier et al., 2013), and cities will be hosting about 80 %
of this population (Despommier, 2010; Islam & Siwar, 2012). Currently, there is
approximately 800 million hectares of land that is designated to soil-based farming globally,
which constitutes about 38 % of the total global land area. Moreover, 80 % of the total arable
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
6
land is currently being utilized across the globe (Ellingsen & Despommier, 2008). Due to the
growing food demand, there is a need for utilizing more arable land for farming as swell as
intensifying farming efforts that would affect global agriculture. A new method that could
potentially meet this demand, is in designing and devloping vertical farms (Despommier,
2013). The proposed designs can be tested through new technologies (Despommier, 2011;
Glaser, 2012), however, VF is a fairly new concept and little studies have explored the issue
of integrating it in the urban context.
In theory, Vertical Farming (VF) is an agricultural technique involving large-scale food
production in high-rise buildings that enables fast growth and planned production by
controlling environmental conditions and nutrient solutions to crops based on hydroponics
(Figure 1), using cutting-edge greenhouse methods and technologies (Abel, 2010; Banerjee
& Adenaeuer, 2014; Despommier, 2010, 2011). According to Perez’s research (2014), VF
incorporates both discplines of engineering and natural sciences, and has multiple
applications in both society and the environment (Perez, 2014).
Recently, producing sustainable food in cities has garnered much interest and attention in
many academic and practical fields (Despommier, 2013; Specht et al., 2014). While there are
still limited daunting technical and practical applications problems in regarding
implementing the VF. However at present, these farms are largely growing and produce
different types of crops inside cities such as China, Holland, South Korea, Japan, Canada,
Italy, U.S, Singapore, United Arab Emirates, and England (Sivamani, Bae, & Cho, 2013).
Table.1 present the details of most effective vertical farms in around the world in different
countries by evaluation of feasibility of VF for various climate/geographical areas by their
type and technologies. According to Table 1, implementation and knowledge related to VF
are growing in number, capacity and size. However, spatial distribution of VF shows that the
evaluation of feasibility of VF for various climate or geographical areas as well as regional
characteristics are largely growing. Because the plants will be grown indoors by controlled
environment agricultural techniques, then changing of seasons will have no effect on the
crops. It is obvious the various amount and types of products determined the VF is not just
happening, it is prospering at multiple cities with different regional characteristics around the
world.
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
7
Table 1: Details of some effective Vertical Farming around the world
N
Name
Location
Height
Type of
Building
Products
Area
Technology
year
Website
1
The Plant
Vertical
Farm
Chicago, IL
3story
Existing
building
in 19
century
Wide variety of
edible crops
includes an
artisanal brewery,
kombucha
brewery,
mushroom farm,
and bakery,
Tilapia
100,000
sq.ft
-Aquaponics systems and
fish breeding areas
- Hydroponic
-Recycling waste to energy
- Using biogas from an
anaerobic digester
-Natural sun energy
2013
www.plantchica
go.com
2
S
ky Greens
Farms
Singapore
9 m
New
leafy green
vegetables
600 m
-Aeroponuic system
-Low carbon hydraulic
water-driven
-Natural sun energy
2009
www.skygreens
.appsfly.com
3
V
ertiCrop
TM
Vancouver,
Canada
Rooftop
of
existing
building
Leafy greens,
micro greens, and
strawberries
50*75
Sq.ft, 120
racks with 24
growing trays
on each rack =
16-acre farm.
-Fully automated system
- Closed loop conveyor
hydroponic
-Room temperature,
lighting, fertilization,
irrigation and recapturing
of the water being used
- Natural and artificial light
2009
www.verticrop.
com
4
Republic of
South
Korea VF
South
Korea
3 story
New
leafy green
vegetables ,almost
wheat, and corn
450 m²
-Renewable resources like
geothermal and solar
-Automated rack system
- LED
2011
www.cityfarmer
.info/
5
Nuvege
plant
factory
Japan
(Kyoto)
4 story
Leafy green
vegetables
30,000
horizontal
sq.ft
57,000 sq.ft of
vertical
growing
space
-Automated rack system
-LED grow lights
-Hydroponics
www.nuvege.co
m
Unauthenticated
Download Date | 8/25/17 12:53 PM
Journal of Landscape Ecology (2017) aaa
8
6
Plantlab VF
Den Bosch,
Holland
3 story
under-
ground
Existing
building
every imaginable
crop, including
beans, corn,
cucumbers,
tomatoes, and
strawberries
-Without the use of
daylight
- Advanced LED
-Aeroponic and hydroponic
2011
www.plantlab.n
l/
7
Vertical
Harvest
plans2
Jackson
Wyoming,
USA
3 story
New
tomatoes,
strawberries,
lettuce, and micro
greens
4500 sq.ft.
footprint into
18,000 sq.ft.,
or four times
the growing
area
-Recirculating hydroponic
methods
- LED
2012
www.verticalha
rvestjackson.co
m/
8
Planned
Vertical
Farm
Linkoping,
Sweden
17
story
New
Asian leafy green
vegetables
-Aeroponic
-Hydroponic
-Using waste products in
the process
- Natural lighting
2012
www.plantagon.
com
9
Green
Sense
Farms
-First farm
in : Portage,
Indiana
-Shenzhen,
china
New
-Micro Greens
-Baby Greens
-Herbs
-Lettuces
20,000 sq./ft
-Using stacking vertical
towers
-Using automated
computer controls, which
provide the precise amount
of light, nutrients, water,
temperature, and humidity
- Minimize waste, and
recycle water technique
-
2014
-201
6
http://www.gree
nsensefarms.co
m
1
0
A
eroFarms
Newark,
New Jersey
9 m
New
250
different types of
herbs
and greens grow
like kale,
arugula, and
mizuna.
20
,000-sq/ft
with 35 rows
and 12 levels
of vertically
grown
-Without any soil,
pesticides, or sunlight. -
Crops sit on stacked trays
outfitted
- LED lights
-Using Sensors that track
the growing process.
- Recycle water technique
2012
http://aerofarms
.com/
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
9
However, there is a paucity of information and a limited number of published critical
reviews on Vertical farming in urban areas. This study, in order to review the major benefits
and challenges, uses the framework of sustainability to realize the role of VF in prospective
food provision in cities and also reviews the main advantages and disadvantages. A total of
60 documents that have been published in international sources are analyzed.
METHODOLOGY
In the current study, a systematic review was performed on previous literature on the
primary research question: what are the opportunities and challenges of VF mentioned in
these academic and scientific papers? The first phase consisted only of peer-reviewed papers.
In the second phase, more documents such as proceedings, dissertations, projects and articles
published in magazines were reviewed. Peer-reviewed academic publications from
well-known databases such as Web of Science, Scopus, ProQuest as well as Google Scholar
were referred to and all related literature could be accessed from online sources. To
investigate a specific topic, it was searched for in titles, abstracts, and keywords from online
sources between 2007 to December 2016. Subsequently, relevant papers included in the
search, were perused for their relevance and eventual results. These papers were examined,
explored and compared in order to identify multiple merits and demerits of VF. In order to
make sure all the sources were picked up were based on the keywords, a Microsoft Excel
spread-sheet was prepared.
Systematic Framework and Key Concepts
To conduct a systematic review of the literature obtained, a systematic framework was
developed, to facilitate in organizing the complicated topics. This framework is rooted in the
concept of sustainability as stated in the Brundtland Report, 1987 (Brundtland, 1985), in
which the three bases (environmental, social and economic) share some similarities at the
core of which is sustainable development. To analyze the content more extensively, a grid
was constructed consisting of 26 groups of sub-topics collected from multiple papers, mostly
from Bohn and Viljoen (2011). Three overall themes were extracted, namely; social,
environmental and economic (Bohn & Viljoen, 2011). A Microsoft Excel file for each aspect
of sustainability was then made for each analyzed article, in case a document referred to
a topic related to VF, that theme would be integrated into the file. In the statistical analysis,
frequencies were used as well as comparability. Through attributing a topic to one aspect of
sustainability, we accept the interaction and mutual relationship between and among all
aspects too.
Systematic Analysis of Sustainability Dimensions
Table 2 indicates that the majority of the papers (47) looked into at least one issue assigned
to the environmental aspect. However, 30 from among 60 sources addressed topics related to
issues concerning the social aspects while 23 were concerned with issues related to
economics. Most of the papers deal with issues of all of the three aspects (Table 2).
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
10
Table 2, Absolute frequencies of sustainability dimensions in the surveyed literature
(n = 60)
Absolute Frequencies of Sustainability Dimensions
With regards to the sustainable dimension of VF, the following tables depict the absolute
frequencies of the environmental dimension (Table 3), the social dimension (Table 4) and the
economic dimension (Table 5).
Table 3: Absolute frequencies of topics in surveyed literature related to the
environmental dimension of sustainability (n = 47)
Environmental Dimension
Absolute Frequency
Reduction of Water Demands
18
Energy Saving
16
More Productivity Per Unit of Area
15
Healthy Food Provision
14
Reduction of Carbon Footprint And The Effect of Air Quality
12
Reduces Fossil Fuel
11
Recycling of Organic Waste
New Landscape Opportunities
11
10
Reduction of Urban Head Island
9
Protect From Natural Disease
8
Reduction of Herbicide and Pesticide Manufacture
7
More Productivity Per Unit of Area
7
Resilient to Climate Change
6
Acting As a Sound Insulator
2
0 5 10 15 20 25 30 35 40 45 50 55 60
Environmental
Social
Economical
Sustainable Dimention of Vertical Farming
Absolute Frequency
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
11
Table 4: Absolute frequencies of topics in surveyed literature related to the social
dimension of sustainability (n = 30)
Social Dimension
Absolute Frequency
Job Opportunity
9
Greater Community
7
Visual Amenity
6
Education
6
Improved Food Security
6
Leisure
4
Psychological/Spiritual Health
4
Table 5: Absolute frequencies of topics in surveyed literature related to the economic
dimension of sustainability (n = 23)
Economic Dimension
Absolute Frequency
Economic Opportunity For Land Scarcity
11
Return of Investment
6
Minimization of Energy Cost
5
Low Price of Food
4
Community Economic Growth
4
OPPORTUNITIES AND CHALLENGES OF VERTICAL FARMING
We proceed with a list of the primary prospects as well as challenges of VF based on the
review of the literature which will be discussed along with the three aspects of sustainability.
Environmental Benefits
As for environmental advantages, farming in cities conserves biodiversity, reduces
wastage and loss and curtails the energy used for producing and providing food for the public
(Ankri, 2010; Perez, 2014; Thomaier et al., 2015). Dspommier (2010) however, comments
that VF is not a panacea for all existing sustainability problems but can contribute
significantly by providing solutions to existing problems. It can potentially replace industrial
agriculture and could be a better alternative by minimizing damages caused by conventional
open field agriculture. VF brings with it many ecological and poral benefits, and can,
therefore, move agriculture towards the direction of agroecology. Other sectors that could
benefit from VF, will be elaborated upon in the following sections.
1. Energy Saving
The body of research on VF has pointed out the role of greenhouses in saving and recycling
energy (Specht et al., 2014), for example the system makes use of natural light, artificial light
and energy to facilitate in environment management (temperature control), water provision
(irrigation) and nutrient delivery (Perez, 2014; Sivamani, Bae, Shin, Park, & Cho, 2014).
Challenges of lighting: Over two-thirds of the global energy is consumed in cities.
A critical point and disadvantage often highlighted by the adversaries of VF is, how will
plants growing inside a building be provided with sufficient amount of energy needed for
plant growth (Al-Chalabi, 2015; Specht et al., 2014). The system make use of both natural
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
12
light as well as artificial light as the main source of energy within the building for
photosynthesis (density and exposure) and photoperiodic (time and duration) as well as the
structure (dimensional light dissemination) of plants (Germer et al., 2011). Since vertical
farms within buildings have less access to natural light, there is a need for artificial lighting
which is often provided by LEDs, which is comparable to greenhouse farming. Nevertheless,
it is an extra cost that needs to be taken into consideration (Banerjee & Adenaeuer, 2014). As
hypothesized by Perez (2014), if the agriculture industry of the United States followed
a vertical approach, the electricity required for lighting would be eight times that of the
amount generated by all power plants annually in the United States. Actually, taking full
advantage of additional lighting in vertical farming still remains a challenge.
Another point that critics of VF usually target is, the lack of natural light source in cities. It
is not plausible or practical to use solar panels for providing energy in vertical farms, due to
the shade of buildings (Perez, 2014). Therefore, in the future The lack of natural lighting will
be less noticeable (Specht et al., 2014).
Ankari (2010), mentioned in his study that, converting a horizontal farm into a vertical one
would be challenging due to limited space. The width of a horizontal field would have to be
divided into smaller portions in order to form the vertical version. However, the primary
problem of growing plants this way is, limited exposure to the sun. Plants may be deprived of
sunlight since many layers are stacked one above another which prevents sunshine from
reaching the plants below. Even if VF were to be put into practice on a large-scale, this would
not completely solve agricultural problems. Not only would plants in such a system be
deprived of soil for growth, but would also be denied a key source of energy namely, natural
light (Ankri, 2010).
The opportunity of lighting: The LED can be turned off and on as frequently as required
for the plants. It does not adversely affect the plants while it helps to further save energy
(Perez, 2014; Thomaier et al., 2015). How Photosynthetically Active Radiation (PAR) is
related to conversion and biomass is important in deciding the amount of energy required for
producing a specific amount of food. A relevant study conducted by NASA, identified
a maximal of 12 % conversion efficiency from PAR to biomass. The estimated PAR
conversion efficiency they reported was, 1.6 gram of dry mass/mol, considering the control
of lighting as well as an optimal enrichment of carbon dioxide. LEDs is the preferred choice
as it is easily manufactured and an ideal choice of artificial lighting for plants. In another
research conducted in Rutgers University, LEDs were recommended as they save electrical
energy while simultaneously facilitating plant growth (Despommier, 2014; Perez, 2014).
Many existing VF in the word using the LED in these technologies such as Republic VF in
South Korea, Nuvege plant factory in Japan and Plantlab VF in Holland.
Challenges of Heating: An issue closely linked to lighting is, the temperature it produces.
More than the brightness, lighting devices produce heat, which especially in summer would
disrupt or interfere with the air conditioning system. Two other crucial requirements for
healthy plant growth indoors, are humidity as well as air conditioning which require
meticulous control and monitoring and involves high energy costs. Still another major
prerequisite and cost is in the building of the towers. The feasibility of these towers remains
questionable, especially problems related to the amount of energy required for lifting
artificial growth equipment, water or other resources such as fertilizers high onto the towers
or moving them down when necessary (Ellingsen & Despommier, 2008).
Opportunities of Heating: Thomaier et al. (2015), suggest that the greenhouses can be
creatively used as a source of energy production, whereby excessive energy produced can be
used to heat up the building itself. The problem however, is that this innovative proposal has
yet to be publicized (Thomaier et al., 2015). Additionally, another advantage of growing
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
13
plants indoors is that they keep the air around them and in the vicinity cool. This phenomena
occurs through a process of evapotranspiration, when plants absorb water from the soil,
which is then transferred to the plant body and leaves and is eventually released into the air,
which consequently brings down the surrounding temperature. Another way plants help to
cool the surrounding environment is through providing shade if they are large enough. In
large buildings, the atrium functions as a means to adjust the temperature inside the building
(Afrin, 2009; Thomaier et al., 2015). It was also reported that, a hydroponic vertical garden
managed to cut down on the amount of energy used in a tall building up to 23 % and reduce
the air conditioning up to 20 % (Specht et al., 2014).
Thus, VF involves sustainable energy sources and power can be sent back to the grid.
Furthermore, other means by which VF saves energy is in reduced transportation,
temperature reduction, power saving, reduction in processing and packing as well as renewal
energy among urban/local areas and industrial or agriculture areas. This can be manifested in
how they utilize surplus heat, cooling water and carbon dioxide from the industrial sectors in
greenhouses (Ahlström & Zahra, 2011; Cicekli & Barlas, 2014; Miller, 2011; Sauerborn,
2011).
2. Reduction of Water Demand
Challenges of Water Demand: It is estimated that approximately, 3000 liters/person/day
of water is regularly used in Europe just for producing food (Perez, 2014). Out of the total
water consumption of human beings, 24-30 % of it is used for watering and producing rice
(Germer et al., 2011).
A key factor in this system is the transport of water especially high loads to higher floors in
tall buildings (Perez, 2014). The transport of water is essential not only in providing the
required water supply in the building but also in managing the sewage system like in any
industrial building. In addition, the water source will aid in supplying nutrients needed for
various crops within the main irrigation system. The fluid provision system needs to be
standardized both in the growing floors as well as the others, exactly like an industrial unit
(Banerjee & Adenaeuer, 2014).
Opportunities of Water Demand by Recycling and Dehumidifying: Perez (2014),
believes that the determining factor which makes it possible to build a VF or not is the water
supply (Perez, 2014). Producing food is not the only application of vertical farms, but it can
also help in recycling the city’s water supplies (Ellingsen & Despommier, 2008; Lam, 2007).
As part of an initiative plan suggested by Despommier (2010), instead of releasing
wastewater into rivers, it can be used for VF irrigation, where the wastewater is purified and
recycled and water drainage will not be necessary. So, the gray or black water can be purified
in vertical farms and converted to drinkable water through evapotranspiration (Banerjee &
Adenaeuer, 2014; Besthorn, 2013; Cicekli & Barlas, 2014; Despommier, 2009, 2010;
Sauerborn, 2011; Thomaier et al., 2015; Voss, 2013). Green Sense Farms in Indiana and
AeroFarms in New Jersey are using this technique to recycle water in their vertical farms.
Opportunities of Water Demand by Aeroponics and Hydroponic Systems: The best and
most efficient method of water consumption in farming is facilitated through two systems
namely; aeroponics and hydroponics. If used together in closed loop systems, it can manage
to save water up to 95 %. They can also help to eliminate farming wastewater which is
potentially hazardous to the environment and to human health (Despommier, 2010; Germer
et al., 2011; Voss, 2013). As described by Toyoki Kozai, the manager of the NPO factory,
when the air is dried and water is circulated back with the help of aeroponics and
hydroponics, the efficiency of water consumption goes up to 97 % as compared to traditional
agriculture. Thus, the amount of water consumed in VF for irrigation is only 3 % that of the
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
14
amount used in conventional farming. Sauerborn (2011) states 10 hectares of agricultural
field can be substituted by a hectare of a greenhouse recirculating hydroponic system
(Sauerborn, 2011; Specht et al., 2014). In addition, a recent study on water consumption in
VF conducted by Despomier (2010) indicated that, new vertical farms used 98 % less water
than traditional farms (Despommier, 2010). In the Den Bosch project, almost all types of
crops have been produced through VF with 90 % less water consumption than traditional
farming (Besthorn, 2013). This amount was reported to be 70 % in another study. Despomier
(2013) also stated that, less water (70-80 %) is assumed to be used in VF as compared to
conventional farming techniques (Despommier, 2011, 2013). Hydroponic and Aeroponic
systems are using vastly in many existing VF projects such as Sky Greens Farms in
Singapore, Nuveg plant factory in Japan and Planned Vertical Farm in Sweden.
3. More Productivity Per Unit of Area
Opportunities: Crop production can increase drastically if full-year stability is maintained
during production, by implementing efficient methods during the process (Banerjee &
Adenaeuer, 2014; Despommier, 2011, 2013; Miller, 2011). The key difference between VF
and traditional farming is in the variety of products that can be produced at a given time. In
traditional farming, only one crop at a time can be produced, which is referred to as
monoculture, whereas in VF, multiple types of crops can be produced simultaneously on
different floors. Another advantage of VF is, that unlike traditional farming which can only
be carried out at a particular time of the year, plants inside a VF can grow all the time
throughout the year (Platt, 2007; Sivamani et al., 2013). Therefore, fewer crops are lost as
compared to conventional agriculture. It is difficult to quantify space efficiency in a closed
environment for farming because some types of plants have a better harvest than other types
of plants in comparison to others (Ellingsen & Despommier, 2008).
This was further demonstrated in a study carried out by Perez (2011), where they reported
that products harvested annually through VF amounts to 470 tons per acre, and 23 times more
lettuce is produced by VF than in the same amount of space in conventional farms (Cicekli &
Barlas, 2014; Perez, 2014). Thus in VF, space is utilized more efficiently, each closed-space
acre is equivalent to 4-6 acres of open field depending on the type of crop. For instance to
grow strawberries, an acre of land that is required for a closed space, would require 30 acres
of open space (Ahlström & Zahra, 2011; Banerjee & Adenaeuer, 2014; Despommier, 2010,
2013; Voss, 2013). According to Besthorn’s (2013) report, three times more crops were
produced in the Den Bosh VF project than traditional farming methods (Besthorn, 2013).
Therefore, if the available space in the greenhouse is doubled or tripled, the amount of crop
production will further increase (Despommier, 2014). In addition, another advantage of VF is
that up to eight types of crops can be harvested yearly, in the case of hydroponically grown
leafy vegetables such as lettuce, spinach, kale, and basil. However in conventional farming,
only a maximum of three crops can be harvested in a year (Despommier, 2013; Eigenbrod &
Gruda, 2015). In summary, VF can therefore make use of all these advantages to provide
more food in the least amount of time.
4. Recycling of Organic Waste
Challenges: A lot of waste is generated in buildings including, wastage of heat, gray water
buildup and so on. Agricultural run-off is one of the major sources of contamination in the
world today (Ellis, 2012).
Opportunities: One way of recycling organic waste is through applying a no-input system
that yields a closed loop, concerning the recycling of waste, which would help drastically cut
down on pollution (Besthorn, 2013; Despommier, 2013; Ellingsen & Despommier, 2008).
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
15
Waste from animals, plants and even from food manufacturing industries or houses can be
a source of organic material. As production is a process that continues throughout the year, in
case of a water shortage crisis, the waste water can be utilized as well as the nutrient contents
and organic waste (Ahlström & Zahra, 2011; Albajes et al., 2013). If nutrients and organic
wastes from wastewater can be effectively harnessed, then there would be no shortage of
some vital minerals such as phosphorus. This would consequently, minimize the number of
landfills which would subsequently reduce the amount of methane diffusion and also help
decrease the vermin population such as rats and cockroaches (Despommier, 2010; Ellingsen
& Despommier, 2008).
Numerous ideas for waste management in VF have been presented in previous literature.
The studies have sought to optimize or possibly close the cycle of nutrients sometimes at
a small scale for example in a building, and sometimes at a larger scale for example, in an
entire city. Compost has already been widely used in cities in an attempt to recycle organic
waste. Conversely, there are mixed farms that close the cycle of nutrients by applying
aquaponic vegetable mixtures, aquaculture, vermiculture along with vegetable systems and
city fisheries that utilize the sewage and waste water as food (Specht et al., 2014). For
example, 300 kilocalories of energy resides within an ordinary amount of human excrement
which is equivalent to about half a pound, when used in a bomb calorimeter. If we assume
that there are eight million residents in New York City, we can infer that approximately,
100 million kilowatt hours of electrical energy can be annually obtained from just bodily
waste. This amount of energy is adequate for managing farms with up to 30 floors. Therefore,
if the copious amounts of waste that is produced can be converted into energy or water, it
would greatly facilitate city life (Despommier, 2009). The Plant Vertical Farm in Chicago
and the Republic of South Korea VF factory are recycling their waste for using the energy.
5. More “Land Use”
Opportunities: If agriculture is moved indoors to form vertical farms, it will not only save
space but will also provide a variety of food products, and crop output per acre of land will be
maximized. Therefore, it is not just the horizontal space that can be used effectively as in
traditional farming. The biggest advantage of VF over conventional farming is that it is not
restricted to one plane (Banerjee & Adenaeuer, 2014; Perez, 2014; Voss, 2013). If outdoor
farming goes indoors, there will be a 20 time reduction in land use, there will be a 1/20 ratio
of improvement in land consumption or 95 % of savings therefore, there seems to be no
reason why not to use VF. As an instance, if one floor is added, there will be a 1/40 advantage
or 97.5 % of savings, as compared to only 95 % of savings realized through a greenhouse.
The ratio of 1/20 is for lettuce production and its benefits mostly originate from plant spacing
and respacing which is not possible in conventional farms. The case however, is different for
tomatoes and other crops. To feed a population of 100,000, each individual would need 1 m2
of space, hence a vertical farm would need to be 100m x 100m x 10 layers with the top floor
acting as a simple greenhouse (Perez, 2014).
In big congested cities where space is a rare commodity and there are not enough parks or
gardens due to a lack of space, vertical farms saves space, in big cities where lack of space is
a serious issue and reason why there is not enough parks or gardens, it can be effectively
employed (Banerjee & Adenaeuer, 2014). This would drastically help to reduce the use of
surface land to produce food in cities effectively. The land that is currently being used for
farming can be restored to its original natural state (Perez, 2014).
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
16
6. Resilient to Climate Change
Opportunities: There are numerous advantages of using VF over conventional farming in
land soil. In VF, all the ideal conditions required for optimum plant growth can be achieved
indoors such as, heating, lighting, water, humidity, amount of nutrients and suitable settings
that can all be controlled and managed for a specific crop. Because the plants will be grown
indoors, the changing of seasons will have no effect on the crops. This will allow for multiple
harvests during the year, unlike traditional farming which enjoys only one harvest a year.
This benefit of VF highly increases production output (Germer et al., 2011; Voss, 2013). In
this method (VF), the overall system design can be adjusted, to cater for the specific and
unique physiological requirements of a particular plant. So, not only will the best-suited
environment for plant growth be decided upon, but also the best and most appropriate and
efficient equipment will be selected for in VF (Germer et al., 2011). Moreover, plants grown
indoors will be protected from pests and climate change, and subsequently more crops can be
harvested due to lower losses as compared to traditional farming. The utmost benefit of VF is
in the ability to control all conditions required for ideal growth of a particular crop where a
variety of edible plants can be grown. In these ideal circumstances, plants have the ability to
grow faster and become larger which leads to an increased annual crop yield than traditional
forms of agriculture. Space is efficiently utilized, where maximum gain is achieved from
every square foot of space. Besides plant crops, VF can accommodate domestic animals and
fowls as well (Banerjee & Adenaeuer, 2014; Despommier, 2013; Germer et al., 2011; Perez,
2014). It means VF can establishes in any parts of the word without any limitation in related
to various climate/geographical areas (Refer to Table 1).
7. Protection From Natural Disaster
Challenges: Change of weather has always influenced farming such as changes in
temperature, water supply and photo intensity which could adversely affect crops and lead to
a loss in production yield. Insufficient amount of water destroys many crops every year in
many countries such as Midwest America (Banerjee & Adenaeuer, 2014; Despommier,
2009). If artificial watering systems are used, plants will be unaffected by drought or other
natural disasters and they can also benefit from the artificial heating system. Photo intensity
and the duration can also be controlled so as to keep all the conditions optimal (Banerjee &
Adenaeuer, 2014; Despommier, 2011; Ellingsen & Despommier, 2008; Voss, 2013).
Opportunities: Another main advantage of VF is that it can be used anywhere and
everywhere in the world since it does not depend on soil (Despommier, 2013). The ultimate
goal of VF is to provide food for the entire population of the world without having to worry
about the climate changes. However, not many people are engaged in this type of agriculture.
In conclusion, it must be stressed upon that VF does not aim to serve only individual persons
but rather, it seeks to serve the world population.
8. Reduction of Fossil Fuel
Challenges: In conventional farming there is too much fossil fuel consumption, for
example, in America alone 20 % of these types of fuels are consumed in farming (Besthorn,
2013). Approximately, 4-8 barrels of oil is used every year by every American citizen to
produce their food. A major portion is used for transportation as well as storage. Fossil fuels
that are used in transportation not only cause local or global air pollution but are also harmful
to human health. It is also responsible for change of weather and greenhouse gas distribution.
In the process of producing agricultural crops, a lot of fossil fuel is required for plowing,
seeding, harvesting, fertilizing and so on (Voss, 2013). Therefore, VF can cut down on
transportation required for transporting food.
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
17
Opportunities: When food is produced within the city, cities become places for both
providing and consuming food crops. The target consumers of crops are those living near the
site of production (Banerjee & Adenaeuer, 2014). This localization attempt helps to reduce
costs, pollution and many other problems (Miller, 2011). The lifestyle it promotes is ‘local
for local’ which minimizes the route between food production and consumption (Specht
et al., 2014).
In addition, as previously mentioned, since VF helps to provide food locally where it is also
consumed, there would be no need for long distance transportation (Banerjee & Adenaeuer,
2014; Germer et al., 2011). Therefore, more energy is conserved and the environment
remains protected. Another problem that occurs during transportation from the site of
production to the site of destination is, infestation or spoilage, which could have certain
negative ecological effects (Miller, 2011). Meanwhile, 30 % of food is lost due to spoilage or
infestation (Despommier, 2009). In conventional farming, food is normally transported as far
at 1500 miles from the area of production, VF would eliminate the need of packing
agricultural crops for transportation and would thus conserve energy (Ellingsen &
Despommier, 2008; Miller, 2011).
Since there is no farming machinery (e.g. tractors, plows or inorganic fertilizers) involved
in VF, fewer fossil fuels are required. No fossil fuels would be required for harvesting,
freezing storage or carrying them away (Banerjee & Adenaeuer, 2014; Despommier, 2010,
2011; Perez, 2014; Specht et al., 2014). In a VF system, everything is facilitated through
robotics (Voss, 2013).
If the VF is located downtown, it would be the ideal location as it would be close to the
major retail outlets. There would be no need for transportation, as immediately after harvest
the food products can be sold in the shops (Voss, 2013). Specht (2014) states that this to be
the response of high technology to transporting local foods (Specht et al., 2014).
9. New Landscape Opportunities
Challenges: A key problem that exists in the current method of farming, is the amount of
land that is needed. Currently, for the purpose of agriculture, millions of hectares of natural
land is converted into farmlands. It has severe detrimental effects on nature, the herbal
ecosystem, and biodiversity. So far great damages have been made to wetlands, meadows,
tropical forests, which in some cases have led to a total loss of these resources (Voss, 2013).
Such examples of total loss are rainforests in the Amazon basins and destruction of ground
water in the Khorezm basin (Banerjee & Adenaeuer, 2014). Since almost half of the earth’s
land is used for farming (and is ever increasing), such research findings can help to support
the argument in favor of nature restoration. When too much land is being allocated for
agriculture, it could seriously affect the earth’s capacity to accommodate human beings on it
(Germer et al., 2011).
Opportunities: A great benefit of VF is that it gradually helps in repairing the land (Voss,
2013), large parts of the ecosystem are restored as a result. When VF and all its common
forms become the norm and replace conventional farming techniques, most vegetables, fruits
and food products will be produced through VF and subsequently many of the fields that are
currently devoted to farming may be restored to their original state (Despommier, 2013).
Consequently, many parts of the damaged ecosystem can be revived (Despommier, 2010,
2011; Ellingsen & Despommier, 2008).
In most cases it is enough to leave it to nature to revive and restore itself with time (Voss,
2013). A sustainable environment can be achieved for urban centers through VF
(Despommier, 2010). When fields are saved from farming, trees will once again become an
integral part of city life, which will help reduce the amount of carbon dioxide and improve
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
18
the atmosphere (Despommier, 2014). The protection of biodiversity will lead to an increase
in genetic varieties of plants and animals (Ahlström & Zahra, 2011) and the reduced stress on
the land will help natural ecosystems flourish (Germer et al., 2011).
10. Healthy Food Provision
Health is related to the food we consume, and the consumption of locally produced food is
related to improve overall health. Health is mostly guaranteed by the ‘freshness’ and
wholesomeness of food. According to Miller (2011), health is affected by the local, organic
food produced by VF (Miller, 2011).
Challenges of Food Nutrition: Foods rich in vitamins, proteins and minerals are
increasingly in demand nowadays, as more countries are moving towards the trend of their
developed counterparts. Contrary to Engel’s law which perceives a negative correlation
between spending on food and higher income, the consumption style of such countries is
changing.
Another common problem that exists among many developing countries is the use of
human or animal feces instead of artificial fertilizers (Despommier, 2010) for farming.
Although fecal matter is an effective fertilizer, it also comes with some unfavorable factors,
such as parasites, infection, and disease.
Opportunities of Food Nutrition: The advantage of vertical farming is that it has the
ability to reduce the threat of these infectious diseases since it does not use fecal matter as
a fertilizer like in conventional agricultural techniques (Despommier, 2010; Ellingsen &
Despommier, 2008). Therefore, it helps to stop the transmission of such harmful infectious
diseases. In environments polluted with fecal matter, many viral or bacterial diseases can
potentially endanger the lives of 2 billion people. However, this is mostly avoided by
implementing VF (Despommier, 2011, 2013; Graff, 2009).
An advantage of locally-produced foods is, that it is really fresh when it reaches the
customer, and consequently the nutritional profile is much better (Despommier, 2010, 2011;
Specht et al., 2014; Voss, 2013). VF also helps to produce organic fish rich in protein with
the use of aquaponic systems. Traditional production of protein rich food was conducted on
a minute scale and was mostly vegan or vegetarian based which was carried out if the
neighborhood and infrastructures could accommodate it. VF however, is a means to
a healthier alternative for the people. The goal of VF is to provide healthy, local food which
is affordable for everyone (Miller, 2011).
Challenges of Laboratory product: One of the drawbacks of the idea of VF is that visitors
might perceive it as similar to a laboratory. The appearance might give the impression that
some genetic engineering is taking place and the products are far from natural. However, in
reality, the place provides for a healthy growth of crops void of any pollutants or pesticides
which is not possible outdoors.
Also, a key obstacle to public acceptance of VF is, the soil-less production technique.
People find it hard to accept and are crucial about this new idea and its products. Many avoid
buying these products and prefer to buy natural soil-based crops (Specht et al., 2014).
Opportunities of Laboratory product: According to Despomier (2010) VF has many
environmental benefits. Less energy is consumed and less toxicity is produced when food
materials are cultivated indoors than outdoors (Despommier, 2010). He states that, natural
landscapes are not appropriate for agricultural products. He further suggests that, since
skyscrapers are expensive to build and were constructed at the cost of the environment and
ecology, why not use them for agriculture? It is also much more feasible to control various
conditions indoors and is void of infections, pests, and bacteria (Voss, 2013). New roles
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
19
should be assigned to agrochemical industries to design safer chemicals for sustainable crops
(Despommier, 2010).
Moreover, VF enjoys many privileges over conventional agriculture. Since these products
are not soil-based, they are not affected by polluted soil or polluted irrigation water and are
therefore much safer. Crops produced by VF are environmentally friendly, rich in nutrients,
safe and fairly made (Besthorn, 2013). Less burden is placed on the environment since there
is no nitrogen (N) and phosphorous (P) runoff into natural water sources (Germer et al.,
2011).
11. Reduction of Urban Heat Island
Challenges: An increase in temperature especially in cities is caused by the absorption and
re-radiation of solar energy, which results in the formation of an urban heat island which
stands as a crisis. As a key human comfort criterion, temperature both, affects and is affected
by people’s lifestyle. Urban heat island is defined as the maximal temperature difference
between city and country areas (Safikhani, Abdullah, Ossen, & Baharvand, 2014). As
reported by the UN, cities account for 75 % of all energy depletion as well as 80 % of the
globally distributed greenhouse gases (Banerjee & Adenaeuer, 2014; Säynäjoki et al., 2013).
For every 1 unit of temperature increase, 10 % of cultivated land is reduced due to the effect
of climate change (Glaser, 2012).
Opportunities: One effective way of reducing city temperatures is the use of green areas
inside cities. Since research has shown that green areas designed at a particular distance from
each other can cool the environment, there is a direct correlation between temperature and
greenery (Nochian et al., 2015). It has also proved to be effective against the urban heat
island phenomena as it helps to enhance the city microclimate (Ahlström & Zahra, 2012;
Cicekli & Barlas, 2014; Safikhani et al., 2014; Tan et al., 2015; Thomaier et al., 2015).
Observational studies have reported that green parks in cities were 1 degree cooler than the
other parts of the city which were not vegetated. Recommendations for new urban designing
projects in Hong Kong have included 20-30 % of green areas to enhance the urban quality of
life (Tan et al., 2015). Afrin (2009) has suggested the use of cool and green roofs for their
indirect role in lowering carbon dioxide emissions of power plants as well as lowering the
temperature during severe conditions in summer days (Afrin, 2009). It is very challenging
however to abide by this standardized green coverage requirement in cities due to the
extensive use of city land for buildings and infrastructure (Tan et al., 2015).
In conclusion, VF manages to lower urban temperatures through the use of vegetation. It
can consequently reduce heat islands and the overall temperature of buildings too (Banerjee
& Adenaeuer, 2014).
12. Acts As a Sound Insulator
Opportunities: Yet another benefit of VF is in the management of noise, they can act as
obstacles to noise disturbances since they are able to lower sound reflection. Soil, vegetation
and air confined in VF acts as a sound insulator (Safikhani et al., 2014). In an investigation
conducted by Afrin (2009), they concluded that indoor sound can be lowered up to
60 decibels by green roofs, because much of the noise produced by traffic, planes,
machinery, etc. is absorbed by green roofs. Plants are capable of absorbing higher
frequencies of noise (Afrin, 2009).
13. Reduction of Carbon Footprint and the Effect on Air Quality
Challenges: As air quality continues to worsen, it has become a cause of serious concern in
cities all over the world (Afrin, 2009). Up to 70 % of the world emission of carbon dioxide is
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
20
accounted for by cities, nowadays. Moreover, health risks associated with polluted food
products either due to contaminated air or water sources, is of utmost concern since it
originates from untreated wastewater (Kalantari, Mohd Tahir, Golkar, & Kalantari, 2015).
Opportunities: A key advantage of VF is providing a sustainable environment in city
centers by cleaning the air and providing an access to greenery which has positive mental
effects on people (Ahlström & Zahra, 2011; Banerjee & Adenaeuer, 2014). People living in
cities are often subjected to high levels of CO2, they are exposed to high levels of carbon in
the soil and a reduction in main functions of an ecosystem (Germer et al., 2011). If an
ecosystem regrows, then nature’s ability to protect itself will also increase as well as its
adaptability and strength against disturbances and pollution. Reviving the key functions of an
ecosystem is the key to reversing the negative effects of climate change, it can potentially
lead to a clean and less contaminated future (Despommier, 2010; Miller, 2011; Vogel, 2008).
According to the findings of Afrin (2009), 4000 kilograms of air particles can be reduced by
2000 square meters of uncut grass on roofs, by trapping it in its foliage. According to
numerous reports, plant coverage can trap particles in air and dissolve them. It can also trap
gas pollutants especially carbon dioxide by means of the stomata of the leaf. The trapping
and dissolution of air particles is dependent on the type of plant, the season, duration of
daylight and so on. This model is at present under investigation in Toronto (Afrin, 2009).
It can be concluded that, the extensive use of farming in a controlled environment inside
cities and the inclusion of vegetation in skyscrapers can positively affect the weather
(Despommier, 2013) as well as cause small or large scale changes in climate, the
environment and eventually improve the ecology (Afrin, 2009; Liu, 2014).
14. Reduction of Herbicide and Pesticide Manufacture
Challenges: The frequency with which mineral fertilizers are used has increased several
times since its use between 1960 to 1990. It has led to the depletion of surface water,
pollution of underground water and distribution of greenhouse gasses along with other
detrimental environmental effects. Furthermore, phosphorus which is limited in supply and is
extracted from mines will continue to increase in use up to the year 2030. However, there is
no strategy to produce food with the least amount of phosphorus (Germer et al., 2011). We
cannot do without pesticides which are inevitably employed in many situations and farmers
cannot control these parameters. The only way to control the use of pesticides, is to use
expensive chemical materials, high-risk food products and also get crops insured. VF aims to
provide solutions for many of these problems (Banerjee & Adenaeuer, 2014).
Opportunities: The entire process of VF is carried out in an organic manner. An advantage
of vertical farms is that they significantly lower or omit the use of these chemicals and try to
find natural solutions for problems, for example, by utilizing useful insects. As previously
mentioned, all vertical farms benefit from controlled contexts and are void of any hazardous
pests (Despommier, 2010, 2011; Ellingsen & Despommier, 2008; Germer et al., 2011;
Sauerborn, 2011), therefore, there is no need for pesticides. In VF there is no need for
burning fields, grass or waste for pest control, other methods of pest control can be
employed.
Social Benefits
The major goal of VF is not only to improve farming but is also a means to serve society,
by bringing people closer together and closer to nature. Therefore, while providing food it
also educates the people (Ahlström & Zahra, 2011). The various aspects of the social benefits
of VF will be elaborated upon in the following section.
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
21
1. Psychological/Spiritual Health
Opportunities: Communication with nature has proved to positively influence human
mental health. Moreover, being close to nature helps to reduce stress and improves obesity
(Safikhani et al., 2014).
Communication with nature is believed by some researchers to be as important and
necessary as interaction with other human beings (Kaplan, 1993). Furthermore, all factors
that act as barriers to such a significant interaction with nature contributes to stress as we are
more and more dissatisfied with the community to which we belong. Research findings have
attested to the relaxing effect of observing nature on human beings especially drivers. Some
other studies have indicated that people prefer enjoying natural scenery over hectic images of
cities and streets. They tend to enjoy the proximity to nature either by watching it through
a window or walking through it. They found that it relieved their job-related stress and
contributed to better concentration at work. Some other studies reported that, children
afflicted with attention Deficit Disorder tend to show improvement after playing for some
time in a green park as compared to those that have no access to nature. Numerous studies
have demonstrated the positive effects of proximity to nature by improving a person’s focus,
creativity, stability, lowering stress and promoting a positive self-perception and self-value.
In summary, closeness to nature has a significant positive impact on mental health (Afrin,
2009).
2. Job Opportunities
Opportunities: Another advantage of vertical farms is the job opportunities they provide in
cities (Cicekli & Barlas, 2014; Despommier, 2010, 2011, 2013; Miller, 2011) as limited job
vacancies is a serious issue in many big cities. Not only are direct jobs involved in the vertical
farm provided, but indirect job opportunities are provided as well. The main jobs involve
working on these farms making, protecting and managing the entire farm structure (Besthorn,
2013). Others jobs include; managing seed production, transplant of seedlings in the VF,
managing resources ranging from water to light, machinery, etc., supervising the growth of
plants, pollination techniques, harvesting, managing waste, managing energy, quality control
(based on lab surveillance of plant pathogens as well as pest control), distribution control,
managing IT personnel and other human resources. These are only some of the work
opportunities involved in the food production industry related to VF (Despommier, 2013).
Once the foundation of VF is established, society outreach, instruction provision as well as
a business center can also be considered (Despommier, 2014). Moreover, VF also includes
grocery stores, food markets, and local distribution centers which provide other work-related
opportunities (Besthorn, 2013; Despommier, 2009).
3. Visual Amenity
Opportunities: Design and application of vertical vegetation systems dates back to the
famous Babylon hanging gardens. Since ancient times, people used plants inside their
buildings or houses to obtain relaxation and relief from them as well as for aesthetic reasons,
it provided them with a sense of closeness to nature (Safikhani et al., 2014). Therefore, it
seems to be a natural instinct in human beings to desire being close to nature (Specht et al.,
2014). VF and its inspiration not only contributes by providing solutions for the challenges of
agriculture in cities and plantation systems related to buildings, but it also affects the
perspective of what ‘natural’ means (Miller, 2011). For instance, possessing greenery is not
only beneficial to the owner of that building (since it adds to the value of that estate) but is
also serves the entire society as everybody enjoys the view and the healthy consequences.
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
22
Beauty is a social asset and is not transactional. Although an owner of the building can raise
the price value of his/her building because of its greenery, they cannot charge others
especially neighbors for enjoying the view (Afrin, 2009; La Rosa et al., 2014).
4. Education
Opportunities: It is very probable in developed countries to provide educational facilities
through VF, providing information on ideas and methods of food production and use. VF acts
as the link between the producer and customer (Specht et al., 2014).
The existence of vertical farms in a society provides a good platform for educating people
on nutrition and health. Since currently, the foods we receive and consume come from fields
outside the city, little is known about how they are produced, transported and finally arrive on
our dining table. If the food we consume is produced in the cities as realized by VF, it will
provide opportunities for educating people on all the procedures involved (Ankri, 2010;
Thomaier et al., 2015). This makes an urban farm a place for innovative ideas, a place for
teaching and learning. Coordination between farms and schools can bring the understanding
of nature to the education system (Specht et al., 2014). Novel ideas for producing food and
sustainable ways of structuring city life and consumption patterns are now realized in
a number of vertical farms. These initiatives are often carried out and supported by research
institutes as well as private organizations. In order to advertise and promote their concepts
and attempts, they usually let the public view their work. This is done through arranging
visits or tours to their sites. This public access would increase their knowledge of vertical
farms and keep them involved in these plans (Thomaier et al., 2015). One such initiative is
carried out by Gotham Greens in New York, where, visitors are voluntarily invited to visit the
farms. When people visit, they will share their knowledge with others and consequently the
knowledge will spread and result in further participation. A well-known example is the
Science Barge greenhouse in New York which is both a greenhouse and an educational
center producing vegetables. It is open to school students and any visitors throughout the year
(Specht et al., 2014). The value of VF lies in connecting people to nature, otherwise the mere
production of food can be served by any form of agriculture. People should be familiarized
with how their food is manufactured, where it comes from, how it is raised and eventually
processed (Miller, 2011).
5. Leisure
Opportunities: Leisure is one key aspect of the quality of city life. Plant-covered land is an
appropriate place for amusement, joy, and rest (Safikhani et al., 2014). No matter where they
are located on top of houses, malls or mixed areas, vertical farms can serve as sites for rest,
joy, amusement and food provision. Residents of buildings can have access to an oasis close
to them. These farms are usually founded by real estate owners who wish to enhance their
property and invest in and benefit from their green and sustainable buildings. Other times
they are established by businessmen who want to improve their working staff’s work
environment. Their products are mainly for personal consumption or to supply a cafeteria
working with them. The foremost function of VF is to provide a recreational purpose to
improve the quality of social life and a to increase well-being in a society (Ellingsen &
Despommier, 2008; Thomaier et al., 2015).
6. Greater Community
Opportunities: Most of the city-related agricultural literature emphasizes the notion of
linking people to nature through connecting them to the land by gardening for example, or
making communal and public places around gardens or forming groups focused on growing
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
23
useful and beautiful plants (Miller, 2011). Other advantages of farming landscapes consist of
all benefits associated with open air and images of the country life and its culture (Kalantari,
Mohd Tahir, Golkar, & Ismail, 2015; La Rosa et al., 2014). Overall, VF demands high
cooperation and public participation since it involves people producing their own products
(Besthorn, 2013).
VF allow for farmers and advocates to work together closely and commit to a common
goal, this forms a direct connection between food production and use. VF is environmentally
friendly since it minimizes the distance between food production and consumption while
simultaneously maintaining the joy of it (La Rosa et al., 2014). Those who work in vertical
farms share the joy of selling their goods directly to customers. Higher satisfaction is also
experienced by vertical farmers when they sell their products to close friends or
acquaintances whom they have known for a long time (Besthorn, 2013).
7. Improved Food Security
Opportunities: Food movement in developing countries is different from developed
countries and so is the issue of food security. Since the main aim of VF is food provision in
low-income countries, it can greatly contribute to the local basic food needs (Cicekli &
Barlas, 2014). In the cities of developed countries, other social benefits are also considered
while in developing countries it is not a priority anymore. In cities, the population of
consumers is very high and there are more poor people in this population too who have
limited or no access to fresh food (Lam, 2007; Sauerborn, 2011). If the existing tall buildings
with numerous floors are incorporated with greenhouses, they can produce the food required
by the entire population of the city (Despommier, 2010; Germer et al., 2011; Specht et al.,
2014). Depending on the number of floors of the vertical farm, the area of land devoted to
farming and consequently crop yield will be multiplied. The concept of the VF project is in
the evolution of urban structures while abiding by ecological rules. In New York City, it is
estimated that a tall building which is 30-storey high is able to provide food for 50,000
citizens (Despommier, 2009; Wagner, 2010). According to these estimations, a vertical farm
which requires one square block of the city and has 30 floors (about three million square feet)
can provide 2,000 calories a day for each person and can, therefore, cater to the needs of
10,000 individuals (Despommier, 2010). VF was used in Israel, as reported by Ankri (2010)
who reported that, 12.5 people could be fed per day by 1 acre of open field, while 97 people
a day could be fed by the products of the same area of land indoors (Ankri, 2010).
Economic Benefit
The use of VF can bring about significant positive economic improvement especially in
(sub) tropical countries (Afrin, 2009; Despommier, 2010). Currently, contrary to
globalization, the concept of a highly adaptable and local economy has attracted a lot of
attention. A manifestation of this local effort is VF in cities. An example is Singapore, an
urban island country which has observed changes in the global market and has therefore set
new goals and have focused their attention towards VF so as to decrease their dependency on
foreign countries. The numerous economic benefits of VF will be elaborated on in the
following section.
1. Minimization of Energy Cost
Challenges: According to the conclusion drawn by this study, VF is possible if certain
ecological and energy consumption issues are taken into account, however, there is still
a need for economic analysis. The initial costs and energy required to construct VF are
considerable and is a fundamental problem and the possible reason why more vertical farms
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
24
are not seen everywhere (Perez, 2014). Products need land, lighting, CO2, and water, which
are all provided by nature itself, however, in VF, in order to acquire these, they must be
‘purchased’ (Banerjee & Adenaeuer, 2014).
Opportunities: Maintaining VF involves certain high costs too, however, cutting down on
costs can be carried out by implementing innovative strategies, such as using the building
waste itself, using compact piece of land and depending on volunteer workers. Another way
to cut down on costs is to integrate vertical farms in the current infrastructure, by sharing
temperature, electricity, and finances (Miller, 2011). Amongst the numerous benefits of VF,
one is the ability it has to decrease heat and decrease the overall costs associated with energy
use (Safikhani et al., 2014). When less energy is consumed, the price of energy will be
affected too. It is evident that if energy consumption is lowered in VF, low prices will follow
too.
Despomier (2009) finds that location is closely related to this issue. In many parts of the
world including Iceland, Italy, New Zealand, South California and east Africa, they make use
of geothermal energy source. In order to get the most out of sunlight, especially in desert
areas where there is abundant sunshine (for example Southwest America, Middle East and
many parts of Central Asia), 2-3 floor structures are used ranging from about 50-100 yards in
width or miles in length for their crops. Lands that have the privilege of steady winds (seaside
and the Midwest) could absorb and harness that energy. A common practice everywhere in
order to produce electricity, is the burning of plant waste which is converted into electricity
or fuel (Despommier, 2009).
2. Community Economic Growth
Opportunities: As for economic benefits, moving food production into the cities is thought
to carry with it public advantages and outcomes (Miller, 2011; Specht et al., 2014). Food is
an integral part of the city economy, all food-sale centers such as restaurants, cafeterias, fast
food shops, supermarkets, wholesale markets or retailers, depend on food and comprise
urban economy. As a result, including local food production into the system is demanding but
at the same time rewarding for urban areas. Producing food inside cities is a kind of
agricultural capital and VF can be set up in public or private buildings. Specht et al. (2014)
maintains that traditional views of urban or country models should be transformed, so should
the wrong assumption that there is no space inside cities for farming (Specht et al., 2014).
There are commercial farms which work just for profit but if they were accompanied by
commercial kitchens, more valuable food products could be provided and sold in markets
(Hui, 2011). Although farming indoors is associated with large production yield and is
expected to be run by professionals, a variety of methods of distribution can exits. In order to
cut down on agricultural economics, organizers could be private corporations, credible
communities or local governments, hiring people to manage all the procedures. It would be
interesting to form social networks among producers, farmers, and consumers, as well as
rural and urban producers (Specht et al., 2014).
3. Low Price of Food
Challenges: Since food price is closely linked to oil price, fossil fuel consumption is an
influential factor. A rise in the price of oil is followed by an increase in the price of food.
However, oil resources and fossil fuels are getting scarce.
Opportunities: For local food, it is very efficient since food materials produced locally
need not be transported to their destination (Despommier, 2009; Ellingsen & Despommier,
2008). Foods usually have to be transported long distances before they are consumed. In VF,
large amounts of food are produced at a low cost of fuel or transportation. The cost is so low
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
25
that it overshadows the real environmental and social benefits of it. This is accompanied by
continuous production which breaks the price shock in the international crop market (Germer
et al., 2011).
4. Return of Investments
Challenges: In VF, there is a need for huge investment for the nutrient delivery systems,
platforms for growing crops and growth equipment, which would significantly raise costs.
This high investment seems to be a disadvantage when compared to traditional farming
methods (Banerjee & Adenaeuer, 2014) but although high costs prevent public reception, it
does not prevent corporate benefits. It is undeniable that some costs can somehow be reduced
but some costs cannot. If VF is of a large-scale type, the investment process becomes very
intensive (Miller, 2011).
Moreover, the location chosen for VF is a key factor as the price of land influences
decisions (Perez, 2014) especially due to the high price of land in cities (Ahlström & Zahra,
2011). This price issue is particularly important in cities and should be considered carefully
before it turns into a potentially serious problem (Voss, 2013).
Opportunities: The initial costs of setting up, equipping and operating a vertical farm is
undoubtedly very high and is mostly due to energy use. As time passes, these costs are
reduced, especially those related to energy provision. Therefore, though it is known that
setting up vertical farms is very costly, to begin with, when it is running and fully functional,
the price of food will come down (Abel, 2010).
As argued by Despommiers (2009), in every city there are numerous appropriate sites for
such projects and if used effectively, they can return and circulate a lot of money back into
the city (Despommier, 2009). The author believes that though it seems very trivial,
evaluating all the conditions on every level is required, so as to thoroughly assess all the
possibilities when deciding upon establishing a vertical farm (Voss, 2013).
Moreover, the idea of VF is a promising move towards the right direction for fans of the
revolutionary resource-based economy movement. Economic analysis as well as
investigations of the effects of VF on post-industrial cities is needed. Further discussion and
analysis is required on the implications of VF on urban life all over the world (Miller, 2011).
5. Economic Opportunity for Land Scarcity
Challenges: Available and accessible land is a key issue in food production in cities and a
major concern in setting up VF is finding an appropriate space within the city. Localization is
the main goal of VF and that is localizing food production (Sivamani, Kwak, & Cho, 2014;
Voss, 2013). Open space is hard to find in many cities, and when there is a dearth of space in
the production unit, certain technologies can facilitate, those that are specialized for limited
spaces (Dubbeling, 2011).
Opportunities: Critics who doubt the feasibility of the concept, tend to focus on the high
costs of properties in expensive cities such as New York, London or Paris, and doubt how it
will ever be economically feasible in in such contexts (Despommier, 2009; Eigenbrod &
Gruda, 2015). Land is expected to become more and more scarce in the future both in cities
and the countryside, however, VF does not intend to seek additional land for its purpose.
Instead, it intends to make use of pre-existing unused areas in cities, for example, empty and
unoccupied buildings. It involves innovative ideas for renewing old unused buildings to
adapt and transform them into indoor farms (Cicekli & Barlas, 2014; Ellingsen &
Despommier, 2008; Thomaier et al., 2015). Building in the city center might not be
affordable, but there are many other areas left in the city that can accommodate and would
encourage such projects. There are usually many empty, abandoned and unused buildings
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
26
located within and around cities (Despommier, 2009; Kim et al., 2014). The issue of land and
food security can be redefined by VF in populated cities when food production is added to the
city building stack (Thomaier et al., 2015).
A survey of New York’s 5 boroughs, that was conducted several years ago, discovered as
many as 120 deserted buildings which could be potentially revolutionized. These buildings
could be turned into vertical farms to serve the needy inhabitants of those parts of the city.
There are infinite number of such sites all over the world as well as available number of
rooftops everywhere (Despommier, 2010).
CONCLUSION
We can conclude that even a little knowledge and awareness of VF can help food security
and viability greatly. New technologies such as aeroponic systems, insulation methods and
pest free plant growth has not only transformed the greenhouse industry but has also paved
the way for new forms of farming such as rooftop farming. In apartments and office
buildings, creative climate management technologies and natural light management
technology helped to save energy and cut down on greenhouse gas distribution (Germer
et al., 2011). These have all made local food production in highly populated city areas
possible, where more people require more food and their needs cannot be met (Thomaier
et al., 2015).
VF has got numerous advantages over traditional farming, which includes more efficiency,
adaptability, and environmental benefits, which is all made possible through carefully
controlled systems of VF. In VF, no waste or pollution is involved, it enjoys high levels of
potentiality. All the above-mentioned benefits in a single system seems rather unbelievable,
but VF has made it possible. If its use becomes common and widespread across the globe, the
fear of starvation will also disappear and detrimental climate change will slow down too.
Practically all famous Vertical Farms were situated in cities with more than 150,000
populations. Europe and North America have the biggest part of sustainable food production,
while in high-density Asian cities, like Hong Kong Tokyo and Kuala Lumpur, the focus
seems to be on improving the sustainable food production inside the city centers.
In addition, VF has provided new opportunities for architecture and urban designing.
Urban designers have attested to the importance of making cities green, healthy and safe. By
combining food production and architecture, VF helps to produce buildings capable of
multiple functions. This is accompanied by many social and ecological advantages
(Thomaier et al., 2015).
REFERENCE
Abel, C. (2010). The vertical garden city: towards a new urban topology. CTBUH Journal,
(2), 20–30. Retrieved September 5, 2010, from http://www.et2050.eu/et2050_library/docs/
tech/land_uses/Vertical_garden.pdf
Afrin, S. (2009). Green Skyscraper : Integration of Plants into Skyscrapers. (Master’s
Thesis).Kungliga Tekniska högskolan (KTH), Stockholm. Retrieved January 15, 2009 from
www.infra.kth.se/sb/sp
Ahlström, L., & Zahra, M. (2011). Integrating a Greenhouse in an Urban Area.
(Unpublished Master’s Thesis).Chalmers University of Technology,Göteborg, Sweden.
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
27
Al-Chalabi, M. (2015). Vertical farming: Skyscraper sustainability? Sustainable Cities and
Society, 18, 74–77. Retrieved February 10, 2015 from http://doi.org/10.1016/j.scs.
2015.06.003
Albajes, R., Cantero-Martínez, C., Capell, T., Christou, P., Farre, A., Galceran, J., Voltas, J.
(2013). Building bridges: an integrated strategy for sustainable food production throughout
the value chain. Molecular Breeding, 32(4), 743–770. Retrieved June 15, 2013 from
http://doi.org/10.1007/ s11032-013-9915-z
Ankri, D. S. (2010). Urban Kibbutz: Integrating Vertical Farming and Collective Living in
Jerusalem, Israel. (Master’s Thesis).Available from ProQuest Dissertations and Theses
database. (UMI No.1482437). Retrieved July 2, 2010 from http://search.proquest.com/
docview/762216845?accountid=10906%5Cnhttp://zsfx.lib.iastate.edu:3410/sfxlcl41?url_ve
r=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&genre=dissertations+%26+
theses&sid=ProQ:ProQuest+Dissertations+%26+Theses+Global&at
Banerjee, C., & Adenaeuer, L. (2014). Up, Up and Away! The Economics of Vertical
Farming. Journal of Agricultural Studies, 2(1), 40. Retrieved January 15, 2014 from
http://doi.org/10.5296/jas.v2i1.4526
Besthorn, F. H. (2013). Vertical Farming: Social Work and Sustainable Urban Agriculture in
an Age of Global Food Crises. Australian Social Work, 66(2), 187–203. Retrieved December
5, 2013 from http://doi.org/10.1080/0312407X.2012.716448
Bohn, K., & Viljoen, A. (2011). The edible city: envisioning the Continuous Productive
Urban Landscape (CPUL). Field Journal, 4(1), 149–161. Retrieved June 12, 2011 from
http://www.field-journal.org/index.php?page=issue-4
Brundtland, G. H. (1985). World commission on environment and development.
Environmental Policy and Law, 14(1), 26–30.
Cicekli, M., & Barlas, N. T. (2014). Transformation of today greenhouses into high
technology vertical farming systems for metropolitan regions. Journal of Environmental
Protection and Ecology, 15(4), 1779–1785.
Despommier, D. (2009). The rise of vertical farms. Scientific American, 301(5), 80–87.
Despommier, D. (2010). The vertical farm: feeding the world in the 21st century. Macmillan.
Despommier, D. (2011). The vertical farm: controlled environment agriculture carried out in
tall buildings would create greater food safety and security for large urban populations.
Journal Für Verbraucherschutz Und Lebensmittelsicherheit, 6(2), 233–236. Retrieved
March 15, 2011 from http://doi.org/10.1007/s00003-010-0654-3
Despommier, D. (2013). Farming up the city: The rise of urban vertical farms. Trends in
Biotechnology, 31(7), 388–389. Retrieved December 7, 2013 from http://doi.org/
10.1016/j.tibtech.2013.03.008
Despommier, D. (2014). Encyclopedia of Food and Agricultural Ethics (Vertical Farms in
Horticulture). (P. B. Thompson & D. M. Kaplan, Eds.) Encyclopedia of Food and
Agricultural Ethics. Dordrecht: Springer Netherlands. Retrieved July 15, 2014 from
http://doi.org/10.1007/ 978-94-007-0929-4
Dubbeling, M. (2011). Integrating urban agriculture in the urban landscape. Urban
Agriculture Magazine, (25), 43–46. Retrieved September 4, 2011 from www.ruaf.org
Eigenbrod, C., & Gruda, N. (2015). Urban vegetable for food security in cities. A review.
Agronomy for Sustainable Development, 35(2), 483–498. Retrieved January 15, 2015 from
http://doi.org/10.1007 /s13593-014-0273-y
Ellingsen, E., & Despommier, D. (2008). The Vertical Farm - The origin of a 21st century
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
28
Architectural Typology. CTBUH Journal, (3), 26–34. Retrieved June 10, 2008 from
http://global.ctbuh.org/resources/papers/download/449-the-vertical-farm-the-origin-of-a-21
st-century-architectural-typology.pdf
Ellis, J. (2012). Agricultural Transparency: Reconnecting Urban Centres With Food
Production. (Unpublished Master’s Thesis).Dalhousie University,Halifax, Nova Scotia.
Germer, J., Sauerborn, J., Asch, F., de Boer, J., Schreiber, J., Weber, G., & Müller, J. (2011).
Skyfarming an ecological innovation to enhance global food security. Journal Für
Verbraucherschutz Und Lebensmittelsicherheit, 6(2), 237–251. Retrieved April 18, 2011
from http://doi.org/10.1007/ s00003-011-0691-6
Glaser, J. A. (2012). Green chemistry with nanocatalysts. Clean Technologies and
Environmental Policy, 14(4), 513–520. Retrieved April 15, 2012 from http://doi.org/
10.1007/s10098-012-0507-0
Graff, G. (2009). A greener revolution: An argument for vertical farming. Plan Canada,
49(2), 49–51.
Hui, S. C. M. (2011). Green roof urban farming for buildings in high-density urban cities. In
World Green Roof Conference (pp. 1–9). Retrieved December 2, 2011 from
http://www.mech.hku.hk/bse/greenroof/110318_WGRC2011_Hainan_SamHui_fullpaper.p
df
Islam, R., & Siwar, C. (2012). The analysis of urban agriculture development in Malaysia.
Advances in Environmental Biology, 6(3), 1068–1078.
Kalantari, F., Mohd Tahir, O., Golkar, N., & Ismail, N. A. (2015). Socio-Cultural
Development of Tajan Riverfront, Sari, Iran. Advances in Environmental Biology, 9(27),
386–392.
Kalantari, F., Mohd Tahir, O., Golkar, N., & Kalantari, S. (2015). Restoration of Tajan River
through ecological design approach. ALAM CIPTA, International Journal on Sustainable
Tropical Design Research & Practice, 8(spec. 1), 52–59. Retrieved April 2, 2015 from
http://psasir.upm.edu.my/42296/
Kaplan, R. (1993). The role of nature in the Context of the workplace. Landscape and Urban
Planning, 26(1), 193–201. Retrieved September 16, 1993 from http://search.ebscohost.
com/login.aspx?direct=true&db=psyh&AN=1985-16132-001&site=eds-live&scope=site
Kim, H.-G., Park, D.-H., Chowdhury, O. R., Shin, C.-S., Cho, Y.-Y., & Park, J.-W. (2014).
Location-Based Intelligent Robot Management Service Model Using RGPSi with AoA for
Vertical Farm. In Lecture Notes in Electrical Engineering (Vol. 279, pp. 309–314).
Retrieved January 15, 2014 from http://doi.org/10.1007/978-3-642-41674-3_44
La Rosa, D., Barbarossa, L., Privitera, R., & Martinico, F. (2014). Agriculture and the city: A
method for sustainable planning of new forms of agriculture in urban contexts. Land Use
Policy, 41, 290–303. Retrieved March 15, 2014 from http://doi.org/10.1016/j.landusepol.
2014.06.014
Lam, S. O. (2007). Urban Agriculture in Kingston : Present and Future Potential for
Re-Localization and Sustainability. (Unpublished Master’s Thesis).Queen’s
University,Ontario,Canada.
Liu, X. (2014). Design of a Modified Shipping Container as Modular Unit for the Minimally
Structured & Modular Vertical Farm ( MSM-VF ). (Master’s Thesis).Available from
ProQuest Dissertations and Theses database. (UMI No.1573000).
Miller, A. (2011). Scaling Up or Selling Out? A Critical Appraisal of Current Development
Unauthenticated
Download Date | 8/25/17 12:53 PM
aaaJournal of Landscape Ecology (2017)
29
in Vertical Farming. (Unpublished Master’s Thesis).Carleton University,ottawa,
ontario,Canada.
Nochian, A., Mohd Tahir, O., Maulan, S., & Rakhshandehroo, M. (2015). A comprehensive
public open space categorization using classification system for sustainable development of
public open spaces. ALAM CIPTA, International Journal on Sustainable Tropical Design
Research & Practice, 8(spec. 1), 29–40.
Perez, V. M. (2014). Study of The Sustainability Issue of Food Production Using Vertical
Farm Methods in An Urban Environment Within The State of Indiana. (Master’s
Thesis).Available from ProQuest Dissertations and Theses database. (UMI No.1565090).
Platt, P. (2007). Vertical Farming: An Interview with Dickson Despommier. Gastronomica,
7(2), 80–87. Retrieved March 15, 2007 from http://doi.org/10.1525/gfc.2007.7.3.80
Safikhani, T., Abdullah, A. M., Ossen, D. R., & Baharvand, M. (2014). A review of energy
characteristic of vertical greenery systems. Renewable and Sustainable Energy Reviews, 40,
450–462. Retrieved August 25, 2014 from http://doi.org/10.1016/j.rser.2014.07.166
Sauerborn, J. (2011). Skyfarming: an alternative to horizontal croplands. Resource:
Engineering & Technology for a Sustainable World, 18(1), 19. Retrieved December 15, 2011
from http://www.highbeam.com/doc/1G1-247226253.html
Säynäjoki, E., Heinonen, J., & Junnila, S. (2013). Urban Density and Local Sustainability –
A Case Study in Finland. In 189TH Annual Pacific-RIM Real Estate Society Conference
Melbourne Australia (pp. 13–16).
Sivamani, S., Bae, N.-J., Shin, C.-S., Park, J.-W., & Cho, Y.-Y. (2014). An OWL-Based
Ontology Model for Intelligent Service in Vertical Farm. In Lecture Notes in Electrical
Engineering (Vol. 279, pp. 327–332). Retrieved January 5, 2014 from http://doi.org/
10.1007/978-3-642-41674-3_47
Sivamani, S., Bae, N., & Cho, Y. (2013). A Smart Service Model Based on Ubiquitous
Sensor Networks Using Vertical Farm Ontology. International Journal of Distributed Sensor
Networks, 9(12), 161495. Retrieved April 20, 2013 from http://doi.org/10.1155/2013/161495
Sivamani, S., Kwak, K., & Cho, Y. (2014). A Rule Based Event-Driven Control Service for
Vertical Farm System. In J. J. Park, I. Stojmenovic, M. Choi, & F. Xhafa (Eds.), In Future
Information Technology (Vol. 276, pp. 915–920). Berlin, Heidelberg: Springer Berlin
Heidelberg. Retrieved September 15, 2014 from http://doi.org/10.1007/978-3-642-55038
-6_138
Specht, K., Siebert, R., Hartmann, I., Freisinger, U. B., Sawicka, M., Werner, A., Dierich, A.
(2014). Urban agriculture of the future: an overview of sustainability aspects of food
production in and on buildings. Agriculture and Human Values, 31(1), 33–51. Retrieved
January 15, 2014 from http://doi.org/10.1007/s10460-013-9448-4
Tan, Z., Lau, K. K.-L., & Ng, E. (2015). Urban tree design approaches for mitigating daytime
urban heat island effects in a high-density urban environment. Energy and Buildings.
Retrieved February 8, 2015 from http://doi.org/10.1016/j.enbuild.2015.06.031
Thomaier, S., Specht, K., Henckel, D., Dierich, A., Siebert, R., Freisinger, U. B., & Sawicka,
M. (2015). Farming in and on urban buildings: Present practice and specific novelties of
Zero-Acreage Farming (ZFarming). Renewable Agriculture and Food Systems, 30(1), 43–54.
Retrieved April 21, 2015 from http://doi.org/10.1017/S1742170514000143
Vogel, G. (2008). Upending the traditional farm. Science, 319(5864), 752–753. Retrieved
August 3, 2008 from http://www.sciencemag.org/cgi/doi/10.1126/science.319.5864.753
Voss, P. M. (2013). Vertical Farming: An agricultural revolution on the rise. Halmstad, 1–21.
Unauthenticated
Download Date | 8/25/17 12:53 PM
Kalantari F., Mohd Tahir O., Akbari Joni R., Fatemi E.: Opportunities and Challenges in Sustainability of Vertical
Farming: A Reviewaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
30
Wagner, C. G. (2010). Vertical Farming: An Idea Whose Time Has Come Back. Futurist,
44(2), 68–69. Retrieved October 30, 2010 from http://content.ebscohost.com/
ContentServer.asp?T=P&P=AN&K=47784788&S=R&D=a9h&EbscoContent=dGJyMNLr
40SeprM4xNvgOLCmr0uep7FSsKu4TLGWxWXS&ContentCustomer=dGJyMPGvrki3rK
5PuePfgeyx44Dt6fIA%5Cnhttps://ezproxy.uttyler.edu/login?url=http://search.ebscohost.co
m/lo
Unauthenticated
Download Date | 8/25/17 12:53 PM
