From Wikipedia, the free encyclopedia
Urban agriculture can reflect varying levels of economic and
social development. It may be a social movement for sustainable
communities, where organic growers, "foodies," and "
locavores"
form social networks founded on a shared ethos of nature and community
holism. These networks can evolve when receiving formal institutional
support, becoming integrated into local town planning as a "transition
town" movement for sustainable urban development. For others,
food security,
nutrition, and income generation are key motivations for the practice.
In either case, more direct access to fresh vegetables, fruits, and meat
products through urban agriculture can improve food security and
food safety.
History
In
semi-desert towns of Persia, oases were fed through aqueducts that
carried mountain water to support intensive food production, nurtured by
wastes from the communities. In
Machu Picchu,
water was conserved and reused as part of the stepped architecture of
the city, and vegetable beds were designed to gather sun in order to
prolong the growing season.
A gardening demonstration in New York City, 1922
The idea of supplemental food production beyond rural farming
operations and distant imports is not new. It has been used during war
and depression times when food shortage issues arose, as well as during
times of relative abundance.
Allotment gardens came up in Germany in the early 19th century as a response to poverty and food insecurity.
In 1893, citizens of a depression-struck
Detroit were asked to use any vacant lots to grow vegetables. They were nicknamed Pingree's Potato Patches after the mayor,
Hazen S. Pingree,
who came up with the idea. He intended for these gardens to produce
income, food supply, and even boost independence during times of
hardship.
Victory gardens
sprouted during WWI and WWII and were fruit, vegetable, and herb
gardens in US, Canada, and UK. This effort was undertaken by citizens to
reduce pressure on food production that was to support the war effort.
During the first World War, President Woodrow Wilson called upon
all American citizens to utilize any available open space for food
growth, seeing this as a way to pull them out of a potentially damaging
situation. Because most of Europe was consumed with war, they were
unable to produce sufficient food supplies to be shipped to the U.S.,
and a new plan was implemented with the intent to feed the U.S. and even
supply a surplus to other countries in need. By the year 1919, over 5
million plots were growing food and over 500 million pounds of produce
was harvested.
A very similar practice came into use during the Great Depression
that provided a purpose, a job, and food to those who would otherwise be
without anything during such harsh times. In this case, these efforts
helped to raise spirits socially as well as to boost economic growth.
Over 2.8 million dollars worth of food was produced from the subsistence
gardens during the Depression. By the time of the Second World War, the
War/Food Administration set up a National Victory Garden Program that
set out to systematically establish functioning agriculture within
cities. With this new plan in action, as many as 5.5 million Americans
took part in the victory garden movement and over 9 million pounds of
fruit and vegetables were grown a year, accounting for 44% of U.S.-grown
produce throughout that time.
Community gardening
in most communities are open to the public and provide space for
citizens to cultivate plants for food or recreation. A community
gardening program that is well-established is Seattle's
P-Patch. The grassroots
permaculture
movement has been hugely influential in the renaissance of urban
agriculture throughout the world. The Severn Project in Bristol was
started in 2010 for £2500 and provides 34 tons of produce per year,
employing people from disadvantaged backgrounds.
City farming
A cow at Mudchute Park and Farm, Tower Hamlets, London. Note Canary Wharf in the background.
City farms are agricultural plots in
urban areas, which involve people working with
animals and plants to produce food. City farms are usually
community-run gardens which aim to improve community relationships and offer an awareness of
agriculture and
farming to people who live in urbanized areas. City farms are important sources of
food security
for many communities around the globe. City farms vary in size from
small plots in private yards to larger farms that occupy a number of
acres. In 1996, a United Nations report estimated there are over 800
million people worldwide who grow food and raise livestock in cities.
Although some city farms have paid employees, most rely heavily on
volunteer labour, and some are run by volunteers alone. Other city farms
operate as partnerships with
local authorities.
During the 1960s a number of
community gardens were established in the
United Kingdom, influenced by the community garden movement in the
United States. The first city farm was set up in 1972 in
Kentish Town,
London. It combined farm animals with gardening space, an addition inspired by children's farms in the
Netherlands.
Other city farms followed across London and the United Kingdom. In
Australia, several city farms exist in various capital cities. In
Melbourne, the
Collingwood Children's Farm was established in 1979 on the Abbotsford Precinct Heritage Farmlands (the APHF), the oldest continually farmed land in
Victoria, farmed since 1838.
In 2010, New York City saw the building and opening of the world's largest privately owned and operated
rooftop farm, followed by an even larger location in 2012. Both were a result of municipal programs such as The Green Roof Tax Abatement Program and Green Infrastructure Grant Program.
Perspectives
Resource and economic
The Urban Agriculture Network has defined urban agriculture as:
[A]n industry that produces, processes, and markets food, fuel, and other outputs, largely
in response to the daily demand of consumers within a town, city, or metropolis, on many
types of privately and publicly held land and water bodies found throughout intra-urban and
peri-urban areas. Typically urban agriculture applies intensive production methods,
frequently using and reusing natural resources and urban wastes, to yield a diverse array of
land-, water-, and air-based fauna and flora contributing to the food security, health,
livelihood, and environment of the individual, household, and community.
Globalization has removed the need and ability of a community's
agency in their food production. This results in an inability to address
food injustice on a smaller, more manageable scale. This is especially
true in cities. Today, most cities have lots of vacant land due to urban
sprawl and home foreclosures. This land could be used to address food
insecurity. One study of Cleveland shows that city could actually meet
up to 100% of its fresh produce need. This would prevent up to $115
million in annual economic leakage. Using the rooftop space of New York
City would also be able to provide roughly twice the amount of space
necessary to supply New York City with its green vegetable yields. Space
could be even better optimized through the usage of hydroponic or
indoor factory production of food. Growing gardens within cities would
also cut down on the amount of food waste. In order to fund these
projects, it would require financial capital in the form of private
enterprises or government funding.
Environmental
Urban agriculture is a complex system encompassing a spectrum of
interests, from a traditional core of activities associated with the
production, processing, marketing, distribution, and consumption, to a
multiplicity of other benefits and services that are less widely
acknowledged and documented. These include recreation and leisure;
economic vitality and business entrepreneurship, individual health and
well-being; community health and well being; landscape beautification;
and environmental restoration and remediation.
Modern planning and design initiatives are often more responsive to this model of urban agriculture because it fits within the current scope of
sustainable design.
The definition allows for a multitude of interpretations across
cultures and time. Frequently it is tied to policy decisions to build
sustainable cities.
Urban farms also provide unique opportunities for individuals,
especially those living in cities, to get actively involved with
ecological citizenship. By reconnecting with food production and nature,
urban community gardening teaches individuals the skills necessary to
participate in a democratic society. Decisions must be made on a
group-level basis in order to run the farm. Most effective results are
achieved when residents of a community are asked to take on more active
roles in the farm.
Food security
Access to nutritious food, both economically and geographically, is
another perspective in the effort to locate food and livestock
production in cities. With the tremendous influx of world population to
urban areas, the need for fresh and safe food is increased. The
Community Food Security Coalition (CFSC) defines food security as:
All persons in a community having access to culturally acceptable,
nutritionally adequate food through local, non-emergency sources at all
times.
Areas faced with food security issues have limited choices, often relying on highly
processed fast food
or convenience store foods that are high in calories and low in
nutrients, which may lead to elevated rates of diet-related illnesses
such as diabetes. These problems have brought about the concept of
food justice
which Alkon and Norgaard (2009; 289) explain is, "places access to
healthy, affordable, culturally appropriate food in the contexts of
institutional racism, racial formation, and racialized geographies....
Food justice serves as a theoretical and political bridge between
scholarship and activism on sustainable agriculture, food insecurity,
and
environmental justice."
Some systematic reviews have already explored urban agriculture
contribution to food security and other determinants of health outcomes.
Impact
Economic
Urban and peri-urban agriculture (UPA) expands the economic base of the city through production, processing, packaging, and
marketing of consumable products. This results in an increase in entrepreneurial activities and the
creation of jobs, as well as reducing food costs and improving quality.
UPA provides employment, income, and access to food for urban
populations, which helps to relieve chronic and emergency food
insecurity. Chronic food insecurity refers to less affordable food and
growing
urban poverty, while emergency food insecurity relates to breakdowns in the chain of
food distribution. UPA plays an important role in making food more affordable and in providing emergency supplies of food. Research into market values for produce grown in urban gardens has attributed to a
community garden plot a median yield value of between approximately $200 and $500 (US, adjusted for inflation).
Social
The needs of urban landscaping can be combined with those of suburban livestock farmers. (Kstovo, Russia).
Urban agriculture can have a large impact on the social and emotional well-being of individuals. UA can have an overall positive impact on
community health, which directly impacts individuals social and emotional well-being. Urban gardens are often places that facilitate positive
social interaction,
which also contributes to overall social and emotional well-being. Many
gardens facilitate the improvement of social networks within the
communities that they are located. For many neighborhoods, gardens
provide a “symbolic focus,” which leads to increased neighborhood pride.
Related to the previous point, urban agriculture increases
community participation through sensibilization and diagnostic workshops
or different commissions in the area of vegetable gardens. Activities
which involve hundreds of people.
When individuals come together around UA, physical activity
levels are often increased. Many state that working in agriculture is
much more interesting and fulfilling than going to the gym, and that it
makes getting
exercise
“fun.” In addition to the exercise that individuals receive while
actually working in gardens, many people say that the majority of the
exercise they receive through urban agriculture is actually getting to
the gardens—many people either walk or ride their bike to the sites,
which provides many physical benefits.
UPA can be seen as a means of improving the
livelihood
of people living in and around cities. Taking part in such practices is
seen mostly as informal activity, but in many cities where inadequate,
unreliable, and irregular access to food is a recurring problem, urban
agriculture has been a positive response to tackling food concerns. Due
to the food security that comes with UA, feelings of independence and
empowerment often arise. The ability to produce and grow food for
oneself has also been reported to improve levels of self-esteem or of
self-efficacy.
Households and small communities take advantage of vacant land and
contribute not only to their household food needs but also the needs of
their resident city. The CFSC states that:
Community and residential gardening, as well as small-scale farming,
save household food dollars. They promote nutrition and free cash for
non-garden foods and other items. As an example, you can raise your own
chickens on an urban farm and have fresh eggs for only $0.44 per dozen.
This allows families to generate larger incomes selling to local
grocers or to local outdoor markets while supplying their household with the proper nutrition of fresh and nutritional products.
A vegetable garden in the square in front of the train station in Ezhou, China
Some community urban farms can be quite efficient and help women find
work, who in some cases are marginalized from finding employment in the
formal economy.
Studies have shown that participation from women have a higher
production rate, therefore producing the adequate amount for household
consumption while supplying more for market sale.
As most UA activities are conducted on vacant municipal land,
there have been raising concerns about the allocation of land and
property rights. The
IDRC and the
FAO
have published the Guidelines for Municipal Policymaking on Urban
Agriculture, and are working with municipal governments to create
successful policy measures that can be incorporated in urban planning.
Over a third of U.S. households, roughly 42 million, participate
in food gardening. There has also been an increase of 63% participation
in farming by millennials from 2008-2013. US households participating
in community gardening has also tripled from 1 to 3 million in that time
frame. Urban agriculture provides unique opportunities to bridge
diverse communities together. In addition, it provides opportunities for
health care providers to interact with their patients. Thus, making
each community garden a hub that is reflective of the community.
Energy efficiency
Edible Oyster Mushrooms growing on used coffee grounds
The current
industrial agriculture system is accountable for high
energy costs for the
transportation
of foodstuffs. According to a study by Rich Pirog, the associate
director of the Leopold Center for Sustainable Agriculture at Iowa State
University, the average conventional produce item travels 1,500 miles
(2,400 km), using, if shipped by
tractor-trailer, 1 US gallon (3.8 l; 0.83 imp gal) of fossil fuel per 100 pounds (45 kg).
The energy used to transport food is decreased when urban agriculture
can provide cities with locally grown food. Pirog found that
traditional, non-local, food distribution system used 4 to 17 times more
fuel and emitted 5 to 17 times more CO
2 than the local and
regional transport.
Similarly, in a study by Marc Xuereb and Region of Waterloo
Public Health, they estimated that switching to locally grown food could
save transport-related emissions equivalent to nearly 50,000 metric
tons of CO2, or the equivalent of taking 16,191 cars off the road.
A windowfarm, incorporating discarded plastic bottles into pots for hydroponic agriculture in urban windows
As mentioned above, the energy-efficient nature of urban agriculture can reduce each city's
carbon footprint by reducing the amount of transport that occurs to deliver goods to the consumer.
Also, these areas can act as
carbon sinks
offsetting some of the carbon accumulation that is innate to urban
areas, where pavement and buildings outnumber plants. Plants absorb
atmospheric carbon dioxide (CO
2) and release breathable oxygen (O
2) through
photosynthesis. The process of
Carbon Sequestration
can be further improved by combining other agriculture techniques to
increase removal from the atmosphere and prevent the release of CO
2 during harvest time. However, this process relies heavily on the types of plants selected and the methodology of farming. Specifically, choosing plants that do not lose their leaves and
remain green all year can increase the farm's ability to sequester carbon.
Reduction in ozone and particulate matter
The reduction in
ozone and other
particulate matter can benefit human health. Reducing these particulates and ozone gases could reduce
mortality rates in urban areas along with increase the health of those living in cities. Just to give one example, in the article “
Green roofs as a means of pollution abatement,” the author argues that a rooftop containing 2000 m² of uncut
grass
has the potential to remove up to 4000 kg of particulate matter.
According to the article, only one square meter of green roof is needed
to offset the annual particulate matter emissions of a car.
Soil decontamination
Vacant
urban lots are often victim to illegal dumping of hazardous chemicals
and other wastes. They are also liable to accumulate standing water and “
grey water”,
which can be dangerous to public health, especially left stagnant for
long periods. The implementation of urban agriculture in these vacant
lots can be a cost-effective method for removing these chemicals. In the
process known as
Phytoremediation,
plants and the associated microorganisms are selected for their
chemical ability to degrade, absorb, convert to an inert form, and
remove toxins from the soil.
Several chemicals can be targeted for removal including heavy metals
(e.g. Mercury and lead) inorganic compounds (e.g. Arsenic and Uranium),
and organic compounds (e.g. petroleum and chlorinated compounds like
PBC's).
Phytoremeditation is both an environmentally friendly,
cost-effective, and energy-efficient measure to reduce pollution.
Phytoremediation only costs about $5–$40 per ton of
soil being decontaminated. Implementation of this process also reduces the amount of soil that must be disposed of in a hazardous waste landfill.
Urban agriculture as a method to mediate chemical pollution can
be effective in preventing the spread of these chemicals into the
surrounding environment. Other methods of remediation often disturb the
soil and force the chemicals contained within it into the air or water.
Plants can be used as a method to remove chemicals and also to hold the
soil and prevent erosion of contaminated soil decreasing the spread of
pollutants and the hazard presented by these lots.
One way of identifying soil contamination is through using
already well-established plants as bioindicators of soil health. Using
well-studied plants is important because there has already been
substantial bodies of work to test them in various conditions, so
responses can be verified with certainty. Such plants are also valuable
because they are genetically identical as crops as opposed to natural
variants of the same species. Typically urban soil has had the topsoil
stripped away and has led to soil with low aeration, porosity, and
drainage. Typical measures of soil health are microbial biomass and
activity, enzymes,
soil organic matter
(SOM), total nitrogen, available nutrients, porosity, aggregate
stability, and compaction. A new measurement is active carbon (AC),
which is the most usable portoin of the total organic carbon (TOC) in
the soil. This contributes greatly to the functionality of the soil food
web. Using common crops, which are generally well-studied, as
bioindicators an be used to effectively test the quality of an urban
farming plot before beginning planting.
Noise pollution
Large amounts of
noise pollution not only lead to lower property values and high frustration, they can be damaging to human hearing and health.
In the study “Noise exposure and public health,” they argue that
exposure to continual noise is a public health problem. They cite
examples of the detriment of continual noise on humans to include:
“hearing impairment, hypertension and ischemic heart disease, annoyance,
sleep disturbance, and decreased school performance.” Since most roofs
or vacant lots consist of hard flat surfaces that reflect sound waves
instead of absorbing them, adding plants that can absorb these waves has
the potential to lead to a vast
reduction in noise pollution.
Nutrition and quality of food
Daily
intake of a variety of fruits and vegetables is linked to a decreased
risk of chronic diseases including diabetes, heart disease, and cancer.
Urban agriculture is associated with increased consumption of fruits and
vegetables which decreases risk for disease and can be a cost-effective way to
provide citizens with quality, fresh produce in urban settings.
Produce from urban gardens can be perceived to be more flavorful and desirable than store bought produce
which may also lead to a wider acceptance and higher intake. A Flint,
Michigan study found that those participating in community gardens
consumed fruits and vegetables 1.4 more times per day and were 3.5 times
more likely to consume fruits or vegetables at least 5 times daily
(p. 1).
Garden-based education can also yield nutritional benefits in
children. An Idaho study reported a positive association between school
gardens and increased intake of fruit, vegetables, vitamin A, vitamin C
and fiber among sixth graders.
Harvesting fruits and vegetables initiates the enzymatic process of
nutrient degradation which is especially detrimental to water
soluble vitamins such as
ascorbic acid and
thiamin.
The process of blanching produce in order to freeze or can reduce
nutrient content slightly but not nearly as much as the amount of time
spent in storage. Harvesting produce from one's own community garden cuts back on storage times significantly.
Urban agriculture also provides quality nutrition for low-income
households. Studies show that every $1 invested in a community garden
yields $6 worth of vegetables if labor is not considered a factor in
investment.
Many urban gardens reduce the strain on food banks and other emergency
food providers by donating shares of their harvest and provide fresh
produce in areas that otherwise might be food deserts. The supplemental
nutrition program Women, Infants and Children (WIC) as well as the
Supplemental Nutrition Assistance Program (SNAP) have partnered with
several urban gardens nationwide to improve the accessibility to produce
in exchange for a few hours of volunteer gardening work.
Urban farming has been shown to increase health outcomes.
Gardeners consume twice as much fruit and vegetables than non-gardeners.
Levels of physical activity are also positively associated with urban
farming. These results are seen indirectly and can be supported by the
social involvement in an individual's community as a member of the
community farm. This social involvement helped raised the aesthetic
appeal of the neighborhood, boosting the motivation or efficacy of the
community as a whole. This increased efficacy was shown to increase
neighborhood attachment. Therefore, the positive health outcomes of
urban farming can be explained in part due to the interpersonal sand
social factors that boost health. Focusing on improving the aesthetics
and community relationships and not only on the plant yield, is the best
way to maximize the positive effect of urban farms on a neighborhood.
Economy of scale
Using high-density urban farming, as for instance with
vertical farms
or stacked greenhouses, many environmental benefits can be achieved on a
citywide scale that would be impossible otherwise. These systems do not
only provide food, but also produce potable water from waste water, and
can
recycle organic waste back to energy and nutrients.
At the same time, they can reduce food-related transportation to a
minimum while providing fresh food for large communities in almost any
climate.
Health inequalities and food justice
A
2009 report by the USDA, determined that "Evidence is both abundant and
robust enough for us to conclude that Americans living in low-income
and minority areas tend to have poor access to healthy food", and that
the "structural inequalities" in these neighborhoods "contribute to
inequalities in diet and diet-related outcomes".
These diet-related outcomes, including obesity and diabetes, have
become epidemic in low-income urban environments in the United States. Although the definition and methods for determining "
food deserts" have varied, studies indicate that, at least in the United States, there are racial disparities in the food environment.
Thus using the definition of environment as the place where people
live, work, play and pray, food disparities become an issue of
environmental justice.
This is especially true in American inner-cities where a history of
racist practices have contributed to the development of food deserts in
the low-income, minority areas of the urban core.
The issue of inequality is so integral to the issues of food access and
health that the Growing Food & Justice for All Initiative was
founded with the mission of “dismantling racism” as an integral part of
creating food security.
Not only can urban agriculture provide healthy, fresh food
options, but also can contribute to a sense of community, aesthetic
improvement, crime reduction, minority empowerment and autonomy, and
even preserve culture through the use of farming methods and heirloom
seeds preserved from areas of origin.
Environmental justice
Urban agriculture may advance
environmental justice and food justice for communities living in food deserts.
First, urban agriculture may reduce racial and class disparities in
access to healthy food. When urban agriculture leads to locally grown
fresh produce sold at affordable prices in food deserts, access to
healthy food is not just available for those who live in wealthy areas,
thereby leading to greater equity in rich and poor neighborhoods.
Improved access to food through urban agriculture can also help
alleviate psychosocial stresses in poor communities. Community members
engaged in urban agriculture improve local knowledge about healthy ways
to fulfill dietary needs. Urban agriculture can also better the mental
health of community members. Buying and selling quality products to
local producers and consumers allows community members to support one
another, which may reduce stress. Thus, urban agriculture can help
improve conditions in poor communities, where residents experience
higher levels of stress due to a perceived lack of control over the
quality of their lives.
Urban agriculture may improve the livability and built
environment in communities that lack supermarkets and other
infrastructure due to the presence of high unemployment caused by
deindustrialization.
Urban farmers who follow sustainable agriculture methods can not only
help to build local food system infrastructure, but can also contribute
to improving local air, and water and soil quality. When agricultural products are produced locally within the community, they do not need to be transported, which reduces
CO2 emission rates and other pollutants that contribute to high rates of
asthma in lower socioeconomic areas. Sustainable urban agriculture can also promote worker protection and consumer rights. For example, communities in
New York City,
Illinois, and
Richmond, Virginia have demonstrated improvements to their local environments through urban agricultural practices.
However, urban agriculture can also present urban growers with
health risks if the soil used for urban farming is contaminated.
Although local produce is often believed to be clean and healthy, many
urban farmers ranging from New York urban farmer Frank Meushke to Presidential First Lady
Michelle Obama have found their products contained high levels of
lead, due to
soil contamination,
which is harmful to human health when consumed. The soil contaminated
with high lead levels often originates from old house paint which
contained lead,
vehicle exhaust,
or atmospheric deposition. Without proper education on the risks of
urban farming and safe practices, urban consumers of urban agricultural
produce may face additional health-related issues.
Implementation
Rooftop urban farming at the Food Roof Farm in downtown St. Louis, MO
Creating a community-based infrastructure for urban agriculture means
establishing local systems to grow and process food and transfer it
from farmer (
producer) to
consumer.
To facilitate food production, cities have established
community-based farming projects. Some projects have collectively tended
community farms on
common land, much like that of eighteenth-century
Boston Common. One such community farm is the
Collingwood Children's Farm in
Melbourne,
Australia. Other community garden projects use the
allotment garden
model, in which gardeners care for individual plots in a larger
gardening area, often sharing a tool shed and other amenities. Seattle's
P-Patch gardens use this model, as did the
South Central Farm
in Los Angeles and the Food Roof Farm in St. Louis. Independent urban
gardeners also grow food in individual yards and on roofs.
Garden sharing projects seek to pair producers with the land, typically, residential yard space.
Roof gardens
allow for urban dwellers to maintain green spaces in the city without
having to set aside a tract of undeveloped land. Rooftop farms allow
otherwise unused industrial roofspace to be used productively, creating
work and profit.
Projects around the world seek to enable cities to become 'continuous
productive landscapes' by cultivating vacant urban land and temporary or
permanent
kitchen gardens.
Tomato plants growing in a pot farming alongside a small house in New Jersey in fifteen garbage cans filled with soil, grew over 700 tomatoes during the summer of 2013.
Food processing
on a community level has been accommodated by centralizing resources in
community tool sheds and processing facilities for farmers to share.
The Garden Resource Program Collaborative based in Detroit has cluster
tool banks. Different areas of the city have tool banks where resources
like tools,
compost,
mulch, tomato stakes, seeds, and education can be shared and
distributed with the gardeners in that cluster. Detroit's Garden
Resource Program Collaborative also strengthens their gardening
community by providing to their member's transplants; education on
gardening, policy, and food issues; and by building connectivity between
gardeners through workgroups, potlucks, tours, field trips, and cluster
workdays. In Brazil, "Cities Without Hunger" has generated a public
policy for the reconstruction of abandoned areas with food production
and has improved the green areas of the community.
Farmers' markets, such as the
farmers' market in Los Angeles,
provide a common land where farmers can sell their product to
consumers. Large cities tend to open their farmer's markets on the
weekends and one day in the middle of the week. For example, the
farmers' market of
Boulevard Richard-Lenoir in
Paris, France,
is open on Sundays and Thursdays. However, to create a consumer
dependency on urban agriculture and to introduce local food production
as a sustainable career for farmers, markets would have to be open
regularly. For example, the Los Angeles Farmers' Market is open seven
days a week and has linked several local grocers together to provide
different food products. The market's central location in downtown Los
Angeles provides the perfect interaction for a diverse group of sellers
to access their consumers.
Queensland, Australia
In Queensland many people have started a trend of urban farming both utilizing
Aquaponics and self-watering containers.
Cairo, Egypt
In Egypt, development of rooftop gardens began in the 1990s. In the early 1990s at
Ain Shams University,
a group of agriculture professors developed an initiative focused on
growing organic vegetables to suit densely populated cities of Egypt.
The initiative was applied on a small scale; until it was officially
adopted in 2001, by the Food and Agriculture Organization (
FAO).
Havana, Cuba
Farming enterprise in Havana, Cuba (2015)
After the disintegration of the
Soviet Union and the
Eastern Bloc,
Cuba faced severe shortages of fuel and
agrochemical inputs.
These products had previously been imported from the Soviet Union in
exchange for Cuban sugar. As a result, Cubans experienced an acute food
crisis in the early 1990s, which in part was met with a popular movement
of urban agriculture. Urban farmers employed – and still employ –
agroecological techniques, allowing food production to take place largely without petroleum-based inputs.
In 2002, 35,000 acres (14,000 ha) of urban gardens produced
3,400,000 short tons (3,100,000 t) of food. In Havana, 90% of the city's
fresh produce come from local urban farms and gardens. In 2003, more
than 200,000 Cubans worked in the expanding urban agriculture sector.
Mumbai, India
Economic development in
Mumbai
brought a growth in population caused mainly by the migration of
laborers from other regions of the country. The number of residents in
the city increased more than twelve times in the last century.
Greater Mumbai, formed by
City Island and
Salsette Island,
is the largest city in India with a population of 16.4 million,
according to data collected by the census of 2001. Mumbai is one of the
densest cities in the world, 48,215 persons per km² and 16,082 per km²
in suburban areas. In this scenario, urban agriculture seems unlikely to
be put into practice since it must compete with real estate developers
for the access and use of vacant lots. Alternative farming methods have
emerged as a response to the scarcity of land, water, and economic
resources employed in UPA.
Dr. Doshi's city garden methods are revolutionary for being
appropriate to apply in reduced spaces as terraces and balconies, even
on civil construction walls, and for not requiring big investments in
capital or long hours of work. His farming practice is purely organic
and is mainly directed to domestic consumption. His gardening tools are
composed of materials available in the local environment: sugarcane
waste, polyethylene bags, tires, containers and cylinders, and soil. The
containers and bags (open at both ends) are filled with the sugarcane
stalks, compost, and garden soil, which make possible the use of a
minimal quantity of water is compared to open fields. Dr. Doshi states
that solar energy can replace soil in cities. He also recommends the
idea of chain planning, or growing plants in intervals and in small
quantities rather than at once and in large amounts. He has grown
different types of fruit such as mangos, figs, guavas, bananas, and
sugarcane stalks in his terrace of 1,200 sq ft (110 m
2) in Bandra. The concept of
city farming
developed by Dr. Doshi consumes the entire household's organic waste.
He subsequently makes the household self-sufficient in the provision of
food: 5 kilograms (11 lb) of fruits and vegetables are produced daily
for 300 days a year.
The main objectives of a pilot project at city farm at Rosary
High School, Dockyard Road, were to promote economic support for street
children, beautify the city landscape, supply locally produced organic
food to urban dwellers (mainly those residing in slums), and to manage
organic waste in a sustainable city. The project was conducted in the
Rosary School, in Mumbai, with the participation of street children
during 2004. A city farm was created in a terrace area of 400 sq ft
(37 m2). The participants were trained in urban farming
techniques. The farm produced vegetables, fruits, and flowers. The idea
has spread the concept of city farm to other schools in the city.
The Mumbai Port Trust (MBPT) central kitchen distributes food to
approximately 3,000 employees daily, generating important amounts of
organic disposal. A terrace garden created by the staff recycles ninety
percent of this waste in the production of vegetables and fruits. Preeti
Patil, who is the catering officer at the MBPT explains the purpose of
the enterprise:
Mumbai Port Trust has developed an organic farm on the terrace of its
central kitchen, which is an area of approximately 3,000 sq ft (280 m2).
The activity of city farming was started initially to dispose of
kitchen organic waste in an eco-friendly way. Staff members, after their
daily work in the kitchen, tend the garden, which has about 150 plants.
Bangkok, Thailand
In
early 2000, urban gardens were started under the direction of the NGO,
Thailand Environment Institute (TEI), to help achieve the Bangkok
Metropolitan Administrations (BMA) priority to "green" Thailand. With a
population of 12 million and 39% of the land in the city vacant due to
rapid expansion of the 1960s–80s Bangkok is a test bed for urban gardens
centered on community involvement. The two urban gardens initiated by TEI are in Bangkok Noi and Bangkapi and the main tasks were stated as:
- Teach members of the communities the benefits of urban green space.
- Create the social framework to plan, implement, and maintain the urban green space.
- Create a process of a method to balance the needs of the community with the needs of the larger environmental concerns.
While the goals of the NGO are important in a global context, the
community goals are being met through the work of forming the urban
gardens themselves. In this sense, the creation, implementation, and
maintenance of urban gardens are highly determined by the desires of the
communities involved. However, the criteria by which TEI measured their
success illustrates the scope of benefits to a community which
practices urban agriculture. TEI's success indicators were:
- Establishing an Urban Green Plan
- Community Capacity Building
- Poverty Reduction
- Links with Government
- Developing a Model for Other Communities
China
Beijing's
increase in land area from 4,822 square kilometres (1,862 sq mi) in 1956
to 16,808 square kilometres (6,490 sq mi) in 1958 led to the increased
adoption of peri-urban agriculture. Such "suburban agriculture" led to
more than 70% of non-staple food in Beijing, mainly consisting of
vegetables and milk, to be produced by the city itself in the 1960s and
1970s. Recently, with relative food security in China, periurban
agriculture has led to improvements in the quality of the food
available, as opposed to quantity. One of the more recent experiments in
urban agriculture is the Modern Agricultural Science Demonstration Park
in Xiaotangshan.
Traditionally, Chinese cities have been known to mix agricultural
activities within the urban setting. Shenzhen, once a small farming
community, is now a fast-growing metropolis due to the Chinese
government designation as an open economic zone. Due to large and
growing population in China, the government supports urban
self-sufficiency in food production. Shenzhen's village structure,
sustainable methods, and new agricultural advancements initiated by the
government have been strategically configured to supply food for this
growing city.
The city farms are located about 10 kilometres (6.2 mi) from the
city center in a two-tier system. The first tier approached from city
center produces perishable items. Located just outside these farms,
hardier vegetables are grown such as potatoes, carrots, and onions. This
system allows producers to be sold in city markets just a few short
hours after picking.
Another impressive method used in Chinese agriculture and
aquaculture practice is the mulberry-dike fish-pond system, which is a
response to waste recycling and soil fertility. This system can be
described as:
Mulberry trees are grown to feed silkworms and the silkworm waste is
fed to the fish in ponds. The fish also feed on waste from other
animals, such as pigs, poultry, and buffalo. The animals, in turn, are
given crops that have been fertilized by mud from the ponds. This is a
sophisticated system as a continuous cycle of water, waste, and
food...with a man built into the picture.
As the population grows and industry advances, the city tries to
incorporate potential agricultural growth by experimenting with new
agricultural methods. The Fong Lau Chee Experimental Farm in Dongguan,
Guangdong has worked with new agricultural advancements in lychee
production. This farm was established with aspirations of producing
large quantities and high-quality lychees, by constantly monitoring
sugar content, and their seeds. This research, conducted by local
agricultural universities allows for new methods to be used with hopes
of reaching the needs of city consumers.
However, due to increased levels of economic growth and
pollution, some urban farms have become threatened. The government has
been trying to step in and create new technological advancements within
the agricultural field to sustain levels of urban agriculture.
"The city plans to invest 8.82 billion yuan in 39 agricultural
projects, including a safe agricultural base, an agricultural high-tech
park, agricultural processing and distribution, forestry,
eco-agricultural tourism, which will form an urban agriculture with
typical Shenzhen characteristics" in conjunction with this program the
city is expected to expand the Buji Farm Produce Wholesale Market.
According to the Municipal Bureau of Agriculture, Forestry and
Fishery the city will invest 600 million yuan on farms located around
the city, with hopes of the farms to provide "60 percent of the meat,
vegetables, and aquatic products in the Shenzhen market".
There has also been an emerging trend of going green and organic
as a response to pollution and pesticides used in farming practices.
Vegetable suppliers are required to pass certain inspections held by the
city's Agriculture Bureau before they can be sold as "green".
Harare, Zimbabwe
Harare is particularly suited for urban agriculture, as its topography heavily features vleis,
land drainage systems that become waterlogged in the rainy season. When
it rains they are difficult to cross, and in the dry season they shrink
and crack, which causes structural damage to infrastructure, even
though the vleis are still storing water underground. Therefore, these
moisture-rich areas are mostly left unbuilt, allowing for urban
cultivation.
Aside from vleis and the private residential land that Harareans
cultivate, considerable public land is used for agriculture in Harare:
along public roads, railway lines, undeveloped plots, road verges, and
the banks of ditches. The land is mostly used for maize, groundnuts, sweet potatoes, green vegetables, fruits, paprika, and flowers. This
unsanctioned cultivation has a history of necessity: in colonial times,
laborers wanted towns where they could cultivate crops like at their
rural homes, and with very low income, needed to supplement their food
supply.
However, urban agriculture in Harare causes harm to the
environment. The practice has reduced rainwater infiltration into the
soil by 28.5 percent and lowered tree species diversity. In addition, most informal urban farmers use harmful chemical fertilizers.
Urban agriculture has also been viewed negatively in Harare because it
impedes on housing and urban development. In the eyes of Zimbabwean
laws, agriculture was not an “urban” activity or a legitimate form of
land use in cities.
In 1983, the Greater Harare Illegal Cultivation Committee was formed,
though its efforts to curb urban agriculture wholly failed.
In the 1990s, the failure of Structural Adjustment Programs
induced greater unemployment, higher prices, and lower incomes, so more
people started growing their own food. Between 1990 and 1994, Harare's cultivation area increased by 92.6 percent.
The boom in urban agriculture improved both the food security and the
nutrition of its practitioners, as well as additional income from
selling excess produce. The practice continued in the 2000s when a major
recession brought about widespread poverty, unemployment, and enormous
inflation. Finally, the 2002 Nyanga Declaration on Urban Agriculture in
Zimbabwe explicitly acknowledged the value of urban agriculture for food
security and the reduction of poverty. Accepting that many people
depend on it to survive, the government allocated sixty thousand
hectares of land in Harare for cultivation purposes.
United States
Nationwide Survey Findings
According to the
USDA,
a farm is defined as a location that produces and sells at least $1,000
worth of products. A study conducted on urban farms in 2012 surveyed
over 315 farms that identified as urban. Of those, over 32% were found
in the Northeast, more than 26% in the South, 22% in the West, and less
than 19% in the Midwest. The survey found that most urban farms in the
United States are structured as either non-profit or solely owned. Urban
farms typically use techniques that allow them to produce intensively
on small land. Mainly, these practices include raised beds, greenhouse,
and
container gardens.
Of the products made, an overwhelming majority of urban farms focus on
fresh vegetable, followed by herbs and flowers. If an urban farm focuses
on animals, the primary animal is hens. Bees and sheep are the second
most common urban farm animals.
Almost half of the urban farms that participated in the survey
made a total gross sale adding to less than $10,000. The majority of
these sales coming from farmers markets,
Community Supported Agriculture
(CSA), and restaurants. Not even 5% of the urban farms could be
considered according to total gross sales statistics. Most urban farms
agree on the main challenges that they face; production costs, managing
pests, managing weeds, and climate. They also see profitability,
financing, and farm labor as big challenges of managing an urban farm.
New York
Garden of Adam Purple, lower east-side, New York City, 1984
Many low-income residents suffer from high rates of obesity and
diabetes and limited sources of fresh produce. The City and local
nonprofit groups have been providing land, training and financial
encouragement, but the impetus in urban farming has really come from the
farmers, who often volunteer when their regular work day is done. In
addition, the New York City Department of Environmental Protection
offers a grant program for private property owners in combined sewer
areas of New York City. The minimum requirement is to manage 1” of
stormwater runoff from the contributing impervious area. Eligible
projects include green roofs, rooftop farms, and
rainwater harvesting
on private property in combined sewer areas. Because of this grant
program, New York City now has the world's largest rooftop farms.
Some urban gardeners have used empty lots to start a community or
urban gardens. However, the soil must be tested for heavy contamination
in city soil because of vehicle exhaust and remnants of old
construction. The City also has a composting program, which is available
to gardeners and farmers. One group, GreenThumb, provides free
seedlings. Another program, the City Farms project operated by the
nonprofit Just Food, offers courses on growing and selling food.
Two alternate means of growing are
rooftop gardens and
hydroponic (soil-less) growing.
The New York Times wrote an article about one of Manhattan's first gardens which incorporate both these techniques.
Another option urban gardeners have used is Farm-in-A-Box LLC, a
company that provides hand-made, ready-to-use garden boxes to residents
and schools.
California
In
response to the recession of 2008, a coalition of community-based
organizations, farmers, and academic institutions in California's
Pomona Valley formed the Pomona Valley Urban Agriculture Initiative.
After the passage of the
North American Free Trade Agreement,
cheap grain from the United States flooded Mexico, driving peasant
farmers off of their land. Many immigrated to the Pomona Valley and
found work in the construction industry. With the 2008 recession, the
construction industry also suffered in the region. It is unlikely to
regain its former strength because of severe water shortages in this
desert region as well as ongoing weakness in the local economy. These
immigrants were dry land organic farmers in their home country by
default since they did not have access to pesticides and petroleum-based
fertilizers. Now, they found themselves on the border of two counties:
Los Angeles County with a population of 10 million and almost no
farmland, and San Bernardino County which has the worst access to
healthy food in the state.
In both counties, there is a growing demand for locally grown organic
produce. In response to these conditions, Uncommon Good, a
community-based nonprofit organization that works with immigrant farmer
families, convened a forum which became the Urban Farmers Association.
The Urban Farmers Association is the first organization of its kind for
poor immigrant farmers in the Pomona Valley. Its goal is to develop
opportunities for its members to support themselves and their families
through urban agriculture. With Uncommon Good, it is a founding member
of the Pomona Valley Urban Agriculture Initiative (PVUAI). The PVUAI is
working with local colleges and universities to expand upon a food
assessment survey that was done in the City of Pomona.
Oakland
Urban agriculture in West Oakland has taken a radical form that can be traced back to community gardening initiatives starting in the 1970s in the cities of
Berkeley and
Oakland, and the city's African-American heritage.
Oakland's manufacturing industry attracted new residents during WWII.
To reduce racial tension, the Oakland Housing Authority established
housing projects for blacks in West Oakland and whites in East Oakland.
With exclusionary
covenants and
redlining
by banks, development capital was kept out of West Oakland while the
African-American population had limited opportunities to rent or buy
housing outside West Oakland.
The
Black Panther Party (BPP) played a role in seeding urban agricultural practices in West Oakland.
One of its social programs aimed to improve the access to healthy food
for the city's black population by providing breakfast in local schools,
churches, and community centers. A small amount of this food came from
small local gardens planted by BPP members. According to Prof. Nathan
McClintock, "The Panthers used gardening as a coping mechanism and a
means of supplementing their diets, as a well as a means to strengthen
community members engaged in the struggle against oppression."
The People of Color Greening Network (PCGN) was created in the 1990s.
The group planted in empty and vacant lots in West Oakland. In addition,
schools around Alameda County began teaching basic gardening skills and
food education. Other groups have carried on those legacies, such as People's Grocery and Planting Justice.
In 1998, the city of Oakland's Mayor's Office of Sustainability
proposed a Sustainable Community Development Initiative towards
sustainable development.
Due to West Oakland's lack of access to nutritious and healthy food,
other organizations including the PCGN and City Slicker Farms demanded
the plan include strategies for creating a sustainable impact on the
local food system. City Slicker Farms was founded in 2001 in response to
the lack of access to fresh produce in West Oakland. Through land
donations from local residents, a network of urban farms was created
through the Community Market Farms Program, and in 2005 the organization
established the Backyard Garden Program to aid West Oakland residents
in growing their own food at home. This program now grows upwards of
30,000 lbs. of food each year.
In 2005, Mayor Jerry Brown signed the UN World Environment Day
Urban Environmental Accords, pledging Oakland to become a more
sustainable city by the year 2012. This gave rise to Oakland City Council Resolutions, such as No. 76980 and No. 80332 which helped develop a Food Policy Council.
It has teamed up with the Health of Oakland's People & Environment
(HOPE) Collaborative, which works to improve the health and wellness of
Oakland's residents. In 2009 the Oakland Food Policy Council started to plan urban agriculture in Oakland.
Canada
Montreal
In Montreal about 100
community gardens
provide plots where citizens can grow fruits, vegetables, herbs, and
flowers. The largest community garden has about 255 allotment plots,
while the smallest site has about 25 plots. Out of 2 million people
living in the urbanized parts of Montreal, about 10,000 residents share
the garden plots. The program has been in place since 1975 and is
managed by the boroughs. Some of the boroughs have a gardening
instructor who visits the gardens regularly to give gardeners tips.
Soil, a water supply, a space for tools, sand, fencing, and paint are
provided by the city, managed by the Department of Sports, Recreation
and Social Development.
Canada has a number of companies working on urban farm technology, including in Montreal.
Lufa Farms
built in early 2011 a 2880 sq metre (31,000 sq ft) hydroponic rooftop
greenhouse atop a warehouse designated as their headquarters.
They built two more large rooftop greenhouses in greater Montreal in
2013 (4,000 sq metre / 43,000 sq ft) and 2017 (5,850 sq metre / 63,000
sq ft), spending almost $10 million for the three structures. Also in 2017, an
IGA supermarket
in Saint-Laurent in Montreal unveiled a green roof of about 25,000
square feet of green space and products certified by Ecocert Canada.
They state that they can provide over 30 different kinds of rooftop
grown organic produce, along with honey produced and harvested from
eight bee hives located on the roof.
Both Lufa and IGA rely on non-rooftop production for some to much
of their produce. Only shallow rooted plant can grow on roofs,
eliminating crops such as potatoes and corn. Some local farmers point
out that the industrial systems are subsidized and are unfair
competetion.
British Columbia
A Canadian urban farmer in
British Columbia has published details on a crop value rating (CVR) system that urban farmers can use to determine which
crops to grow, based on each crop's contribution to supporting the farm economically. This entails forgoing some crops in favor of others, but he points out that urban farmers can develop
business networking
with rural farmers to bring some of those other crops to the urban
point of sale. For example, the urban farmer may not be able to
economically justify growing
sweet corn (based on long
days to maturity and low
yield
density per linear foot of row), but a networking arrangement is
mutually beneficial, as it lets a rural sweet corn grower gain an
additional point of sale at
retail price while also letting the urban farmer fill the gap in his product line offering.
Several community projects in
Victoria, British Columbia
were born to promote urban agricultural practices such as the Sharing
Backyards program. This program exists to help people living in urban
areas get connected with others who have extra space in their yards for
the purpose of urban farming. Organizations also exist to educate people
living in the urban parts of Vancouver on farming and growing food in
an urban setting by running public demonstration gardens.
Covering the roof of the west building of the
Vancouver Convention Centre
is the largest green roof in Canada and one of the 10 largest green
roofs in the world. With around six acres of living space, it is home to
more than 400,000 indigenous plants and grasses that provide
insulation. It is also home to four
Western honey bee beehives which pollinate the plants on the roof and provide honey. The living includes other
sustainable practices such as recycling and reusing water.
The city of
Kamloops,
in British Columbia, are actively promoting urban agricultural
practices within their community. They stress on the importance of food
security and its affect on the economy as well as the ecology. They
created the Food and Urban Agriculture Plan (FUAP), initiated in 2014,
which lays out goals and strategies to implement a
sustainable
food system. The Areas which they cover include: Food Production and
Land Availability, Food Processing and Preparing, Food
Distribution/Retail/Access, Cooking/Eating and Celebrating Food, Food
Waste and Resource Management, as well as Education/Governance and
Capacity Building. The FUAP greatly emphasizes on Urban Agriculture.
Ontario
Ontario
is the second biggest province and has one of the most urbanized cities
in Canada, Toronto. The provincial government of Ontario has a website
dedicated to providing information to those who are interested in
establishing an urban farm or for those who just want to learn more
about urban agriculture in Ontario.
UrbanHensTo is a 3-year pilot program that launched in the City of
Toronto
on March 2, 2018. This program allows eligible resident in 4 wards
across the city to keep a maximum of 4 hens (no roosters) for the
purpose of enjoyment or personal consumption of only the eggs. There are
other requirements included with rearing these hens under this program
such as
zoning
and guidelines for building the enclosure, waste and disposal. The
wards eligible for this program from the UrbanHensTo site include:
- Ward 13 (Parkdale-High Park)
- Ward 21 (St. Paul's)
- Ward 5 (Etobicoke-Lakeshore)
- Ward 32 (Beaches-East York)
Workshops are also available to those interested in rearing urban
hens. However, failure to abide by these rules and regulations can
result in fines.
Toronto has a green roof policy and bylaw which has promoted the
practice of installing green roofs. According to the Green Roof Industry
Survey in 2016, the city was recognized as having the most green roofs
installed on buildings in all of North America. This came to be after
they developed a green roof strategy in 2009 where new development
buildings are required to install a green roof.
UK
Todmorden is a town of 17,000 inhabitants in
Yorkshire,
United Kingdom with a
successful urban agriculture model. The project, which began in 2008, has meant that food crops have been planted at forty locations throughout the town. The produce is all free, the work is done by volunteers, and passers-by and visitors are invited to pick and use the produce. Some Todmorden plots have been permission plots while others have been examples of
guerilla gardening.
All are "propaganda gardens" promoting locals to consider growing
local, to eat seasonal, to consider the provenance of their food, and to
enjoy fresh.
There are food plots in the street, in the health center car park, at
the rail station, in the police station, in the cemetery, and in all the
town's schools.
Argentina
The city of
Rosario
(population: 1.3 million) has incorporated agriculture fully into its
land use planning and urban development strategy. Its Land Use Plan
2007-2017 makes specific provision for the agricultural use of public
land. Under its Metropolitan Strategic Plan 2008-2018, Rosario is
building a “green circuit”, passing through and around the city,
consisting of family and community gardens, large-scale, commercial
vegetable gardens and orchards, multifunctional garden parks, and
“productive barrios”, where agriculture is integrated into programmes
for the construction of public housing and the upgrading of slums. In
2014, the green circuit consisted of more than 30 ha of land used to
grow vegetables, fruit and medicinal and aromatic plants. The city has
five garden parks – large, landscaped green areas covering a total of 72
ha of land, which are used for agriculture and for cultural, sports and
educational activities.
Benefits
The
benefits that UPA brings along to cities that implement this practice
are numerous. The transformation of cities from only consumers of food
to generators of agricultural products contributes to sustainability,
improved health, and poverty alleviation.
- UPA assists to close the open loop system in urban areas
characterized by the importation of food from rural zones and the
exportation of waste to regions outside the city or town.
- Wastewater and organic solid waste can be transformed into resources
for growing agriculture products: the former can be used for
irrigation, the latter as fertilizer.
- Vacant urban areas can be used for agriculture production.
- Other natural resources can be conserved. The use of wastewater for irrigation improves water management and increases the availability of freshwater for drinking and household consumption.
- UPA can help to preserve bioregional ecologies from being transformed into cropland.
- Urban agriculture saves energy (e.g. energy consumed in transporting food from rural to urban areas).
- Local production of food also allows savings in transportation
costs, storage, and in product loss, what results in food cost
reduction.
- UPA improves the quality of the urban environment through greening and thus, a reduction in pollution.
- Urban agriculture also makes the city a healthier place to live by improving the quality of the environment.
- UPA is a very effective tool to fight against hunger and
malnutrition since it facilitates the access to food by an impoverished
sector of the urban population.
Poverty alleviation: It is known that a large part of the people
involved in urban agriculture is the urban poor. In developing
countries, the majority of urban agricultural production is for
self-consumption, with surpluses being sold in the market. According to
the FAO (Food and Agriculture Organization of the United Nations), urban
poor consumers spend between 60 and 80 percent of their income on food,
making them very vulnerable to higher food prices.
- UPA provides food and creates savings in household expenditure
on consumables, thus increasing the amount of income allocated to other
uses.
- UPA surpluses can be sold in local markets, generating more income for the urban poor.
Community centers
and gardens educate the community to see agriculture as an integral
part of urban life. The Florida House Institute for Sustainable
Development in
Sarasota, Florida,
serves as a public community and education center in which innovators
with sustainable, energy-saving ideas can implement and test them.
Community centers like Florida House provide urban areas with a central
location to learn about urban agriculture and to begin to integrate
agriculture with the urban lifestyle.
Urban farms also are a proven effective educational tool to teach kids about healthy eating and meaningful physical activity.
Trade-offs
- Space is at a premium in cities and is accordingly expensive and difficult to secure.
- The utilization of untreated wastewater for urban agricultural
irrigation can facilitate the spread of waterborne diseases among the
human population.
- Although studies have demonstrated improved air quality in urban
areas related to the proliferation of urban gardens, it has also been
shown that increasing urban pollution (related specifically to a sharp
rise in the number of automobiles on the road), has led to an increase
in insect pests, which consume plants produced by urban agriculture. It
is believed that changes to the physical structure of the plants
themselves, which have been correlated to increased levels of air
pollution, increase plants' palatability to insect pests. Reduced yields
within urban gardens decreases the amount of food available for human
consumption.
- Studies indicate that the nutritional quality of wheat suffers when
urban wheat plants are exposed to high nitrogen dioxide and sulfur
dioxide concentrations. This problem is particularly acute in the
developing world, where outdoor concentrations of sulfur dioxide are
high and large percentages of the population rely upon urban agriculture
as a primary source of food. These studies have implications for the
nutritional quality of other staple crops that are grown in urban
settings.
- Agricultural activities on land that is contaminated (with such
metals as lead) pose potential risks to human health. These risks are
associated both with working directly on contaminated land and with
consuming food that was grown in contaminated soil.
Municipal greening policy goals can pose conflicts. For example,
policies promoting urban tree canopy are not sympathetic to vegetable
gardening because of the deep shade cast by trees. However, some
municipalities like Portland, Oregon, and Davenport, Iowa are
encouraging the implementation of fruit-bearing trees (as street trees
or as park orchards) to meet both greening and food production goals.
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