ArticlePDF Available
Thematic Paper 2
Urban Agriculture and Sustainable Cities
43
URBAN AGRICULTURE AND SUSTAINABLE CITIES
Tjeerd Deelstra and Herbert Girardet
1. Introduction
At the end of the 20th century, humanity is involved in an unprecedented
experiment: we are turning ourselves into an urban species. Large cities, not
villages and towns, are becoming our main habitat. Urban growth is changing the
face of the earth and the condition of humanity. In one century, global urban
populations have expanded from 15 to 50% of the total, which itself has gone up
from 1.5 to nearly 6 billion. The size of modern cities in terms of numbers as
well as physical scale is unprecedented. In 1800, there was only one city with a
million people, London. By 1990, the world's 100 largest cities accommodated
540 million people and 220 million people lived in the 20 largest cities, mega-
cities of over 10 million people, some extending to hundreds of thousands of
hectares.
Urban agglomerations and their resource uses are becoming the dominant feature
of the human presence on earth, profoundly changing humanity’s relationship to
its host planet and its ecosystems. The cities of the 21st century are where human
destiny will be played out, and where the future of the biosphere will be
determined. It is unlikely that the planet will be able to accommodate an
urbanised humanity that continues to draw upon resources from ever more
distant hinterlands, or which uses the biosphere, the oceans and the atmosphere
as a sink for its wastes at the current accelerating rates. The challenge faced is
whether cities can transform themselves into self-regulating, sustainable systems
- not only in their internal functioning, but also in their relationships to the
outside world. Is it possible to make a world of cities viable in the long term
socially, economically, as well as environmentally? The answer to this question
is critical to the future well-being of the planet, as well as of humanity. There can
be no sustainable world without sustainable cities.
1.1 Cities and the environment
Many of today’s cities function very differently from those we have inherited
from history, and relationships with the environment are changing. Low
transport costs, based on the ubiquitous use of fossil fuels and facilitated by
Thematic Paper 2
Urban Agriculture and Sustainable Cities
44
substantial government subsidies for transport infrastructure, often make
distances irrelevant plugging cities into an increasingly global hinterland. The
actual location of settlements is also becoming less important as global trade
treaties come to determine the fate of national and local economies. Today, urban
dwellers don’t really live in a civilisation, but in a mobilisation - of natural
resources, people and products.
The concept of an urban ecological footprint can be used to help illustrate how
surrounding rural and natural areas are being affected by cities. Ecological
footprint analysis assumes that every category of energy and material
consumption and waste discharge requires the productive or absorptive capacity
of a finite area of land or water (Wackernagel & Rees 1996). The sum of all land
and water required to meet material consumption and waste discharge of a
defined population is that populations' ecological footprint on the earth. This
does not have to coincide (and often does not) with the populations' home
region. Ecological footprint analysis reveals the growing competing demands on
natural capital, and it also raises the issues both of equity and the long-term
sustainability of production. By establishing the ecological footprint of different
life styles, infrastructure, consumption patterns and certain densities separately,
it is possible to develop strategies to reduce environmental impacts and the
depletion of natural resources. Local Agenda 21 cities are required to list
activities to reduce the ecological footprint, while at the same time increasing the
quality of life for the inhabitants. Food supplies to cities are an important
component of the footprint of cities and a key issue in this context.
1.2 Cities and food
Cities require vast areas of land for their sustenance and have come to depend on
large amounts of food being brought in from outside the land area they actually
occupy. London, for instance, has a surface area of some 160,000 ha. With only
12% of Britain's population, London requires the equivalent of 40% of Britain's
entire productive land for its food. In reality, these land surfaces, of course,
stretch to far-flung places such as the wheat prairies of Kansas and Iowa, the
soybean fields of Mato Grosso, the orchards of France and Spain, and the tea
gardens of Assam or Mount Kenya. But this global dependence of Londoners has
never been a big issue. Food is there to be bought and enjoyed the
environmental impact of food supplies, including the energy required for food
production, processing and transport, is rarely discussed.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
45
However, today’s retailing and food distribution systems, relying on motorised
transport and, increasingly, airfreight exact a heavy environmental toll in terms
of fossil-fuel use, air pollution and damage to wildlife habitats through road
building (SAFE Alliance 1994). The largest land surfaces required for feeding
cities in developed countries are for producing grains, and animal feed such as
maize and soybeans to meet the demand for meat. As countries with huge
population, such as China and India, urbanise, worldwide demand for land to
feed cities will continue to grow. Sooner or later, cities that have come to take
large-scale food imports for granted may need to consider reviving agricultural
production in urban areas or the urban fringe to reduce the demand for land
surfaces elsewhere.
1.3 Urban sustainability
In a world increasingly dominated by cities, the international community is
starting to address the issue of urban sustainability. The process began in Rio
with Agenda 21 and continued at the 1996 UN City Summit in Istanbul. The
100-page Habitat Agenda, signed in Istanbul by 180 nations, states: “Human
settlements shall be planned, developed and improved in a manner that takes full
account of sustainable development principles and all their components, as set
out in Agenda 21. ... We need to respect the carrying capacity of ecosystems and
preservation of opportunities for future generations. … Science and technology
have a crucial role in shaping sustainable human settlements and sustaining the
ecosystems they depend upon.”
It is recognised that cities nowadays use too many natural resources and produce
too much waste. The ecological footprints of cities are stamping out the habitat
of many species. The city’s impact stretches far beyond its physical boundaries.
Moreover cities are confronted with an increasing number of people and,
therefore, an increasing number of mouths to feed. Along with other initiatives
and activities, urban agriculture therefore has an important role in contributing to
the future sustainability of cities.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
46
2. Urban agriculture
2.1 Farming in cities today
Despite their inherent density, cities do have enormous potential for food
growing. Smit et al. (1995) reported that:
The 1980 US census found that urban metropolitan areas produced 30% of the
dollar value of US agricultural production. By 1990, this figure had increased to
40%. There are 80,000 community gardeners on municipal land in Berlin with a
waiting list of 16,000. Singapore is fully self-reliant in meat and produces 25% of
its vegetable needs. Bamako, Mali, is self-sufficient in vegetables and produces
half or more of the chickens it consumes. Dar-es-Salaam, one of the world's
fastest growing large cities, now has 67% of families engaged in farming
compared with 18% in 1967. Presently, 65% of Moscow families are involved in
food production compared with 20% in 1970.
These are remarkable figures given the neglect of agriculture in urban planning
policy. Planners tend to think that urban food growing is a messy business, and
have little understanding of peoples' need to grow food in cities. But for
hundreds of millions of urban people, it is a vital component of their livelihoods
and during hard times it is an important survival strategy, and city dwellers are
increasingly trying to persuade planners to give them space for growing crops.
This is true not only in developing countries, but also increasingly in the
developed countries, particularly in cities where unemployment is endemic. In
addition, many people like to spend part of their time growing things as a leisure
pursuit.
In times of crisis, like war or recession, growing food in cities has always been
essential to urban people. Schrebergaerten were started In Germany after the
First World War, when city people had the choice to go hungry or to grow some
of their own food. In the Second World War in Britain, the Dig for Victory
campaign brought much urban land into cultivation. Today we face a new kind
of crisis: chronically high levels of unemployment are a growing concern in
some cities, forcing many people to adapt or adopt new survival strategies,
including spending some of their time on growing food.
Urban agriculture therefore contributes to the sustainability of cities in various
ways socially, economically and environmentally.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
47
2.2 Farming in cities and ecology: constraints and opportunities
In this section, we concentrate on the major environmental constraints associated
with urban agriculture and its potential role to help improve the ecological
performance of cities. One of the major constraints is obvious: the lack of space
in cities for growing food. However, there are several advantages and
opportunities to improve the environment and ecology of cities. Urban farming
can help to create an improved microclimate and to conserve soils, to minimise
waste in cities and to improve nutrient recycling, and to improve water
management, biodiversity, the O
2 - CO2 balance, and the environmental
awareness of city inhabitants.
2.2.i Space for growing food
In the western world since the Second World War, few provisions have been
made for space for urban food production. The economic boom of the last 40
years has led to the assumption that city people will buy food, not grow it
themselves. But at a time when work sharing is widely seen as essential for
assuring a dignified existence for large numbers of people, additional
opportunities for people to create livelihoods for themselves are essential. Urban
food growing is certainly one of the options.
In cities that have experienced industrial decline, provision of derelict land for
food growing is certainly a planning policy option. In American cities such as
Detroit and New York, thousands of acres of land have been given over to
unemployed workers for food growing. In Britain, city-farm projects have been
established on areas of derelict land in some 20 cities. In Germany, land in
former coal-mining areas in cities such as Essen is being set aside for urban
agriculture projects.
There has been concern about the suitability of contaminated urban land for food
growing, and it has been suggested that it is prudent not to grow crops less than
ten metres from busy roads, particularly in countries where lead fuel is still in
use. Generally, land polluted by heavy metals, such as cadmium and lead,
requires special precautions. However, research in the USA and the UK has
shown that these problems can be tackled in a number of ways: firstly,
maintaining a high pH with additions of plenty of lime, and high organic matter
levels through additions of compost or manure helps to immobilise heavy metals
in the soil.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
48
The Chinese are famous for their highly intensive urban cropping systems and, to
this day, many of their large cities are largely self-sufficient in food produced on
adjacent land areas administered by them. Beijing, now a city of over 10 million
people, still administers its own adjacent farmland extending to an area the size
of Belgium. In Shanghai, only 20% of the land administered by the city
authorities is actually built on; 80% of the land, mainly in the urban perimeter, is
used for crop growing, making the city region self-sufficient in vegetables and
producing much of the rice, pork, chicken, duck and carp. With their unique
system of governance, Chinese cities administer vast adjacent areas of farmland
and aim to be self-sufficient in food from this. Is this model of urban-rural
linkages relevant to cities elsewhere in the world?
In many cities there are areas which are less suitable for housing, and often offer
excellent positions to produce food. Dar es Salaam in Tanzania provides a good
example. The city has a spacious urban pattern and many areas near the rivers are
not suitable for housing, because of regular flooding in the rainy season. These
areas are well suited, and well used, for growing food.
2.2.ii Microclimate improvement
If appropriately planned and integrated into urban design, urban agriculture can
contribute to the comfort of citizens. Green spaces around apartment blocks and
houses, as well as neglected spaces in the city, help to improve the physical
climate because vegetation can:
help increase humidity, lower temperatures and introduce more pleasant odours
to the city;
capture dust and gases from polluted air through deposition and capture by the
foliage of plants and trees, and soils; and
help break wind and intercept solar radiation, creating shadow and protected
places.
One good example is the city of Cairo, where air pollution has risen to dangerous
levels. For this reason, urban green areas now have a high political priority. The
Tree Lovers' Association aims to expand the green areas in Maeâdi. The
Association takes charge of planting and caring for the trees in the location of
the old canal in this district of Cairo. Another example is Sofia, the capital of
Bulgaria, where growing of food around housing compounds, along riverbanks
and in other vacant spaces where public green spaces have been neglected by the
municipality has led to an increase in vegetation and an improved microclimate.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
49
2.2.iii Conservation of urban soils
Creating fertile soil is not usually a problem in cities because, by definition, they
are places where fertility accumulates in great abundance. There is little need to
use chemical fertilisers, although in some cities like London, urban agriculture
can also be highly chemical intensive. A great variety of materials are available
that can be composted and incorporated into garden soil crop residues, kitchen
wastes, old newspapers, the leaves of city trees and even human faeces. The
Chinese have long used a system of meticulously recycling and composting
human and animal wastes, thus maintaining the fertility of their farmland by the
most appropriate means. Whilst this system has been weakened in recent years,
the Chinese are reluctant to abandon it altogether. Instead, they are exploring
ways of upgrading sewage-recycling technology.
Urban farmers have always utilised the great variety of fertile materials they
have found in cities. The best-known example is the vegetable growers in Paris
who, until the end of the First World War, were famous for the abundance of
their crops. They used to heap up to 0.3 m of horse manure on top of their
vegetable beds every year, and used many different methods to control soil and
air temperature. They were able to grow between three and six crops of fruit and
vegetables a year, making a good living on no more than 0.75 ha. In Paris of a
century ago, 100,000 tonnes of high-value out-of-season crops were grown on
1400 ha, around one-sixth of the surface area of the city, using about one million
tonnes of horse manure. The crops were so abundant that they were even
exported as far away as London. However, the introduction of motor-powered
transport ended the supply of horse manure to the marais. In addition, more and
more crops were brought in by train from the south of France.
Provided that organic amendments are not contaminated, the use of abundant
fertile materials and the growing of trees, crops and other greenery in cities will
help keep urban soils fertile. Natural soils are rich in life; there are numerous
“recycling” systems at work in the top layers of the earth. Through urban
agriculture, soil systems can be kept in balance. Examples of good practice can
be found in Accra (Ghana) and Dakar (Senegal) where urban agricultural
activities have shown a positive effect on stabilising the soil against water and
wind erosion “Filao” plantation both hinders quick movement of sand through
wind erosion and produces compost.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
50
2.2.iv Waste and nutrient recycling
A key factor in urban ecology is the process of waste management and nutrient
recycling. The metabolism of many traditional cities was circular, whereas that
of most “modern” cities is linear: Resources are funnelled through the urban
system without much concern about their origin and about the destination of
wastes; inputs and outputs are treated as largely unrelated. Contemporary urban
sewage systems are a case in point. They have the function of separating people
from their wastes. Sewage, treated or not treated, is usually discharged into rivers
and coastal waters downstream from population centres, and its inherent fertility
is lost to the world’s farmland. Today, coastal waters everywhere are polluted
both by sewage and by toxic effluents, as well as the contaminated runoff arising
from use of fertilisers and pesticides applied to farmland growing food for the
cities.
Justus Liebig, a pioneer of modern chemistry in the 19th century, took a close
interest in the history of urban food production and studied the environmental
history of ancient Rome. For two centuries, much of Rome’s grain supply was
imported from North Africa, with a dramatic impact on the area's soil fertility.
The minerals contained in the grain nitrogen, potash, phosphate, magnesium
and calcium were removed from the farmland and, via Rome's Cloaca Maxima,
flushed into the Mediterranean, never to be returned to the land of North Africa.
Despite having studied Rome’s mistakes, most modern cities have repeated this
pattern. In a letter to Sir Robert Peel, Prime Minister of the UK in 1840, Justus
Liebig wrote:
The cause of the exhaustion of the soil is sought in the customs and habits of the
towns people, i.e., in the construction of water closets, which do not admit of a
collection and preservation of the liquid and solid excrement. They do not return
in Britain to the fields, but are carried by the rivers into the sea. The equilibrium
in the fertility of the soil is destroyed by this incessant removal of phosphates
and can only be restored by an equivalent supply. ... If it was possible to bring
back to the fields of Scotland and England all those phosphates which have been
carried to the sea in the last 50 years, the crops would increase to double the
quantity of former years.
When London's authorities decided to construct a sewage disposal rather than a
recycling system, Liebig decided that it was necessary to find ways to replace the
fertility removed by cities from farmland by artificial means. He set about
developing artificial fertilisers to keep the land feeding cities productive. Today,
the use of artificial fertilisers is the norm all over the world. The systemic
Thematic Paper 2
Urban Agriculture and Sustainable Cities
51
problems inherent in this are well documented. For instance, coastal waters
everywhere now contain both urban sewage as well as the runoff of mineral
fertiliser applied to the farmland feeding cities. This is both a massive waste of
nutrients as well as a major cause of eutrophication of coastal waters.
The linear metabolic system of most contemporary cities is unsustainable. It is
profoundly different from the metabolism of nature's own ecosystems, which
could be likened to a large circle: every output by an organism is also an input,
which renews and sustains the whole living environment. Urban planners and
educators should make a point of studying the ecology of natural systems. On a
predominantly urban planet, cities need to adopt circular metabolic systems to
assure their own sustainability and the long-term viability of the environments
on which they depend. Urban outputs will need to be regarded as crucial inputs
into urban production systems, with routine recycling and composting of organic
materials for re-use on local farmland. Very up-to-date methods for recycling
urban wastes into nutrients for urban and urban-fringe farming and gardening are
now available to us.
Efforts for waste reduction require three different approaches: reducing the
amount of waste, re-using what can be re-used, and recycling the remainder.
Urban agriculture can play an important role in all three approaches. It can help
to reduce the need for food packaging. Much of the packaging of food is
cosmetic or its purpose is to get it safe and undamaged across long distances to
its destination. Food-growing sites can be the repositories of much re-usable
household waste. Old carpets, bits of polythene, wood, glass, rubber tyres and
clothing may be used in production activities. Food growing also makes use of
recycled materials. Organic waste accounts for 20% of household waste and,
when composted, it can produce an excellent fertiliser.
The relation between urban agriculture and waste management is most
pronounced in the use of organic wastes. Food production by livestock eating
food remainders is a tradition in many Asian and African countries, but also in
northwestern Europe. Observation of daily life in Hubli-Dharwad, India shows
that keeping livestock in urban centres has some advantages, because there are
sources of fodder, such as waste materials from hotels, markets and homes, and
easily accessible markets for produce, particularly for fresh milk from urban
dairies. The cycle of nutrients through the use of urban waste within Hubli-
Dharwad (and in many other regions of India) is also a good example of urban-
rural linkages. Such linkages include the sale of dung from cows, and the sale of
Thematic Paper 2
Urban Agriculture and Sustainable Cities
52
market waste to rural farmers. There are a number of advantages for the
Municipal Corporation arising from these informal waste markets. These include
the removal of much wet organic waste from the streets and bins, the revenue
from selling waste, creation of more space at the dumpsites, and the use of dung
as a cooking fuel reducing the demand for fuelwood and liquid petroleum gas
(LPG). Although keeping animals in an urban area does have disadvantages, it
can serve a useful role in solid-waste management.
Farmers in Accra (Ghana) are also well engaged in solid-waste recycling (see
case study). The waste generated from crop farming (dried vegetables) is
recycled and used as mulch and compost to enrich the soil. Waste generated from
livestock farming, such as cow dung and chicken droppings, is the main source
of fertiliser for vegetable farming. Livestock is fed on leftover food from
restaurants or “chop bars”. The skeleton waste from livestock is collected,
cremated and processed into powder for feed and paints. In this way, re-use of
wastes helps contribute to a well-functioning agricultural system.
2.2.v Water management
Agricultural activities in cities can indirectly improve urban water management,
because green spaces with permeable land surfaces allow rainwater and runoff to
drain through the soil. This is important because the growing areas of hard-
covered surfaces in cities (e.g. streets, roofs and car parks) leads to increased
volumes of runoff during storms, with risks of floods and landslides. The need
for costly storm water sewers and drainage can be minimised when enough green
space is available. To invest in urban agriculture, therefore, is just as necessary
as developing a network of channels and drains.
The direct use of recovered wastewater for food production in cities can also
improve the efficiency of water use especially important in countries with
limited water resources. Given the existing nature of most sewage systems,
which combine wastewater with numerous pollutants, wastewater re-use requires
significant investment in separation or treatment, and improved organisational
capacity. Unfortunately, investments in water infrastructure and conservation
measures are often not made because of unclear land rights. The case of Dakar,
Senegal, however, demonstrates how a wastewater recycling system can be set
up. There are two stations for the filtering of used water, combining collection
points of solid waste to make compost. The recovered water is used to irrigate
land. Recycling of wastewater is not without its problems though. In Cairo,
environmental contamination of soils arising from use of untreated sewage water
for irrigation is a serious problem.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
53
Lack of water is a major problem to many, if not all, developing countries. For
example, Hubli-Dharwad struggles as a result of a declining number of lakes and
water tanks over the last 20 years, as the urban settlement has grown and tanks
have been filled in and built over. Farmers in horticulture have responded to the
shortage of water through the use of sewage water for the irrigation of vegetable
crops. Wealthier farmers also often sink bore-wells to establish more secure
water supplies, though this is inevitably affecting the water table of the area and
the availability of water resources for other purposes.
Urban agriculture can also pose serious risks to water resources, for example, by
leading to increased pesticide levels in groundwater. To reduce risks of
pollution, in Cagayan de Oro in the Philippines (see case study), farmers have
begun to use organic fertilisers. The local government launched an Integrated
Pest Management (IPM) programme aimed at training and educating farmers.
Thus far, however, only 27% of the participants have decreased the level of
pesticide application.
2.2.vi Biodiversity
Urban agriculture can have a positive effect on increasing biodiversity. The
urban environment is often already richer in flora and fauna than rural farmland;
beehives in cities in some developed countries like the United Kingdom or
Germany actually produce more honey than those in the countryside. This is
because cities are often home to more trees and flowers than intensively-farmed
agricultural land with large fields, limited crop diversity and little uncultivated
area. In Cagayan de Oro (Philippines), a “Greening” project that constitutes part
of the City Agricultural Office’s (CAO) urban agriculture programme aims to
increase the production of fruit and forest tree seedlings, specifically to improve
the biodiversity in the city.
2.2.vii Global warming and atmospheric pollution
Urban agriculture can help contribute to reducing the net discharge of CO2, one
of the gases contributing to global warming, from activities in cities. If more
cities were to produce food within their boundaries, bringing places of
production and markets closer to each other, the transport of products can be
reduced; this would contribute to reducing emissions of CO2 and other polluting
gases. Urban agriculture is also a means for reducing the net discharge of CO2,
because plants and trees capture CO2. The captive capacity is at its highest in the
growth phase of vegetation. Through agricultural activities in cities, urban
ecosystems are kept continuously in their “primary production phase”; which
Thematic Paper 2
Urban Agriculture and Sustainable Cities
54
means that much more CO2 per surface area is captured than in natural systems
like tropical forests. In cities, however, much of the carbon stored in vegetation
is likely to be quickly released through decomposition of organic matter and
there may be little lasting benefit.
2.2.viii Environmental awareness
Urban agriculture can also change the perception of people in cities regarding
food. The direct experience of growing food is largely absent in urban life in the
“developed” countries; people harvest at the supermarket and most people have
come to expect food to be packaged and even pre-cooked. As city people, they
are hardly aware of the impacts of food consumption on the fertility of farmland
supplying them, often from distant places. Too many people eat unhealthy “junk”
food.
The recognition of urban agriculture among citizens is related to the size of
production activities in this sector within the city (Barrs 1997). People will often
have more interest in the food-growing process and the biophysical processes
involved when crops are locally cultivated. Their knowledge can be expanded
through agricultural and environmental training and education. This could
increase the influence citizens have over the way food is produced. People will
understand what sort of inputs are used in the farming process and they can
quickly respond to any harmful environmental practices. Urban agriculture can
re-educate us about the ecological base of food, and the links of food production
to natural food chains, as well.
Skills associated with urban food growing and related enterprises are not
necessarily simple or primitive. Organic growing techniques, for example, can
make use of the results of innovative scientific research. If any of the produce is
sold processed or not then the people involved will develop a whole range of
sales and marketing skills of varying degrees of sophistication. And food
growing is adaptable to nearly everybody’s circumstances; from a window box
to several acres, from conventional gardening to full-scale organic, from a few
herbs and a tomato plant to bees, chickens and goats.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
55
A good example of growing environmental awareness among citizens can be
found in London, where local councils promote urban food growing through
Local Agenda 21 strategies in almost all boroughs. There are various community
projects aiming to improve the environmental performance of urban agriculture
(see Box 1).
BOX 1: Becontree Organic Growers, London
This is a co-partnership of local people formed to revitalise an overgrown site in East London
(see case study). The site is located next to allotments, many of which have fallen into disuse.
Permaculture techniques will be used and the group hopes to keep much of the wildlife which
has established itself on the derelict site by not removing all the nettles and weeds. It also
hopes to boost honey production by doubling the three hives they already have. They will re-
use and recycle resources, save energy by recycling water and using solar heating, monitor the
local environment, conserve nature, use “green” buildings, work with students and local
schoolchildren, and develop the local economy, particularly by using Local Employment
Trading System (LETS) schemes. LETS is a scheme whereby people exchange goods or
services instead of using money.
2.3 Prospects for urban farming: policies and approaches for the 21st
Century
Urban farming is clearly alive and well in many countries. New marketing
initiatives and approaches to promote participation in urban environmental
management auger well for the future of the sector.
2.3.i Marketing initiatives
New ways of marketing urban produce are helping to advance the case for urban
and urban-fringe agriculture. Clever marketing, as well as the desire of
consumers to know where their food comes from, has a lot to do with the
surprising growth of farmers’ markets in the USA. Some 2000 new farmers’
markets have been set up in US cities in recent years, often run by the growers
themselves on the urban fringes of cities such as New York, Chicago, Detroit,
Washington and San Francisco.
Nobody would suggest that all city people will want to grow food themselves.
But urban agriculture also has the potential for bringing growers and consumers
closer together. Vegetable box schemes, providing customers with a selection of
vegetables in-season from locals farms, enjoy growing popularity.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
56
Another scheme to bring together growers and local customers in a mutually
beneficial arrangement is community-supported agriculture. This is becoming
popular in both Europe and the USA: in such schemes, participants purchase a
share in any produce in advance. Participants acquire the right to visit a farm and
to help in the cultivation and harvesting of crops, if they wish. An additional
benefit is that participants may also get a say in what crops are grown. Such
schemes have proved that crops produced for local consumption can be very
lucrative and that mutual arrangements between growers and consumers can also
be environmentally and culturally beneficial.
2.4 Promoting integration and participation: challenges to urban
planners and policy- makers
Urban agriculture can reduce the “ecological footprint” of cities when
environmental goals are combined into an overall urban policy (Van Delft &
McDonald 1998). Such overall urban policies would include environmental
awareness-raising and wide public participation in urban development. In this
section, examples are given of such integrated policies which provide examples
of good practice and challenges to planners and policy-makers around the world.
Local authorities and specialists in Vancouver (Canada) have promoted
progressive programmes on urban agriculture utilising wastewater/sewage
streams from buildings (Barrs 1997). The wastewater stream from residential
buildings represents a potential resource (water and nutrients) that can be used
for urban food production. The “Solar Aquatic” sewage-treatment system
introduced in Vancouver duplicates the natural purifying processes of meadows
and wetlands, utilising bacteria, algae, plants and aquatic animals to produce
treated wastewater ready for use to irrigate crops. The process is accelerated
using controlled greenhouse conditions, reducing the amount of costly urban
space required. Another approach adopted in Vancouver is to reduce the
production of organic waste at source. This will be achieved by providing
consistent composting messages across the region, and providing training in
composting techniques, educational resources and support to member
municipalities for the delivery of education and promotion programmes. The aim
is to create greater awareness in Vancouver about the potential of organic waste
for city farming.
The town of Kolding, Denmark, provides another example. A group of apartment
buildings used to surround a piece of wasteland, which was occupied by old cars
Thematic Paper 2
Urban Agriculture and Sustainable Cities
57
and other pieces of waste. The area was considered to be unpleasant and unsafe.
To regenerate the buildings and the surrounding space, a clever system has been
developed. Nowadays, the wastewater from the buildings is being collected,
together with the rainwater, and filtered through a cascade system. The system
culminates in a glass pyramid that has been built in the middle of the
neighbourhood. At the bottom of the pyramid, the final nutrients from the
wastewater are used to breed fish. Other parts of the pyramid serve as
greenhouse areas for plants and vegetables. Some people have now found a
green job in the pyramid, and are working in the greenhouse. The area has
become a very nice place for the inhabitants to meet and relax and also for
children to play, especially because of the visual and acoustic effects of the
flowing water.
Other examples of urban agriculture find their origin in community spirit and
existing strong social cohesion. This co-operative spirit can be found in many
developing countries. An example is city farming in Albania (Chisholm 1996).
The end of communist rule was accompanied by the destruction of many
irrigation systems, greenhouses and other infrastructure. On account of poor
living conditions, people were forced to take their own initiatives in adapting
their survival strategies. Agriculture for self-consumption and trade are
fundamental sources for food security. Many people live in apartment buildings
and have no access to land, so they grow tomatoes in old bowls on their
balconies. Several people have even managed to create a flourishing garden on
rooftop spaces. Onions, garlic, tomatoes and grapes have transformed ugly
buildings into nicer places. People made use of their local environment, fully
exploiting their own limited devices. There are even persons who raise pigs in
their houses. Despite bad odours and noise, neighbours don’t complain because
they understand that people need to survive. Almost every small space of land is
used productively. Urban agriculture in a developing country like Albania shows
that, despite the limited resources available, opportunities exist to make human
settlements sustainable. This is a lesson to be learned in industrial countries.
2.5 Implications for urban policies and programmes
Traditionally, agricultural policies whether oriented towards export production
or local food production have focused on maximising short-term profits rather
than on long-term environmental management of local resources. Many urban
managers and planners think of their city more in terms of housing, transport,
Thematic Paper 2
Urban Agriculture and Sustainable Cities
58
commercial services and industry, rather than in terms of agriculture, which
generates relatively low yields (Girardet 1992).
Generally, urban agriculture suffers from a combination of political restraints,
that include (Van den Berg & De Zeeuw 1998):
restrictive urban policy, laws and regulations (due to the mainly illegal status of
urban agriculture);
uncertainty about property rights of land;
lack of supportive services;
unfeasible implementation of environmental technologies; and
lack of organisation and representation of urban farmers.
As a principal issue, it is proposed that urban farmers and consumers should
receive more information and training on environmental risks (e.g. wastewater
treatment and composting techniques) because more urban people will be
engaged in growing food and more cities are beginning to try to use their
agricultural waste to curb pollution and optimise freshwater usage (Reijntjes et
al. 1992).
There is a need to stimulate dissemination of good practices in urban agriculture
to farmers and consumers. In this respect, Barrs (1997) envisions an important
role of policy-makers. They are, or should be, able to support farmers and
consumers to build up knowledge about the opportunities of urban agriculture to
protect city ecology. The key issue is how opportunities of urban agriculture can
be translated into sustainable initiatives. National governments need to reduce
the environmental risks of (urban) agriculture by adopting pesticide reduction
targets, and promoting biological pesticides and fertilisers. Finally, governments
must also provide funds for information and grant-aid schemes to assist
conversion to less chemically-intensive systems. At first sight, small-scale
farmers in developing countries need appropriate strategies and production
techniques that lead to higher yields. However, many farmers recognise that they
cannot continue to increase yields, because more resource-intensive production
methods inevitably lead to the depletion of available natural resources.
To support farmers in making their production systems more productive and
sustainable, development workers in their turn need suitable instruments for
co-operation with these farmers. The question is how development workers can
support farmers in urban agriculture to protect or improve city ecology.
Reinforcing farmers’ capacity to develop and manage technology is of vital
Thematic Paper 2
Urban Agriculture and Sustainable Cities
59
importance for the actual creation of environmentally-friendly ways of farming.
There may be many steps required to reach that objective.
A fundamental step in order to set the right conditions for city farming is to
develop an urban agriculture plan and policy, recognising the interrelated nature
of food, agriculture, health and ecology by forming a municipal working group
that can deal with food issues from a total system perspective. This could
involve, among others: the health department, planning department, engineering,
local economic development, water management and waste management.
Following this, the urban agriculture plan should be incorporated into the land-
use planning system. This implies that urban agricultural activities are
recognised as major components of green zoning systems, for which a dedicated
policy must be formulated, developed and implemented.
It is hard to regulate good practice, but labelling food to show how and where it
is produced at least allows people to make informed food choices and to support
sustainable approaches to production. Programmes such as the provincial “BUY
BC” campaign in British Columbia, Canada, encourage people to purchase
locally-grown food and other products. In British Columbia, there are strict
guidelines for production, operation and farm management. Only those farms
certified by an approved certification agency (in this region, British Columbia
Association of Regenerative Agriculture, BCARA) are allowed to market and
label their products as “organic” and attach the “BC Certified Organic” label.
As urban agriculture becomes more sophisticated, lending institutions will
become aware of the financial possibilities involved. However, this is not yet
generally recognised. Difficulties in obtaining sufficient capital and credit to
start an urban food-production business hamper all sorts of initiatives. However,
government bodies can offer favourable conditions to city farmers in less
developed countries regarding urban agriculture, through for instance the
following policy interventions (Barrs 1997):
start-up grants/loans for small urban agricultural businesses;
subsidisation of inputs such as municipal compost for a limited time to stimulate
projects.
If the potential of urban agriculture is going to be realised, much more has to be
done than what is happening in many cities at present. What is needed is a policy
for the city that focuses on encouraging the productivity of open urban space,
integrating the various components necessary to make urban agriculture healthy
and sustainable, and combating bad practices where necessary. Urban agriculture
Thematic Paper 2
Urban Agriculture and Sustainable Cities
60
can have a positive effect on the availability of healthy, nutritionally balanced
and culturally appropriate food, in particular for low-income groups of the urban
population. Since food is a basic requirement for a healthy life, this should be
seen as an absolute priority in urban policies. Local food production may never
replace the need of a decent level of income, but it can substantially contribute to
adequate and culturally appropriate sources of human nutrition.
3. Conclusion
All in all, prospects for urban farming are good in many parts of the world.
However, it is crucial that planners start recognising the importance of urban
farming in the rich mix of activities that characterise modern cities. As the world
urbanises, greater local food self-reliance, using nutrients accumulating in our
cities, must be regarded as an important aspect of sustainable urban
development. Together with initiatives on energy efficiency, high resource
productivity and policies for containing sprawl, urban agriculture has an
important contribution to make towards shaping the cities of the future.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
61
References
Aalbers H, Balkema A & Heijndermans E. 1996. Workshop on Sustainable
Municipal Waste Water Treatment Systems. ETC Netherlands in
cooperation with WASTE, Leusden, 12-14 November 1996.
Armar-Klemesu M & Maxwell D. 1999. Urban agriculture: a case study of
Accra. Legon: University of Ghana.
Barrs Robert. 1997. Sustainable urban food production in the City of Vancouver:
an analytical and strategy framework for planners and decision-makers.
Vancouver, BC: City Farmer, Canada’s Office of Urban Agriculture.
Berg Leo van den & Zeeuw Henk de. 1998. Urbane landbouw: vele vormen. In:
Albert Heringa et al. Uitdagingen van het stedelijk milieu voor ons werk.
Den Haag: Stichting Nederlandse Vrijwilligers, pp 18-22.
Bowyer-Bower TAS & Tengbeh G. 1995. The environmental implications of
(illegal) urban agriculture in Harare, Zimbabwe. Working Paper 4.
Presented at ODA Workshop on the Environmental, Social and Economic
Impacts of (Illegal) Urban Agriculture in Harare, Zimbabwe.
Carley M & Spapens P. 1998. Sharing the world: sustainable living & global
equity in the 21st Century. London: Earthscan Publications.
Chambers Robert. 1990. Microenvironments unobserved. IIED Gatekeeper
Series 22. London: Sustainable Agriculture Programme.
Chisholm A. 1996. City farming in Albania. Vancouver: City Farmer.
Deelstra T & Nijwening S. 1997. Environmental sustainability of cities:
management issues and experiences in developing countries. Delft / Den
Haag: The International Institute for the Urban Environment & SNV.
Delft Yvonne van & McDonald Frank (eds). 1998. The ecological footprint of
cities. Delft: The International Institute for the Urban Environment.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
62
Egziabher AG, Lee-Smith D, Maxwell DG, Memon PA, Mougeot LJA, Sawio C.
1994. Cities feeding people: an examination of urban agriculture in East
Africa. Ottawa: IDRC.
FAO. 1999. Spotlight urban food marketing. FAO Newsletter. Rome: FAO.
Foeken D & Mboganie-Mwangi A. 1999. Urban agriculture: the case of Nairobi.
Leiden: African Studies Centre / Nairobi: Unit of Applied Human
Nutrition.
Fudge C, Smook R & Sougareva N. 1996. European sustainable cities. European
Commission DG XI. Report by the Expert Group on the Urban
Environment. Luxembourg: Office for Official Publications of the
European Communities.
Garnett Tara. 1996. Growing food in cities: a report to highlight and promote the
benefits of urban agriculture in the UK. London: National Food Alliance
& SAFE Alliance.
Garnett Tara. 2000. Urban agriculture in London: rethinking our food economy.
Gertel Jörg & Samir Said. 1999. Urban agriculture in Cairo: First draft. GTZ
Project No. 90.2039.7 - 011.00. Leipzig: University of Leipzig. Cairo:
Roxy Research Center.
Girardet Herbert. 1992. The Gaia Atlas of cities: new directions for sustainable
urban living. London: Gaia Books Ltd.
Jacobi P, Amend J & Kiango S. 2000. Urban Agriculture in Dar es Salaam:
providing an indispensable part of the diet.
Jacobs Jane. 1969. The economy of cities. Chapter 1. New York: Random
House, pp. 3-48.
Khouri N, Kalbermatten JM & Bartone CR. 1994. Reuse of wastewater in
agriculture: a guide for planners. Water and Sanitation Report 6.
UNDP-World Bank Water and Sanitation Program. Washington DC: The
World Bank.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
63
Konstanczak K, Rudaat H & Sabel-Koschella U. 1998. Nutzung organischer
Abfälle urbaner Zentren. Überregionales Sektorvorhaben. Bonn: GFA-
Umwelt / GTZ.
Mara D & Cairncross S. 1989. Guidelines for the safe use of wastewater and
excreta in agriculture and aquaculture: measures for public health
protection. Geneva: WHO & UN Environment Programme.
Maxwell Daniel G. 1995. Alternative food security strategy: a household
analysis of urban agriculture in Kampala. World Development 23 (10):
1669-1681.
Mbaye, Alain & Moustier Paule. 2000. Market-oriented agricultural production
in Dakar.
Midmore David. 1995. Social, economic and environmental constraints and
opportunities in peri-urban vegetable production systems and related
technological interventions. In: DSE (ed.), Vegetable production in
peri-urban areas in the tropics and subtropics: food, income and quality of
life (Feldafing: DSE), pp 64-87.
Mougeot Luc JA. 1998. Farming inside and around cities. Ottawa: IDRC.
Moustier Paule. 1996. Organization in the Brazzaville vegetable market.
Doctoral thesis. London: University of London, Wye College.
Nunan Fiona. 1999. Urban agriculture in Hubli-Dharwad, India. Birmingham:
University of Birmingham.
Olson Michael. 1994. MetroFarm: the guide to growing for big profit on a small
parcel of land. Santa Cruz: TS Books.
Pinstrup-Andersen Per, Pandya-Lorch R, Nygaard D & Rose B. 1995. A 2020
vision for food, agriculture, and the environment: the vision, challenge,
and recommended action. Washington DC: International Food Policy
Research Institute.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
64
Potutan GE, Schnitzler WH, Arnado JM, Janubas LG & Holmer RJ. 2000. Urban
Agriculture in Cagayan de Oro (Philippines): a favourable response of city
government and NGOs.
Reijntjes C, Haverkort B & Waters-Bayer A. 1992. Farming for the future: an
introduction to low-external-input and sustainable agriculture. London:
Macmillan Education / ETC / ILEIA.
Ruddle Kenneth & Zhong Gongfu. 1988. Integrated agriculture-aquaculture in
South China: the dike-pond system of the Zhujiang Delta. Cambridge:
University Press.
SAFE Alliance. 1994. The Food Miles Report: the dangers of long distance food
transport. London: SAFE Alliance.
Schilter Christine & Kusiaku Y-K. 1999. Urban agriculture in Lomé (Togo).
Lomé.
Scientific American. 1993. Special issue on ancient cities.
Smit J, Ratta A & Bernstein J. 1996. Urban agriculture: an opportunity for
environmentally sustainable development in sub-Saharan Africa. Building
Blocks for AFRICA 2025 Paper 11. Post-UNCED Series. Washington
DC: The World Bank.
Smit Jac, Ratta Annu & Nasr Joe. 1996. Urban agriculture: food, jobs and
sustainable cities. Publication Series for Habitat II. Volume 1. New York:
United Nations Development Program (UNDP).
Todaro Michael P. 1994. Economic development. 5
th Edition. New York:
Longman.
United Nations. 1995. Declaration and programme of action of the World
Summit for Social Development, Copenhagen, March 1995, par 46.
United Nations. 1995. World urbanisation prospects: the 1994 revision. New
York: Population Division.
United Nations Population Fund. 1996. World population report 1996. New
York: UNFP.
Thematic Paper 2
Urban Agriculture and Sustainable Cities
65
United Nations Population Fund. 1998. State of the world population report.
New York: UNFP.
Wackernagel Mathis & Rees William. 1996. Our ecological footprint: reducing
human impact on the earth. Gabriola Island, BC / Philadelphia: New
Society Publishers.
___. 1995. Global trends in food production, nutrition and natural resources:
back-grounder. Workshop on Policy Implications of Global Trends in
Food Production, Nutrition and Natural Resources, International
Agriculture Centre (IAC), Wageningen, November 1995.
___. 1998. Options for closed water systems: sustainable water management.
Preprints, International WIMEK Congress, Wageningen, 11-13 March
1998. Wageningen: Wageningen Agricultural University.
... Há uma forte relação entre os sistemas agroalimentares em vigência, as crises ambientais e os modos de vida nas cidades, pois o modo de consumo nas cidades alimenta uma produção agroalimentar baseada nas monoculturas, nos pastos e no uso intensivo de agrotóxicos, que têm graves consequências ambientais e sociais. Além disso, os hábitos urbanos, também são marcados pelo desperdício de água e de alimentos, da produção demasiada de lixo e da drenagem generalizada dos recursos naturais (Deelstra, Girardet, 2000). ...
... Por isso determina-se uma mudança urgente no modelo de desenvolvimento urbano e agrícola. A Agricultura Urbana e Periurbana (AUP), portanto, além de ser uma atividade de geração de renda, promove uma maior aproximação entre consumo e produção, diminuindo as emissões de CO2, e aproximando as pessoas do processo de produção alimentar promovendo maior consciência alimentar e ambiental (Deelstra, Girardet, 2000;Nugent, 2000, Mougeot, 2005. Soma-se a isso a contribuição da agricultura urbana para o estabelecimento de áreas verdes, o que promove a absorção das águas das chuvas e favorece o microclima, colaborando com a qualidade do ar e a diminuição das ilhas de calor (Deelstra, Girardet, 2000). ...
... A Agricultura Urbana e Periurbana (AUP), portanto, além de ser uma atividade de geração de renda, promove uma maior aproximação entre consumo e produção, diminuindo as emissões de CO2, e aproximando as pessoas do processo de produção alimentar promovendo maior consciência alimentar e ambiental (Deelstra, Girardet, 2000;Nugent, 2000, Mougeot, 2005. Soma-se a isso a contribuição da agricultura urbana para o estabelecimento de áreas verdes, o que promove a absorção das águas das chuvas e favorece o microclima, colaborando com a qualidade do ar e a diminuição das ilhas de calor (Deelstra, Girardet, 2000). ...
Conference Paper
Full-text available
A Agricultura Urbana e Periurbana (AUP) agro-ecológica tem sido difundida por agricultores e movimentos sociais como uma solução pública de múltiplas dimensões para o desenvolvimento local ao proporcionar resultados para a segurança alimentar, geração de renda, fortalecimento dos laços comunitários e sustentabilidade ambiental. Todavia, essa atividade ainda não é plenamente reconhecida por alguns setores da sociedade civil e do governo e enfrenta diversos obstáculos para se consolidar, como falta de infra-estrutura, recursos públicos e regulamentações. O artigo trata de uma análise dos processos de legitimação da AUP nas diversas arenas da sociedade civil e do governo local e os seus resultados. Três tipos de ações coletivas organizadas em rede são analisadas: (I) atividades de agricultura urbana como expressão ativista, através da rede Hortelões Urbanos; (II) atividades de conscientização a respeito da agroecologia urbana por meio da rede MUDA-SP; ações de pressão e negociação política com o poder legislativo e executivo do município de São Paulo através da Plataforma de Apoio à Agricultura Orgânica da Cidade de São Paulo.
... Honey bees are one of the most common insect pollinators worldwide, extensively used in agricultural and urban settings for their generalist pollination ability and honey production (Aizen et al., 2009;Deelstra & Girardet, 2000;Klein et al., 2007). Large global declines in colony numbers (Dainat et al., 2012;Ellis et al., 2010;Seitz et al., 2015;vanEngelsdorp et al., 2010) have led to growing interest in improving hive management practices. ...
Article
Monitoring biodiversity is a growing and pressing challenge, particularly as climate change threatens species with extinction and leads to widespread shifts in plant distribution and phenology. Tracking changes via ground vegetation surveys is costly and time‐consuming, hence monitoring of complex and heterogenous communities remains an ongoing challenge. Molecular DNA methods are rapidly being developed to provide fast and reproducible results for environmental monitoring, including diet and ecosystem assessments. Here, we used DNA metabarcoding of pollen foraged by European honey bees (Apis mellifera) to investigate their floral resource use in an urban reserve. We collected three different pollen samples from hives: individual bees, raw honey and pollen traps, and identified plants using two metabarcoding markers (ITS2 and trnL). We then compared the results to a ground vegetation survey of surrounding flowering taxa. Pollen DNA metabarcoding detected 74 taxa (48.6% identified to species) across all pollen sources, compared to 44 taxa recorded by the survey (93% identified to species). Within the metabarcoding results, we identified 25% of the genera and 9% of the species found during the survey, with three of the top 10 flowering genera represented. While honey was the most taxon‐rich pollen source (mean = 8.5, SD = 3.5), followed by honey bees (mean = 5.8, SD = 6.1) and pollen traps (mean = 4.2, SD = 1.7), combining the results of six individual bees could detect similar taxa numbers to honey, while 20 bees were required to detect as many taxa as the survey. We demonstrate how DNA metabarcoding of the pollen foraged by honey bees can detect more flowering taxa than traditional survey methods, and how different pollen sources and genetic markers affect the level of detection of plant taxa. The foraging choices of honey bees matched few species detected by the vegetation survey, therefore pollen metabarcoding is recommended as a complementary approach to ground surveys. Rigorous validation and stringent filtering of metabarcoding results were also required to exclude potential false positives. Altogether, this molecular approach can be used to augment vegetation surveys, while tracking the floral resources used by bees. Monitoring biodiversity is a growing and pressing challenge, particularly as climate change threatens species with extinction and leads to widespread shifts in plant distribution and phenology. Tracking changes via ground vegetation surveys is costly and time‐consuming, hence monitoring of complex and heterogenous communities remains an ongoing challenge. Molecular DNA methods are rapidly being developed to provide fast and reproducible results for environmental monitoring, including diet and ecosystem assessments. Here, we used DNA metabarcoding of pollen foraged by European honey bees (Apis mellifera) to investigate their floral resource use in an urban reserve. We collected three different pollen samples from hives: individual bees, raw honey and pollen traps, and identified plants using two metabarcoding markers (ITS2 and trnL). We then compared the results to a ground vegetation survey of surrounding flowering taxa. Pollen DNA metabarcoding detected 74 taxa (48.6% identified to species) across all pollen sources, compared to 44 taxa recorded by the survey (93% identified to species). Within the metabarcoding results, we identified 25% of the genera and 9% of the species found during the survey, with three of the top 10 flowering genera represented. While honey was the most taxon‐rich pollen source (mean = 8.5, SD = 3.5), followed by honey bees (mean = 5.8, SD = 6.1) and pollen traps (mean = 4.2, SD = 1.7), combining the results of six individual bees could detect similar taxa numbers to honey, while 20 bees were required to detect as many taxa as the survey. We demonstrate how DNA metabarcoding of the pollen foraged by honey bees can detect more flowering taxa than traditional survey methods, and how different pollen sources and genetic markers affect the level of detection of plant taxa. The foraging choices of honey bees matched few species detected by the vegetation survey, therefore pollen metabarcoding is recommended as a complementary approach to ground surveys. Rigorous validation and stringent filtering of metabarcoding results were also required to exclude potential false positives. Altogether, this molecular approach can be used to augment vegetation surveys, while tracking the floral resources used by bees. Pollen DNA metabarcoding, a novel method for monitoring honey bee floral resources, shows potential as a tool for the rapid bioassessment of flowering vegetation, complementary to ground surveys. Here, we compare three pollen sources taken from honey bees to a botanical survey. While honey was the most taxon‐rich source of plant identifications, pooling six individual bees could detect similar numbers of taxa to honey, with twenty bees required to match the numbers of taxa detected by the survey.
... Many examples on this basis has been cited both in Western and South East Asian countries. In Havana they have implemented 'organoponics' to fight against the food crisis and Beijing and Shangai had organic farms and greenhouses by allotting land areas only for food production [16]. Planning body APA has integrated urban agriculture to land use planning in different scales [17]. ...
Article
Full-text available
The rise in population has affected the environmental quality and liveability of urban areas. This brings in new challenges to address the resilience capacity of the cities. The multifunctionality of urban areas are considered to be one of the strategies to build urban resilience. The paper explores the development of multifunctional landscapes from a neighbourhood planning perspective. For this, it considers open spaces within a neighbourhood as an element which can be conserved and transformed to productive spaces where waste generated within a neighbourhood is treated and used for developing green spaces. Besides, the system provides an opportunity to transform such land parcels within the city into productive spaces thereby integrating solid waste management and landscape development sustainably. The proposed concept discusses the social, economic and environmental benefits of implementing such spaces which are inevitable in the pursuit of wellbeing and quality of life of the people in a resilient city. At a broader level, the system proposed contributes in making green spaces in any neighbourhood and in the long run, this concept should find its place in urban planning policies of similar city contexts to ensure that our cities, its system of waste management and their landscapes remain sustainable.
... No Brasil, o processo de urbanização se encontra ainda mais avançado, com 85% da população vivendo em áreas urbanas (MENDONZA et al., 2019). Em um mundo com cada vez mais centros urbanos, a comunidade internacional, por meio da ONU, vem voltando a atenção para a questão da sustentabilidade urbana, ou seja, para a consideração de aspectos ambientais e socioculturais no desenvolvimento das cidades para além dos econômicos (DEELSTRA; GIRARDET, 2000). ...
Article
Full-text available
The article proposes an exploratory investigation on the phenomenon of community gardens from a pragmatic perspective, in order to understand the dynamics of this type of collective action. For this, it analyzes the ethnographic and historical material of the trajectory of the PACUCA Community Garden. Based on the understanding of community gardens as dispositifs (DODIER; BARBOT, 2017) and taking into account their material and linguistic elements, the analysis describes the five-year trajectory of collective action and highlights the modalities of agent's engagement with the support of three analytical operators of action: action strategies, normative work and the meanings attributed by the subjects to elements of the device. The analysis made it possible to identify the game of negotiations and forces between two groups with different normative expectations regarding the purposes of the community garden and the principles to be followed for their organization. This dispute, operated by moments of search for consensus and others of logic of dissent, called into question the meanings of "community", the "pedagogical" purpose attributed to collective action and the purpose of "occupying" a public space, which produced transformations in the community garden along its trajectory.
... One study showed that some inner-city vacant lands are too contaminated due to past uses and are not usable to grow crops safely without incurring prohibitively high remediation costs [2]. Another drawback in urban agriculture is the space availability [3]. People who live in densely populated cities or in apartments and high rise buildings often do not have the space and sunlight to grow edible plants. ...
Article
Full-text available
Urban agriculture requires sustainable solutions to secure its water resources. A wicking bed (WB) is a simple system that could provide high yield and water use efficiency. This single trial glasshouse study compares the performance of a WB and surface irrigation (SI) system for growing tomatoes (Solanum lycopersicum L.) using fresh (FW) and recycled water (RW). The performance of both treatments was compared when irrigating 2 days per week and for two environmental conditions (indoor and outdoor). In addition, the reliability of using FW and RW at a 7-day irrigation interval was studied for WBs alone. Results showed that the irrigation water use efficiency (kg/m3) and the yield (kg/plant) are significantly different only between WB (FW) and SI (RW) considering all conditions. The accumulation of salts and the sodium absorption ratio (SAR) were high in the surface layer of WBs compared to SI. This indicates that the use of RW affects the level of salinity and sodicity in soil, which in turn may decrease the yield. However, WBs perform similar to, if not better than, SI with FW. The WBs show the advantage of reducing the leachate of nutrients into groundwater, compared to SI systems. Further research into irrigation and nutrient management in WBs to reduce the effect of salinity at the surface is recommended to increase the efficiency of the system.
... Similarly, conservation of wetland or minimum green space as constraints could be different in different cities. Some cities may impose conversion of agricultural land (Deelstra & Girardet, 2000) while others may not; some cities may want to increase residential area (Cook, Hall, & Larson, 2012) while others may want to increase commercial area. So, the selection of constraints is completely area-specific. ...
Article
Full-text available
Land use optimization is a promising approach to achieve urban sustainability. Despite the increasing number of literature on land use optimization, a little investigation is made to systematically review urban land use optimization: its objectives, methodological approaches, and spatial data used etc. This creates room to review the methodological approaches to urban land use optimization. This study systematically reviews 55 articles following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol to understand important aspects of urban land use optimization. We have found that the most common objectives which were used in urban land use optimization are maximization of spatial compactness (16.67 %, n=28) and maximization of land use compatibility (13.69%, n=23), followed by maximization of land use suitability (11.90%, n=20). The findings suggest that a) one and only one land use in each cell, b) minimum and maximum area of certain land use, and c) restriction on specific land use change are the important constraints. This study also identifies that urban sustainability has been merely touched upon in urban land use optimizations. While environmental (including ecology) and economic aspects of urban sustainability were included in 46.67% and 43.33% studies respectively, the social aspect (10%, n= 3) was mostly ignored. Our findings also indicate that there is no generalized method to measure economic, environmental, and social benefits from land use planning. This study also finds that the Genetic Algorithm (GA) (32.14%, n=18) accounts for a major contribution to solve the urban land use optimization problem. Based on the findings, this study proposes some recommendations for further research and practice. The most important of them include a) framing land use optimization objective functions considering urban sustainability, b) developing a standard method to calculate values of objective functions, and c) integrating a participatory approach with mathematical optimization to derive more feasible solutions. These recommendations could be the scope of future research.
Conference Paper
Full-text available
Considering the importance of Public Open Spaces (ELP) as a support for public life, this article aims to assess the appropriation of Rosário Square, in Campina Grande - PB, between 2010 and 2021. We sought to expose how the transformation processes that have been taking place in its surroundings are the result of the joint and continuous actions of space producers, guided by their interests, establishing constructive and land use trends that can result in the denial and privatization of the ELP, since private multi-storey developments, linked to health and residential services, have programs of needs that meet the demand for these spaces. The work was based on an investigation carried out remotely, due to the context of the COVID-19 pandemic, through prior obtaining of morphological and socioeconomic data, in addition to a survey of bibliographic research.
Chapter
Full-text available
Description of peatland conservation and drainage avoidance as a SOC conservation practice. Impact on SOC, other benefits, potential drawbacks and recommendations.
Article
Full-text available
Through structured comparison, this article seeks to present the different approaches to urban agriculture in the cities of Singapore and Kigali. The former is seen as a model ‘smart city’ worth following worldwide, while the latter is frequently referred to as the ‘Singapore of Africa’. The research conducted was divided into two stages. The first one was desk-based and included the analysis of satellite and aerial images along with the analysis of legal documents regarding land ownership and urban agriculture management. The second one was based on field work carried out in 2019 in both cities and comprised the mapping of areas encompassed by urban agriculture, the collection of photographic documentation, field observations, as well as semi-structured interviews. The research was summarized in line with a comparative analysis of institutional and legal framework of urban agriculture and policy towards its development; spatial features of urban agriculture, including distribution, location, and area; as well as inherent features of urban agriculture, including systems of production, main crops, production methods, and functions. The process makes it clear that despite the fact that urban agriculture is considered in planning documents of both cities, the scale of the activity and the approach towards it differ markedly. In Singapore, the authorities support mainly the high-technology and land-efficient solutions, with other, low-profit forms of agricultural activity being pushed out from the urban space. In turn, in Kigali, where the scale of agricultural activity is incomparably greater, the inhabitants enjoy a certain freedom to make use of unused land in cultivation, which increases their food security and enhances their ability to cope with external stresses.
Conference Paper
Full-text available
Agradecimentos à CAPES, à Fundação Getulio Vargas e à HEC-Montreal. Resumo: A literatura de análise de políticas públicas tem como foco a análise de ações públicas governamentais, onde essas organizações são colocadas como protagonistas centrais. Mas, como analisar ações emergentes, onde os principais protagonistas são cidadãos, movimentos sociais e ONGs, que acionam as esferas estatais para se tornarem parceiras e regulamentadoras? Não se trata de Nova Governança Pública, onde há descentralização e contratualização com ONGs, muito menos de Parcerias Público-Privada. Trata-se de um movimento em rede da sociedade civil, que executa ações ao mesmo tempo em que pressiona por mudanças e ações institucionais. Agricultura urbana, economia circular, empresas sociais, economia criativa são ações protagonizadas por cidadãs e cidadãos que buscam respaldos institucionais para a expansão de suas ações. Como analisar esse fenômeno? O presente artigo propõe um ensaio teórico para analisar a emergência de novos campos de soluções públicas através da sociologia da ação pública e, mais especificamente, das teorias da análise cognitiva de ações públicas de Muller (2000) e Surel (1998), e da teoria ator-rede de Latour (2005). Palavras-chave: ações públicas emergentes, sociedade em rede, sociologia da ação pública INTRODUÇÃO O presente ensaio teórico tem o objetivo de propor uma alternativa à literatura de análise de políticas públicas, com base na epistemologia da sociologia da ação pública. Essa proposta tem dois objetivos principais, (I) sugerir uma base analítica para a construção e legitimação de novos campos de políticas públicas e (II) incluir a ação de instituições não-estatais, pessoas e movimentos sociais no protagonismo das ações públicas. Essa proposta se consolida ao identificar dois grandes problemas na literatura tradicional de análise de políticas públicas: foco nas ações e decisões do estado, assim como a abordagem etapista dos processos de políticas públicas (Lindblom). Partindo da observação do processo de ação e institucionalização de um novo campo institucional de política pública, observou-se que novos campos de soluções públicas, muitas vezes, são consolidados pela sociedade civil, em primeiro lugar, que ao se deparar com as limitações institucionais do estado propõem mudanças institucionais e ação governamental. Dessa forma, o estado não mostra-se como o protagonista principal de determinada ação, mas sim, como um dos agentes, que, ao mesmo tempo, é determinante para a continuidade da ação pública, pois, seu posicionamento pode representar a repressão ou incentivo de determinada atividade. Essa reflexão partiu da análise da estruturação do campo da Agricultura Urbana, que é uma atividade tradicionalmente vista como atividade rural, mas com cada vez mais representatividade no meio urbano, e que enfrenta uma série de restrições e dificuldades ao se
Book
In this book, the authors set out to create an equitable and ecologically sound framework which encompasses the diverse needs of North and South. An innovative philosophy and measurement system is proposed which is based on the concept of environmental space. Drawing on original research in 38 countries, and funded by the EU, the book attempts to establish an agenda for sustainable production by the year 2020. Readers are given an explanation of the opportunities of the global market economy as a tool of development, and it is suggested that this be altered in ways which would lead to the achievement of genuine quality of life rather than just economic growth. The book challenges all countries and peoples to join in a pro-active movement towards sustainable development in the 21st century.
Article
London's food system exemplifies and symbolises its fundamental unsustainability. The city's ecological footprint is 125 times its surface area, requiring the equivalent of the entire productive area of Britain to sustain itself; each year, Londoners eat 2,400,000 t of food (Girardet 1995). Twenty-nine percent of vegetables and 89% of fruits are imported (MAFF 1998); in 10 years the amount of food transported along UK roads has increased by 22% and the average distance travelled by 46% (DETR 1998g). London creates 883,000 t of organic waste a year (Murray 1998), of which households contribute 607,000 t or 40% of their total waste. The vast majority is landfilled, creating polluting leachate and methane (Murray 1998). This said, around 37% of the households compost at least some waste (DETR 1998e), though how much is not clear. The food industry contributes significantly to the city's GDP (gross domestic product), and accounts for 11% of total jobs (Heasman & Rumfitt 1996). However, the jobs are generally poorly paid and of low status. Four supermarkets account for 67% of food purchases (Mitchell 1998). The London farmer is a dying breed and most commercial agricultural activity is chemical- intensive.