urban farming 4

URBAN FARMING

Densely built-in areas, many-storeyed buildings

The possibilites of urban farming• In case of inner parts of the difficulties are quite similar.• There are housing estates, brownfields, industrial zones, downtowns,

traffic areas.• The first problem in general in this case is not the possibility of urban

food production, but the existence of urban green areas.• On the one hand the greatest problem is the extremley great rate of

artificial surface cover (pavements, rails, buildings). This is a typical problem of brownfields, industrial areas and downtowns.

• The other great problem is the extremely great size of buildings. This is typical in case of housing estates and downtowns.

• Downtowns have the greatest disadvantages from the point of view of urban farming.

• The extreme density of functions means an other great problem (traffic areas, industrial zones).

Housing estates I.

Housing estates II.

Housing estates III.

• In case of housing estates the real problem is the size of the buildings and the property questions.

• The rate of green surface is (in case of Hungary) relatively high (around 50%), or at least it can be relaively high.

• On the green surfaces the possibilities of urban farming is the same that of garden cities.

• The only difference is the property. In case of common owner the harvest is more difficult. Social organisation, existing communities and existing community gardening is necessary for viable urban farming in case of housing estates.

• The buildings, which are usually huge, with at least 10 storeys and many flats, cover almost the 50% of the total area. Its possible usage is a great question, which appears also in case of downtowns.

Housing estates IV.

• Agriculture is based on crop production till the Agrucultural Revolution (for 10000 years).

• The main crops

Fruit production on public green surfaces I.


• The main crops

Fruit production on public green surfaces II.

Urban fruit trees (turkish hazelnut)• Property problems: there are many solutions. The so called

community garden, moreover the hiring (a community hires a garden, or an inner yard; an urban farmer hires an allee from the local government, or simply a band of unpaved property and plant into it fruit trees etc.). In urban circumstances the stealing is a much smaller problem, due to the cameras public lights and the permanent appearance of other unknown people.

• Plant protection is a great problem: Current chemicals are not suitable. There are two possible solution: 1. developing new chemicals (needs a lot of money and time and the success is not sure); 2 choosing such selected fruit tree types which do not require chemicals, highly resistant for insects and fungus (already exist such selected fruit tree types).

• In case of greater buildings (higher than 10 metres) there are many problems from the point of view of traditional food production and also greening.

• In case of smaller buildings, the usage of greater trees and rambling plants can be very effectively provideing the necessary green for the dwellers.

• As it was mentioned previously, the appropriate trees and climbing plants make possible the food production on the these ways.

• In case of greater buildings lianas can not reach higher storeys. To be able to effectively use up the surfaces (roof and facades) of the building, different kind of green roofs must be applied.

• Using green roofs the question of water supply is extremely important. In case of food production the appropriate nutrition must be also solved.

The problems of greater buildings.

• Considering the necessity of green roofs, there are many kind of them, but their main purpose is recreation (rooftop gardens), or heat insulation (extensive green roof).

• Besides these main features they have a lot of advantages, like positive effects on urban climate, increased building structure lifetime, increasing spaces for urban ecosystems, water retain/rainfall buffer.

• The usage and effects are very similar to ordinary urban green areas, although the conditions for plants are less friendly.

• Considering the food production aim, the ordinary extensive green roof (without irrrigation, using only succulent plants and mosses) can not be appropriate.

• Similarly to traditional extensive and intensive food production areas, in most cases the irrigation is necessary.

• Irrigation must be sustainable.

Green roofs on greater buildings

Extensive green roofs

• In case of extensive green roofs the role of the vegetation is only the stablizitation of the surface of the soil/growing medium.

• The positive effects are rather due to the soil layer, than the vegetation, not suitable for urban farming.

Intensive green roofs

• In case of intensive green roofs the soil layer is much thicker (at least 40-50 cm as against by the extensive green roofs 5-15 cm), and the irrigation is provided.

• The main purpose is recreation.

• In Hungary the main difference between extensive and intensive green roofs is the possibility of permanent irrigation.

• Considering the question in global, the main difference must be the thickness of the soil layer. If the soil layer is thick enough, then there is the possibility to planting trees and shrubs onto the roof.

• The necessity of irrigation is basically a question of climate. In case of Hungary, these green surfaces requires irrigation. Considering oceanic, tropical, monsoon, rainforest climates irrigation is neglectible.

• In case of desert and semi-desert and mefiterranean climate types irrigation is necessary.

• In case of nediterranean-type climates there can be some exceptions in case of food production.

Green roofs and climate

Intensive green roof on semi-desert climate

• A church in Salt Lake City. Covered by intensive gren roof, which need almost permanent irrigation.

• Unsustainable solution.

Intensive green roof on oceanic climate

• An intensive green roof in Manhattan. Oceanic climate, rain occur in every season, irrigation is neglectable.

• Sustainable solution.

• In case of traditional agriculture: In ordinary case agriculture do NOT require irrigation!!!

• Among every climate circumstances there were already found and selected the most appropriate plants for food production (wheat for mediterranean, rice for monsoon climate).

• The so called intensive agriculture produce such goods, which can not be considered as basic food (vegetables, fruit).

• Moreover, these plants can be easily cultivated in smaller gardens, only in case of greater plantations cause the production an environmental problem.

• In case of green roofs the thickness of soil layer is important (to do not hurt the building structure by the cultivating machines).

• Moreover, in certain cases, where irrigation is necessary, water can be provided on sustainable way.

Irrigation and sustainability

Wheat


• The main crops

Rice


• The main crops

• In case of thick (40-50 cm) soil layer wheat can be effectively cultivated without irrigation on mediterranean-type climates.

• In case of thick (40-50 cm) soil layer rice can be effectively cultivated without additional irrigation on monsoon-type climates.

• Nutrition is an other important factor.• First question is the soil: in present day green roofs the quality of soil

is quite bad from the point of view of food production, because the main purpose is not the product, but to keep up without earthwork the structure of the soil.

• Thus, traditional, good quality soil must be put onte green roofs adn below ot must be taken a good drainage soil type layer.

• The question of nutritions: the situation is similar to traditional agriculture, the nutrition must be taken up to the roof. The nutritions can be chemical or traditional manure. Organic farming is the real solution instead of using herbicid, fungicid and pesticid chemicals.

Irrigation and sustainability

• Water management in case of such greater buildings is the most important.

• It consists of two greater parts: the first is the rainwater management, while the second is the so called „grey water” management.

• Rainwater management can be solved on the simplest way by the appropriate building construction.

• The scheme is the following: the roof of such a multi storeyed building is flat, and covered by a green roof, with 40-50 cm thick soil layer, and wheat or rice is cultivated in it.

• The greatest amount of rain will be used up by the rice or wheat. The minor (but still momentous) part will be collected in water reservoirs under the roof. This can be used for irrigating plants which can be planted on thin belting green roofs around the building on the appropriate levels/storeys. These can be used for fruit, or vegetable production. This water can be also used up inside flats in bathrooms.

Water management I.

• Grey water management: using up the appropriate waste water .• Grey water= wastewater, which does not contain human manure.• Grey water can be excellently used up for irrigating green roofs, or

green walls.• If it does not contain poisonous materials (and this can be awaited),

then it can be used up for irrigating plants of food production.• There exist already excellent examples (Bosco Verticale, Milano) for

using up grey water for irrigating green walls, altough these green walls was made not for food production.

• The corellation with the previously mentioned rainwater management is strong, because rainwater can be used up also in bathrooms, while greywater can be used up for plant irrigation.

• The appropriate construction is essential to be able to provide the necessary circumstances for effective urban farming.

Water management II.

Bosco Verticale (vertical forest)

Columnar fruit trees

Spalier

Trellis work

• Green roofs, even extensive green roofs are much heavier than any other roof.

• In case of urban farming, the necessary thick soil layer means an even greater weight.

• Thus the building construction must be stronger.• On the one hand this means, that the initial cost of a building is

higher.• The greater problem is the existing housing estates. For example in

Hungary most of them can not be maintained with any kind of green roof, because their structural qualities.

• This means that urban farming is possible rather in case of new buildings.

• Even in case of stronger existing buildings the necessary changes has much more cost, than by creating a new building, where these features are already involved into the design.

Static/structural problems.

• In case of greater buildings fungus farming is always a viable way.• Moreover aquaponics and hyroponics is also viable.• There must be mentioned the so called blue roofs.• In case of existing blue roofs (i.e. Oasis 21 in Nagoya) the main goal

was climate modification.• Nevertheless providing a water ecosystem with rainwater can be

ideal for aquaponics.• There exists also the possibility of using rainwater (if the quality is

appropriate) for hydroponics. • The great advantage of blue roofs and the usage of water ecosystems

and hydroponics that the specific weight of water is only about the thid of soil. Moreover a thinner layer of water is enough for this purpose.

• Using glasshouses on the flat roofs, make the water usage optimal and provides the control of the quality and quantity of water.

Further opportunities.

Blue roof

• In case of traffic zones urban farming is not possible directly.• There can be created pavements both for vehicles and pedestrians, which

can produce energy (by containing solar panels, or rather piezoelectric units).

• The urban water management system has to deal with the rainwater, which is collected in the traffic areas. On the one hand, these surfaces can not be water covered, on the other hand this water must be collected and cleaned to be able to use up for irrigating urban green areas.

• In case of brownfields the revitalization is the most important. Among the existing stage the natural appearing ruderal plants can have momentous effect on the local climate and ecology.

• Brownfields usually consist of traffic zones and greater buildings, thus these can be treated separately similarly to housing estates and traffic zones.

• The question of downtown is similar to that of housing estates, excepting the rate of green area is much smaller.

Further opportunities.

Thank you for your attention!

urban farming 4

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