Does urban farming have the potential to have a sustainable influence on the future of food production?
This is the exciting question that we are now going to look at more closely.
The fact is that traditional agriculture has already reached its limits. Climate change is having a negative impact on yields, more and more forest areas are being cleared in order to create new arable farmland.
And: most of the cereal crops being planted are not for direct human consumption but will be used mainly to feed farm animals.
On top of this, the world’s population is continuing to increase, with more than half the population already living in cities today. By 2050, this figure will reach 60 percent, according to recent research carried out by the Fraunhofer Institute.
It is therefore high time to consider the alternatives to traditional agriculture. urban farming is such an alternative.
What is the potential for agriculture in the city. And how is urban farming already being practiced today?
Let’s take a look.
There is currently no exact definition of the term. In the first sufficiently large study of urban farming, published in 2018 by the Fraunhofer Institute, urban farming “can be defined as the cultivation, processing and distribution of food and other products for commercial purposes through crop production in urban areas, mostly to feed the local population.” (p22).
What makes urban farming significantly different to traditional agriculture is the use of innovative technology. This allows agriculture to be independent of the prevailing weather conditions or the seasons. Planting and harvesting can be done all year round.
Urban farming, as it is already being practiced today, often has very little to do with what we would associate with traditional agriculture.
These farming types are now well established, for example, and we will examine them in more detail later.
Urban farms mainly produce vegetables, leaf lettuces, herbs, tomatoes and strawberries, and in addition pisciculture and the cultivation of microalgae.
Before we examine each farming type and method individually, we should take a brief look at the term urban gardening, which is often used synonymously with urban farming. However, there is a fundamental difference between the two
The main difference between the two types is that urban farming is above all a commercial venture, whereas urban gardening describes a system that is all about growing plants for personal consumption.
With urban gardening, the focus is often additionally on social and educational aspects; in contrast, urban farming’s priorities are professional agricultural methods and marketing strategies.
A lovely and very well-known example of urban gardening is the Prinzessinnen-Gärten in Berlin.
Urban gardening has is origins in New York’s underprivileged districts in the 1970s, where just like today in many cities a growing social movement led to the creation of the community gardens. They can indeed also be regarded as the precursors of urban farming, even though, from a commercial point of view, developments in Cuba were to have an even greater influence.
Let us take a look at the history of urban farming.
The Community Gardens of 1970s New York are regarded as an important precursor of today’s urban farming. In order to reduce crime rates in the Bronx, a citizens’ movement arose that regenerated brown field sites into gardens and vegetable patches.
The aim was firstly to get children and teenagers off the streets and give them something meaningful to do. And secondly to improve the area and make it more attractive by growing plants there. In these cases, it was the social aspects and educational background that played the main role, ahead of the need to actually produce food.
By contrast, this was of major concern in Cuba at the end of the 1980s, which is why urban farming there is considered to be the true precursor of modern urban farming.
After the collapse of the socialist system worldwide, and because of the sanctions imposed by the USA on Cuba, many Cubans were all but compelled to become self-sufficient farmers, literally overnight.
The Cuban state ordered the introduction of farming in every city in the country. The universities also provided support and know-how. The preferred cultivation method was the so-called organopónicos, concrete enclosures filled with organic substrate in which vegetables were grown. They are still being used in Havana today, where 70 percent of the vegetables consumed are cultivated in the country’s capital city.
The formative ideas for vertical farming, which is widely used today, were developed in 1999 by Dickson Despommier, a former professor at the Columbia University. His idea was to cultivate crop plants in high-rise multi storey buildings in cities to supply the food requirements of tens of thousands of their inhabitants.
At the beginning of the millennium, there were plans to build such a ‘farm-scraper’ in Rotterdam, including the industrial livestock farming of pigs and battery hens. However, due to massive public resistance the project was never realized.
In the urban farms in existence across the globe today, several methods have now become established, particularly indoor farming – whether in greenhouses on roofs or inside buildings.
Indoor farming differs from traditional agriculture above all because it is highly controlled, with technology such sensors and computers monitoring the growth and the care of the plants as well as ensuring that the crops are provided with enough light and nutrition. Modern urban agriculture thrives without sunlight and soil, as well as with much less water than traditional farms.
We will now take a closer look at what makes this possible and how the individual methods work.
With outdoor farming, crops are more or less grown in a way that we are all familiar with: soil, water and sunlight. Outdoor farms in urban environments are normally located on brown field sites, green spaces and flat roofs, but also in domestic gardens at the back of houses.
How this works is demonstrated by the Urban Homestead Farm in Pasedena USA. Annually, the family business harvests over 3000 kilograms of vegetables on its farm, and sell it at markets in the immediate vicinity or directly to private customers.
The Werkhof-Gärtnerei in Dortmund operates on a similar principle. Starting as a project for difficult to employ young adults from socially challenged backgrounds, the market garden has now been growing organic vegetables for over 20 years, delivering its food products to private customers in the area or selling it at local weekly markets.
Open areas are rare in large cities. Roofs on high buildings offer spaces that can be used for urban farms, and this is where both classic outdoor farming and cultivation in greenhouses have established themselves.
One such example has been run for many years by Gotham Greens. Started in New York, there are now rooftop farms in San Francisco. Gotham Greens makes use of greenhouses and a closed system that allows cultivation and harvesting all year round.
Europe’s biggest rooftop farm is in Brussels. With a total of 4,000 square meters, the roof of the „Ferme Abattoir“ is divided equally between a vegetable garden and an aquaponic farm. Together they produce around 35 tonnes of striped bass, 20 tonnes of cherry tomatoes, and a large selection of herbs, right in the centre of Brussels on the location of a disused abattoir.
In vertical farming, crops are not cultivated on a horizontal surface but vertically on the outside or inside of high-rise buildings or abandoned warehouses. This can also include the planting of crops or the cultivation of microalgae on the outside of buildings. Above all however, vertical farming describes a multi-layered closed, controlled indoor system of cultivating crops
An excellent example of a vertical farm is the Good Bank restaurant in Berlin, where salad greens, herbs and vegetables are grown in special glass cabinets in full view of the restaurant’s visitors. The system was made by the Berlin start-up infarm, which develops vertical farming systems for both private and business customers.
Singapore’s Sky Greens is another example. Sky Greens claims to have built the world’s first low-carbon, hydraulic water driven vertical farming system. Using minimal land, water and energy resources, the owners want to produce fresh, high-quality vegetables for the city’s inhabitants.
At the university of Kaiserslautern, a research group has developed a system that allows microalgae to be cultivated on the outside of buildings. Algae are very nutritious and are regularly on the menu in Asia.
Indoor farming is a type of agriculture in buildings, containers or greenhouses and is a closed, controlled system that is independent of the seasons and sunlight. Lighting is provided by LED lamps; the system uses absolutely no soil to support the plant roots.
These three established cultivation methods are now used in indoor farming
Hydroponics is defined as growing plants without soil. They are cultivated in a water tank, with a nutrient-rich solution that flows through tube system. These tubes have holes in which the plants are grown at an optimal distance to each other. The water is circulated and distributed through the tubes in a closed system, which cuts out water waste. Moisture lost from the plants is re-captured, treated and fed back into the system.
This method is mainly used to cultivate salad greens and lettuces, herbs and strawberries.
One example is Farmbox Greens, the first vertical farm in Seattle in the US. Beginning in a small office in Georgetown, the founders moved to Seattle from where they started selling their salad greens and herbs at local markets and restaurant in the whole of the US northwest Pacific region.
A further example is Growing Underground in England. 33 metres under the streets of Clapham, this urban farm mainly produces micro greens and salad greens, supplying wholesalers, local restaurants and private customers in London.
And COMCROP – which claims to be the first and only company in Singapore specializing in rooftop farming – uses hydroponics as a cultivation method to sustainably grow salad greens and herbs for the local population without using pesticides.
The aquaponics cultivation method can be metaphorically described as “tomato-fish”. It is a mixture of hydroponics and aquaculture, or fish farming.
Aquaponics works on the same principle as hydroponics. But instead of tanks filled with a nutrient-rich solution they are filled with fish. Their water, including the fish excrement, is used to produce the nutrients for the plants. The fish then feed on these plants. The combination of cichlid (tilapia) and tomatoes has proved successful.
Europe’s most modern aquaponics farm is in Berlin: ECF Farmsystems.
At the heart and pivotal centre of the farm is the self-designed regulation system, which analyses and efficiently controls all the aquaponics and hydroponics systems, enabling the production of fish, vegetables, herbs and fruit with only low impact on resources.
Aeroponics is a cultivation method where the plants are fixed in a position so that their roots hang in the moist air and are sprayed with a mixture of water and nutrients. The method was developed in the 1980s and was later improved by NASA scientists.
It was perfected by the multiple award-winning company Aerofarms. Since 2004, Aerofarms has been developing innovative technology for modern indoor farming. At its headquarters in Newark, New York, the company operates one of the world’s biggest indoor vertical farms in a disused steel works.
There is a range of arguments in favour of urban farming as a closed, controlled indoor system, but also some against.
Short transportation distances: generally, urban farms deliver their produce to local citizens, supermarkets, hotels, and restaurants. This is a real advantage because it shortens delivery distances accordingly, and therefore has less impact on the environment.
No need for pesticides: Because cultivation takes place in highly controlled closed systems, there is absolutely no need for pesticides.
Reduced use of water and fertilizers: due to the closed circulation system, the use of water and fertilizers is also much lower than in conventional agriculture. Particularly when it comes to water usage, somewhere between 70 and over 90 percent less water is required, depending on which method is used.
Harvesting all year round: modern indoor farming is independent of the prevailing weather conditions and instead uses LED lighting. This makes it possible to plant and harvest crops all year round.
Disadvantages and challenges
There are of course also a few disadvantages and challenges for urban farmers. According to the Fraunhofer study, these result mainly from the fact that investment costs are very high because these methods require the use of innovative technology. The very high cost of renting space in cities is also a factor. Furthermore, technology maintenance is also regarded as a challenge.
One major criticism of urban farming is high energy consumption, mainly due to the fact that the technology, such as LED lighting and computer control systems, require a lot of electricity. However, by using renewable energy but also because current and future developments will lead to technological improvements, it can be expected that this problem will be solved or alleviated in due course.
Innovative high-tech plays a major role in modern urban farming. Compared with traditional agriculture, the use of high-tech gives it the advantage of being a significantly more efficient and more effective method of farming, with much less impact on precious resources.
The main areas of technology are LED lighting, the Internet of Things and automation.
According to the Fraunhofer study, technology is most commonly used for:
In addition, artificial lighting can be regarded as a central factor for modern urban agriculture. According to a Fraunhofer survey, 92 percent of the companies use LED lighting
Agriculture in combination with high-rise buildings or an urban environment is increasingly inspiring architects all over the world. Above all, rooftop gardening is now a major trend. Meanwhile, there are ever more architects who are now specializing in the construction of greenhouses for high-rise buildings.
It is certainly no coincidence that the architects at Studio NAB, who specialise sustainability, proposed a giant greenhouse as their idea to replace the roof of Notre Dame after the massive fire in April this year.
Furthermore, there are ideas and visions of how cities could look in the future. This includes cultivating crops for food as well as the use and production of energy and drinking water.
One current example is the vision for the future of Cairo, created by the Dubai based architects Islam El Mashtooly and Mouaz Abouzaid in cooperating with Steven Velegrinis, Drew Gilbert & Abdelrahman Magdy. Their concept Lifelines envisages, on the one hand, the idea of parks as cultivated oases that will serve as sources of food all year round; and on the other hand, a building in every subdistrict where vertical farms operating on multiple stories produce organic quality food for the local citizens.
Another current example is The Farmhouse, a concept by the Austrian architect Chris Precht. The multi-story building is so designed that its inhabitants can grow their own food produce in a vertical farm system. The idea that plays a large role here is to bring city dwellers face to face with agriculture and to inspire them to living a more sustainable life.
How can we feed a permanently expanding world population? This is one of the biggest questions that we will occupy have to face in the future.
Traditional agriculture today is already in a crisis. Climate change is negatively impacting harvests, arable land is being depleted. New farmland is being created at the expense of the existing natural environment.
It is imperative that alternative cultivation methods are carefully considered.
Because today over half of the world’s population lives in cities, with this figure increasing, it seems reasonable that some food production should also be moved into the cities too.
Innovative technology and the ingenuity of visionary entrepreneurs have already made it possible today to produce vegetables, salad greens, fruit and even fish in large amounts in an urban environment, without pesticides, all year round and with very little water or fertilizer.
This high-tech type of agriculture may not have very much to do with the romantic view of farming in the countryside as we know it. But traditional agriculture as it is practiced today also has very little in common with this image.
If urban farming finds greater acceptance among politicians, business and society it has the potential to make an important contribution, not only towards guaranteeing humanity’s food supplies but also towards strengthening awareness for living sustainably.
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