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Issue 005 Cover

005 / Urban Agriculture

Published June 2019

The restaurant chain Le Pain Quotidien (LPQ) offers a rustic experience. Complete with earthy wooden furniture and coffee served in bowl shaped mugs. They make their own jams and spreads. The most jovial member of staff runs the floor, cajoling you to sample the spreads. Part of what sets LPQ apart is the fact that they try to serve as much organic produce as possible. In time honoured tradition of fine hipster establishments, the following thought provoking quote adorns their walls, organic food is what our parents used to call food. Which brings up several questions. If this generation has renamed our parents food as organic, what name will the next generation choose to give our food? How different will our food be from that consumed 30 years from now?

This generation has been sowing the seeds for a more considered food future. Several movements have become prevalent as the realities behind food production become understood. This has given rise to vegan products, organic certified, non-fertiliser produce and sustainable farming (both on land and in sea). These practices and initiatives alone cannot resolve our ongoing food and land challenges. We need different solutions to tackle a growing population that is hungry multiple times a day. After water, food is the most basic need in our lives. The lack of it makes us act strangely and irrationally. We structure our lives around our meals (you’re going to need to eat sometime). We try to eat less of it or burn more of it off. We go out to supermarkets to buy it. We build farms to produce it. We build food theatres to present and eat it. Yet as more of us move into cities, our connection to our food has diminished. As we have developed our built environment, we have hidden where food is actually coming from. This false sense of reality is then compounded with just-in-time delivery infrastructure. Our network has been built in such a fashion that goods are not stored locally, rather shipped within a few days, when needed. This means that local centres do not store very much food. Stock for large populations, is usually a few days worth at best. This has given the illusion that food is an abundant resource. Except it isn’t. Food production around the world faces a series of considerable challenges. As a species we have mostly managed to get by1. The reality is we need to evolve our practices from production to distribution and finally consumption.

What puts that LPQ quote into perspective is the position we’d be in had we not changed the way we created food. The estimates show that we would have required 82% of the Earth’s land to produce the same amount of food (between 1960 and 2000). In 2005, the University of Wisconsin released maps that showed the extent of croplands distributed across the world. These maps confirmed that 40% of all the area of the world was being used to grow crops and raise livestock. That is equal to an area the size of South America. Food production changed, because it had to and this shift came at a cost. The challenge with growing crops spreads across several key areas:

  1. Soil
  2. Time
  3. Land
  4. Water
  5. Light
  6. Warmth

Each one of these areas has been or is being disrupted to the detriment of the final product. Over time, the final produce has become more homogenised and a pale imitation of the original.

Food by Numbers

Clear inefficiencies exist with the production, delivery and consumption of food. Considering the effort and resources it takes to produce food, we don’t always help ourselves. 30% of everything that is produced is either lost or wasted globally2. Future global population projections offer a window into the challenge that lays before us. Our numbers currently exceeds 7.6 billion, the UN projects that our numbers rise to 9.7 billion by 2050. If we don’t change the way we make and distribute and consume our food, the area of the world used for growing crops will increase to over 70%. Further creativity and human innovation is necessary to remain ahead of the food security curve.

World Median Population Projections (Billions).
Source: UN Probabilistic Population Projections based on the World Population Prospects: The 2017 Revision

Challenges Ahead

To meet demand, food production will need increase by around 70% in the next 30 years. In order for us to develop a more sustainable future, we will need to disrupt each of the core food production blocks. Some of this disruption will come from the actual plant technology. Some from plant growing technology. Finally, some will come from the new type of farm building and structure to grow everything. To enable this last idea, the construction industry will need to understand what is necessary to grow crops. This will allow the profession to develop an understanding of how best to replicate this environment in a sustainable manner within cities.

Soil

Soil fertility is the ability of soil to sustain agricultural plant growth. Soil fertility has continued to drop globally. The issue, originally thought limited to developing countries, is now acknowledged to affect us all. In response, new technologies are being developed to help stave off this decline. The development of hydroponics and polyurethane foams offer a form of soil replacement. Hydroponics is the method of growing plants without soil, rather by adding mineral nutrients solutions into a water base. The technology is still in its infancy which is best highlighted by the plethora of different solutions entering the market. Solutions are available from ZipGrow, Evergreen Grow360 and even Ikea3. It may seem like replacing one natural resource for another, hydroponics would help reduce water consumption.

Water

Water can be better utilised and persevered through a closed loop or recirculating system. In essence a solution of nutrient solution is pumped directly to the plant’s roots. When feeding is over the water drains back to a reservoir and used again. This means that water is not lost to the ground as it would be in traditional agriculture. The water loses in a closed loop range between 2-7% per day4. By comparison, traditional method requires multiple times the water use of a recirculating system. Agricultural flood irrigation loses water to simple evaporation, run-off, and dispersion beyond the reach of plant roots. The agricultural industry is changing its practices to be more water savvy with better drip technologies. This technology can reduce the losses by 20-40%, dependant on the type of crop.

Type of Crops

An important consideration is deciding on the type of crop best suited to the constraints within an urban farm. Currently, indoor farms limit their produce output to leafy greens such as basil, parsley, pea shoots, coriander, rocket and lettuce. Technically, while any plant can be grown in indoor farms, there are practical considerations to be made. As a start, plants that provide a small fraction of output (compared to their size) would need to be ruled out - this would be trees, shrubberies, etc. While urban farms can (and will) become more capable, there is a glass ceiling to their output. The type of crops not practical to be grown inside a building will need to rely on updated practices to existing methods.

Seed technology will play a crucial role if this transition is to become successful. Existing seeds will need to be modified, adjust and adapted to the new reality. Currently the same seeds or cultivars used in the field are being used in vertical and urban farms. The genetics of existing seeds produce uniformity in variable conditions. Seeds for use in indoor farms don’t need these characteristics. 5

Land

One clear advantages urban farms hold is the efficient use of vertically stacked layers of crop above each other. The land is augmented through vertical farms as a building of 2000m2 and 6 levels can provide up to 12000m2 of farming land instead. Another advantage is being able to operate from many different types of existing facilities and locations. This does feed well into the circular economy, where abandoned facilities are given a new lease of life.

Energy

One of the biggest challenges facing urban farms from realising their potential is their ability to manage their biggest expense, energy. The energy usage in this type of building is intense out of design. In order to maximise the available crop area and provide complete control of the growth of the crop itself, the farming space is enclosed, artificially lit and climate controlled.

To make an accurate comparison between crops produced in a traditional manner when compared to those grow in an urban farm, all energy is taken into account. Broadly, the energy in food production can be divided into four parts:

  1. Agriculture
  2. Transportation
  3. Processing
  4. Food handling

For an indoor farm, the time, water consumption, and transportation are all reduced. These reductions have to collectively make up for the excess use of energy. The economic balance has not tipped in favour of urban farms as the entire stack has not developed sufficiently. Existing urban and vertical farms have addressed their economic realities through the production of higher value produce such as micro greens, transplants and cannabis (where it’s legal). This is partly down to adapting and learning, as many facilities have opened their doors only to close them a few years later.

Opportunities Ahead

The idea of vertical farms was originally explored in Dickson Despommier‘s book Vertical Farms, first published in 2010. Radical ideas sometimes take a while to mature - consider the electric car which began life at the time of the combustion engine. The idea has not achieved wide adoption, that isn’t to say it doesn’t have some future. It’s unlikely to solve our food security challenges but it can contribute to the solution.

Urban agriculture has space to grow both in and on top of existing buildings. Adoption could accelerate once bespoke cultivars are developed. While repurposing existing buildings and converting them into urban farms provide a seemingly great value proposition, this is a makeshift solution. Expressive architectural designs that understand the many needs of crops grown within internal spaces need to be developed. Rather than pretty architectural renderings with little practical application. Understanding these constraints will allow energy to be better utilised. A new type of building will need to evolve, one optimised for this type of function. If we are to embrace this new paradigm, architects, engineers, manufacturers and cultivators need to all work together to find solutions to the plethora of challenges that lay ahead.

We have accumulated an immense amount of debt to the earth (both figuratively and literally). It’s time we started to grow our future in a more considered manner.


  1. The United Nations Food and Agriculture Organization (FAO) estimates that about 815 million people of the 7.6 billion people in the world, or 10.7%, were suffering from chronic undernourishment in 2016. This number has fluctuated up and down over the last decade.

  2. There is a difference between the two terms. Lost refers to food that is lost in the supply chain between the producer and the market. Waste refers to food that is safe and nutritious for human consumption that is discarded.

  3. Ikea’s solution is but a prototype, their interest in this field is encouraging to try and democratise urban farming.

  4. These losses come from evapo-transpiration (which is the evaporation of water through the plants) and leaks.

  5. Such as growing in a fraction of the time. The less time spent in the urban farm, the less energy used to grow them.