Bringing Farms to Cities

The  Urban Skyfarm  by Aprilli Design Studio,   a vertical farm design proposal for a site located in downtown Seoul. 

The Urban Skyfarm by Aprilli Design Studio, a vertical farm design proposal for a site located in downtown Seoul. 

Author: Luiz Guidi Edited by: Burcu Anil Kirmizitas

Presented with the image of a tech-savvy, data-driven startup founder whizzing through meetings with angel investors, how many of you think of a farmer? Most of us probably imagine someone trying to setup the new Uber, Airbnb or Dropbox, with no clue of what type of soil works best to grow tomatoes, or when to harvest watercress, or the optimal CO2 concentration needed for crunchy lettuces. That would be stuff for ‘country folks’, some may say, not for someone living in metropolitan London, New York or Stockholm. But a new crop of farmers is sprouting, driven by technology- and data-driven innovations in agriculture, and they are bringing food production to cities and making farming ‘smarter’.

Urban agriculture is, of course, nothing new and has been around for a long time, from the Hanging Gardens of Babylon around 600 BC or the floating farms of Aztecs. But as cities and their inhabitants grew in size over time, food production became more and more rural, driven by the need for space and the desire to keep cities clean. Still, 15-20% of the world’s food today is produced in peri-urban areas, typically done in small scale by low-income urban residents as a way to fight poverty. There are a few exceptions, with Beijing as a remarkable example with more than half of vegetables consumed in the city coming from its market gardens, or in Havana, Cuba, where the government invested heavily in local production during the late 80s to fight an impending food crisis resulting from trade embargoes and the fall of the Soviet Union.

But with the growth in the world’s population predicted to require a 70% increase in food production if we are to feed everyone, and with increasing urbanisation (the urban population is likely to grow from 50 to 80% by 2050), the idea of producing food at large scale around cities may be one of the answers to improve security and resilience in the food chain. It makes food more accessible to the local population and dramatically reduces food miles – in the US, for example, leafy greens travel more than 3,000 km before they are consumed.

According to many, recent innovations in agriculture such as ‘vertical farms’ in skyscrapers or shipping containers, and greenhouses on building rooftops are seen as the future of agriculture: they can produce food right next to the point of sale in cities, slashing the cost of transport and carbon footprint associated with it. Their controlled environments are weather-resistant and virtually eliminate the need for pesticides, fungicides, etc (their produce is ‘post-organic’); their artificial growth environment uses around 70-95% less water than traditional agriculture; and they can produce crops all year round and anywhere, independently of the local climate conditions. Availability of land is also a big factor: 80% of the world’s farmable land is already in use, reducing the likelihood for traditional agriculture to close the food gap – and climate change is likely to impact on productivity in many of these areas.

On the face of this, many companies have started turning abandoned, empty buildings within cities to grow food ‘hyper-locally’. For example, GrowUp in London, the first urban farm in the UK, combines vertical farming with fish tanks to grow salad, herbs and tilapia in an old warehouse in East London. In Berlin, the Metro Cash & Carry supermakets have their own store-grown produce, completely eliminating the need for food transport. Another London-based startup, Growing Underground, has converted old air raid shelters built during World War II and now delivers fresh herbs to restaurants within four hours of harvesting. The promise of these urban farming initiatives has also caught the attention of Kimbal Musk, the less well-known brother of Elon, who started an incubator program in Brooklyn, called Square Roots, where 10 wannabe entrepreneurs develop their vertical farms inside shipping containers. With sustainable food and agriculture predicted to give a 7-fold return on investment by 2030, the incentives are also financial and go beyond benefits to the environment and to food access. Riding on the wave of local and organic food movements, urban agriculture startups have boomed in the last five years.

A farmer checking the produce in the GrowUp Urban Farms, London. 

A farmer checking the produce in the GrowUp Urban Farms, London. 

But how do these systems work and what are the technologies behind them?

Typically, these new urban farms are based on sensor- and data-rich indoor environments that use artificial lighting in combination with hydroponics or aeroponics: in these soil-free systems, plants are grown in trays or tanks, and receive nutrients through either water-based solutions or water puffs targeted at their roots, with light for photosynthesis supplied by LED racks. Hydroponics can also be integrated with fish tanks in a recirculating integrated ‘aquaponic’ system where ammonia waste produced by fish is converted into nitrate by bacteria and used to feed plants. The growing process of plants then purifies the water, which is then filtered and pumped back into fish tanks in a circular system. By stacking crop trays on top of each other in these closed environments, indoor farms can produce a lot more per square meter than horizontal farms. For example, one of the biggest vertical farms in the world to date, AeroFarms, in Newark, New Jersey, USA, has 12 layers of trays stacked along 30-feet between floor and ceiling, and their organisation is estimated to be 100 times more productive than traditional, ‘horizontal’ farming.

Most of this technology has been known and available for years – think of people growing cannabis at home in closets or sheds – and NASA has been playing with aeroponics since the 1990s, looking of ways to grow crops in space. But it is only with the recent development of low-energy, high-efficient LED lights that indoor farming became more realistic and viable at larger, commercial scale. Modern LEDs permit growing fruit with an estimated 400% less power than traditional high-pressure sodium (HPS) lamps. LEDs are also cooler, literally. By emitting 70% less heat, lights can be placed closer to plants, minimising light waste and maximising the amount of energy used for actual plant growth. According to Paul Gray, a senior scientist at lighting startup Illumitex, LEDs can now be fine-tuned for their emission of specific wavelengths; number of photons, and their lighting distribution is very uniform across the lamp. The wavelength selectivity is what gives most indoor farms their characteristic pink look, from the combination of blue and red lights, which provide the optimal combination for leaf expansion, root branching, etc. Analytical advances in lighting such as multispectral analysis is also key as farmers can monitor light absorption and reflection with specific sensors. Through varying combinations of light intensity and frequency, producers can optimise conditions for each of their crops individually – instead of the all encompassing power of the sun in traditional agriculture.

It is the combination of such data-heavy approaches with connectivity – i.e. the internet of things – that lies behind the growth of urban farming. ‘Precision agriculture’ is also being used in rural farms but it is in the controlled environment of indoor farms that it holds most power, where the most minute details can be manipulated at a level impossible in traditional agriculture. In indoor farms, it is possible to control well-known variables important for plant growth and quality such as temperature, humidity, lighting, airflow, and nutrients, but also more sophisticated ones such as CO2 concentration, dissolved oxygen levels, electrical conductivity, and so on. The secret to produce those mouth-watering crunchy lettuces quickly is to adjust each of these variables with precision. This, in turn, will affect the expression of genes in plant cells and ultimately determine the crop’s texture, colour, size, shape and taste.

These conditions are carefully monitored using a plethora of sensors embedded within growing chambers and trays, generating huge masses of data for each of them. For example, AeroFarms controls around 30,000 data points for each harvest with their ‘smart farming’ systems. The data can be accessed and controlled 24/7 via remote platforms online from anywhere; the office, the scientist’s bed or a business meeting in London. This level of detail is also used for tracking each stage of plant development, from seeding, germination and harvest, as done with FreightFarms’s farmhand app – which can also be used to schedule tasks, access climate history, logs and many more. This data-rich approach to farming also has its advantages when it comes to transparency, as it makes possible for companies to publish the data on their crops so that consumers and regulators can directly evaluate how their food is grown.

A growing number of new startups are trying to bring these innovations to the wider public, building bridges between the farming entrepreneur and home users. For example, Grove Labs has created a mini in-home garden for your living room with an aquaponic platform designed as a piece of furniture that comes coupled with an app for remote tracking of pH, light and bacteria levels, and sends reminders to add nutrients and water, and so on. In Detroit, SproutsIO is testing a similar system targeted at offices at homes with an online platform that records plant health, predicts optimal harvest time, and allows users to engage with other plant growers via their forums or buy newly-available seeds.

This democratisation of farming is the idea behind Caleb Harper’s Open Agriculture Initiative at Massachusetts Institute of Technology. Caleb believes that the use of data and technology in agriculture will define a Fourth Agricultural Revolution and has set out to educate the public and produce the farmer of the future with their Food Computers – an open-source software and hardware platform that can be scaled from the office table top to warehouses for new commercial ventures. Food computers collect data not only on plant growth environment but also on the resulting plant phenotypes, with all data uploaded to a database of ‘climate recipes’. Open Ag wants to promote users to experiment with different climatic conditions and simulate extreme weather to create a large-scale dataset and find new environmental recipes. They are using basil as a model organism and have been playing with stressful growing conditions in the search for the tastiest basil, measuring the molecular composition of leaves using gas chromatography mass spectrometry.

Automation and robotics also play a big role in urban agriculture. CityFarmSystems’ rooftop greenhouses can be built at the point of consumption or sale, bringing ‘food miles’ to close zero and use fully automated modules that can transport food to and from the production area. In addition, using heat and CO2 from the warehouses below the farm, their greenhouses produce sustainable crops whilst minimising waste and environmental impact of buildings – an initiative backed by RBS for their bank branches as they work towards greener operations. Spread, a company in the indoor farming business in Japan since 2006, is due to take their operations to next level of automation and eliminate the need for labour between seeding and harvest in their ‘Vegetable Factory’, expected to grow 30,000 heads of lettuce a day starting next year.

The development and application of these technologies has brought a huge buzz and the promise of a revolution. But does it stack up? Critics say that, as it stands, urban agriculture at large scale is only fanfare and excitement. When experts look hard at the numbers, the environmental impact of energy usage actually outweigh the benefits of reduced transport. And with high operational costs, their produce is premium and only available for a portion of the population with high income, who are ready to jump on the hype of ultra-local, post-organic salads and vegetables. Some say this comes from the danger of entrepreneurs launching innovations which may not be fully backed up by research too quickly or overestimating their benefits and feasibility (as in recent questioning of the value of doing 10,000 steps as encouraged by fitness trackers). These challenges are made clear by the closure of the biggest vertical farm in the US, FarmedHere, with its 90,000 square foot facility in Chicago for financial reasons in January, joining other unsuccessful ventures such as Local Garden in Vancouver that declared bankruptcy in 2014 and Podponics, which went out of business last summer. Even Google killed off its vertical farming project, previously one of its promising ‘moonshot’ targets in their X labs, alleging issues with limited viability of crops.

There are other limitations too as the range of crops is still very narrow and they do not meet the dietary requirements of the population, or in terms of policy restrictions as urban farming is illegal in many places. It is also unclear how these tech-heavy solutions can be implemented in countries where food insecurity is very high and, thus, have the most need.

Whilst indoor agriculture still has many challenges to overcome, advances in technology, particularly in energy-efficient lighting, will continue to gradually increase the viability of urban farms. Anyone expecting one miraculous solution to close the food gap and make agriculture sustainable on its own must, naturally, revise their expectations – complex problems such as this require a combination of approaches in a multi-layered fashion. And urban farming may be one of them.