Is vertical farming a good answer to the wrong question?

Feeding a growing population sustainably is an urgent policy and design
issue, for which new technology can only be part of the solution

INDOOR vertical farming is often credited with being the next evolution of our agricultural system [1], enabling us to feed the growing world sustainably, but might the focus on efficiency in this high tech model of farming risk making the root cause of our unsustainability worse? The logic behind the approach is straightforward: in a world where land area is precious, more value can be made from a farm by increasing productivity on the same sized footprint. Equivalent to that of sky scrapers in city centres, crops of smaller plants are grown in stacks of trays, in towers up to 6m high[2].

Stacking in this way would not have been feasible if not for the two recent trends of well understood soil-less growing techniques, and low cost, efficient LEDs[3].

By reducing the necessary depth of these layers, Soil-less techniques such as aero- and hydroponics make vertical farming feasible. Hydroponic systems use a shallow continuous flow of water beneath and through the root mass of the plant, delivering nutrients dissolved within, aeroponics is similar but using a fine mist. Each layer is lit by an array of LED lights, often tuned to a pink spectrum to yield the greatest growth for the energy used, and to stimulate the production of certain chemicals within the crop, providing nutrients or flavour.[1]

These factors together simulate the most fertile agricultural site, under an optimal full sun at just the right temperature, 365 days a year. Growing speed is therefore very high, with a head of lettuce available after only 35 days.[4] Soil-less techniques use up to 95% less water than field farming [5], and produce a yield 11 times higher per year.[6] When stacked vertically the productivity per ground footprint is 390 times higher.[5]

 

It is easy to understand the enthusiasm[1] for vertical farming: with the world population expected to reach 9.8 billion by 2050[7], a greater supply of food will be needed quickly, on a smaller land area. Its potential is huge, especially if the crops available are nutritious, fresh and have a short travel distance, providing healthier food at a lower price than is currently possible.[8]

The benefits extend beyond the people eating the food too. Kept in a closed environment as they are, the crops have no need for pesticides to protect them. Good news for the ecosystems, which are reliant on insects and pollinators at the bottom of the food chain, and so are struggling under our current intensive farming methods.

A smaller footprint has another major advantage: allows scope for reducing the conflict of interests between farmers, whose livelihoods depend on the land they cultivate, and the essential ecosystems agriculture has replaced.

So there’s a strong case for the merits of vertical farming in place of intensive field farming, but the issues surrounding our current system are not about growing in soil. The problem has been our approach.

Our incentives in cultivating food are for the highest yield in the shortest time, and for uniformity over diversity. These are pursued without consideration for any harm done to the natural environment from overuse of fertiliser and pesticides.

Though vertical farming has become popular for environmental reasons, it is a very profitable tool in line with this narrow and problematic approach.

The question that really needs answering is how will we align the incentives of food production with respect for our environment in our modern context. How might we farm with a conscience?

 

Each successive generation finds a new ‘normal’, based on what they grew up with; this shifting baseline has gradually altered our perception of how our interaction with nature was, and could be. [12], [13]

Might the sealed off, artificial method of vertical farming worsen this disconnection? Some already leave the fresh pears in their garden to fall and rot, preferring to buy them from a shop. If food really no longer came from the ‘mucky’ earth but was born as it appears in the supermarket, selected for regularity, entirely uniform and totally sanitised[11], do we risk further disconnection, reducing our understanding further?

This is our real design task: to change attitudes and incentivise sustainable behaviour. Our disconnection from nature is part of the issue, with the younger generation growing up unable to identify several common species[9], and not associating a food supply with respect for the planet. Some, for example, are unaware that chips come from a potato growing in the earth.[10]

 

 

There is also the concept of unknown unknowns: by precisely controlling the exact properties and qualities of lighting, nutrients and water, there is an assumption that all relevant growing factors are fully understood.

Nature is however rarely so straightforward in its intricacies: it is almost inconceivable that we might ever control it perfectly. If our food system were entirely based on food grown without soil, we cannot know all the consequences.

There are other approaches to growing more food on a smaller land area. Proactively enabling the world’s current capacity of family farms, who currently produce 80% of the world’s food on only 24% of the current farm area[14], would help farmers, their cultures and native wildlife

 

They are already often more efficient than their industrial scale competitors for land. It is estimated that if central America’s large farms were as productive as its small ones, the region would produce three times as much food.[14] Applying principles of agroecology, which would not only make the system more hospitable towards nature but could double today’s yields over the next ten years[15] and, simultaneously, a stronger connection with nature.

Many of the larger farms are part of the 140 million hectares of our agricultural capacity goes toward just four crops, mostly grown for other industries such as fuel and cosmetics, or unhealthy processed foods[16].

Does vertical farming as a technique have more risks than benefits? That will depend on how we choose to utilise it. As we design our future of food production, we must remember to learn from previous mistakes, that bigger is not always better, and that we should resist throwing technology at our problems without changing attitudes.

The right question: what really needs redefining, and ought to be the focus of our efforts, is how we redesign the system. The bigger picture of how we nourish ourselves and the processes of the earth we depend on[17], can be seen as a complete service, of which vertical farms will be one very useful element. Perhaps for growing ‘industrial crops’, or designing ways in which it enhances our connection with our food and the ecosystems the plants are embedded in. Its efficiency and mess free qualities make it ideal for urban sites, even windowsills. Empowering individuals to do something proactive which can improve the situation, adapting our collective mind-set, should be our priority in this design challenge.

Article by Jai Sandhu

For more information and references, please contact: 1310429@brunel.ac.uk