
Background information
Gardening with children: The basics of sowing seeds
by Ann-Kathrin Schäfer
Our cities are expanding, pushing up population figures with them. So, does this mean we need new ways of producing food, such as vertical farming? Let me give you the skinny on vertical crop growing – and what you, the consumer, have to gain from it.
It may be cold, grey and bleak in Zurich, but in a container belonging to the start-up Yasai, there’s a budding sense of Italy’s la dolce vita. Hundreds of little heads of basil stretch up towards the LEDs, millimetre by millimetre, layer by layer. I’m talking about a vertical farm, a crop growing system
that’s being posed as a potential answer to one of the burning questions of our time: how can we feed eight billion people sustainably? Can traditional, field-based farming still hope to cover high demand in times of drought and downpours?
4.4 billion people currently live in cities worldwide. That’s 56 per cent of the global population – and the numbers are rising sharply. For instance, the World Bank says that 6 billion of us will be living in urban areas by 2050. «Future city planning efforts should definitely take vertical farms into account,» says Eldrid Funck of Swiss start-up Yasai. «It’s the only way cities will be able to function sustainably in the future.»
A glance in the direction of Austria, for example, demonstrates that change is indeed afoot. Large retailers such as the REWE Group are showing increasing interest in and subscribing to the vision of vertical farming. One example is the pilot vertical farming project underway at grocery retailer Billa. In summer 2022, the company started vertically cultivating fresh, homegrown lettuce in containers in the city centre.
The organisation pioneering vertical farming in Switzerland is Yasai, which, alongside the Fenaco agricultural cooperative, has been championing sustainable farming in urban areas since 2020.
Unlike in greenhouses, the growing areas in vertical farms are stacked on top of each other. This creates a big opportunity for city-based food production, where space is a highly sought-after resource. «The vertical system increases yields by up to 200 times per square metre,» Funck says. At Yasai, basil is cultivated on 15 layers – and, as Funck explains, that’s just a test farm.
These 15 layers are planted in a hydroponic system – the plants don’t need soil, and are instead grown in water-based nutrient solutions. Any runoff water is captured, recirculated and reused. «As a result, we’ve reduced our farm’s water consumption by 95 per cent.» Last but not least, vertical farms produce food locally, in a way that conserves resources, all year round. And they do this exactly where consumption will be at its highest in the future – in cities. However, this does present vertical farms with some sizeable challenges. Year-round indoor production means one thing in particular: high operating costs.
Vertical farming has one major drawback: high energy consumption. That’s down to the artificial lighting it requires all year round. According to a report, vertical farms need 38.8 kilowatt-hours of energy per kilogramme of crop. By contrast, the same amount of crop grown in a greenhouse under natural sunlight requires just 5.4 kilowatt-hours of energy. To be able to offer products from vertical farms as sustainable alternatives, the most important thing you need is renewable energy. Yasai has been running on 100 per cent hydroelectric power from the very beginning, which presented yet another challenge because «the decision initially came at a higher cost».
High operating costs are one reason why produce from vertical farms hasn’t yet become mainstream. For growers, developing these kinds of farms is a big investment, «Vertical farms are capital intensive, and it also takes a lot of investment to grow and become profitable.» End consumers, however, are seemingly unwilling to bear the additional costs generated by expensive production. But is there any reason why you should opt for vertical farm produce anyway?
Local production, less resource consumption and space-saving farms are all well and good. If we’re being honest, though, plenty of things drive our consumer behaviour, but morality is rarely one of them. Price and taste, to name two examples, are often more decisive factors when buying food products than ideology is. This is good news for vertical farming enthusiasts, as the produce from such farms tastes better. Why? Because the ideal nutrient supply is more likely to be ensured by a vertical farm than by a field or greenhouse.
«The soil in a field can be depleted. Over the year, it might rain too little or too much,» says Eldrid Funck. «We’re not exposed to these fluctuations at the vertical farm. We can simulate the ideal conditions for growth here.» Numerous studies have also addressed the question of how influential environmental factors are on the taste of food. A report published in RSC Advances examined the influence of heat, pH, oxygen and light on the taste of watermelon juice. The authors concluded, «Environmental factors had a significant impact on colour [...] and taste.» According to the results, the most influential factor is the supply of light.
In traditional farming carried out in fields or greenhouses, the use of chemicals to prevent crop failure is standard. Pesticides are used to protect seeds from pests and diseases, therefore reducing the number of failed crops. Not only are they linked to massive biodiversity loss, but they also end up in the groundwater and on the plate of the end consumer. The WWF (link in German) says 2,000 tonnes of pesticide are sprayed onto crops in Switzerland every year. Consequently, toxic residues could be found on almost all types of fruit and vegetables in 2019.
In vertical farms, the problem is easily avoided. Unexposed to environmental fluctuations, the plants aren’t introduced to any pests (viruses, fungi, insects or microorganisms) that would need to be tackled with pesticides. What’s more, they get to grow in an ideal cocktail of nutrients. That makes the produce from vertical farms more natural, says Funck: «Yes, the plants within a vertical farm grow in an artificial environment, but they get everything they need to grow. In addition, they’re not sprayed with chemicals that end up in the environment or the human body.»
A large proportion of our food products are imported from far-flung places. The logical consequence of this is that food is less fresh when it arrives at its destination country and thus at consumers’ homes. «Long transportation routes increase the probability of the produce being delivered damaged or less fresh,» confirms Funck.
Given that food imports to Switzerland have nevertheless almost doubled in the last 25 years, this argument doesn’t seem to be winning many people over. It’s not just the produce itself that suffers on account of the long delivery routes – the environment comes under heavy strain too. According to one study, global food miles account for about 20 per cent of emissions from food systems.
One goal of vertical farming is to grow produce where it’s consumed. According to Funck, this means it can be harvested ripe and sold and eaten fresh without putting the environment under strain: «We deliberately ensured we’d have a journey time of just 10 minutes from the farm to the distribution centre. This way, our produce doesn’t lose any of its freshness.»
A major challenge of vertical farming is profitability. Many crops aren’t financially worthwhile, nor can they be grown in hydroponic systems. Examples include wheat, potatoes or soya beans to be used in the production of animal feed. Instead, Funck says, a lot of experiments are being done with lettuce, herbs and medicinal plants. «The goal is to organise production as efficiently as possible in the future. This will also allow us to plant crops that aren’t yet financially viable at the moment.»
Vertical farming is currently unable to replace traditional farming (and it isn’t yet the way to feed the world’s future population). «We see vertical farming as an essential building block for making the food system complete. The goal isn’t to compete with domestic producers, it’s to complement them.»
I'm a sucker for flowery turns of phrase and allegorical language. Clever metaphors are my Kryptonite – even if, sometimes, it's better to just get to the point. Everything I write is edited by my cat, which I reckon is more «pet humanisation» than metaphor. When I'm not at my desk, I enjoy going hiking, taking part in fireside jamming sessions, dragging my exhausted body out to do some sport and hitting the occasional party.