According to the UN, we will need almost three planets’ worth of natural resources if we are to maintain current lifestyles for a human population that is expected to swell to 9.8 billion people by 2050.
Scientists, farmers, institutions and businesses both big and small have been responding to this emergency by trying to revolutionise agricultural practices – one of the most resource-intensive sectors of the global economy. Their priorities include systems for more predictable crops, less waste, more intense indoor farming methods that have a lower impact on the environment, and relocating agriculture closer to urban populations in order to minimise food miles.
One startup at the forefront of these efforts is Bristol-based LettUs Grow. Managing director Charlie Guy says he and his fellow co-founders were spurred into action by the amount of food that gets wasted during its cultivation and distribution. “Around 50% of bagged salad we buy in the UK ends up being thrown in the bin,” he says. “Part of it is to do with portion sizes; part of it is consumer behaviour. But the main thing that shocked us and got us into the industry is how much is wasted in the supply chain.”
Alongside biologist and “plant whisperer” Jack Farmer, and design engineer Ben Crowther, Guy started investigating ways to reduce this waste by perfecting a system to grow crops all year round, close to consumers – and perhaps even ready to pluck straight from their grow beds inside a supermarket.
LettUs Grow’s patent-pending technology is based on aeroponics, which is the process of growing plants by using a nutrient-rich mist environment rather than through cultivation with soil. The plants are fed with artificial LED light and can be stacked into space-efficient “vertical farms”. The company’s technology also incorporates software called Ostara, which collects data and can help farmers manage their crops more efficiently.
Aeroponics uses up to 98% less water than traditional, soil-based agriculture. It can also involve lower carbon emissions than similar, soil-free hydroponic systems in which the roots are simply dipped in nutrient rich water. “We have developed a very efficient way of growing plants in completely controlled environments,” explains Guy, a Bristol University engineering design graduate. “We can control all inputs to growth with a novel aeroponic system, which has been shown to increase growth rate and yield. Typically, aeroponics is plagued with the problem of nozzles getting clogged – we’ve removed all of the nozzles, [effectively combining] the benefits of aeroponics with the simplicity of hydroponics.”
The idea is generating plenty of interest. Last November, LettUs Grow won a €100,000 Postcode Lotteries Green Challenge prize – it has pilots with UK farmers, and is exploring whether its technology could be used to grow salad veg in retail space.
Guy says that farmers see a commercial case for buying the £75,000-plus technology. “Farming can be a very difficult industry with low margins, and farmers are savvy business people,” he says. “Indoor farming and vertical farming offer another route to grow in a predictive manner, all year round.”
The hope is that new technologies such as that offered by LettUs Grow will also enable farming in places that couldn’t previously be farmed. Different countries have different needs and different resource shortages. Some, for example, lack agricultural land, while others have too much rain or not enough.
Guy adds that there is demand closer to home for high-value crops that don’t travel well, such as micro greens. “Lots of people have entered the vertical farming market growing micro greens, which are high in nutrition and extremely tasty, as well as looking good on plates, so chefs love them,” he says. “They are extremely delicate, so it makes sense to grow them as locally as possible.”
Martin van Ittersum, professor of plant systems at Wageningen University and Research, says this kind of growing innovation should be part of a circular shift in our whole system of cultivating, consuming and recycling.
“To maintain some biodiversity and keep climate change within 1.5 or 2C, a lot needs to happen,” he says. “Circularity [is about] using modern technology to make sure we have the highest yields of plant products for human consumption, to make sure we can reuse and recycle human waste in a safe manner, and to raise modern livestock species that can be productive just by consuming waste and byproducts.”
Other experts warn, though, that the vertical farming business case is still tricky: last year Europe’s largest urban farm, based on hydroponics and fish farming at the top of an office block in The Hague, went bust and a Portuguese modular indoor farming idea, CoolFarm, also failed.
Jan Willem van der Schans, a sustainable farming expert from Wageningen University and Research, says such systems make most commercial sense currently in extreme environments. “Vertical farming is a clever technology, but we should use it at those places on planet Earth where it is really competitive, at the equator and poles, where stacking is a more efficient use of light and water,” he says.
He adds that indoor farming also raises sustainability questions due to a higher use of electricity instead of free sunlight – although this could be compensated for by using the agricultural land saved to grow carbon-sinking forests.
Guy is aware of these challenges, but believes his system’s benefits could spread beyond controlled-environment farms to how we treat all of our land. “We want to be able to provide a predictable, resilient supply of produce that means we don’t over-farm or overproduce, but take pressure off the ecosystem so we can farm traditionally in a more sustainable way as well,” he says. “But it has to start with the market case.”
Are you working on an idea with the potential to contribute to a sustainable planet? The Postcode Lotteries Green Challenge is one of the world’s largest sustainable entrepreneurship competitions. This year’s contest is now open and looking for innovations with a viable business plan and the potential to scale. Find out more at greenchallenge.info. Deadline for entries: 1 May 2019.
