The Brislington team that has developed a way to grow plants with sound

An innovation in growing plants has the potential to meet the increasing demand for food without sacrificing sustainability, according to the scientists behind it.

The team at LettUs Grow have developed a method that uses ultrasonics and water instead of soil. Trials indicate it can grow some crops up to twice as fast as in comparable hydroponic systems, while also using much less water.

Ultrasonics is sound that travels at frequencies above 20,000 Hz – higher than the range of human hearing. It’s commonly used in sonar or imaging, but its application in large-scale, commercial horticulture is completely novel.

LettUs Grow, which specialises in aeroponic indoor farming technology, says this alternative growing method allows plant roots to grow healthier and faster than in hydroponics – currently the most common irrigation system used in greenhouses and vertical farms.

Charlie Guy, a co-founder and CEO of the Brislington-based company, said: “Events in recent months and years have shone a spotlight on the scale of the problems posed by our current globalised food system.

“Now more than ever, it’s vital that we have the technology and infrastructure in place to support sustainable, domestic food production. Being able to grow more food, closer to where it’s eaten, whilst also using less resources, can have a massive impact on food security and our net zero ambitions.

“By harnessing our unique ultrasonic technology, we can offer growers the ability to grow consistent, healthy and high-quality produce with far less impact on our natural environment.”

With ultrasonic technology, instead of growing in soil, plant roots are suspended in air

To grow plants with sound, ultrasonic technology is harnessed to create high-frequency sound waves that shake water until it disperses into lots of tiny droplets like a mist. This mist can be distributed and controlled to provide the exact amount of water and nutrients to plant roots depending on their needs and stage of growth.

Instead of growing in soil, plant roots are suspended in air, which scientists say mimics the air pockets found in a healthy soil system, boosts access to oxygen and results in faster growth.

Professor Antony Dodd, a research group leader at the John Innes Centre, says controlled environment agriculture such as this “represents an important part of the sustainable production of safe and nutritious food”.

“Now more than ever, it’s vital that we have the technology and infrastructure in place to support sustainable, domestic food production,” says Charlie Guy, CEO of LettUs Grow

Aeroponics commonly uses nozzles to generate mist but technical complexities and issues with maintenance have prevented this technique being successful in larger scale agricultural applications.

A key component of ultrasonic aeroponics is the use of an atomiser to transform liquid into mist, meaning it could be used in larger commercial growing spaces.

Lilly Manzoni, the head of research & development at LettUs Grow, explains: “If you can increase the speed of growth even by one or two per cent on a large scale, you can have a huge impact on your ability to grow nutritious food that is so greatly needed, in a far more sustainable way – and we’re seeing increases of up to double.”

All photos: LettUs Grow

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