Q & A with LettUs Grow

Our Agriculture team recently got the chance to talk with LettUs Grow, a Bristol based start-up who are designing irrigation and control technology for indoor farms.

You create aeroponic technology for indoor farms. We understand this is a way of growing plants without soil, can you briefly explain how this works?

Our novel technology builds on the successes of hydroponics and addresses many of the issues which have been holding back indoor farming. A common misconception about plants is that they only “breathe” through their leaves, but part of the oxygen and CO2 they use is also absorbed through their roots. By suspending our plants’ roots in the nutrient-dense mist rather than in water, we have overcome some of the problems faced by hydroponics. Because they are not submerged, plants can respire optimally during their whole life cycle. Using this system, called aeroponics, we have seen up to a 70% increase in crop yields over hydroponics.

Aeroponic technology uses a great deal less water than traditional farming. Are there any techniques which you currently use indoors which could be applied to external farming to help reduce water use?

We achieve up to 95% water savings over traditional agriculture. The bulk of this is due to recapture and reuse within the system which is unlikely to be able to be replicated in outdoor agriculture. However, the precise control system we have developed, Ostara®, could play a role in reducing water use outdoors – particularly in drip irrigated operations. The closed loop control allows for a dynamic response to the environment without farmers needing to do anything.

What other advantages are there to aeroponic technology and indoor farming?

• Full control over all inputs to plant growth, thus resulting in predictable yields, 365 days per year. This also enables greater control over germination, propagation and triggering fruiting processes.
• Space efficiency. Vertical growing techniques can grow much more produce in the same footprint, compared to greenhouse and outdoor production.
• No additional heat inputs are required in most vertical growing systems, enabling 24/365 growing.
• Due to recapture and reuse, we use about 95% less water than traditional field-based agriculture and 30% less than typical hydroponics with our unique aeroponic technology.
• In an aeroponic system, plants are able to respire optimally throughout their whole lifecycle, thus reducing the energy inputs required.
• Indoor and vertical farming is not affected by the seasons or a changing climate. Using our technology, farmers can grow year-round, hence reducing the need for global supply chains.
• Controlled environment agriculture eliminates the need for chemical pesticides thereby reducing the cost to the farmer and the impact on the planet.
• Growing vertically takes the pressure off of depleted soils without the need to create new farmland and can even be implemented in urban environments.
• Our systems can be used to diversify existing farm revenues, making use of otherwise disused spaces such as old agricultural buildings, providing a year-round, predictable revenue stream.
• Our farm management software, Ostara®, is breaking down barriers to entry for indoor farming and aeroponics. Aeroponic technology has historically been seen as complex and difficult to implement. Ostara® makes aeroponics easy, making your next harvest just the push of a button away which, alongside our ongoing farming and technical support, makes the learning journey short and smooth. Its inherent versatility means that it has the ability to control, collect data from and optimise any automatable growing operation, from vertical farms to orchard irrigation, to greenhouse production.
• Hydroponics is often seen as an enabler for the future of food production. LettUs Grow has shown 70% crop growth rate increase over traditional hydroponics across a range of leafy green crops and herbs in crop trials.
• Most aeroponic systems produce their mist by pushing nutrient-rich water through strips of nozzles. The small holes quickly become clogged with falling plant debris and a build up of salts and nutrients – much like how limescale forms inside a kettle. This has put many farmers off trialling aeroponic systems. We have developed a system without any nozzles, so there is nothing to clog and break.
• Modularity means farmers can grow at their own pace.

What sort of crops is aeroponic technology used for?

 Our core crops are: coriander (micro), fennel (micro), leek (micro), kale, pea shoots, sunflower shoots, radish, red cabbage, lettuce (many varieties), coriander, watercress, basil, pak choi, strawberries, carrots, spring onions.

What inspired you to become involved in indoor farming and irrigation?

When we discovered just how much food was wasted in supply chains before even getting to supermarkets. We wanted to get in and shorten supply chains. However, once we began exploring agriculture we realised just how many issues we could address with our technology: soil depletion, water usage, pesticide damage, fertiliser runoff, the list just goes on and on!

What other products in the agri-tech industry are you interested in or consider may be important in future farming?

As far as we are concerned, knowledge is power. The application of sensors throughout the food supply chain could have a massive impact. They can provide labour and resource savings as well as being used to monitor food degradation to prevent unnecessary waste.

Do you think indoor farming can work alongside traditional outside farming?

Absolutely 100%! We have never envisioned indoor and vertical farming displacing traditional outdoor agriculture. Like a tractor, controlled environment agriculture is simply another tool in the farmers’ toolbox. It can be implemented into existing farms to help diversify their offering and provide a consistent revenue stream all year round irrespective of the weather.

If traditional farmers wanted to consider diversifying into indoor farming, where would you suggest they begin and how?

Aeroponic systems are perfect for fast, effective and consistent propagation. This would be a great place to start. Indoor farming systems can be used to diversify a traditional farmer’s offering by turning unused barn space into a growing space for out of season crops.

Do you have any tips for traditional farmers seeking to reduce their waste/carbon footprint?

There are lots of brilliant technologies out there which can be used for sensing and crop monitoring. These can be used to catch issues before they arise thus reducing losses and increase yields.