Improving the productivity, sustainability and scalability of hydroponic growing systems - reducing agrochemical dependency through UV, electrolysis and organic biofilters

"**VISION:** Growing Underground are the UK's leading hydroponic farm, utilising an abandoned air raid shelter in Clapham, to grow microgreens and salads for local supermarkets and restaurants.

Crops are sown into felt and then grown using nutrient-enriched water, which is then recycled and reused in the system. Hydroponic growing (HG) has a number of advantages over traditional farming, requiring 90% less water, 80% less space, producing yields 50% quicker and enabling crop production in areas typically not considered viable (NCBI comparison:2016). Investment in HG and its adoption, technologically and commercially, is being held back however through inconsistent yields and a reliance on agrochemicals.

**OBJECTIVES:** Working with the Department of Sustainable Agriculture at Nottingham Trent University, we intend to improve the productivity, sustainability and scalability of hydroponic growing systems, utilising UV, biofilters and other organic materials including slightly acidic electrolyzed water to sterilize water, seeds and replace agrochemical use in the growing process.

**FOCUS:** Chlorine Dioxide/Chlorates (CD) has been the sterilisation technology of choice for the vast majority on hydroponic, vertical and greenhouse growers, despite environmental issues associated with its use. As the regulatory and consumer landscape move away from the use of agrochemicals, it is now vital that a safe, sustainable, environmentally friendly alternative to CD use in closed-loop systems is developed.

**INNOVATION**: Focussed on growing our main crops micro herbs (fennel, coriander, salad rocket, purple radish, red mustard, wasabi mustard, garlic chive) and pea shoots, the project will result in innovations in three areas;

1. A chemical-free system to purify water in the closed loop growing processes - utilizing an optimised combination of UV, agrobacterium, carbon filters and polysaccharides (WP2)
2. A chemical-free system for the sterilization and disinfection of seeds - using UV, swelling and vibration system toto 'swell' the bacteria-occupying crevices on a seed's surface and purge bacteria and contaminates (WP3).
3. Determine the optimal UV light configuration combination for each crop to boost yield (30%), growth rate (26%) and reliability (reduction in disease-related crop loss (30% vs other agrochemical-free technologies)

**OUTCOME:** Hydroponic, vertical and other non-traditional growing systems have long promised to be an environmentally-friendly, sustainable and resource efficient alternative to traditional agriculture and meet the 60% increase in demand for crops expected by 2030.With latent consumer demand for UK-grown salads, and regulatory demand for farmers to go agrochemical free, we see this as a £24m opportunity (5-year cumulative revenue) that is strategically important long-term food security."