Vertical farming may promise bumper yields and major water savings, but a new University of Surrey study warns the technology still produces higher carbon emissions than traditional lettuce growing.
Published in Food and Energy Security, the research is the first to fully account for soil emissions from field-grown crops while comparing them with a commercial UK vertical farm. Using a cradle-to-store assessment, the team analysed two British lettuce farms – one on mineral soil and one on peat – plus a Spanish supplier, then set those against a vertical system.
The results show striking advantages in yield and water use: vertical farms produced around 97 kg of lettuce per square metre, over 20 times the 3.3 kg/m² achieved in fields, and used just 0.9 m³ of water per kg compared with up to 7.3 m³/kg in Spain. But the carbon numbers tell a different story. Even when powered by renewable electricity, vertically grown lettuce emitted 0.93 kg of greenhouse gases per kg, compared to 0.57 kg/kg from UK field farms.
Lead author Michael Gargaro said vertical systems could 'transform food security in the UK" as drought and climate change increasingly threaten traditional agriculture'.
Read more at The Scottish Farmer
