Vertical crop-growing technology pioneered at Devon's Paignton Zoo could soon be used to grow large-scale commercial crops if trials underway prove successful.
VertiCrop is a closed-loop hydroponic system that uses conveyor belts to ensure plants have equal access to light. This enables them to be stacked up in multiple levels, which greatly increases the plant density.
Iglo Foods Group, which owns the Birds Eye brand, is trialling the system, supplied by Canadian firm Alterrus, alongside the zoo's own award-winning project that provides food for the zoo's animals. Trials of basil began there last month, with further trials of peas and spinach to follow.
Iglo head of agriculture and vegetable procurement James Young said: "This enables us to grow crops indoors in a controlled environment - reducing energy usage, removing the need for pesticides and eliminating the threat of bad weather while maximising space."
Alterrus has already installed a commercial cropping system on top of a building in Vancouver, Canada, believed to be the first of its kind in North America, that began production for local outlets in November.
Also based on the Paignton trial, it is expected to yield about 70 tonnes of fresh greens a year - 10 times more crop per hectare than conventional field horticulture.
Alterrus chief executive Christopher Ng pointed out that the VertiCrop system enables efficient same-day supply of produce to local urban markets.
"The smaller carbon footprint involved is a critical point," he added. "Food production represents one of the world's largest sources of unwanted gas emissions."
Multi-storey plans - Swedish glasshouse
In Linkoping, central Sweden, the Plantagon company has begun building a 54m-high multi-storey glasshouse that will begin production of leafy green salads by next year. It will also house a centre of excellence for urban agriculture.
Later this month, Linkoping will also play host to the second Urban Agriculture Summit, which is being billed as the largest-ever gathering on the subject. Two further such summits are planned in the city over the next two years.