Subterranean salad: underground farmers seek solution to food crisis in disused UK mines

Researchers in North Yorkshire feel the clock ticking as they aim to transform British food production

It has the vibe of a Bond villain’s underground lair but the workers in hi-vis and helmets aren’t weighing and packing hard drugs or parts for a death laser. It’s pak choi and lettuce.

More than 1,000 metres down, researchers in North Yorkshire have created the world’s deepest underground farm and are running trials for a project that could transform UK food production.

They want to use disused mines to grow crops, believing the stable environment and ability to use existing infrastructure could reduce the high energy costs associated with conventional vertical farming.

It’s a game-changing idea, but the team behind it need evidence that it will work – and the clock is ticking.

“We need to double food production by 2050 to support the world’s population,” says Jacob Nickles, a University of Sheffield research fellow and one of the project’s leaders. “That is the long and the short of it. Is it possible? Maybe if we start using mines.”

While Nickles and his colleagues might in previous years have been talking about the food crisis looming far in the future, this year’s extreme weather has shown it could be even closer.

In England, the dry, hot summer has led to crops dying and livestock using winter feed because there is no grass. “The crisis is less looming,” says Nickles, “it’s here … now.”

The underground farm operation has been set up in a science facility at Boulby mine, near Saltburn. The mine itself is a working one: the world’s only commercial producer of polyhalite, which is used as an agricultural fertiliser.

Drive through the ICL-UK mining operation and you will come to offices of the UK government-funded science facility, which hosts mind-blowing experiments – often involving the search for dark matter.

This week, the Guardian accompanied Nickles two-thirds of a mile (1.1km) underground as he and colleagues harvested pak choi and lettuce from vertical towers in the mine.

Getting there involves two detailed health and safety inductions, a change into bright orange hi-vis and an eight-minute descent in the original lift, constructed more than 50 years ago.

Once there, it feels strangely warm. “You’re experiencing a million times less radiation than you were 10 minutes ago. Does it feel nice?” asks the lab’s engagement officer, Jonny Gutteridge.

The experiments take place in the salty tunnels and also the air-conditioned lab facilities where, away from the extensive research going on, you feel you could be anywhere.

The kitchen kettle boils water to make tea, although it boils it hotter than it would on the surface. The toilet flushes, although it is the deepest flushing toilet in the UK.

The farming project is a partnership between Sheffield University and Farm Urban, a socially conscious food producer.

“We’re not here to replace conventional farming,” says Nickles. “We’re here to work alongside it and there are some things that are just uniquely better suited to controlled environment agriculture. Lettuce is a really good example.”

The aim is to gather the first real-world evidence that uniform, marketable crops can be grown underground.

During our visit to the site, there were mixed results. Some crops appeared spectacular, with lettuce bigger than a human head. Others looked less impressive but Nickles is consoled by the fact it is a technical, engineering issue rather than a scientific one.

“It’s sad when it doesn’t work … but I have to keep reminding myself that this is only the first growth.”

Overall, the 12-month study is going well and Nickles is optimistic about the possibility of samphire and tomatoes being trialled next.

As well as producing food at scale that can be sold and eaten, the project is about reusing the thousands of redundant mines that exist in the UK, creating new jobs and improving access to fresh produce in economically deprived areas.

It is backed by the government, with Patrick Vallance, the then science minister, last month saying: “Growing fresh food while using less energy and land – and being less reliant on changeable British weather – could strengthen food security across our country and protect our environment.”

The farm research is taking place in a facility that, its supporters say, should be better known.

“We are in a hole in North Yorkshire,” says Gutteridge. “We’re a small team of 20-25 people. But the science that goes on … In the past we’ve hosted the world’s most sensitive dark factor detector. We’re doing the world’s first deep underground quantum mechanics experiment. We should be so proud as a country to have a place like this.”

The lab’s full name is Science and Technology Facilities Council (STFC) Boulby Underground Laboratory. It is the only place like it in the UK and is regarded as internationally important, one of only 12 in the world.

Among the work going on is Durham University’s Quasar project, which involves supercooling atoms and aims to “open a completely new frontier for quantum technology in the UK”. Nearby is Birmingham University’s Bond-sounding DarkSphere.

The success of the lab means expansion is already under way with stage one: a new cavern providing a factor 5 increase in space, scheduled to be completed in 2030.

Further expansion will happen if Boulby is chosen as the site for a project known as XLZD – the construction of a giant, next-generation liquid-xenon observatory to search for dark matter.

A decision could come next year. “We would love to host XLZD,” says Gutteridge. “The socio-economic benefits, the skills, the outreach, the education, the investment, the industry partnerships, the advanced manufacturing, all of it that would be coming inwards to the north east, to the UK. The impact of hosting a detector like that in the region would be phenomenal.”