North Yorkshire mine hosts world’s deepest underground farm trials

Researchers in North Yorkshire are conducting trials in a disused section of a working mine to test the viability of growing crops deep underground. The project, which has established what is described as the world’s deepest underground farm, aims to address the high energy costs associated with conventional vertical farming by utilising the stable environmental conditions found below the surface. The initiative is part of a broader effort to find sustainable solutions to the growing pressure on British food production systems.

The operation is based at the Boulby mine near Saltburn, a site that currently serves as the world’s only commercial producer of polyhalite, a mineral used in agricultural fertilisers. The farming trials are taking place more than 1,000 metres below ground, within a facility that also hosts advanced scientific research. Jacob Nickles, a research fellow at the University of Sheffield and one of the project’s leaders, stated that the team is operating under significant time pressure. He noted that global food production must double by 2050 to support the world’s population, suggesting that the utilisation of mines could be a necessary component of achieving this target. Nickles highlighted that recent extreme weather events in England, including a dry and hot summer that has damaged crops and forced livestock to consume winter feed, have made the food security crisis feel immediate rather than a distant threat.

The project is a partnership between the University of Sheffield and Farm Urban, a food producer focused on social consciousness. The team emphasises that the goal is not to replace conventional agriculture but to work alongside it. Nickles explained that certain crops are uniquely suited to controlled environment agriculture, with lettuce cited as a prime example. The primary objective of the current 12-month study is to gather real-world evidence that uniform and marketable crops can be successfully cultivated underground. During a recent site visit, the results were mixed. While some lettuce plants grew to a size larger than a human head, other crops were less impressive. Nickles attributed these inconsistencies to technical and engineering issues rather than fundamental scientific limitations, noting that this is only the first growth cycle. He expressed optimism about the overall progress of the study and indicated that trials for samphire and tomatoes are planned for the future.

Beyond food production, the project seeks to repurpose the thousands of redundant mines across the United Kingdom. This approach aims to create new employment opportunities and improve access to fresh produce in economically deprived areas. The initiative has received backing from the government, with Patrick Vallance, the then science minister, stating that growing fresh food with reduced energy and land use could strengthen national food security and protect the environment. The use of existing mine infrastructure is central to the project’s economic argument, as it potentially lowers the energy requirements compared to surface-based vertical farms.

The Boulby site is also home to the Science and Technology Facilities Council Boulby Underground Laboratory, a facility regarded as internationally important. It is one of only 12 such laboratories in the world and the only one of its kind in the UK. The laboratory hosts various high-profile scientific projects, including Durham University’s Quasar project, which involves supercooling atoms for quantum technology, and Birmingham University’s DarkSphere, which searches for dark matter. Jonny Gutteridge, the lab’s engagement officer, noted that the facility is a source of national pride, hosting sensitive detectors and pioneering quantum mechanics experiments. Expansion of the laboratory is already under way, with a new cavern scheduled for completion in 2030 that will increase the available space by a factor of five. Further development may follow if the site is selected for the XLZD project, a next-generation liquid-xenon observatory designed to search for dark matter, with a decision on the location expected next year.