Abstract:
Chinese scientists have proposed a rather bold idea: to reuse a large number of abandoned coal mines across the country and transform originally idle underground tunnels and caverns into agricultural experimental spaces to study new agricultural models for growing crops in a highly controlled environment. Researchers believe that as global climate change intensifies and extreme weather becomes more and more frequent, these underground spaces may become important experimental sites for exploring future agriculture.
China currently has more than 12,000 abandoned coal mines, which have left behind huge underground spaces and a large amount of infrastructure that can be reused. The research team believes that by around 2030, about 15,000 coal mines in China may cease production, which means that the scale of underground space available for transformation and utilization will further expand in the future.
This idea was proposed by researchers from Shanxi Provincial Coal-based Resources Green and Efficient Development Engineering Center and other institutions, and was published in the magazine "China Mining". Researchers believe that abandoned coal mines are not just industrial relics that need to be treated, but can also be regarded as a special underground resource. If qualified mines can be safely transformed, it may be possible to transform the otherwise idle underground space into a closed agricultural experimental unit.
Compared with traditional agriculture, the biggest advantage of underground coal mines is that the environment is relatively stable. Above-ground agriculture is affected by temperature, rainfall, drought, heavy rains, strong winds, and other extreme weather conditions, while underground mines can be largely isolated from the outside climate. Researchers therefore believe that the underground environment is particularly suitable for "closed environment agriculture" research, where most of the key factors affecting plant growth can be artificially controlled.
Of course, underground planting first faces a very obvious problem: no sunlight and no natural rainfall. Researchers propose that natural conditions can be replaced by artificial light sources and environmental control systems, so that factors such as light, temperature, moisture, air, and carbon dioxide can be independently supplied and accurately adjusted. In this way, the underground space no longer relies on the natural environment, but can become a highly controllable agricultural experimental system.
The research team conducted a preliminary assessment of whether the abandoned coal mine is suitable for transformation. They believe that first of all, it is necessary to ensure that the surrounding rock structure is stable and meet the corresponding engineering safety requirements. At the same time, the mine must have reliable ventilation, drainage and safety monitoring systems. Only after these basic conditions are met, some underground tunnels and caverns will have the engineering foundation to build agricultural experimental units.
The mine’s existing infrastructure may also be an important advantage of this transformation model. Abandoned coal mines often already have tunnels, power supply systems, ventilation systems and drainage facilities, which means that if these facilities can be reused, there is no need to build a complete underground agricultural facility from scratch, potentially reducing some construction costs.
There is also a resource in underground coal mines that cannot be easily obtained by traditional greenhouses and open-air farms, and that is geothermal energy. As depth increases, the underground environment can usually maintain a relatively stable temperature, and researchers believe that geothermal energy can be further utilized as a heat source for crop production. Geothermal energy has lower greenhouse gas emission potential than traditional heating methods that rely on fossil fuels, so it may also become an important energy source in underground agricultural systems.
Mine groundwater may also be transformed from an environmental burden into a exploitable resource. After coal mine closures, groundwater may repool and contain sulfates, metals, and other contaminants from long-term contact with coal seams and surrounding rock. Therefore, this water cannot be used directly for agricultural irrigation. However, researchers propose that mine water can be treated and used for agricultural production after removing pollutants, thereby simultaneously solving the two problems of abandoned mine water treatment and underground agricultural water supply.
From this perspective, the transformation of abandoned coal mines into agricultural facilities is not simply "moving farmland underground", but a recycling model that reintegrates mine space, energy, water resources and original infrastructure. What the researchers hope to explore is a comprehensive solution that can simultaneously deal with the environmental issues of abandoned mines and agricultural production issues.
This type of underground farming also has the potential advantage of reducing the impact of natural disasters on agricultural production. Because crops are placed in a closed environment, extreme weather on the ground such as heavy rains, floods, droughts, cold waves, heat waves, and strong winds will not directly damage the production environment like traditional agriculture. As global climate change makes extreme weather events more frequent, this highly controllable production model may have increasing research value.
However, what the researchers propose is not to immediately transform abandoned coal mines across the country into commercial farms on a large scale, but to first use these spaces to conduct agricultural experiments. Through small-scale experiments, it is possible to study the growth patterns of different crops in underground environments and test how systems such as artificial lighting, temperature control, water circulation, carbon dioxide supply, ventilation and energy utilization work together.
If these experiments can prove that underground agriculture is technically and economically feasible, it will be possible to further expand its application scope in the future. Researchers believe that this model is particularly suitable for studying environmental factors that are difficult to control in traditional agriculture, and can also provide technical experience for future agricultural production in extreme environments and closed environments.
This idea is actually related to the rapid development of vertical farming, plant factories and controlled environment agriculture in recent years. The difference is that abandoned coal mines naturally have huge underground spaces, and part of the infrastructure already exists, so in theory they can provide a closed agricultural environment that is much larger than an ordinary laboratory.
Of course, there are also a lot of unresolved problems in underground agriculture. Artificial lighting itself consumes a lot of electricity, and the energy cost of plant factories has always been an important factor limiting their commercialization. At the same time, mine structural safety, long-term ventilation, humidity control, drainage, fire protection, and potential contaminants in the underground environment must all be rigorously evaluated. In particular, the geological structure and pollution levels of different mines vary greatly, and not all abandoned coal mines are suitable for transformation into agricultural facilities.
Therefore, this solution is still in the research and exploration stage, rather than a mature agricultural technology that can be promoted on a large scale. The core idea of the researchers is that as climate change continues to intensify and traditional agriculture faces increasing uncertainty, underground mines, which were regarded as industrial heritage or even environmental burdens in the past, may be redefined as a special kind of agricultural infrastructure.
If breakthroughs are made in related technologies in the future, a large number of abandoned coal mines may no longer just be closed and abandoned underground spaces, but may become huge "laboratories" for studying future agriculture. Through artificial lighting, precise environmental control, geothermal energy, and treated mine water, humans can even try to establish new food production systems in environments that were completely impossible for agricultural production in the past.
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