Horticulture LED lighting has opened a new horizon for farming. Indoor farming, vertical farming and many other alternative ways to grow crops free the weather limits for food production. Now, British scholars at University of Nottingham suggested that abandoned underground coal mines could be suitable environments for growing vegetables. With hydroponic systems and LED lighting, crops can be grown in subterranean environments some advantages. For example, groundwater could be directly used in the hydroponic systems. Besides, crop production is unaffected by climatic or sea...