Former mining towns find prosperity through innovationThe city of Boryeong was a major mining town in South Chungcheong province until the late 1980s. But by 1992, all 47 coal mines in Boryeong had been shut down. Left with abandoned mine shafts and high unemployment, two men from Boryeong’s agricultural technology center, Park Seong-gyu and Bae Geun-seok, came up with an idea.
Just a year earlier, they noticed a cool wind coming out of a coal mine while they were resting near the entrance. If the breeze was properly channeled, they thought, it would be possible to raise mushrooms even in the summertime.
Moreover, they expected the 5,000 miners who lost their jobs after the coal mines were shut down would be able to convert to mushroom farming instead. The two men prepared a plan for mushroom cultivation and presented it to the Boryeong county office, asking for 20 million won ($19,200) in funds.
However, county officials didn’t show any interest in the project and had doubts on whether raising mushrooms in a mountainous area was possible. But after consistently lobbying the mayor and public officials, they succeeded in getting about 5 million won.
As soon as they secured the budget, they recommended the miners grow mushrooms. A former miner, Bok Yeong-ho, stepped forward. In March 1992, Mr. Bok used 5 million won of his own money and funds from the technology center and started cultivating mushrooms in a 200- square-meter (2,152-square-foot) greenhouse.
After four months, the first crop of mushrooms was produced using the cool winds from the coal mines. Boryeong city officials evaluated the project, and the county head and citizens all agreed that the superior quality exceeded that of ordinary mushrooms. As news of the burgeoning mushroom crop spread, other farms elected to participate. In 1995, 60 farms participated; by 2004, the number had climbed to 150. Over half of the farms are run by ex-miners.
Last year, the farms produced 2,800 tons of mushrooms, 15 percent of the national production and raking in sales of 9.2 billion won. The average income per household is about 30 million won.
When you walk into a mushroom greenhouse on the outskirts of Mount Seongju in Boryeong, you get goosebumps due to the chilly wind. Inside, the temperature reads 12 degrees Celsius (54 degrees Fahrenheit), 18 degrees lower than the outside temperature. Inside, the white mushrooms flourish, absent air conditioners or electric fans.
The wind is drawn from a closed mine 100 meters (328 feet) away into the greenhouse. Natural chilly winds ― with temperatures of 11 to 14 degrees Celsius ― blow from the 5-kilometer-deep mine shaft. Because of convection, the cold wind comes out of the mine during the summertime, and the outside wind blows into the mine during the winter. By using this principle, farmers maintain a greenhouse temperature of 15 to 18 degrees Celsius year-round.
In order to harness the cool wind, a tunnel shaped like a greenhouse is placed in front of the coal mine. The 100- to 200-meter-long tunnel has several holes that are 60 centimeters (23 inches) in diameter that the wind is channeled through. The wind blows at a speed of 6 meters per second, and the humidity of the wind is 70 to 80 percent, perfect for raising mushrooms.
A single coal mine can provide enough wind for 10 to 16 greenhouses. The farms in the region use the natural air conditioning from May to October. The method produces about 40 kilograms of mushrooms per square meter. In 1996, the Boryeong agricultural technology center filed a patent for the method.
Farmers save on electricity costs for air conditioners and fans usually employed for growing mushrooms. Additionally, the highest quality mushrooms are grown in cool environments, which make for superior color and taste. Compared to ordinary mushrooms, cool wind mushrooms are more expensive. The method yields 10 percent more mushrooms as well.
by Kim Bang-hyeon