CHICORY (CICHORIUM INTYBUS) PRODUCTION OF USING LOCAL SNOW AND TERRESTRIAL HEAT ENERGY IN MID-SUMMER, JAPAN

Since big Tohoku Earthquake hit Japan on March 11, 2011, nuclear power system was no longer sustainable for future energy use. For the new energy source, this research investigates alternative agro-production style by using natural energy from the local resources, such as snow and the terrestrial heat for cooling the crop growing environment during summer. In the city of Yubari, Hokkaido, the heavily snow region of northern Japan (470 m above sea level), snow was stored in under-ground vault of 4.5 mL x 3.6 mW x 2.7 mH with attached antifreeze solution pipe in the bottom. The pipe was connected to the bottom of cultural beds to cool down the soil directly, and Chicory (Cichorium intybus) which grows normally under 20°C in dark condition was cultivated in those beds to analyze this system. Sizes of these beds were 6.3 mL x 0.9 mW x 0.6 mH covered by heat insulator with three different temperature set-ups. Three levels of temperature of cultural bed, 15°C, 18°C and non-treat were designed, by changing flowing volume of antifreeze solution. In the mid-summer of 2012, maximum outdoor temperature was more than 30°C or high in average, underground soil temperature of 2 to 3 m in depth were stable around 11-14°C. 25 m pipe was buried in underground at 2 m in depth to circulate the room air to cool down the room temperature below 20°C. The experimental room temperature was stabilized at 20°C or lower from July 21 to August 15, 2012, it was 3°C lower than the non-treated room. However the air entrance and exit of the pipe had only 1°C of difference, which means lower cooling ability, this maybe indicates 25 m underground pipe was too short for heat exchange. Snow cooling system control the temperature of cultivation beds to 15°C in full-open regulation valve, and 18°C in half-open valve. Chicory production in mid-summer can be possible by regulating the temperature of cultural beds by using snow and terrestrial heat energy.