Takumi KUBOTA 

Research on Wasabi Cultivation Technology and Growing Environment Utilizing Sewage Heat

Himeno Shuji

The temperature of sewage is constant throughout the year, and it is characterized by being cold in summer and warm in winter. Since a large amount of sewage flows in stably at a sewage treatment plant where sewage is concentrated, it is possible to recover cold heat in summer and hot heat in winter as abundant heat sources. Therefore, we are cultivating plants using sewage heat at a sewage treatment plant.
Currently, 540 strains of wasabi are cultivated in the plant. Since a cool environment is essential for wasabi cultivation, the cultivation water is kept at 12 to 14 (��) by a heat recovery process and given to wasabi. As the position of this research, we are cultivating wasabi using sewage heat at the plant, and we are verifying whether wasabi grows due to sewage heat. However, in circulation cultivation, the problem of concentration of components arises. Since the verification of the problem would affect wasabi in the plant, we evaluated the effect of the substance of concern on wasabi using a scaled-down container. In addition, this facility consumes electricity to cool and heat the cultivation water to keep the water temperature constant. In container cultivation, heat insulating material is laid on the side of the medium to insulate in order to save energy, but it is not known how much power can be reduced by heat insulating. Therefore, the effect of laying the heat insulating material on the side was evaluated from the estimated value.
It is said that AITC is concentrated and inhibits growth in circulation cultivation, but the concentration of 0 to 0.002 (mg / L) does not affect the growth of wasabi. In addition, no concentration is observed in 1/4 of the total cultivated water in the current week. Next, by comparing the amount of heat consumed by wasabi based on the estimated values, it is possible to reduce the amount of heat by 20% by using a heat insulating material.