Using latent heat of water evaporation to cool the culture medium for high-bench strawberry culture.

摘要

We designed a system that uses latent heat of water evaporation to cool the culture medium in a high-bench culture system for out-of-season production of strawberries. The culture bench was constructed from film bags and metal frames. The film, which contained the culture medium, was composed of two layers. The inner layer was a silver-coloured plastic film while the outer layer was cotton cloth exposed to the air below the bench. A little water was dripped continuously onto the cotton layer to keep it wet. The water supply tube was contained in the frame of the bench to make it a simple structure. The heat of the medium evaporated the water, thereby cooling the medium. The temperature of the medium measured at 5 cm below the surface (medium depth was 10 cm), was 5 to 6 degrees C lower than that of the control, which had no cooling system. Moreover, when air was circulated by a fan placed under the bench, the temperature at 5 cm depth was more than 10 degrees C less than that of the control. We expect that this technique will allow early transplanting around the end of summer..