| 摘要 |
PROBLEM TO BE SOLVED: To carry out hydroponic to produce crops having high quality while suppressing the growth of pathogenic fungus without using a bactericide and a pH-adjusting chemical, and supplying minerals by injecting ozone into circulating hydroponic culture medium and passing the medium through a packed bed filled with granular granite porphyry. SOLUTION: Hydroponic is carried out by injecting ozone into circulating hydroponic culture medium at least with passage of time and passing the hydroponic culture medium through a packed bed 10 filled with granular granite porphyry 9. Further, it is preferable that the hydroponic is carried out by using the following maintenance and control apparatus 1 for the hydroponic culture medium: a partition board 4 on which a number of small holes 3 have been board is placed at a position of a halfway height of the container 2 whose upper side is open; in a space 8 above the partition board 4, granular granite porphyry 9 is filled; and in a space below the partition board 4, an ozone distributor 6 communicating with an ozone source is placed and an inlet opening 7 for introducing circulating hydroponic culture medium is formed. |
