Abstract
We conducted a trial of microporous film as a hydroponic bed for supplying oxygen to nutrient solution and promoting plant growth. Gas and water vapor can permeate through the microporous film, whereas water cannot. Containers were made with the microporous film, and these were filled with 500 mL of water (4 mgL-1or 6 mgL-1dissolved oxygen (DO) ) . DO was found to increase 2-h later, and the oxygen supply rate increased linearly as the increase in the area of the microporous film. Oxygen supply rate at low DO concentration was higher than that at high DO concentration. Water evaporation rate increased linearly as the increase in the area of the film. There was a significant negative correlation between the water evaporation rate and water temperature.
Fresh weight of spinach shoots grown in a container using the microporous film was higher than that without aeration. DO concentrations in a container with aeration by an air pump at 4-h intervals were higher than those treated with the microporous film, although the fresh weight of spinach was same the two plots. It is possible to grow two spinach plants to a commercial size using 800 cm2of the microporous film.
