園芸ジャーナル
オープンアクセス

概要

A New Technique to Realize a Drastic Acceleration of Crop Growth in the DFT Hydroponic Cultivation with Hyper-oxygenated Nutrient Solution

Hiroaki Tsutsumi, Risa Higashi, Takahiro Kinugasa

Aeration of the nutrient solution has been tried in order to enhance the growth of leaf vegetables such as lettuce, rape, spinach etc, in the hydroponic cultivation with the DFT hydroponic cultivation system in greenhouses. In this study, we chose mini-bok choy as a test crop, and examined the daily changes of oxygen intake by the root in the hyper-oxygenated nutrient solution of the DFT hydroponic cultivation system, and revealed the presence of an unknown capacity of the root for oxygen intake from the nutrient solution, responding to the changes of light intensity, as it can take in oxygen from the hyper-oxygenated nutrient solution as an alternative oxygen source, but the oxygen intake does not run in the light conditions enough for photosynthesis. Mini-bok choy cultivated with the hyper-oxygenated nutrient solution with DO between 8.85 and 22.06 mgO2 L-1 exhibited approximately 2.0 and 1.7 holds of the growth acceleration of its aerial part and root in the period of the experiment over 23 days. We presented a micro-bubble technique to create a hyper-oxygenated nutrient solution for realizing the dramatic acceleration of the crop growth with a minimum cost applicable to the actual hydroponic cultivation of the crop in a greenhouse.