PROBLEM TO BE SOLVED: To take measures to prevent young plants roots growing down into a culture container from affecting the work of transplantation or the like and the water supply and drainage operation of a water level variation type hydroponic apparatus while the young plant is hydroponically cultivated for a long time.SOLUTION: A mesh-like mat 18, which is not fixed to a medium container 3, is provided between the medium container 3 and a medium 5. After a predetermined time has passed since a low water level sensor 9 detected a water level at the time of draining, the draining is stopped. A high water level sensor 17, the low water level sensor 9, and a submerged drain pump 11 are installed away from the medium container 3, and a shield plate 19 is provided between the medium container 3 and them.COPYRIGHT: (C)2015,JPO&INPIT【課題】長期間の水耕栽培時に苗から栽培容器中に伸びて来る根が、植替え等の作業や水位変動型水耕栽培装置の給排水動作に影響することがないよう対策する。【解決手段】培地容器3と培地5の間に、培地容器3に固定せずに網目状マット18を設ける。排水時に低水位検出センサ9が水位検出してから所定時間後に排水を停止する。高水位センサ17、低水位センサ9及び排水用水中ポンプ11を培地容器3から隔てて設置し、培地容器3との間に遮蔽板19を設ける。【選択図】図1
