PROBLEM TO BE SOLVED: To prevent plants from withering and dying because of expansion of roots of plants hindering circulation of a liquid fertilizer when cultivating perennial plants continuously for a number of years with hydroponic culture or the like.SOLUTION: To supply a liquid fertilizer to a cultivation tank satisfactorily and continuously for a long time, a water pipe system is constructed by directly connecting a water supply port and a drain port to a water conduit in a bottom part of the cultivation tank, water permeable holes made in the water pipe system enable both supply of the liquid fertilizer and water drainage of a surplus if any. In addition, wrapping the water pipe system with a material that has water permeability and can inhibit invasion by roots of plants realizes a structure that prevents invasion of the water permeable holes by the roots and that does not hinder circulation of the liquid fertilizer.COPYRIGHT: (C)2014,JPO&INPIT【課題】水耕栽培等により、多年草植物を数年間継続的に栽培する場合には、植物の根の拡張により液肥の循環が阻害され、植物が枯死してしまうなどの致命的な問題が生じる恐れがあった。【解決手段】栽培槽への液肥の供給を長期にわたり良好かつ継続的に行うために、栽培槽底部の導水管に給水口、排水口を直結した水管系統を構成し、この水管系統にあけた通水孔により、液肥の供給と余剰が生じた際の排水を合わせて行えるようにする。また、水管系統を通水性が良くかつ植物の根の侵入を阻止できる素材で梱包することにより、通水孔への根の侵入を防止し、液肥の循環を阻害することのない構造とする。【選択図】図2
