PROBLEM TO BE SOLVED: To provide a method for supplying water to plants which improves the quality of fruit vegetables and causes no reduction in crop yields: and to provide a hydroponics system to which the method is applicable.SOLUTION: The method for supplying water to plants includes setting the fertilizer concentration of a fertilizer solution for nighttime water supply higher than that of a fertilizer solution for daytime water supply so as to set a limit to the amount of water fed to the fruits and the like from their roots at night. Specifically, the concentration or the electric conductivity of the fertilizer solution supplied at night is set about 4-5 times the concentration or the electric conductivity of the fertilizer solution supplied in the daytime. One of the hydroponics system (1) for implementing the method includes: a cultivation cylinder (19), a primary water supply device (11) supplying a primary fertilizer solution (A), and a secondary water supply device (15) supplying a secondary fertilizer solution B the concentration of which is higher than that of the primary fertilizer solution (A). In the system, the primary fertilizer solution (A) is supplied from the primary water supply device (11) in the daytime, and the secondary fertilizer solution B is supplied from the secondary water supply device (15) at night each to the cultivation cylinder (19) manually, or automatically with a control device (20).COPYRIGHT: (C)2010,JPO&INPIT【課題】 果菜類の品質を向上させ、収穫量も減少させることのない植物への給水方法、並びに該方法を適用可能な水耕栽培システムを提供する。【解決手段】 夜間給水用の肥料溶液の肥料濃度を昼間給水用の肥料溶液のものよりも高くし、夜間に根から果実等へ供給される水分量を制限する。具体的に、夜間に与える肥料溶液の濃度又は電気伝導度を、昼間に与える肥料溶液の濃度又は電気伝導度の約4~約5倍とする。これを実施する水耕栽培システム(1)の1つは、栽培筒(19)と、第1の肥料溶液Aを供給する第1の給水装置(11)と、第1の肥料溶液Aよりも濃度の高い第2の肥料溶液Bを供給する第2の給水装置(15)とを備え、手動、または制御装置(20)による自動で、昼間には第1の給水装置(11)から第1の肥料溶液Aを、夜間には第2の給水装置(15)から第2の肥料溶液Bを栽培筒(19)へ供給する。【選択図】図1
