To provide an irrigation method in which, no nutritious liquid is supplied to a plant in irrigation stop time, even when an irrigation amount adjustment mechanism (dripper) in which a liquid drips, is used.SOLUTION: When a nutritious liquid is supplied to plants 10 using an irrigation hose 42 to which a dripper 44 for adjusting the irrigation amount, is attached, pressure release means is provided on a part other than the dripper 44 on the irrigation hose 42, in stop of a pump 40, the nutritious liquid is discharged from the pressure release means, for rapidly reducing pressure in the irrigation hose 42 to pressure which is lower than pressure at which liquid dripping occurs by the dripper 44, for preventing liquid dripping from the dripper 44.SELECTED DRAWING: Figure 3【課題】液垂れする潅水量調節機構（ドリッパー）を用いた場合でも、潅水停止時に養液が植物に供給されない潅水方法を提供する。【解決手段】潅水量を調節するためのドリッパー４４を取付けた潅水ホース４２を用いて植物１０へ養液を供給する際に、潅水ホース４２のドリッパー４４以外の部分に、圧力解放手段を設け、ポンプ４０停止時にこの圧力解放手段から養液を抜くことにより、潅水ホース４２内の圧力をドリッパー４４が液垂れを起こす圧力よりも低い圧力まで急激に低下させて、ドリッパー４４からの液垂れを防ぐ。【選択図】図３
