PROBLEM TO BE SOLVED: To perform proper irrigation by identifying a condition in which a plant is damaged, without consideration of difference due to a kind of soil and soil temperature.SOLUTION: The invention is configured to measure oxygen density in the soil, and if the measured oxygen density becomes equal to or less than a prescribed value, irrigation is suppressed. At the time, it is possible to measure oxygen density at a position where activity of a root of a plant can be kept according to a culture purpose.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2020,JPO&INPIT【課題】土壌の種類や地温等による違いを考慮することなく、植物に害が及ぶ条件を識別して的確な潅水を行う。【解決手段】土壌中の酸素濃度を測定し、測定された酸素濃度が所定値以下となった時は、潅水を抑制する。ここで、栽培目的に合わせて根の活性を保つことが有効な位置の酸素濃度を測定することができる。【選択図】図３
