PROBLEM TO BE SOLVED: To provide a soil moisture supplying apparatus which is inexpensive, high general-purpose properties, and does not cause corrosion.SOLUTION: The present invention provides a soil moisture supplying apparatus having a detection sensor 2 which is buried in the soil and detects soil moisture, and a water supply valve supplying moisture when determining that moisture is insufficient or dry. The detection sensor incorporates a light emitting and receiving element 6, has a transparent plastic container with waterproofness, and has controlling means which measures and stores a first output value V2 of the light emitting and receiving element in a state where the soil is dry, measures and stores a second output value V1 of the light emitting and receiving element in a state where the soil is filled with moisture, stores the threshold value between the first output value V2 and the second output value V1, and controls water supply based on the threshold value.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2017,JPO&INPIT【課題】安価で汎用性が高く、腐食が発生しない土壌水分供給装置を提供すること。【解決手段】土壌内に埋められ、土壌中の水分を検出する検出センサ2と、水分が不足もしくは乾燥していると判断したときに、水分を供給する水供給バルブを有する土壌水分供給装置において、検出センサは、投受光素子6を内蔵し、透明で、防水性のある樹脂製容器を有すること、土壌が乾いた状態で投受光素子の第1出力値V2を計測し記憶し、土壌が水分で満ちている状態で投受光素子の第2出力値V1を計測し記憶し、第1出力値V2と第2出力値V1の間のしきい値を記憶し、しきい値に基づいて水分供給を制御する制御手段を有する。【選択図】図4
