Method and apparatus for irrigation control

摘要

A method and apparatus for controlling an irrigation cycle of an area of soil or like material are disclosed. The irrigation cycle may stop as soon as a wetting front of the applied fluid reaches a depth Zi. The wetting front may continue downward into the soil by drainage and percolation to a predetermined final depth Zf. The irrigation cycle controlling apparatus may include an irrigation controller such as a water valve and a wetness sensor configured as a tubular rod. The wetness sensor may be composed of a plurality of porous, hydrophilic plastic material rings, which are separated from each other by a plurality of non-porous, non-conductive rings. A pair of electrodes may contact the top and bottom surfaces of each porous ring and may emit signals to a central processing unit in accordance with the degree of soil wetness. A switching circuit may be connected to the central processing unit and to each of the electrodes. The central processing unit may cause irrigation to stop as soon as the wetting front has reached the depth Zi. A liquid crystal display and/or external terminal may also be connected to the central processing unit.