Which statement best describes a Weather/Soil-Moisture Based Controller?

• A. It uses weather or soil-moisture data to control irrigation
• B. It is always central-based
• C. It is the same as a conventional timer
• D. It requires two wires only

Answer: (A)

Weather or soil-moisture data drives the irrigation schedule. These controllers gather information from a local weather station or soil-moisture sensors and use that input to estimate plant water needs (often via evapotranspiration) and to decide when and how long to water. They can also adjust or skip irrigation after rainfall, helping avoid overwatering and conserve water. This dynamic, data-driven approach sets them apart from fixed-timer controllers that run on a set clock.

They aren’t inherently central-based; they can be stand-alone or part of a larger system. The number of wires isn’t fixed to two—the wiring depends on how many irrigation zones (valves) the system has, not the controller type itself.