What is the function of soil moisture sensors or a low-water cut-off in irrigation?

• A. They increase irrigation system pressure.
• B. They measure rainfall and forecast drought.
• C. They provide feedback on soil moisture or plant needs to adapt watering, preventing overwatering.
• D. They determine fertilizer requirements.

Answer: (C)

Soil moisture sensors and a low-water cut-off act as a feedback system for irrigation. They monitor how much water is in the root zone (or how tense the soil is), and send that information to the irrigation controller. The controller then decides when to water and when to stop, aiming to keep soil moisture at an optimal level for the plants. This helps the system respond to actual plant needs, preventing overwatering and water waste.

They aren’t primarily about measuring rainfall or forecasting drought, which would rely on weather data rather than soil signals. And they don’t determine fertilizer requirements, which depend on soil nutrients and plant needs. The key idea is using soil moisture data to adapt watering so plants get enough water without overdoing it.