According to a survey, only 11% of the U.S. agriculture has been exposed to any type of soil or plant sensors! The number of farmers who use any effective method for irrigation scheduling is even smaller than that.
Knowing that the main educational source for many is YouTube videos from random people, this does not surprise me. It's also hard to find good sensors, which adds to the problem.
Soil moisture sensor is not the only tool used for irrigation scheduling, but reliable sensors are always needed to establish irrigation thresholds for other methods.
In a study at Washington State University, we developed and compared seven different irrigation scheduling algorithms based on soil-, plant-, & weather-based approaches. We used Watermark and Decagon 10HS sensors, plus neutron probe to monitor soil water status in an apple orchard. Only neutron probe yielded acceptable readings. Please read paper below to learn more about our findings: