The sensed soil moisture values in this paper used volumetric water content.
Volumetric water content is the ratio of the volume of water and the total sample volume of dry soil.
The soil sample used to get the calibration curve of the EC-5 sensor came from Dai-Yun Organic Farm [9].
In getting the calibration curve of the EC-5 soil moisture sensor our group used the standard direct method of determining
the soil moisture [10].