This is a simple arduino project ... for 100kΩ in dry soil and 10kΩ in wet). The other method to find the resistor’s value is to try different values or use a potentiometer. Insert the probes into the ...

a 2022 paper by Maja Škiljo and colleagues in Sensors covers an interesting way to make use of this signal attenuation property of changing moisture levels in soil. By quantifying the exact ...