That's a great idea! I think I'll try that with one of my leaf wetness sensors. I have a separate radiation shield I could try it in as well.
We get a lot of fog here in the mornings, so I'll have something to look at, and I can compare it to regular leaf wetness sensor.
Regarding the soil sensor array, that looks nice, as well. My only comment is that rather than stagger them, I think would put the moisture and associated temp sensors closer together. did you have a reason for staggering them?