Soil Water Monitoring Techniques

Soil Water Monitoring Techniques

As garden season is upon us, I thought a good discussion of soil moisture sensing was in order.

Years ago, when I was designing radiation thermometers, ag was a potential market that few addressed. I’m guessing it was mostly an economic issue. The sensors of that era were spendy, and it was rare that one could set one up just for soil measurements.

I’ve thought about doing so, as I have problems remembering to water houseplants. My thumb is anything but green. Still, the issues of interfacing X sensors around the house to monitor leaf differential temperature are less than trivial. It would be a wiring mess.

So…. infering soil moisture via a gypsum block seems pretty interesting. If I could manage to couple a small transmitter, and battery to a gymsum sensor, it would be slick for inside plants. Of course, the technical issues are still there. Bandwidth, and power are both concerns.

My last thought is to go simple. A gympsum block, a Tiny13, and a button cell battery and LED would seem a simple solution. When the LED starts flashing, the plant would need water. Then again, one needs a power indicator, so perhaps a bi-color led is in order. A green flash for power, and a red flash when water is needed.

I shall have to think more on this one.