Archive for October, 2012

Soil Moisture Recharge?

Saturday, October 27th, 2012
Watermark soil moisture sensor

Watermark soil moisture sensor

After a long period this past summer of little precipitation, the month of October has provided some regular intervals of modest rainfall. This is helping to recharge the depleted soil moisture. I have a soil temp/moisture station with soil moisture sensors buried at 4, 12, 24, and 36 inch depths paired with soil temperature sensors near our garden. The Watermark® Soil Moisture Sensor is an indirect, calibrated method of measuring soil water content. It is an electrical resistance type sensor. The Soil Moisture/Temperature Station converts the electrical resistance reading from the sensor into a calibrated reading of centibars of soil water suction with a range from 0 to 200 centibars where zero is saturated and 200 is completely dry. I have daily readings available on my Garden Weather page.

One of the problems when “planting” the sensors is ensuring that the sensor makes a good contact with the surrounding soil. I suspect that with our very clayey soils in this recent drought that the soil surrounding the 4 inch depth moisture sensor may have shrunk, thereby resulting in higher readings from that sensor than were present. Although given the extended dry period, it may not have been that far off from reality. Essentially, the sensor maxed out at the driest 200 cb reading back in early June and has not changed until the last 2 days.  This may indicate (hopefully) that we are finally starting to see some recharge of soil moisture.

Soil Temperature/Moisture Station.

We still have a way to go to make up for the soil moisture deficit but perhaps this winter will provide some beneficial snow that can be very efficient at soil moisture recharge.

Stay tuned…


4 inch Soil Moisture Plot

4 inch Soil Moisture Plot. Zero indicates saturated soil and 200 is dry.