Soil Temperature and Moisture Readings Now Available

I’ve just added 2 new measurements to the Goose Lake Weather station, soil temperature and soil moisture. Readings for these 2 parameters are now available at 4, 12, 24 and 36 inch depths. The data is currently available from the Daily Stats link. I hope this data will yield information useful to gardeners like myself. It will also help to estimate the frost depth in the winter and early spring. I also hope to install a frost tube in the near future but more on that later.

Watermark Soil Moisture Sensor

The soil moisture readings utilize a Watermark brand sensor. The Watermark sensor (granular matrix sensor) is an indirect, calibrated method of measuring soil water. It is an electrical resistance type sensor,  which converts the electrical resistance reading to a calibrated reading of Centibars (or kPa) of soil water tension. It does take some time (weeks to months) for the soil moisture readings to stabilize to the surrounding soil.

Centibar Reading Soil Condition

0-10 Saturated Soil. Occurs for a day or two after irrigation.
10-20 Soil is adequately wet (except coarse sands which are drying
out at this range)
30-60 Usual range to irrigate or water (except heavy clay soils).
Irrigate at the upper end of this range in cool humid climates
and with higher water-holding capacity soils.
60-100 Usual range to irrigate heavy clay soils
100-200 Soil is becoming dangerously dry for maximum production.
Proceed with caution.

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