Soil Moisture Equation Change
The Natural Resources Conservation Service (NRCS), in cooperation with the Agricultural Research Service (ARS), has
implemented a new Soil Moisture Equation for use on select Soil Climate
Analysis network (SCAN) sites. This work has been peer reviewed and
published (Seyfried, M.S., L.E. Grant, E.Du, and K Humes. 2005. Dielectric
loss and calibration of the hydra probe soil water sensor. Vadose Zone J.
On February 19, 2010, selected SCAN sites were remapped with the new 'loam'
equation, which has been shown to better represent the volumetric moisture
content in these soils (Seyfried et.al 2005). Further evaluation is
currently being done before the new equation is implemented on the remaining
SCAN sites and the SNOTEL database. Site metadata will reflect this change
and all historic and current data will be calibrated using the same
(Historical soil moisture data will be remapped by March 5, 2010).
Additional information concerning the original 'silt' equation is
Inc. 1994. Hydra soil moisture probe user's manual, version 1.2. Vitel Inc.,