It is fairly easy to measure soil conductivity at DC and power
frequencies. See program EARTHRES. Such measurement values apply up to
a few hundred kHz.

A few years back I became curious about what happens to conductivity
at HF. And at what frequencies does soil permittivity begin to matter.
Most amateur activity is at HF and above. Yet, without even thimking
about it, we persist in plugging in power frequency values into
formulae and computer programs.

A simpler method that avoids all the digging and repacking of
the soil is described at

http://www.antennasbyn6lf.com/2005/0...arameter_.html

I've been meaning to try it at my qth this summer.

Torsten
N4OGW/5