Yuri, K3BU wrote:
"If anybody cares to discuss the subject, or explain how the conductor
laid on the ground can lose its conductivity, bring it on."

"Lose its conductivity" is likely a mischaracterization.

Conductivity of a wire at a particular temperature and frequency is a
function of the form, size, and material the wire is made of.

Proximity of the earth should not affect conductivity directly.

Loss from an R-F carrying conductor can come from energy coupled into
the surroundings. Obvious source is the R-F in the conductor. Closer the
conductor comes to the earth, the higher its capacitive coupling, and
the more current flows in the lossy earth, especially in the case of an
unbalanced conductor.

The fact that a conductor laid on the ground can lose R-F does not mean
it lost conductivity. It means the conductor has induced loss in the
ground upon which it is laid.

Best regards, Richard Harrison, KB5WZI