Control writes

Ooops, I think you misunderstood me. I'm not concerned about ground
quality changes or anything like that, I'm looking for a method to
detect old (several centuries) locations of vineyards. If copper was
used as a fungicide before 1800, then copper concentration
measurements might be worth a try.

Apparently not, according to torsten.

Does anyone know if copper-lime fungicides are used for other crops
than for wine? Anything I might have to consider mistaking for old
vineyards (planted on south facing hillsides, treated with copper)?

Potatoes, but you don't find them on dry south facing slopes.

Judging by archaeological programs in the UK, you might be able to
detect the rows of posts and probably deep vinous root remains with soil
conductivity or ground radar. You would be looking for rows at vinyard
spacing.

They may even be visible at the right time of year and the right season,
by crop colour changes where there is a little more moisture where an
old root was.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
Note: soon (maybe already) only posts via despammed.com will be accepted.