ahem...copper can be toxic.If there's too much - i would watch tha plants and better not let it touch the roots...
just some search, cos i was already just in the mood:
"Too much of a good thing can be deadly as well, especially in hydro. Remember that some fungicides rely on copper as an active ingredient. Symptoms include stunted roots and leaf tip burn. If cannabis leaf tissue analysis results reveal more than 25 ppm of copper, toxicity was almost certainly the issue."
But I don't know for sure what an effect such a copper wire in the soil has. Doing it this way just doesn't feel right to me...I'll be watching your experience.
Good Luck!