This article helps to explain the science behind it:
Discussion
This is why people say it's pseudo science. Because people talk about actual science like potentially effecting magnetic and electric fields around a plant and in the same breathe will tell you to just bury some copper in the ground like that will do anything.
I see your point. I probably shouldn't have linked to this video and just commented on electroculture. I've seen many other videos where they install a higher (50 foot) conductor pole.
Tesla did experiments with the conductivity of ether and earth, which is where this comes from.
If I had land to farm, I would do more research.