A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire
https://blogfreely.net/galenacmeo/electroculture-and-compost-synergy-in-the-soil
A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire, positioned near crops to capture atmospheric ions and gently influence local electrostatic conditions.