A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire
https://thrivegarden.com/pages/which-is-more-affordable-electroculture-tools-or-traditional-gardening-equipment
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.