A basic setup involves a wooden pole, a copper spiral winding upward, and a grounding spike or buried wire

https://telegra.ph/ElectroCulture-A-Practical-Approach-to-Sustainable-Gardening-04-30

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.