I know StackExchange wrote "But avoid responding to other answers."
Sorry, but great answer from AG6YO.
arcing — another nonlinear phenomenon famous for creating harmonics
... or setting your lawn on fire
If the arcs are big enough, you'll hear them in an AM transistor radio while you transmit, such as on voice peaks. You'd be able to hear the staticy sound through the transistor radio's front-end overload.
And I think you'd see your SWR jump around, especially on power-peaks, if the ground plane is arcing.
Ham radio antennas are often a compromise: bent, shortened, less-than-textbook radials, not high enough, etc. If there's a voltage difference between two points that are the same distance from the feedpoint, I guess the first question to ask would be "How different?" (Not that I'd know what to do with the answer.) A difference would indicate that the groundplane isn't perfect. But if you're not arcing and sparking when you transmit, then your antenna is certainly better than many others'. Perfection is overrated.
I'm also thinking of DeoxIT, Amazon item # B00006LVEU.
Deoxit dissolves corrosion, and then puts down a protective layer that prevents future corrosion. It's a nice thing to dab onto the edge-connectors of PC boards. I've never used it outdoors on the lawn, but I imagine treating connections with DeoxIT, clamping or crimping them, maybe spraying on a 2nd layer so the clamps don't corrode, and then being good for a long time.
Adding a clamp around every point on chicken fencing where the wires cross sounds like an arduous task. Maybe we could get rich inventing chicken fencing especially for ground planes where all the crossover points are electrically secure.
A few decades ago, you could have depended on neighbors complaining about TVI as an indicator that sparking and rectification is occurring in or around your antenna. But now that everyone has cable TV, you can't depend on them, anymore.