Researchers have found that rust-coated irrigation pivots could signal an absence of nitrate in nearby groundwater -- and position them as a guidepost when monitoring for the contaminant, which has ...

Oh, we don’t have to worry about that area. They have red pivots. On its face, the anecdote was clear enough. The “red” in question, Troy Gilmore knew, was rust. The pivots, meanwhile, were center ...