© David Eggen for The New York TimesJon Kiel, left, and Verlyn Sneller of the agriculture company Verity with a corn stalk produced without a glyphosate-based herbicide.
On a windy day this spring, his neighbor sprayed glyphosate on his fields, and some of the herbicide blew onto Mr. Von Arb's conventionally grown corn, killing the first few rows.
He's more concerned, though, about the soil. During heavy rains in the summer, the runoff from his neighbor's farm soaked his fields with glyphosate-laden water.
"Anything you put on the land affects the chemistry and biology of the land, and that's a powerful pesticide," Mr. Von Arb said.
But 20 miles down the road, Brad Vermeer brushes aside such concerns.
