LEBANON, Pennsylvania — You may not be aware that there’s a symmetry in Pennsylvania between farmers and the natural gas industry. But just walk into the Keystone Pork, Poultry Progress and Mid-Atlantic Manure Summit here at the expo center in Lebanon County, put your hands on the propane-shaped stress ball, and you’ll start to understand it.

“Kind of tells you everything,” said Chris Herr, the executive director of PennAg Industries Association, who was holding up the merchandise everyone received when they walked into the door.