Silver:

One of the points of contention being the farm vehicles strewing corncobs along the road, you may want to check Indiana's roadway and litter laws and see if the state has a statute like this one:

27-51-1405. Throwing destructive or injurious materials on highway prohibited.

(a) No person shall throw or deposit upon any highway any glass bottle, glass, nails, tacks, wire, cans, or any other substance likely to injure any person, animal, or vehicle upon the highway.

(b) Any person who drops, or permits to be dropped or thrown, upon any highway any destructive or injurious material shall immediately remove it or cause it to be removed.

(c) Any person removing a wrecked or damaged vehicle from a public highway, as defined by § 27-51-101, shall remove any glass or other injurious substance dropped upon the public highway from the vehicle.
I'm sure the laws in the Corn Belt are as protective of farmers as they are here in the Cotton Belt... but this is a good statute to keep in mind for this issue as well as those retread tire casings that truckers keep scattering everywhere...

Tom