Could be alfalfa or any livestock forage plants. It might have orchard grass in it but that is not a typical haying operation.

No way to answer that accurately. Depends on the region. It can be Rye Brome, Fescure, Bermuda, Orchard, Alfalfa, Wheat stubble, Peanut foliage, Tall Clover, and another dozen of grasses or legumes I cannot think of at the moment.

Agreed. Much worse than orchard grass would be coastal bermuda. They call it wire grass in Florida. It is very difficult to get rid of.

Whatever it is, I guess I'm going to have to paint it with Roundup.