It's now common to see grass and weed killers that are touted as being able to control weeds and grass for several months after spraying.

Does this mean they'll also hinder the growth of your food plot seeds planted during that time? Are they adding something that prevents or hinders germination of seed in addition to killing the existing foliage through contact with the blades and leaves?

Not sure about all of them, but I bought some stuff to spray my gravel drive with to keep the Bermuda from growing up in the edges. It advertised that it sterilized the soil for 12 months and nothing would grow. I'm about 7 or 8 months in an there is nothing growing in the places I sprayed.