If you till the pasture under, chickens will be more than happy to eat your weed seeds and fertilize the area, and you'll get delicious, 'free' eggs out of the deal. BTW...
it's normal in the East to bale the corn fodder and even the soybean fodder for winter bedding in the group pens. It's dry and absorbent and the dairy farmers don't have to buy it if it's already on their field. I don't see anyone selling it, but the farmers who have it , use it.
We utilize cornstalks here. It's amazing how much the cows will eat. They pick through them and eat most of the husks, cobs, and leaves, then they begin to chew on the coarse stalks. Sure, they waste quite a bit of the really coarse parts, but they use that as bedding, and when the ground gets really cold, they can keep themselves up on a nice bed of stalks.