Old field free lease

Decent land is pretty hard to come by but the is a 20 acre field just down the road from me. The land owner bush hogs it once a year. It has alot of weed growth but the owner didn't want me to turn it up and replant. If I keep it cut and keep fertilizer on it, do you guys think it will make decent beef hay? Just trying to figure out if it's worth the time and money. The land itself is free.

Old field free lease