we bought a 10 acre farm several years ago; 5 acres were covered with pheasant pens. After pulling out the posts and ripping out chicken wire that had been buried 10 inches underground to prevent fox from getting at the pheasants we were left with a disaster..... post holes every 8 feet that were begging to break a horse's leg and a very uneven terrain that would bounce me all over when trying to brush hog the field.
I bit the bullet and had a farmer in the area come over... he tilled the ground first then used a 18' wide disc to go over the ground in three directions, then picked rocks and gave it a final discing before he seeded it and put in soy beans. There was green poking up in about 3 days and now, what a difference! The ground is nice and smooth and I haven't found one remaining post hole to worry about.
The cost to me is that he gets to use the land rent free this year, next year I'll either have him put into soy beans again or I'll pay him to disc it and plant some kind of cold/ warm weather grass.