Getting your ground weed free??

In the spring of 2015 I picked up 25 acres that was loaded with pretty much every kind of grass and broad leaf weed you could ask for. I wasn't worried about broad leaf weeds to much because I knew I could spray them out after planting orchard grass, but the crab grass and Johnson grass had to go since couldn't spray it out once I planted the Orchardgrass. So in the spring of 2015 I sprayed it with glysphate let it green back up sprayed it again and did this every month which was four times. In August I disked the ground up cultimulched and seeded with my brillion. The new orchard grass came up awesome and very very clean so I know this system works. My question is there another way to exhaust the ground of weed and grass seeds without taking the land out of production for a year? I hope to close on 54 acres of new ground in December. As of right now I plan to plow it this winter. Disc and cultimulch in the spring to create a false seed bed. Let the weeds flush burn em down and do this 4 times like I did on my last property then disk and cultimulch the ground next fall and plant.

Getting your ground weed free??