My home lawn is two acres of turf. 635 feet deep x 135 feet wide. The previous owner had sectioned it off for horses. We removed the fences and now keep it mowed with a John Deere 727-A zero turn mower. Problem is::::the lawn is very uneven and bumpy. Some ruts are ten inches deep. It's a nightmare to mow. Can I use a "farm disc" to disc it up (to even it out) and not kill my existing Kentucky bluegrass lawn??? I thought about bringing topsoil, but it would take many semi loads. Also, when is the best time to have a neighborhood farmer to come in and disc it up - yet have the best chance of my bluegrass surviving???