Hi, I have a two year old 1 acre lawn. About 1/3 of the lawn is bumpy and I have some tire indentations from when I had some post holes for my deck dug. I had originally planned on rolling the lawn this spring but having read some previous threads I understand that it may not be a good idea. What other ways can I smooth out the lawn? The grass has come in very thick and healthy. The bumps are not moles or rocks just settling.