It is advised to stay off the field until conditions are fit for traffic, but sometimes we never reach those conditions. At least, try to avoid creating ruts. If you have different soil types on the farm, start harvest on the better-drained soil types first. Although this is a bit early yet, a little frost in the soil will also help to make the soil much less sensitive to compaction.
Most farmers are aware of the great importance of increasing tire foot print by using flotation tires, duals and reducing tire pressure. Key research in this area was done by Bob Holmes and Randall Reeder at Ohio State University. Their research also showed that tracks can do a very good job as long as the weight of the vehicle is equally distributed along the whole length of the track. The effectiveness of flotation tires is all determined by inflation pressure – inflated at high pressures they will cause much more compaction than at low pressures. Check inflation tables to determine what the minimum allowable pressure is for your tires.
If you need to get new tires, ask your equipment representative about tires that cause less compaction. Radial tires have a bigger footprint than bias-ply tires and are therefore recommended to avoid compaction.
As far as harvest traffic: Keep those trucks with road tires out of the field. Axle load also plays a role, with axle loads above 10 tons being able to cause subsoil compaction that will be virtually permanent and very difficult to alleviate. Also, try to limit repeated traffic to certain areas of the field. Although these will be more compacted, it will be possible to correct compaction here without having to do remedial action on the whole field.