First of all, not many farmers in the East use grain buggies or carts. The fields just are not big enough for that. Instead, we use wagons. Wagons have four wheels not two. No Wagon I have ever seen uses tracks.
Carts and buggies (which do often have tracks or big huge ballon tires) are dragged all over the place following the combine to unload on the fly. This is to maximize combine efficiency. On the other hand, Wagons are parked on laneways at the end or sides of the field and the combine goes to them. Wagons are seldom used on the field. They are too heavy and as you say, the compaction would be terrible. They are only driven on the field when they are empty and even then only to get them into position for a quick exit. Wagons don't dump into another form of transport. They are pulled directly to one of the local licensed grain elevators to be dumped. Typically one or two wagons are pulled by one tractor on the highway to take them to the elevator while one or two other wagons are being filled.
My Wagon tires are all steering tires from concrete mixer trucks that have been recycled to farm use on grain wagons. As I understand it, concrete truck steerage tires cannot be retreaded. So they are ideal for usage on a grain Wagon.
