The contact area of a Challenger tractor approaches 90 square feet. Tracks reduce soil compaction . If you have ever walked in a freshly tilled field you know that your feet compress the soil and leave footprints. If you were to wear snow shoes you would compress the soil less by spreading out the load. Large tractors weigh tens of thousands of pounds, so spreading out the load to reduce compaction is important.
Tracks also give better flotation .
If a wheel tractor tried to drive through a muddy field, it would likely get stuck. Tracks, however, allow a Challenger tractor to work right through the wet field. The fact that the belts are made of rubber is also unique. Most Caterpillar bulldozers use steel tracks instead of rubber because steel tracks last a very long time and have great traction. The problem with steel tracks is that you cannot take them on the road because they chew up the asphalt.