buickanddeere
Super Member
When I was growing up and still on the farm we had twelve tractors the two largest were 4WD. They did the heavy pulling in ground prep. Very seldom did we actually engage the 4WD. The other tractors were used in row crop cultivation, orchard crop hauling, loader, harvesters and general purpose use. Most had specific uses and were reserved for that. Some were only used for harvesting, Corn and green beans.
My brother whom is a agricultural equipment mechanic maintains about two dozen machines. The harvestors are 4WD. The three largest are dedicated 4WD groundworking units. Everything else is 2WD. The theory is. If the ground is too wet to work don't bother with 4WD to prep the seed bed. The harvesters are 4WD drive because you can't stop because the field is wet. The three 4WD are hardly ever in 4WD but when pulling big equipment in soft ground extra traction is needed. They have one FEL for road maintenance.
Even if the 2WD will pull the load without apparent slippage. The same tractor with 4WD i the identical conditions will burn less fuel and compact the soil less. Less slippage and less weight on the rear tires.