[universa1]

What one has to keep in mind as well, that even though tractors are really heavy they spread that weight across a large area (using low tire pressures and having massive tires to begin with). So, iirc, the per area impact is even lower then a human. It impacts a lot larger area, though!

Plowing vs tilling is also very much about soil erosion and depends very much of the location you are in.

[bluGill]

Compaction is sublinear with weight, make the tractor heavier so it combacts more makes a small difference where the tires are - but you can now pull something bigger (assuming horsepower) and that means less of the field is touched by tires and in turn less compaction. compaction is worse where the tires touch but they touch less.

the above is also why tires are better than tracks in many cases. The tire has more compaction, but when you turn it touches less land and so overall is better than a track.

of course every soil is different. For details of you particular land you need an expert who knows your soil.