Within the limits of our experimental conditions, we can arrive
at the following conclusions.
In the case of both tractors on the three soil conditions, a greater
MR force was observed in the soil with the lowest bearing capacity
(ploughed soil). This loss decreased for both tractors as the soil
bearing capacity increased.
For the three different soil conditions, the results are consistent
with the notion of topsoil damage related to ground pressure, and
subsoil damage being related to total axle load.
One pass of the tractors with high total weight (up to 90 kN) on
the soil under the direct sowing system produced subsoil
compaction.
The smallest power loss ratio due to MR and engine power was
found with the 4WD tractor on the three soil conditions