As farm sizes continue to increase, the size, working width and overall weight of farm equipment continues to grow proportionally. Some of the heaviest farm equipment has axle loads exceeding 20 tons.
Increasing the footprint of the tractor by adding larger tires, duals or tracks does reduce levels of surface compaction, but it doesn’t change the axle load or damage to the soil at depth.
Subsoil compaction is rare with axle loads under 5 tons, but highly likely with loads greater than 10 tons per axle, according to University of Minnesota Extension.
Research from Aarhus University in Denmark suggests that when soil pressure created by tires or tracks exceeds approximately 7 pounds per square inch (measured 16 inches below the soil surface), significant soil damage starts to occur.
Most larger tractors, combines, manure-handling equipment and grain carts available on the market exceed 42 pounds per square inch, measured at 16 inches below the soil surface.
While soil type and soil-moisture levels both have a significant influence on the depth and severity of soil compaction, the soil-to-tire contact area and overall axle loads are the major culprits for overall soil damage.
Most farmers across the U.S. and Canada utilizing no-till or conventional-tillage systems use random traffic patterns, where farm equipment passes for harvesting or grain handling aren’t on the same tracks as seeding, fertilizing and spraying.
This is frequently a result of a lack of repeatable-accuracy GPS systems such as RTK, as well as different equipment widths and…