Soil Physical Properties as Affected by Grain Cart Traffic
Changes in soil physical properties resulting from multiple passes of an 18 m3 single-axle grain cart with a 15.2 t axle load were measured one year after the traffic occurred. Air permeability, air-filled porosity, and dry density data were analyzed to determine how the soil responded to grain cart traffic and pre- and post-traffic tillage. Four repeated passes of the cart decreased air-filled porosity and permeability by as much as 50% in the 200- to 400-mm depth range when compared to the effect of a single wheel pass. With pre-traffic chisel plowing to a depth of 200 mm, most of the compaction in the 100- to 200-mm depth occurred on the first pass. However, four repeated passes had a greater effect on soil properties in the plots that received no tillage compared to the plots that were chiseled before trafficking.