Influence of single passes with high wheel load on a structured, unploughed sandy loam soil

In a field experiment, a sandy loam was subjected to single passes with a sugar beet harvester at two different soil water potentials and two different hopper fillings. The moist plot responded to a wheel load of 11,23 t with an increase in bulk density and pre-consolidation pressure as well as with a decrease in air permeability and macroporosity at a depth of 0,12-0,17 m. With a wheel load of 7,47 t on the moist plot and with both wheel load levels on the dry plot, only slight changes of the soil structure were detected. At a depth of 0,32-0,37 m and 0,52-0,57 m, the measurements did not indicate any compaction. An ANOVA indicates that the factor “soil water potential” had the stronger influence than the factor “wheel load”.