A Field Study on the Influence of M1A1 Abrams Tank Traffic on Soil Compaction

Military training exercises using heavy-tracked vehicles is an intensive land-use activity that may result in vegetation disturbances and soil compaction. In this study, the focus was on soil compaction as a result of M1A1 Abrams battle tank traffic. For this purpose, two main treatments were investigated: tank trafficking rates at the time of tank training maneuvers and moisture content of the soil profile. The influence of Abrams tank traffic on soil bulk density and mechanical impedance was measured immediately after the tank passes on plots having three different soil moisture levels. We found increased soil bulk density as a result of tank traffic regardless of the number of tank passes. Overall soil bulk density increases throughout the soil profile were 0.04, 0.07, and 0.04 g/cm for the low-, medium-, and high-moisture plots, respectively. After three, six, and nine tank passes, consistent increases in penetrometer resistance measurements were observed. However, the effects of the number of passes appear somewhat inconsistent when low-moisture contents were dominant in the soil profile (0.12–0.17 cm/cm). For plots with the highest moisture level (0.37–0.38 cm/cm), the impact of tank traffic was concentrated in the surface 15 cm, with an average increase of 1 MPa regardless of the number of tank passes. We conclude that the effects of different tank passes on soil compaction did not follow a clear trend. Moreover, based on the residual impact of tank traffic, we conclude that efforts should be made to avoid tank exercises when the moisture content in the soil profile is 0.26 cm/cm. We further conclude that tank traffic should be restricted when possible when the soil moisture content is in the 0.40- to 0.46-cm/cm range.