Study of the energy abrasion rates of five soil types subject to oblique impacts

To measure the energy abrasion rates in inter-particle collisions, we bombarded 12 soil samples from five textural classes (sandy loam, silty loam, loam, silty clay loam, and silty clay) with 350 μm diameter glass beads falling freely from heights of 5 to 100 cm. The results indicated that brittle cracking plays a major role in the erosion of brittle soil surfaces during bombardment with impacting particles. The occurrence of such brittle cracking would be likely to chip off large pieces of irregular, sharp-edged fragments and aggregates, and would also give rise to a wide range of abrasion rates and dust production rates under the same impact velocity and by the same impacting particles. The soil abrasion rate is approximately proportional to the impact energy, and inversely proportional to the PM2 content of the soil raised to the power 2.56 and the PM10 content of the soil raised to the power 3. The sandy loam, loam, silty loam, silty clay loam, and silty clay had averaged energy abrasion rates of 0.791, 0.300, 0.033, 0.024, and 0.008 g J− 1, respectively.