
Effect of soil compaction on root and seedling growth at three different soil bulk densities: Low, 0.7 g/cm3; Medium, 1.1 g/cm3; High, 1.6 g/cm3. (Stephanie Nelson, Honors Program project).

Links:
[1] http://www.ipm.iastate.edu/ipm/icm/2006/6-19/variablesoil.html