ABSTRACT
An aggregate is a group of primary particles that adhere to each other more strongly than
to surrounding soil particles (Kemper and Rosenau 1986). Aggregate stability can be
defined as the resistance to disruption or breakage of the bonds within the aggregates by
external forces of impact, shearing, and abrasion and internal forces arising from the escape
of entrapped compressed air (slaking) and differential swelling. Methodologies have been
developed so that aggregate stability can serve as an indicator of the resistance of soils
to water erosion, surface seal or crust formation, compaction leading to decreased infiltra-
tion and subsoil aeration, and as a general soil quality indicator (Doran and Parkin 1994;
Le Bissonnais and Arrourays 1996; Larney et al. 1996). The methodologies devised for
measuring aggregate stability have been numerous and diverse (e.g., Yoder 1936; He´nin
et al. 1958; Kemper and Rosenau 1986; Le Bissonnais 1996; Marquez et al. 2004).
Nimmo and Perkins (2002) discuss some of the variations or modifications to widely used
standardized methods.
