ALDC = -[A.sub.0][exp(-[k.sub.1] E) - exp(-[k.sub.2] E)] + [C.sub.2] (3)
In the ALDC model it is assumed that at E = 0, the amount of aggregated and discrete material starts at [C.sub.2], and as energy is applied to the system, the amount of liberated aggregated and discrete material in a chosen size range approaches a maximum, [B.sub.a], at which the rate of aggregate liberation is equal to the rate of breakdown into smaller sized fractions.
A component of the ALDC model is a measure of the critical energy ([E.sub.crit]), which is the point where the rate of aggregate liberation equals the rate of dispersion.
The shape of the ALDC is determined by the rate constants [k.sub.1] and [k.sub.2] which describe the rates of aggregate liberation and subsequent dispersion, respectively.
Finally, the initial theory underlying the ALDC assumes that aggregates first breakdown into the predefined size fraction 2-20 [micro]m in diameter.
The results obtained indicate that the ALDC, devised by Field and Minasny (1999) for Vertosols, can be used to model the liberation and subsequent dispersion of soil aggregates in the topsoils of Chromosols and Ferrosols, by using a range of different size fractions between 2 and 100 [micro]m in diameter for each soil type.