Comparison of fractal dimensions estimated from aggregate mass-size distribution and water retention scaling

Relating soil structure to soil hydraulic properties is an important issue for understanding and managing soil functioning. Fractal models were applie d to relate soil water retention and soil structure. One such model develop ed by Rieu and Sposito (1991a) predicts an equality of(i) soil matrix fract al dimensions derived from 'aggregate bulk density- aggregate size data' an d (ii) soil fractal dimensions derived from water retention. The objective of this work was to test the statistical hypothesis of such equality for mo del soil systems of packed soil aggregates. Typic Argiudol and Typic Argiaq uol soils were sampled at eight locations that differed in long-term manage ment practices, Soil water retention was measured at 12 levels of soil matr ic potential ranging from -1200 to -20 kPa, The 'aggregate hulk density-agg regate size' data were obtained for seven ranges of aggregate sizes from 0. 25 to 16 mm, The statistical hypothesis about the equality of mass fractal dimension as derived from the aggregate bulk density data and the scaling d imension of water retention could not be rejected in our study.