FRACTAL FRAGMENTATION, SOIL POROSITY, AND SOIL-WATER PROPERTIES .2. APPLICATIONS

The fractal model of Rieu and Sposito contains seven predictive equations that can be tested experimentally with data on aggregate characteristics and soil water properties for structured soils. However, data with which to test the model are extremely limited at present because of the need to have precise, concurrent measurements of aggregate physical properties (bulk density and size distribution) along with soil water properties for an undisturbed soil. For the five sets of suitable physical soil aggregate data currently available, good agreement was found with the fractal model bulk density-aggregate size and size-distribution relationships. For the single set of aggregate/soil water properties data available, good agreement also was found with the fractal model water-potential scaling relationship, moisture characteristic, and hydraulic conductivity-water content relationship. Model simulations of the last two soil water relationships for hypothetical sandy and clayey soils also were qualitatively accurate and showed the sensitivity of the model to the value of the fractal dimension. These encouraging results suggest that the model should have success in further experimental tests with natural soils.