Estimating specific surface area and cation exchange capacity in soils using fractal dimension of particle-size distribution

Fractal scaling has been proposed as a method to evaluate spatial variability of soil properties. Fractal scaling of particle-size distribution, which controls many dynamic and static processes such as transmission of water and solutes, water holding capacity, heat storage and conductivity, etc., has been widely studied. We evaluated surface fractal dimensions for particle-size distributions, Ds, and their relation to specific surface area, SSA, and cation exchange capacity, CEC, for 22 soils with textures, ranging from sandy loam to clay, derived from distinct parent materials under diverse soil forming processes in central Anatolia, Turkey. Values of Ds ranged from 2.45 to 2.94, finer textures giving greater Ds values. Relationships between Ds and SSA or CEC were successfully described by second degree polynomial regression equations (R2 = 0.76 and 0.74 for SSA and CEC, respectively). The results revealed that Ds can be used as an integrating index in estimating the SSA and the CEC of soils from particle-size distribution, which can be useful in modeling studies.