ArticleSOIL PORE SIZE AND GEOMETRY AS A RESULT OF AGGREGATE-SIZE DISTRIBUTION AND CHEMICAL COMPOSITIONLebron, I.1; Suarez, D. L.1; Schaap, M. G.1 Author Information 1USDA-Salinity Laboratory, 450 W. Big Springs Rd., Riverside, CA 92507-4617. *Trade names are provided for the benefit of the reader and do not imply any endorsement by the USDA. Dr. Lebron is corresponding author. E-mail: [email protected] Received July 27, 2001; accepted Nov. 27, 2001. Soil Science: March 2002 - Volume 167 - Issue 3 - p 165-172 Buy Abstract Soil pore size and pore geometry are important properties affecting soil hydraulic properties. Using scanning electron micrographs and image analysis, we quantified the actual pore-size distribution and pore shape in undisturbed soil cores. Aggregate-size distribution was also quantified for the same micrographs. For soils with similar texture, we observed a decrease both in the median aggregate size and in the aggregate-size distribution when the sodium content in the soil increased. We hypothesize that the decrease in the aggregate stability is caused by the weakening of the binding capacity of the cementing agents bonding the domains that form the aggregates. An equivalent decrease in the pore-size distribution was found with increasing sodium and pH. There was a significant correlation between median aggregate size and median pore size, but there was not a significant correlation between median pore diameter and soil texture. © 2002 Lippincott Williams & Wilkins, Inc.