Soil Physics with HYDRUS Chapter 1 Equations Tables

Soil Physics with HYDRUS: Chapter 1 Equations, Tables, and Figures

1. 6 – 1. 10

1. 11 – 1. 13

TABLE 1. 1 Approximate charge characteristics of soil colloids (Brady and Weil, 2008) Colloid Type Organic matter Smectite Vermiculite Fine-grained micas Chlorite Kaolinite Aluminum oxide Iron oxide Allophane CEC cmolc kg-1 200 150 30 30 8 4 4 30 AEC cmolc kg-1 0 0 0 2 5 5 15

TABLE 1. 2 Specific surface area range for selected colloids (Skopp, 2000) Colloid s m 2 Kaolinite Illite Bentonite Montmorillonite Crystalline iron oxides Amorphous iron oxides Organic matter 15 -20 80 -100 115 -260 280 -500 116 -184 305 -412 560 -800 TABLE 1. 3 Specific surface area for bulk soils (Skopp, 2000) Soil Textural Class s m 2 Sands loams and silt loams Clays g-1 <10 5 -20 15 -40 >25

TABLE 1. 4 Size classes of soil structure (Soil Survey Manual, 2008) Size Class Very fine Fine Medium Coarse Very Coarse Platy† Mm <1 1 -2 2 -5 5 -10 >10 Prismatic or Columnar Mm <10 10 -20 20 -50 50 -100 >100 Blocky Granular Mm <5 5 -10 10 -20 20 -50 >50 mm <1 1 -2 2 -5 5 -10 >10

TABLE 1. 5 Cecil soil series description (plot 4 from Bruce et al. , 1983) Horizon Textural Class Structure Color Ap Depth cm 0 -21 Loamy sand Brown BA 21 -26 Clay loam Bt 1 26 -102 Clay Bt 2 102 -131 Clay BC 131 -160 Clay loam 251+ Sandy clay loam Weak, medium granular Weak, medium, subangula r blocky Strong, medium, subangula r blocky Weak, medium, subangula r blocky Massive C Red with few strong brown mottles Red Red with light red and weak red mottles