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

1.1 – 1.5

1.6 – 1.10

1.11 – 1.13

TABLE 1.1 Approximate charge characteristics of soil colloids (Brady and Weil, 2008) Colloid Type CEC AEC cmolc kg-1 Organic matter 200 Smectite 100 Vermiculite 150 Fine-grained micas 30 Chlorite Kaolinite 8 2 Aluminum oxide 4 5 Iron oxide Allophane 15

TABLE 1.2 Specific surface area range for selected colloids (Skopp, 2000) Colloid s m2 g-1 Kaolinite 15-20 Illite 80-100 Bentonite 115-260 Montmorillonite 280-500 Crystalline iron oxides 116-184 Amorphous iron oxides 305-412 Organic matter 560-800 TABLE 1.3 Specific surface area for bulk soils (Skopp, 2000) Soil Textural Class s m2 g-1 Sands <10 loams and silt loams 5-20 Clay loams 15-40 Clays >25

TABLE 1.4 Size classes of soil structure (Soil Survey Manual, 2008) Size Class Platy† Prismatic or Columnar Blocky Granular Mm mm Very fine <1 <10 <5 Fine 1-2 10-20 5-10 Medium 2-5 20-50 Coarse 50-100 Very Coarse >10 >100 >50

Depth Textural Class Structure Color cm TABLE 1.5 Cecil soil series description (plot 4 from Bruce et al., 1983) Horizon Depth Textural Class Structure Color cm Ap 0-21 Loamy sand Weak, medium granular Brown BA 21-26 Clay loam Weak, medium, subangular blocky Red Bt1 26-102 Clay Strong, medium, subangular blocky Red with few strong brown mottles Bt2 102-131 BC 131-160 C 251+ Sandy clay loam Massive Red with light red and weak red mottles