Weathering’s Physical Influence on Soil Directly • Texture - sand, silt, clay • Structure • Porosity • Consistency • Aeration • Temperature • Moisture Indirectly • Bulk density • Color 3
Soil Physical Properties • Horizons
• Color • Texture • Structure
• Consistence • Bulk Density
Weathering’s Visual Influence on Soil: Soil Layers/Horizons
5
Soil Color • Depicts OM – brown or black, • moisture – moist is darker, and • parent material – eg, if Fe: aerobic = red, or anaerobic = gray/blue • salts - lighter, • ?? Affects temperatures Indirectly, if OM, it affects nutrients, moisture, etc???
6
Soil Color
7
Texture Soil texture refers to the proportion of the soil “separates” that make up the mineral component of soil (fine earth fraction < 2mm). These separates are called sand, silt, and clay. These soil separates have the following size ranges: Sand =
