GPHY 208 Lecture Notes - Lecture 9: Cation-Exchange Capacity, Clay Minerals, Soil Texture

• School: Queen's University
• Department: Geography
• Course: GPHY 208
• Professor: Melissa Lafreniere

Document Summary

Physical properties of soil: soil colour- minerals and organic matter, soil texture- relative proportions of sand, silt and clay size particlces (fine particle size fraction, sand and below is your fine fraction) Soil colour: darker soil= more organic matter, depends on parent material ( different minerals will have different properties) Iron- reflection of the oxidized state ( oxidized= red and yellow; reduced= grey and olive: salts, where you have salt precipitates. Soil texture: fine fraction: sand, silt, clay, clay sized particles tend to be cohesive, more clay you have the soil is sticker, influences aeration= root penetration, water holding capacity and cation exchange capacity, ternary diagram of soil texture* Chemical properties: mineralogy, primary minerals, only most resistant remain- reflects origin of parent material, reflects origin of parent material, secondary minerals, weathering intensity. Soil organic matter: a mix of material, takes on different states, humus-most highly decomposed matter. Important for water retention, good structure and good for the cation exchange capacity.