ENV100Y5 Midterm: Module 3
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ENV100Y5 Full Course Notes
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Document Summary
Soil is a complex material: mineral matter, organic matter, water, gases, dead living microorganism, bacteria, supports plat growth. Soil formation starts with bedrock: parent material= base geological material of soil, bedrock= continuous mass of solid rock (the earth"s crust, regolith (sediment)= broken up rock. Weathering = processes that break down rocks: physical (mechanical)= no chemical changes in parent material (wind, rain, chemical= substances chemically interact with parent material (water gases, biological= organisms break down parent material (tree roots) Soil formation is very slow: factors that affect soil formation: Biological activity (soil microbes and fauna; decomposition and accumulation or organic matter) Can take 10 000 years to have good soil. A soil profile consists of horizons: soil profile = the cross section of soil as a whole, horizon= layer of soil. Layer differ in colour, texture, nutrients: leaching: dissolved particles move down through horizons. Soil colour: black or dark brown= organic matter, pale grey or white= leaching, red=iron.
