EVPP 108 Lecture Notes - Lecture 5: Humus, Soil Horizon, Soil Fertility
21 Aug 2016
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Document Summary
Soil is defined as an uncemented aggregate of mineral grains and decayed organic matter with liquid and gas, occupying the void spaces between the soil particles. It serves as the bearing material for roads, pipelines etc. and act as a construction material for mud-built houses. Beneficial impact to man: he gets all nutrient indirectly (by eating plants) It is a resource (for plant growth) and environmental medium: what are the impacts of man on soil. Soil erosion, loss of soil fertility, salination, desertification, Pollution: formed in situ from rocks or sediments or they may be deposited after transport. Soil exhibits distinctive layers with increasing depth called horizons. A horizon (humus and mineral) zone of organic debris zone of organic accumulation. D horizon zone of leaching zone of accumulation zone of weathering bed rock/parent material. Fine texture (clays, < 2 m: medium- texture (silt, 2-50 m)
