FROM BEDROCK TO SOIL

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FROM BEDROCK TO SOIL
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WHAT YOU WILL DO

• Define soil
• Explain the difference between residual and
  transported soil
• Describe three soil horizons
• Describe how various climates affect soil

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SOURCE OF SOIL

• Parent Rock the source of weathered rock in
  soil
• Residual Soil - the soil formed from
  under-laying bedrock layers
• Transported Soil soil that has been blown or
  washed away from its parent rock

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RESIDUAL SOIL ON QUARTZ BEDROCK
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Living Things Also Add to Soil

• Humus (HYU muhs) particles of decayed plant and
  animal
• Contains nutrients necessary for plant growth
• 20 30 humus indicates healthy soil for growth

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SOIL LAYERS

• Discovery website

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SOIL AND CLIMATE

• Tropical
• Desert
• Temperate
• Arctic

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TROPICAL CLIMATE

• Humid air
• Large amount of rain
• Rain moves quickly and removes nutrients
• through leaching
• Top soil is very thin

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DESERT CLIMATE

• Very little rain low chemical weathering
• Death valley evaporation of water leaves toxic
  salts behind

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TEMPERATE CLIMATE

• Abundance of both chemical and mechanical
  weathering
• Enough rain to cause chemical weathering but not
  enough to cause leaching out ou nutrients
• Breadbasket some of the most productive
  regions

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ARCTIC CLIMATE

• Cold deserts so little precipitation
• Slow chemical weathering slow soil formation
• Very thin and does not support much life

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SECTION REVIEW

• 1) What is the difference between residual and
  transported soils ?
• 2) Which layer of soil is the most important for
  growth of crops ? Explain.
• In which type of climate would leaching be more
  common tropical or desert ? Explain.