Soils

• What are the main components of soil composition?

  Air 25%, Mineral Particles 45%, Water 25%, Organic Matter 5%
• What is a soil profile?

  A vertical section from soil surface to parent material
• What are the layers of a soil profile called?

  Horizons
• What does the A horizon contain?

  Decomposed organic material (humus)
• What is the B horizon also known as?

  Sub-soil
• What is the C horizon composed of?

  Weathered rock
• What are zonal soils?

  Soil profiles related to climate regions
• What does the acronym "CROPT" stand for in soil forming factors?

  Climate, Relief, Organisms, Parent Material, Time
• How does climate influence soil formation?

  It affects temperature and moisture levels
• What is the role of organisms in soil formation?

  They contribute to the organic part of soil
• How does time affect soil development?

  Younger soils are more influenced by parent material
• What are the processes leading to soil formation?

  • Weathering of parent material
  • Decomposition of dead organic matter into humus
• What are the two types of humus?

  Mull humus and Mor humus
• What is Mull humus characterized by?

  Nutrient-rich plant remains, dark brown crumb structure
• What conditions lead to Mor humus formation?

  Wet climatic conditions with slow breakdown
• What is leaching in soil processes?

  Downward movement of dissolved compounds in water
• What materials are commonly moved during leaching?

  Calcium, magnesium, sodium, potassium compounds
• What is capillary action in soil?

  Upward movement of water from sub-soil
• What is eluviation?

  Physical translocation of minerals down through soil
• What is illuviation?

  Re-deposition of material from A horizon to B horizon
• What are the key characteristics used to distinguish between soils? (DCATS)

  • Depth
  • Colour
  • Acidity
  • Texture
  • Structure
• How does soil depth relate to soil age?

  Deeper soils are generally older
• What does soil colour indicate?

  Soil chemistry and nutrient levels
• How does acidity affect soil fertility?

  More acidic soils are less fertile
• What does soil texture describe?

  Mix of sand, silt, and clay particles
• What is the best soil texture for plant growth?

  Loam soil
• What does soil structure refer to?

  How soil particles and humus combine
• What is the ideal soil structure for drainage?

  Crumb structure
• How do soil properties influence vegetation in biomes?

  • Mineral and nutrient content affects plant growth
  • Organic matter influences soil color
  • Moisture levels indicate soil structure
• What is the zonal soil found in Temperate Grasslands?

  Mollisol or Chernozem
• What is the significance of earthworms in Mollisol?

  They mix nutrients into the upper horizons
• How does precipitation affect nutrient leaching in Mollisol?

  Limited leaching occurs due to precipitation levels
• What is the effect of capillary action in Mollisol?

  It brings calcium carbonate into the upper horizon
• What is the pH level of Mollisols?

  Neutral, around 6-7
• What are Gelisols?

  Soils found in the Tundra with permafrost
• Why are Tundra soils considered young?

  They were freed of permanent ice only 10,000 years ago
• What limits the decomposition of organic material in Tundra soils?

  Cold climate and waterlogging conditions
• What is the pH level of Tundra soils?

  Can reach below 4.5, very acidic
• What is permafrost?

  Permanently frozen layer in the soil
• What are the impacts of thawing permafrost?

  Causes erosion and soil movement