Science

• Soil

  The thin topmost layer of Earth. It is a mixture of minerals, air, water, plant materials, and decomposing animals and their wastes.
• Soil can be seen in various shades of black, brown, red and yellow, depending on the main mineral that is found in it.
• Munsell Chart


  Used by soil scientists to determine the color of the soil
• Things that settle on Earth's surface


  • Dust
  • Ash
  • Microplastics
• Dust and Ash


  Mineral particles that come from burning solids or the breaking down of other solid structures into fine particles due to weathering
• Microplastics


  Plastics, fibers or particles from broken down plastic that are very tiny
• One piece of clothing can produce 1,900 pieces of microplastics in every wash
• What soil is made up of

  • 45% Minerals
  • 25% Water
  • 25% Air
  • 5% Organic Materials
• Minerals found in soil

  • Iron
  • Potassium
  • Manganese
  • Calcium
  • And a whole lot more, depending on the parent rocks present
• Organic Materials


  Once part of living things that have decomposed. These dead plants, animals, and waste materials of animals are known as Humus.
• Soil particles


  • Sand
  • Silt
  • Clay
• Sand


  Very small compared to rocks
• Silt


  Finer than sand and contains minerals carried by water
• Clay


  The finest of the soil particles
• Loam


  The mixture of sand, silt and clay
• Loam is the type of soil to be used in planting
• Soil Horizons


  • Organic Horizon (O Horizon)
  • Topsoil (A Horizon)
  • Subsoil (B Horizon)
  • Parent Material (C Horizon)
  • Bedrock (R Horizon)
• Organic Horizon (O Horizon)


  Where organic materials are located. It's where humus and loam are found. It is rich in microorganisms that decompose the organic materials.
• Topsoil (A Horizon)


  Where some burrowing animals and insects are found. It is also where plant and tree roots can be seen.
• Topsoil (A Horizon)


  Composed of a mixture of loam, clay, silt, and sand
• Subsoil (B Horizon)


  Has little to no loam and collects the minerals and nutrients from decomposed organic materials mixed with water
• Parent Material (C Horizon)


  Made up of large rocks that are hardly broken down. There are no animals here.
• Bedrock (R Horizon)


  Made up of solid rock