Soil Profile

1
Soil Profile

• All the different layers or horizons present in
  the soil.
• Mature soil consists of topsoil, subsoil, and
  parent material above bedrock.
• Topsoil is best for plant growth. Most animals
  live in the topsoil horizon.

2
Soil Composition

• Soil is a mixture of rock particles, minerals,
  decayed organic material (humus), air, and water.
• The sand, silt, and clay in the soil comes from
  weathered bedrock.
• The combination of sand, silt, and clay affects
  the types of plants and animals that grow and
  live there.

3
Soil Texture

• Determined by the size of individual soil
  particles or the percentage of sand, silt, and
  clay in the soil.
• Texture names may include loam, sandy loam
  clay, silt loam, or clay.
• Affects the amount of water that can be absorbed
  and used by plants and animals.

4
Particle Size

• Soil particles are classified by size.
• Largest to smallest includes
• Coarse Sand ? Very Fine Sand ? Silt ? Clay
• Soil particles larger than 2mm are called gravel.

5
Soil Permeability

• Soil particles have open spaces between them that
  allow water to flow through.
• How freely that water flows is the permeability
  of the soil.
• Tightly packed soil particles reduce the drainage
  of the soil.

6
Soil pH

• Soils can be basic or acidic and usually measure
  4 10 on the pH scale.
• Most plants grow best in soils with a pH between
  5 and 7.
• Lime is a kind of fertilizer that can be added to
  make the soil more basic (less acidic).