4.3 Soil Composition and Properties

• What role does water play in soil?

  Dissolves nutrients for root uptake
• What is soil composed of?

  Mineral particles, organic matter, water, and air
• Organic matter in soil enhances both fertility and water retention
• Air in soil supports root respiration.
• What type of mineral particles are found in soil?

  Sand, silt, and clay
• Water in soil dissolves nutrients, facilitating their uptake
• Order the soil horizons from top to bottom.

  1️⃣ O

  2️⃣ A

  3️⃣ E

  4️⃣ B

  5️⃣ C

  6️⃣ R
• Match the soil component with its role:

  Mineral matter ↔️ Provides structure and nutrients

  Organic matter ↔️ Enhances fertility and water retention

  Water ↔️ Facilitates nutrient uptake

  Air ↔️ Supports root respiration
• What does organic matter in soil consist of?

  Decayed plant and animal material
• Air in soil fills pores and supports root respiration
• What are the primary components of soil composition?

  Mineral matter, organic matter, water, air
• Mineral matter in soil includes particles such as sand, silt, and clay
• Organic matter in soil enhances fertility and water retention.
• Air in soil fills pores, enabling root respiration and biological activity
• Arrange the soil horizons in order from top to bottom.

  1️⃣ O

  2️⃣ A

  3️⃣ E

  4️⃣ B

  5️⃣ C

  6️⃣ R
• Which soil horizon is known as the organic layer?

  O
• The A horizon, also known as topsoil, is rich in humus and mineral particles
• The E horizon is depleted of nutrients due to leaching.
• What type of minerals accumulate in the B horizon?

  Leached minerals
• The C horizon consists of weathered parent material transitioning to bedrock
• Match the soil horizon with its description:

  O ↔️ Organic layer with decomposed matter

  A ↔️ Topsoil rich in humus

  E ↔️ Leaching layer depleted of minerals

  B ↔️ Subsoil storing leached minerals
• What does soil texture refer to?

  Proportions of sand, silt, clay
• Soil texture affects water retention, aeration, and nutrient availability
• Soil structure enhances porosity and water infiltration.
• What does soil porosity determine?

  Water storage and air circulation
• Soil permeability affects drainage and nutrient leaching
• Match the soil formation factor with its influence:

  Parent Material ↔️ Determines mineral composition

  Climate ↔️ Affects weathering rates

  Topography ↔️ Influences water drainage

  Organisms ↔️ Adds organic matter
• What role does parent material play in soil formation?

  Determines mineral composition
• Climate influences soil formation through temperature and rainfall patterns.
• Topography affects soil formation by influencing water drainage and erosion
• How do organisms influence soil formation?

  Add organic matter