soil resources

• What is soil?

  Soil is the loose surface material that covers most land.
• What are the main components of soil?

  Soil consists of inorganic particles and organic matter.
• What role does soil play in agriculture?

  Soil provides structural support to plants and is their source of water and nutrients.
• What are the different types of soil?

  • Clay Soil
  • Sand Soil
  • Silt Soil
  • Loam Soil
• What is clay soil composed of?

  Clay soil is comprised of very fine mineral particles and not much organic material.
• Why is clay soil considered sticky?

  Clay soil is sticky because there is not much space between the mineral particles.
• What are the characteristics of sand soil?

  Sand soil is light, warm, dry, tends to be acidic, and low in nutrients.
• What is silt soil?

  Silt soil is a solid, dust-like sediment transported by water, ice, and wind, made up of particles larger than clay but smaller than sand.
• Why is loam soil considered ideal for garden plants?


  Loam soil holds plenty of moisture but also drains well, allowing sufficient air to reach the roots.
• What is the O horizon in soil layers?

  The O horizon is the upper layer of topsoil mainly composed of organic materials.
• What is the A horizon also known as?

  The A horizon is known as the humus layer and is rich in organic material.
• What occurs in the A horizon?

  Seed germination takes place in the A horizon.
• What is the E horizon or eluviation composed of?

  The E horizon is composed of nutrients leached from the O and A horizons.
• What is the B horizon or subsoil like?

  The B horizon is harder and more compact than topsoil and contains less humus and organic matter.
• What is the C horizon or saprolite/parent rock layer made of?

  The C horizon is devoid of organic matter and is made up of broken bedrock.
• What is the R horizon or bedrock?

  The R horizon is a compacted and cemented layer containing different types of rocks.
• What is soil pollution?

  Soil pollution refers to the contamination of soil with abnormal concentrations of toxic substances.
• Why is soil pollution a serious environmental concern?

  Soil pollution is a serious environmental concern because it harbors many health hazards.
• What are the causes of soil pollution?

  • Man Made
  • Natural Pollutants
• What are some man-made causes of soil pollution?

  Accidental spills, mining activities, and agricultural activities are man-made causes of soil pollution.
• What are some natural pollutants that cause soil pollution?

  Natural accumulation and leaks from sewer lines are natural pollutants.
• What are the effects of soil degradation?

  • Desertification
  • Salinization
  • Water logging
• What is desertification?

  Desertification is the degradation of land in arid and semi-arid regions due to drought and overgrazing.
• What causes salinization?

  Salinization is caused by over-irrigation, where salts are left behind when water evaporates.
• What is water logging?

  Water logging is a problem associated with excessive irrigation on poorly drained soils where water can't penetrate deeply.
• What are the two categories of soil degradation?

  1. Displacement of soil (erosion)
  2. Physical and chemical deterioration
• What are some natural hazards that can lead to soil degradation?

  Natural hazards include climate, steep slopes, and frequent flooding.
• What inappropriate land use can lead to soil degradation?

  Inappropriate land use includes overgrazing and nutrient depletion.
• What is erosion in relation to soil?

  Erosion is the removal of trees or vegetation that affects soil stability.
• What is the most influential factor on global soil degradation?


  Water erosion is the most influential factor on global soil degradation.
• What factors influence water erosion?

  1. Amount of precipitation
  2. Soil texture
  3. Slope
  4. Ground cover
  5. Land use
• What is the composition of soil?

  Soil is composed of 45% mineral particles, 5% organic matter, 25% water, and 25% air.
• What is the role of soil organisms?

  Soil organisms provide ecological services such as decomposition, nutrient cycling, and cleansing water.
• How do ants contribute to soil health?

  Ants aerate the soil by constructing tunnels and chambers, and they help decompose organic matter.
• What is the symbiotic association between roots of plants and fungi?

  Mycorrhizal fungi help in the reestablishment of certain tree species when present in the soil.
• What are the roles of soil nutrients N, P, and K?

  • N: Needed for production of amino acids/proteins; important for photosynthesis.
  • P: Important component of nucleic acids and phospholipids.
  • K: Enzyme activator that allows stomates to open and close.
• What is the typical pH range of most soils?

  Most soil ranges from pH 4 to 8.
• What happens at low pH in soil?

  At low pH, aluminum and manganese in soil water are more soluble and can be absorbed in toxic concentrations by roots.
• What happens at high pH in soil?

  At high pH, essential mineral salts for plant growth become less soluble and less available to plants.
• What is the difference between soil porosity and permeability?

  • Porosity: Volume of water that fits between soil particles.
  • Permeability: Rate of flow of water through soil.