What is soil science?
a) The study of plants
b) The study of soil formation
c) The study of rocks
d) The study of soil properties, composition, and processes
Answer: d) The study of soil properties, composition, and processes
Which of the following is NOT a primary component of soil?
a) Minerals
b) Organic matter
c) Water
d) Air
Answer: d) Air
What is the term for the uppermost layer of soil, usually rich in organic matter and microbial activity?
a) Subsoil
b) Bedrock
c) Topsoil
d) Horizon
Answer: c) Topsoil
Which soil particle has the largest size?
a) Clay
b) Silt
c) Sand
d) Humus
Answer: c) Sand
Which soil horizon contains partially weathered parent material?
a) A horizon
b) B horizon
c) C horizon
d) O horizon
Answer: b) B horizon
What is soil pH?
a) The amount of organic matter in soil
b) The measure of soil particle size
c) The measure of soil acidity or alkalinity
d) The depth of soil layers
Answer: c) The measure of soil acidity or alkalinity
Which nutrient is commonly deficient in acidic soils?
a) Nitrogen
b) Phosphorus
c) Potassium
d) Calcium
Answer: d) Calcium
What is the role of soil organic matter?
a) Providing structural support to plants
b) Holding and releasing nutrients
c) Increasing soil compaction
d) Preventing soil erosion
Answer: b) Holding and releasing nutrients
Which soil texture has the best water retention capacity?
a) Sandy soil
b) Silty soil
c) Clay soil
d) Loamy soil
Answer: c) Clay soil
What is the term for the movement of water downward through the soil?
a) Percolation
b) Erosion
c) Leaching
d) Capillarity
Answer: a) Percolation
Which soil microorganism is responsible for fixing atmospheric nitrogen into a form that plants can use?
a) Fungi
b) Bacteria
c) Algae
d) Protozoa
Answer: b) Bacteria
What is soil compaction?
a) The process of adding organic matter to soil
b) The process of soil particles sticking together
c) The process of soil particles being squeezed together, reducing pore space
d) The process of soil particles breaking down into smaller particles
Answer: c) The process of soil particles being squeezed together, reducing pore space
Which of the following factors does NOT influence soil formation?
a) Parent material
b) Climate
c) Vegetation
d) Human activity
Answer: d) Human activity
Which soil horizon contains the highest amount of organic matter?
a) O horizon
b) A horizon
c) B horizon
d) C horizon
Answer: a) O horizon
What is the term for the ability of soil to exchange cations with the soil solution?
a) Cation absorption capacity
b) Anion exchange capacity
c) Cation exchange capacity
d) Soil buffering capacity
Answer: c) Cation exchange capacity
Which of the following nutrients is a macronutrient required in large quantities by plants?
a) Iron
b) Zinc
c) Magnesium
d) Manganese
Answer: c) Magnesium
What is the term for the process of minerals being dissolved and carried away by water in soil?
a) Leaching
b) Erosion
c) Weathering
d) Percolation
Answer: a) Leaching
Which of the following is a characteristic of well-drained soil?
a) High water retention capacity
b) Low infiltration rate
c) Poor aeration
d) Waterlogging is a common issue
Answer: c) Poor aeration
What is the primary source of organic matter in soil?
a) Plant roots
b) Soil microorganisms
c) Decaying plant and animal material
d) Atmospheric deposition
Answer: c) Decaying plant and animal material
Which of the following soil types has the highest water infiltration rate?
a) Sandy soil
b) Silty soil
c) Clay soil
d) Loamy soil
Answer: a) Sandy soil
What is the term for the loss of soil due to wind or water action?
a) Erosion
b) Weathering
c) Leaching
d) Percolation
Answer: a) Erosion
Which of the following is NOT a primary soil-forming factor?
a) Climate
b) Relief (topography)
c) Soil texture
d) Parent material
Answer: c) Soil texture
What is the role of soil aggregates in soil structure?
a) Facilitating soil compaction
b) Reducing soil aeration
c) Enhancing water infiltration and root penetration
d) Preventing water movement in soil
Answer: c) Enhancing water infiltration and root penetration
Which of the following soil horizons contains the most weathered material?
a) A horizon
b) B horizon
c) C horizon
d) O horizon
Answer: c) C horizon
What is the term for the gradual breakdown of rocks and minerals into smaller particles by physical, chemical, and biological processes?
a) Weathering
b) Erosion
c) Leaching
d) Percolation