ESCI-UNIT 8

Multiple Choice

Which of the following is a factor that affects soil formation?

• Climate

• Color of soil

• Shape of leaves

• Amount of sunlight

Open Ended

Why is understanding soil formation important for agriculture and the environment?

Multiple Choice

Which of the following best describes soil?

• A consolidated layer of rock

• Unconsolidated regolith modified over time by water, air, and organic material

• A mixture of only minerals and water

• A type of organic matter only

Multiple Select

Which of the following are components of fertile soil?

• Minerals

• Air

• Water

• Plastic

Multiple Choice

Arrange the following steps of soil formation in the correct order: A) Formation of C Horizon, B) Addition of Organic Matter, C) Formation of A Horizon, D) Formation of B Horizon.

• A, B, C, D

• B, A, C, D

• A, C, B, D

• A, B, D, C

Open Ended

Based on the diagrams and descriptions, explain how soil is formed and what factors influence its formation.

Multiple Choice

Which of the following is NOT a layer of soil as shown in the diagram?

• O horizon

• A horizon

• Z horizon

• C horizon

Multiple Choice

Which layer in the soil profile contains the most nutrients for plant growth?

• Horizon O – Organic Layer

• Horizon A – Topsoil

• Horizon B – Subsoil

• Horizon R – Bedrock

Multiple Choice

Which soil horizon is found directly below the topsoil?

• Horizon O – Organic Layer

• Horizon B – Subsoil

• Horizon C – Parent Material

• Horizon R – Bedrock

Multiple Select

Which of the following are characteristics of Horizon B – Subsoil?

• Contains many nutrients and tiny living things

• Made mostly of clay and minerals washed down from above

• Usually lighter in color and harder than topsoil

• Made up of weathered rock pieces

Open Ended

What is the main difference between Horizon R and Horizon C in the soil profile?

Open Ended

Explain how the different soil horizons work together to support plant life.

Multiple Choice

Which branch of soil science is concerned with how soil influences organisms, especially plants?

• Edaphology

• Pedology

• Geology

• Ecology

Open Ended

What is the relationship between topography and soil formation?

Multiple Select

Which of the following are factors that can influence soil texture?

• Particle size

• Organic matter content

• Water retention

• All of the above

Open Ended

Why is soil texture considered a basic property of soil?

Multiple Choice

Which three components are used in the USDA soil classification system as shown in the soil triangle?

• Clay, silt, and sand

• Nitrogen, phosphorus, and potassium

• Water, air, and minerals

• Organic matter, rocks, and gravel

Open Ended

Explain how the USDA-NRCS classifies soil orders around the world and why this classification is important for agriculture.

Multiple Select

Which of the following are types of soil classified by their unique characteristics?

• Gelisols

• Histosols

• Spodosols

• Andisols

Open Ended

Compare and contrast the characteristics of Vertisols and Ultisols, and discuss how these properties affect their agricultural use.

Multiple Choice

Which type of soil is most likely to be found in dryland regions?

• Aridisols

• Ultisols

• Oxisols

• Histosols

Open Ended

Reflecting on today's lesson, what is one factor that you think most significantly affects soil formation, and why?