Soil Formation

What is the top layer of soil called?

• Subsoil

• Topsoil

• Bedrock

• Clay

What type of soil particle is the largest?

• Clay

• Silt

• Sand

• Loam

What is leaching in soil?

• A process where nutrients are added to the soil

• The process by which water-soluble substances are washed out from the soil, often leading to nutrient loss.

• A method of soil erosion caused by wind

• The technique of irrigating soil to enhance crop growth.

What is the role of plants in soil formation?

• Plants contribute organic matter to the soil when they die and decompose, enriching the soil with nutrients.

• Plants absorb water and minerals from the soil, preventing erosion.

• Plants provide shade to the soil, reducing temperature fluctuations.

• Plants compete with soil organisms for nutrients, hindering soil formation.

What is weathering in the context of soil formation?

• A process of breaking down rocks into smaller particles due to environmental factors like water, temperature, and biological activity.

• The process of transporting soil from one location to another by wind or water.

• The formation of new soil from organic matter and decomposed materials.

• The chemical alteration of minerals in rocks without physical breakdown.

Which organisms are primarily responsible for decomposing organic matter in soil?

• Fungi, bacteria, and worms

• Plants and trees

• Insects and mammals

• Algae and protozoa

What factors influence soil formation?

• Climate, parent material, topography, organisms, and time

• Only climate and organisms

• Topography and urban development

• Soil pH and moisture levels

How does climate affect soil formation?

• By influencing the rate of weathering, organic matter decomposition, and moisture levels.

• By determining the color of the soil.

• By affecting the types of plants that can grow in the area.

• By controlling the soil's mineral content.

What is humus?

• A type of fertilizer used in gardening.

• The dark, organic material in soil formed from the decomposition of plant and animal matter.

• A mineral found in rocks.

• A type of soil that is sandy and dry.

What is the smallest soil particle?

• Sand

• Silt

• Clay

• Gravel