Soil Profile Terminology Quiz

Questions and Answers

What is the O-horizon?

Soil layers with a high percentage of organic matter.

What is the A-horizon?

Topmost mineral horizon; often referred to as topsoil.

What does the B-horizon contain?

Deposits of leached material.

What is the C-horizon composed of?

Weathered rock little affected by soil-forming processes. Signup and view all the answers

What is the D-horizon?

Soil layer that has not been subjected to weathering. Signup and view all the answers

What is humus?

Organic component of soil formed by the decomposition of leaves and plant material. Signup and view all the answers

What is topsoil?

Upper outermost layer of soil, usually the top 2-8 inches. Signup and view all the answers

What is subsoil?

Layer of soil under topsoil composed of a mixture of small particles. Signup and view all the answers

What are weathered rock fragments?

Consist mostly of loose rock fragments. Signup and view all the answers

What is bedrock?

Lithified rock that lies under loose softer material called regolith. Signup and view all the answers

Study Notes

Soil Profile Components

O-horizon: Rich in organic matter, typically includes layers of leaves, pine needles, twigs, and decomposed humus.
A-horizon (Topsoil): The uppermost mineral layer, known for its darker color due to high levels of humified organic matter.
B-horizon: Characterized by leached material accumulation, including soluble materials and minerals like clay, iron, or aluminum.
C-horizon: Composed of weathered rock that has minimal influence from soil-forming processes.
D-horizon (Bedrock): The deepest layer, consisting of unweathered mineral matter or different mineral complexes that form the foundation of soil layers.

Soil Features

Humus: Organic component created from the decomposition of plant material, essential for soil health and fertility.
Topsoil: The uppermost layer, typically 2-8 inches deep, crucial for plant growth due to its highest organic matter content.
Subsoil: Located beneath the topsoil, a mix of fine particles lacking organic matter and humus, important for water and nutrient retention.
Weathered rock fragments: The lowest zone in soil profiles, primarily made up of loose rock materials that may serve as a substrate for soil development.
Bedrock: Solid, intact rock located below regolith; serves as the foundational layer from which soil layers develop.

Description

Test your knowledge of soil profiles with this quiz focusing on the terminology related to soil horizons. Learn about the O-horizon and A-horizon, their compositions, and their significance in the ecosystem. Perfect for students studying soil science or environmental studies.