Plant Agriculture Exam

What is partially decomposed plant and animal matter, rock particles containing minerals such as iron, potassium, sulfur, and phosphates, Water, Air, Living organisms

• soil

• erosion

• windbreak

• irrigation

Physical breakdown of rock by wind, water, cold, and heat.

• Mechanical weathering

• Chemical weathering

Molecular nature of rock is changed due to reactions with water, oxygen, etc.

• Mechanical weathering

• chemical weathering

Each layer of soil is called a....

• map

• weather

• horizon

• layer

The O horizon is composed of...

• Humus. Non-decomposed plant matter.

• Topsoil. Organic matter mixed with weathered rock particles.

• Subsoil. Tiny rock particles that leach down from the topsoil.

• Parent material. Rock that has undergone little weathering because it is so deep underground.

The A horizon is composed of...

• Humus. Non-decomposed plant matter.

• Topsoil. Organic matter mixed with weathered rock particles.

• Subsoil. Tiny rock particles that leach down from the topsoil.

• Parent material. Rock that has undergone little weathering because it is so deep underground.

The B horizon is composed of...

• Humus. Non-decomposed plant matter.

• Topsoil. Organic matter mixed with weathered rock particles.

• Subsoil. Tiny rock particles that leach down from the topsoil.

• Parent material. Rock that has undergone little weathering because it is so deep underground.

The R horizon is composed of...

• Topsoil. Organic matter mixed with weathered rock particles.

• Subsoil. Tiny rock particles that leach down from the topsoil.

• Parent material. Rock that has undergone little weathering because it is so deep underground.

• Bedrock. Unweathered, solid rock.

Which of the following is not considered a rock particle found in top soil?

• sand

• silt

• clay

• minerals

The great planes of the US is made of what type of ecosystem?

• Prarie

• planes

• desert

• temperate grassland