Soil

Standard 3.7

Objectives

  1. Explain what soil is
  2. Describe the different components of soil
  3. Identify the five factors of soil formation
  4. Explain the process of weathering and erosion

From Rock to Soil

Related Standards of Learning 3.7d


Objectives

  • The students should be able to explain how soil forms over time.


Materials needed

Per student:

  • Plastic egg

  • Sugar cube


Directions:

  1. Ask the students how they think soil forms, and list their responses on the board. Lead a class discussion on the topic, prompting them to mention the various components of soil.

  2. Give each student a plastic egg and a sugar cube, and have him/her place the cube (representing a rock) inside the egg.

  3. Explain to the students that they will be shaking the egg to simulate weathering and erosion of the “rock” by the action of wind, water, and plant roots over time. Let the students shake the eggs for several minutes.

  4. Have the students open the eggs, pour out the “soil,” and draw a picture of their observations.

  5. Then, have them place the larger portions of the sugar cube back into the egg and repeat the process.

  6. Have the students examine their particles of “soil” to identify each small grain as a soil particle and the larger pieces as pebbles, rocks, etc.

  7. Have the students draw or write about what their parent “rock” looks like after each shaking.

What do you think Soil is?

Vocab Break:

Soil: the thin, outermost layer of the earth’s crust in which plants grow
Big image
From Rock to Soil

Science Enhanced Scope and Sequence – Grade 3, related Standards of Learning 3.7d

Why is Soil Important?

Also:

  • Modifies atmosphere

    • Emits and absorbs dust and gases

  • Source of gas, and stores gas

  • Records human activities at present and from the past

  • Purifies waste

What Makes Up Soil?

Humus

  • Decayed plant and animal matter in the soil
  • It provides nutrients to the soil

Sand

  • Made up of small grains of weathered rock
  • DOES NOT hold water well!

  • Few nutrients

Silt

  • Made up of very small pieces of broken rock.
  • Sand > Silt > Clay

Clay

  • Formed when fine particles of soil sink to the bottom of a river or lake and stick together

  • Holds water well

  • Provides nutrients

  • Yellow-red or blueish-gray

Rock

  • Solid and made of minerals