In this unit, students investigate the properties of three soil components—sand, clay, and humus—as well as their own local soil. They also explore the relationship between soil, roots, and plants. From their experiences, they are introduced to the following concepts, skills, and attitudes.

Concepts

• Soil contains particles of different sizes.
• Soil may contain animals, plants, and their remains.
• Over time, dead plants become part of soil.
• Composting—especially with worms—is an effective way to recycle old plants and other discarded organic matter.
• Sand, clay, and humus are three of the basic components in soil.
• Every soil component has unique properties that can be identified using simple tests.
• Different soils absorb water at different rates.
• Many factors, including soil, affect plant and root growth.

Skills

• Performing simple tests to describe and identify soil components.
• Observing, recording, and organizing test results.
• Interpreting test results to draw conclusions about soil composition.
• Reflecting on test results to predict how plants will grow in different soils.
• Assembling laboratory materials for soil experiments.
• Communicating results and ideas through writing, drawing, and discussion.
• Applying previously learned concepts and skills to analyze unfamiliar soil samples.

Attitudes

• Developing enthusiasm for investigating soil.
• Appreciating the importance of soil for plant growth and animal life.
• Accepting that a range of outcomes is valid.
• Valuing the importance of recycling.