Soil

What this chapter teaches

Soil is rock grains, humus from rotted plants and animals, water and air. Shaken in water and left to settle, the biggest grains sink first, so soil sorts into stones, sand, silt and clay, with humus floating. Sandy soil has big gaps and drains fast. Clay soil has tiny gaps and drains slowly.

Three questions to ask

There is no one right wording. Listen for the idea.

1. What do you see when you shake soil in a jar of water and leave it?
2. Why does sandy soil drain faster than clay soil?
3. What is humus, and where does it come from?

After the chapter, the learner can

• Separate soil into layers by shaking it in a jar of water
• Compare how fast water drains through sandy soil and clay soil