Rocks and Soils Lesson plan

Lesson plan

Links to National Curriculum

KS2 Science; Rocks and Science SCN 3 1-17a
KS3 Geography; Rocks, Weathering & Soils

  • Estimated time: 60 minutes
  • Location: Outdoors & Indoors
  • School term: All year round
  • Key stage(s): KS2, KS3
  • Subject(s): Science, Geography

Learning objectives

  • To understand soils are made from rocks and organic matter.
  • Identify similarities and differences between types of soil.
  • Investigate soil from the local environment.
  • Look at how the parts a soil is made of affect how it behaves.
  • To begin to understand the value of soil.

Key vocabulary

Rock, soil, bedrock, weathering, organic matter, humus, living organisms, particles, drainage

Introduction

Fully investigate a tray of soil and collect words to describe the appearance and texture. This collection might include dirt, earth, mud, worms, crumbly etc. What is soil made of? List the parts that can be identified – use magnifiers to help.

Activities

  • Separate soil into its constituent parts. Ask for suggestions and list how this could be done – sieving would be one way or you could: Make a soil shake: Use a wide necked, transparent container with a well-fitting lid. Half fill with water and add a spoonful of soil. Screw the lid on tightly and shake vigorously to combine, then leave to settle for at least 5 minutes. Observe how different components sink into layers, whilst others float. Are the layers clearly visible? Due to differing particle size the bottom layer will be sand, the middle silt and the top clay. The largest layer will indicate the general soil type.
  • Make a soil cake: Go outside and collect the ingredients to make soil. Have you made soil? What’s missing? Use the ‘What is soil of made of?’ info sheet to explain this.
  • Explore soil characteristics. Pour water onto different samples of soil (sandy and clay), observe what happens – does the water drain through or sit on the surface?
  • Soil texturing test – the way a soil feels describes its texture and this is dependent on the size of the particles it contains. Test different soil types to see if you can feel the difference. Use the Soil texture test activity to find the answer. Test different soils from a range of locations in your outdoor space, to see if they are the same. Record this information on a map of your grounds. Make sure you are testing soil, not compost (especially if taking a sample from a raised bed).

Plenary

'The nation that destroys its soil destroys itself' is a quote from Franklin Roosevelt (President of the United States from 1943 - 45). What does this mean?
Ask for a description of soil again - has the content changed from words used at the beginning of this lesson?

Background information

Soil is vital to all living things and is made from a mixture of tiny particles of rock, humus (dead plants and animals), air and water.
The solid rock, underlying the loose soil (bedrock) will differ from place to place and this has an effect on the soil type. There are three main kinds of soil – sand, silt and clay. Loam is a mixture of all of them.
It takes 400 years to develop 1cm of typical soil and 3,000 – 12,000 years to form enough to farm! Check out the How much soil activity to really appreciate this precious natural resource.

Resources

Soil samples
Transparent lidded container, spoon, water
Soil texturing flow diagram (ideally laminated)
Collecting bucket, spoon
Magnifiers


Differentiation

  • Create a recipe card for soil
  • Extension: What would be the ideal type of soil to grow crops and why?


Next steps

Try growing plants in different types of soil - what can you discover? Use the 'Be a soil scientist' activity to give you ideas.

Assessment questions

  • Name the main ingredients of soil
  • What was missing from the soil recipe?
  • Is soil as precious as gold?