Science // Earth's Systems

Rocks and soil

Recognise that soils are made from rocks and organic matter, and that different soils have different properties

Ages
7 to 8
Type
Concept
Builds on
1 topic
Leads to
1 topic
Standards
1 code

Quick check

Can the learner explain that soil isn't just dirt — it's made from tiny broken-down bits of rock mixed with dead leaves and other organic material?

Ask this to see whether the topic is secure.

Topic // Mastery

What mastery looks like

What a learner can do once this topic is secure.
  • State that soil is a mixture of broken-down rock particles and decomposed organic matter (humus)
  • Compare at least two types of soil (sandy, clay, loam) and describe their different properties
  • Explain that soil formation takes a very long time as rocks gradually break down

Topic // Map

Where this fits

What to learn first and what this topic opens up, with the reason for each link. Required links come first.
  • RequiredMust come first
  • HelpfulHelps, but not essential

Before this

1 topic
  • Properties of materialsRequired

    Earth's Systems // Ages 7 to 8

    Must know about rocks before learning that soil comes from broken-down rock

You are here

Rocks and soil

Ages 7 to 8 // Concept

Leads to

1 topic
  • The Rock CycleHelpful

    Matter & Materials // Ages 12 to 14

    Understanding that soils are derived from weathered rock provides concrete grounding for rock cycle weathering and erosion processes

Topic // Research-informed

Teaching notes

From the Marble Skill Taxonomy. These notes have not been validated in classrooms, so treat them as a starting point for your own judgement.

The approach

For 7–8 year olds: soil is a MIXTURE of broken-down rock particles (sand, silt, clay) plus decomposed organic matter (humus), not a single 'brown stuff'. Children investigate by hand — a settling jar separates soil into layers, a fair drainage test compares soil types, and a hand lens reveals rock grains and leaf bits. A second big idea is TIME: rock breaks down into soil very slowly. Hands-on investigation with real local soil is the core experience; cutaway diagrams, profiles and sorting tasks support vocabulary and classification.

Common misconceptions

  • 'Soil is just dirt / one single substance' — not seeing it as a mixture of rock particles and organic matter.
  • 'Soil has nothing to do with rock' — missing that soil is broken-down rock.
  • 'All soils are the same' — not distinguishing sandy, clay and loam by property.
  • 'Soil forms quickly' — underestimating the very long time rock takes to break down.
  • 'Clay soil is best because it holds water' or 'sandy is best because it drains' — treating one soil as universally superior rather than suited to different conditions.

Useful representations

  • A settling jar showing soil separating into layers (stones, sand, silt, clay, floating humus).
  • A drainage/percolation comparison of sandy vs clay vs loam soils.
  • A soil-profile / cutaway diagram (organic layer over broken rock over bedrock).
  • A soil-property comparison table (gritty/sticky, drains fast/slow, colour).

Teaching practices

  • Teach soil as a MIXTURE of broken rock + organic matter; separate the two components explicitly (a settling jar shows sand/silt/clay layers with humus floating on top).
  • Compare soil types (sandy vs clay vs loam) by testable properties, especially a fair drainage/percolation test with equal water and time.
  • Use hands-on investigation with hand lenses and jars — soil properties are felt and observed, not told.
  • Connect to prior rock work: soil begins as rock that has been broken down, and this takes a very long time.
  • Draw out why soil type matters (drainage affects which plants grow) to make the properties meaningful.

Activities to try

  1. 1

    Settling jar: watch soil pull apart into its parts

    Why it works: Soil is a mixture: it separates into broken-down rock particles (sand/silt/clay) plus decomposed plant matter (humus), so it is not one single substance.

    1. Scoop soil into a clear jar and fill with water, leaving space at the top.
    2. Put the lid on, shake well, then set the jar down and leave it to settle.
    3. Watch and record what settles first, what settles last, and what floats — you will typically see heavy stones and sand sink first, finer silt next, cloudy clay settle slowly on top, and dark bits of rotted leaf (humus) float; write down what you actually observe, as real soils vary.
    4. Draw and label the layers you see, naming which are broken-down rock and which are once-living matter.
    5. Use a hand lens on a pinch of dry soil to spot rock grains and small pieces of plant material up close.
  2. 2

    Fair drainage race: sandy vs clay vs loam

    Why it works: Different soils have different, testable properties: water drains fast through sandy soil and slowly through clay, and these differences matter for which plants grow well — no single soil is universally 'best'.

    1. Set up three funnels or pots, one with sandy soil, one with clay soil, one with loam, each with the same amount of soil.
    2. Pour the SAME amount of water into each at the same time to make it a fair test.
    3. Watch and time how fast water drains through each, and record which is fastest and slowest.
    4. Feel each soil (with permission) and note whether it is gritty or sticky.
    5. Describe how the soils differ and suggest why a plant might prefer one soil over another.
  3. 3

    Soil profile and the slow story of soil

    Why it works: Soil forms slowly as rock gradually breaks apart over very long periods into particles that mix with decomposed living matter; in a profile like this one, the layers show that journey from solid bedrock up to soil (some soils instead form from rock pieces carried in by rivers, ice or wind).

    1. Examine a soil-profile cutaway (organic layer on top, broken rock below, solid bedrock at the bottom) and label each layer.
    2. For each layer, say what it is and where it came from.
    3. Discuss or write how the solid rock below slowly breaks apart over a very long time to make the loose particles above it.
    4. Use a lift-the-flap or 'what is soil made of?' task to recall the two main ingredients: broken rock and humus.

Topic // Standards

Curriculum standards

Codes for the curriculum statements this topic maps to. Each publisher owns its standard text.
The national curriculum in England: Key stages 1 and 2 framework document
Y3.Sci.R.3

Science // Earth's Systems

More in Earth's Systems

All 18 topics