🌍 Earth Systems Study Center
🌱 Soil Formation Simulator
Build a soil profile layer by layer — O, A, B, C horizons and all.
📄 Printable handout
🌱 Soil in a nutshell — tap a card
Soil forms from weathered rock over hundreds to thousands of years. Five factors control soil development: parent material (bedrock type), climate, time, vegetation, and topography. Soil profiles show distinct layers called horizons (O, A, B, C, R).
- Select one option from each of the five formation factors
- Click “Build Soil Profile” to generate your soil layers
- Click on any layer to learn detailed information about that horizon
- Check your Soil Quality Score to see how good your soil is
- Try different combinations and compare the results!
Healthy soil is essential for agriculture and food production, provides stable foundations for construction, and supports entire ecosystems from earthworms to bacteria. Without quality soil, life as we know it couldn’t exist!
- Which combination of factors produced the highest quality soil? Why?
- How does climate affect soil formation? Compare tropical to arid climates.
- Why is soil on steep slopes thinner than soil on flat land?
- Which horizon is most important for plant growth? Explain.
- Why is soil conservation important if soil takes so long to form?
🎮 The Simulator
Pick your five formation factors, build the profile, and click each layer to inspect it. Aim for the best Soil Quality Score! Download the handout to record your experiments.
📊 The Soil Horizons — tap a layer, top to bottom
A real soil profile is a stack of layers. Read them the way nature stacks them:
🍂 O — Organic (the leaf litter)
Organic Layer: Decomposing leaves and organic matter. Rich in nutrients. Depth: 1-5 cm
🌱 A — Topsoil (where plants live)
Topsoil: Dark, nutrient-rich layer where most roots grow. Contains humus and minerals. Depth: 5-30 cm
⛰️ B — Subsoil (mineral collector)
Subsoil: Lighter layer where minerals accumulate. More clay, less organic matter. Depth: 30-90 cm
🪨 C — Weathered rock (parent material)
Parent Material: Partially weathered rock fragments transitioning to soil. Depth: 90-200 cm
🏔️ R — Bedrock (the source)
Bedrock: Solid, unweathered parent rock. Source material for all soil layers above. Depth: 200+ cm