Soil is the brown, crumbly stuff that plants grow in. But where does it come from?
Here is a big secret: soil starts as hard rock! 🪨
Over a very, very long time, big rocks turn into tiny bits, mix with bits of dead plants and tiny animals, and become soil.
Let's find out how, step by step. Tap Next to begin! 👉
Sun, rain and cold weather push on rocks every day. Slowly they make cracks. This is called weathering.
Tap the weather buttons to attack the rock and watch it crack! 👇
Many things help break rock into smaller and smaller pieces. Tap each card to find out how. 🔎
The little rock bits are not soil yet — they are just sand and grit. To become real soil, they need help from living things.
Worms, bugs and tiny living things called microbes live in the ground. They mix everything up and break things down.
When leaves and plants die, worms and microbes turn them into dark, rich food for soil called humus.
Tap each ingredient to drop it into the ground and make humus! 🍂
Soil builds up in layers. Tap the layers in the right order, from the bottom (hard rock) up to the top. ⬆️
Making soil takes a very long time.
To make just 1 centimetre of new soil — about the width of your fingernail — can take 100 to 1,000 years!
That's older than your grandparents, your great-grandparents, and lots more! So soil is precious — we should look after it. 💚
Soil is made when…
Quick check: What is the very FIRST thing soil is made from?
🎉 Well done, soil scientist! You now know how soil is made!