Reprinted with permission from Snackable Science Experiments by Emma Vanstone, Page Street Publishing Co. 2019. Photo credit: Charlotte Dart
Snack your way through this fun project! Make sure to take note of the learning points so that you can teach as you create.
When you think of soil, you probably think of the layer of mud where you plant flowers and where worms and other animals live. Did you know there are several layers of soil, and soil is not just mud or dirt but a mixture of decayed plants and animals, minerals and small pieces of rock?
This science craft uses different types of cake to model the layers that make up soil. You can bake the cakes yourself or use store-bought varieties.
- Different types of cake
- Green icing
- Ready-to-roll brown fondant icing (optional)
- Gummy worms
- Icing bag
- Rolling pin
- Soil plays a huge role in supporting life on our planet. Plants not only grow and support themselves in soil but also absorb nutrients to grow using their roots.
- Many small organisms live in soil, such as earthworms, ants, beetles and flies.
- Soil also affects our atmosphere by releasing carbon dioxide.
- Did you know that in just 1 teaspoon of soil there can be several hundred million bacteria?
- To make a cake model of soil layers, you need to think about the look and texture of each layer and build from the bottom layer upward.
- How about a nutty granola bar for the bedrock layer, followed by a nutty cake for the parent layer?
- The subsoil layer needs to have fewer rocks and needs to be a lighter color than the topsoil.
- Once you’ve built up the layers of cake, use an icing bag to pipe green icing onto the top to represent grass and leaves.
- With a rolling pin, roll the brown fondant icing into a long, thin shape and use this to model sticks and roots in the cake. Place gummy worms among the sticks and roots.
Can you make an Earth layer cake? Try using different colored sponge cake to represent each layer.
Soil is made up of the following layers:
- Organic layer (a thick layer of plant remains, such as leaves and twigs)
- Topsoil (a thin layer 5- to 10-inches thick, organic matter and minerals where plants and organisms live)
- Subsoil (clay, iron and organic matter)
- Parent material (upper layers develop from this later; it’s mostly made up of large rocks)
- Bedrock (several feet below the surface, a solid mass of rock)