Lesson 6: Soil layers and earthworms

Remind the class that soil is made from grains of sediment and that different types of grains are different sizes. Hand out a whiteboard and pen to each pupil and arrange the class into groups of four. Ask the pupils to write the following labels on their whiteboards (one on each whiteboard):

Sand: large grains. Silt: medium grains. Clay: small grains. Organic matter.

Explain that the pupils will pretend to be individual grains (sand, silt, clay or organic matter) represented by their whiteboards. Choose one area to be the ‘soil formation zone’ and another as the ‘waiting room’. Ask everyone to move to the ‘waiting room’.

Create different soils by calling the following into the 'soil formation zone':

1. Sandy soil: All the sand children move. Then choose three more children to represent small amounts of the other grains.
2. Clay soil: All the clay children move. Then choose three more children to represent small amounts of the other grains.
3. Peaty soil: All the organic matter children move. Then choose three more children to represent small amounts of the other grains.
4. Loam soil: Everyone moves!