The experiments also demonstrate the difference between biodegradable and non-degradable waste. Pupils can observe what is happening to a plastic bottle in the compost and thus conclude why bottles should not bethrown on a forest soil.

The teaching unit consists of three experiments:

• The Classroom Compost Box guides pupils through a simple composting process and provides them with a model of biodegradation in natural soils. It teaches how to produce a good compost and allows them to observe how different materials are degraded in nature.
  
  
• Worm composting introduces pupils to the importance of earthworms in the natural cycle by way of observing their actions and benefits in the composting process.
  
  
• Compost grows Tomato teaches pupils how to use compost as a fertilizer for growing crop plants. In the growth experiment pupils discover how nature reuses nutrients and how this recycling can be beneficial for human waste management and food production.