COMPOSTING: A GREAT, ROTTEN IDEA (Grade 7-9)

When we mention "recycling," we often think of recycling glass bottles, aluminum cans, and newspaper. But another 30% of the household garbage we throw out also can be recycled. These recyclables are food scraps, leaves, grass clippings and other biodegradable organic wastes. Organic waste can be recycled by composting. Simply stated, composting creates optimal conditions for decomposition to occur. Decomposition is the biochemical process by which bacteria, fungi and other microscopic organisms break organic "wastes" into nutrients that can be used by plants and animals. Decomposition occurs in nature whenever a leaf falls to the ground or an animal dies. The results of decomposition in a compost pile is a nutrient-rich humus that is excellent for improving soil quality and plant growth.

MATERIALS:

PROCEDURE:

  1. Define: recyclable, biodegradable. List items that are recyclable and/or biodegradable. Discuss: Are there recyclable materials that aren't biodegradable? (e.g., aluminum.) Are there biodegradable materials that aren't recyclable? (e.g. food scraps).

  2. Feel, smell, and look at the rotting log, grass clippings, leaves or food scraps. What words would you use to describe these materials? List these words. Do the words have positive and/or negative connotations? Why?

  3. Explain what is happening to the rotting material. Discuss: What is the natural process that breaks biodegradable material into particles that can be used again by plants and animals? (decomposition) What organisms assist in this decomposition process? (fungi, bacteria, earthworms, springtails, mites, etc.) Take a look under a microscope to find out what you cannot see with the naked eye. What will your rotting material finally become? (humus)

  4. Imagine a world where decomposition doesn't take place. Discuss: What would happen to organic materials like dead animals, leaves or sewage? Could plants and animals survive if decomposition didn't occur? Why or why not? Is decomposition important? Why?

  5. List items you throw away that are biodegradable. Discuss: How might you and your family recycle these materials? What is composting? Why do you think people compost household organic wastes?

  6. What are some benefits of composting household food and yard wastes? For example:

  7. What are some possible problems with composting? What suggestions do you have for solving the problems? For example:

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