Composting is a huge topic, and one that I used to feel a bit overwhelmed by the thought of teaching. But I’ve collected a bunch of hands-on, interactive activities to really help students visualize the processes at work. I feel that before you even talk about the compost pile, it’s best to provide some background lessons. Here are a few background activities on decay and rot, as well as an activity to get kids thinking about what common objects are made from.
- You may want to start this unit with an activity where students learn to distinguish and sort organic (material that was once living) and non-organic (non-living) objects. Additionally, I would have students sort objects into groups of either man-made or natural materials. Bring in a variety of objects to sort. For organic objects, bring it things such as feathers, a book, a leather jacket, a cotton cloth, something wooden, an apple, and perhaps a picture of a steak. For non-organic objects, bring in things like a food wrapper, plastic bottle, a rock, coins, something made from clay. Start off by sorting a few objects as a class and then split students into groups to work on sorting more objects. After sorting, I would ask students to compare and contrast the groups of objects. I really like to start off with this type of activity because it gets kids thinking about what objects are made of and it prepares students to be able to distinguish materials that will and will not decompose, and sorting objects for recycling.
- Next, you may want to discuss the topic “what is decomposition?”. Use this activity where you compare a decayed pumpkin/jack-o-lantern to a fresh one. If you are worried about allergies to mold, you may want to perform this observation outside and make sure students wash hands after the activity. Alternatively, you could provide small groups of students with two Ziploc bags to observe, one containing a rotten apple and one containing a fresh apple. Ask students to write observations in their plant journal and also to hypothesize WHY the pumpkin or apple has changed. Encourage students to think about experiences with food that has gone bad at home and how it’s smell changed (like sour milk). Finally, tell them about the microscopic critters that are eating the apples or pumpkins.
- Use this really great video/song from the PBS show Sid the Science Kid, called “It’s not scary, it’s decayed.”
- Bury a nylon stocking filled with organic and non-organic materials. In three months, dig it up and explore the contents comparing the decay of the organic and non-organic materials.
- Bring in Ziploc bags of leaf litter from a forested area nearby and also Ziploc bags of the topsoil created from decomposed leaves. Ask students what the bags have in common. After accepting students’ answers, tell them that the topsoil was once leaves and now it has decomposed into soil. Allow students to examine, compare, and contrast the bags. Discuss how soil made from decomposed material is the best soil for our gardens, as it is full of vitamins and minerals for our plants (just like kids need vitamins and minerals). This is a great point to introduce the concept of composting, telling students that gardeners can collect materials to decompose from their gardens and kitchen to turn it into that rich, dark composted soil.
These activities provide a great background for learning about compost. In my next post, I’ll describe some more activities about the actual compost pile, critters that help the compost pile, and also how composting helps our earth.