Summary

Composting is an easy way to drastically reduce the amount of waste we send to the landfill. In the classroom, students can learn to compost the organic waste of their lunches, thus reducing the amount of waste the class produces. This learning activity can also inspire students to try composting at home. After learning to compost at school, one student in my mother's 3rd grade class even asked for a compost pile for Christmas! The soil from your class compost pile can be used to fertilize your school garden or classroom potted plants, reducing the need for artificial fertilizers.

Part I: Preparation

Part II: Creation

Part III: Maintenance

Part I: Preparation

There are many intricate ways of designing and maintaining a compost pile. However, as your class probably has no urgency to use the fertile soil produced from the compost pile, I recommend you approach the project in a more relaxed fashion. Worm bins, which can be purchased from local gardening stores, can be left inside the classroom to monitor worm behavior. However, worm bins are generally not used for large production of compost. If your class has access to space outdoors, I recommend constructing one or two simple wooden boxes with mesh ventilation or drilled holes and secure lids. This makes a good project for a parent who has skills in construction. You could also use large plastic bins with holes drilled or cut for ventilation.

Part II: Creation

Begin by reviewing what the class learned at Hidden Villa about what can be put into a compost pile. Have your students save the organic waste from their lunches. (Before putting the waste in the compost pile, put it all into a bucket and have students weigh it.) Spread a thin layer of soil on the bottom of your compost pile, then add the students' lunch waste. Cover with a top layer of soil. (To speed things along, I recommend using soil that already contains decomposers such as worms and rolly-pollies, or buy a starter container of earthworms at a gardening store. Have your students make scientific observations and sketches of these helpful decomposers.)

After your compost pile is created, how much energy you put into maintaining it is entirely up to you and your students. At a minimum, you need to keep the compost pile decently moist (but not soaking) and turn it with a shovel from time to time. To be slightly more ambitious, have your students consistently compost their organic waste. This is an incredible opportunity to develop life-long environmental habits. When your compost pile fills up, cover it up with some dry weed cuttings and let it sit for several weeks to let it decompose. Meanwhile, your class can use another compost bin. As mentioned above, there are many different projects you can do with your class to integrate the powerful hands-on experience of composting with other standard-based learning. As an experiment, you could add a few items that do not decompose well (plastic snack wrapper, glass bottle) and let your students make direct observations about what happens.

Here are step-by-step instructions for production-oriented composting:

1. Make sure compost material is in small pieces - surface area will determine how quickly you get compost.
2. Layer browns (i.e. straw, corn stocks, dried leaves) and Greens (i.e. food scraps, manure, grass clippings) in a 1 to 1 ratio by volume, sprinkling each layer with water.
3. Build to height of compost bin, cover with browns and let sit for a day.
4. Bring air into the compost by turning the pile daily or if/when temperatures exceed 140 degrees (beyond that point, you are killing necessary bacteria).
5. Expect usable compost in 2 weeks to 3 months, depending on how fine the pieces are.