Composting recycles materials like food scraps and yard waste that otherwise go into the trash. As demonstrated by the Cornell Waste Management Institute's "Composting in Schools" program, building a miniature composting project in a clear water or soda bottle allows you to observe the process (see References 1). This project is a valuable teaching tool in the home or classroom.
Items you will need:
- 2 clear plastic bottles, 2-liter or larger
- Short plastic container to fit in 2-liter bottle
- Craft knife
- Pen or marker
- Nail, wood burning tool or drill
- Styrofoam produce tray
- Dried leaves
- Chopped food scraps
- Shredded paper and cardboard
- Packing tape
- Nylon stocking
- Rubber band
- Meat thermometer
Cut off the top of one plastic bottle with the knife at the point where it begins to widen out below the pouring spout. Keep the cut as straight as possible as you go around the bottle. Cut off the top of a second bottle, about 3 to 4 inches from the top, and save the spout portion. (See References 1)
Set a small plastic container, upside down, into the bottom of the first bottle, as a support for the tray that holds the composting materials. Mark dots on the bottle with a pen, about 1 inch apart, around the outside, just below where the container bottom shows through the plastic. Remove the container from the bottle interior.
Poke air holes in the first bottle at each dot marked around the container; gently pierce through the heavy plastic using a sharp nail, wood burning tool or drill.
Place the foam tray under the second bottle and trace the circumference of the bottle onto the tray with the pen. Cut a circle from the foam using the knife. Poke air holes all over the foam circle.
Set the container back into the bottom of the first bottle, upside down. Place the foam circle on top of the container. (See References 1)
Place a layer of small, broken stick pieces on top of the foam, and add crumbled dried leaves on top of the sticks.
Spoon a layer of ground-up food refuse on top of the dried materials. Top this with more dried leaves, shredded paper or cardboard, and moisten with a small amount of water. Keep layering the food waste and dry materials in equal proportion until the bottle is about two-thirds full. For better air circulation, don't tightly pack the layers. (See References 1)
Place the top of the second bottle, spout up, on top of the compost-filled first bottle. Fit the bottle parts together securely by wrapping packing tape around the outside where they overlap. (See References 1)
Place a piece of nylon stocking material over the open top of the bottle instead of replacing the cap. Secure the fabric in place by wrapping a rubber band around the nylon and the open neck of the bottle.
Set the bottle on a flat surface out of direct sunlight.
Insert a meat thermometer through the nylon at the top, or through a hole punctured into the side of the bottle, to allow observers to record the temperature as the materials heat up during the composting process. The materials will compost over several months. (See References 1)
- Insects may infest the compost in the bottle. Cover the entire unit with a nylon stocking to prevent this problem. (See References 1)
Suzie Faloon is a freelance writer who has written online content for various websites. As a professional crafter and floral designer, Faloon owned a florist business for nearly 25 years. She completed the Institute of Children's Literature course in 1988.
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