K I D · C O N N E C T I O N

Composting Observation Exercise

Materials Needed:

  • Three two-liter plastic soda bottles with labels removed
  • milliliter measuring cup
  • plastic and newspaper or school paper
  • scissors
  • razor blade knife
  • rubber band
  • nylon stocking or other mesh material
  • electrical or duct tape
  • water marking pen
  • centigrade thermometer
  • yard waste (grass clippings and leaves)
  • food scraps (such as potato, carrot, or fruit peelings)
  • Two cups of garden soil.

Allow a minimum of one to three months for observation, depending on what is composted. This activity can be monitored throughout the school year for a long-term project.

Note: The three two-liter bottles can be easily separated for student monitoring.

Procedure:
  1. The teacher or some other adult will need to cut the plastic soda bottles. Cut the top off one bottle and the bottoms off two others (A). Arrange the bottles into a column as diagram (B) indicates. Cut out three or four windows (air holes) in the top two bottles to approximate the diameter of your thumb. Cover the windows with a nylon stocking or other mesh material and tape them securely.

  2. Place the nylon stocking or other mesh material over the middle bottle opening and secure the stocking or mesh with a rubber band (C).

  3. Place soil in the middle bottle (D). Bury vegetable or fruit scraps, grass, newspaper, plastic, etc. in the soil. (Note: The smaller the pieces, the faster they will decompose.) Add just enough water to moisten the soil, and allow a few drops to drain into the bottom of the column.

  4. Replace the top bottle, making sure the windows remain uncovered to allow air flow in and out of the compost column.

  5. During monitoring, keep the soil moist by recycling the compost water from the bottom to the top bottle. As students make their observations, remind them to turn the soil with a spoon (E).

  6. Use the Creative Compost Column chart to record any observable changes over a period of time.

Adapted with permission from Bottle Biology Resource Network
University of Wisconsin-Madison, 8-37 Russell Laboratories, 1630 Linden Dr., Madison, W153706
(606) 263-5845. Funded by the National Science Foundation.

Louisiana Environmentalist
September - October 1993.

Return to the Kid's Connection Table of Contents Page

Return to the Louisiana Environmentalist Magazine Home Page