TEAMS Navigation Bar HOME Subscribe Add/Update your URL Guestbook Contact Us Site Map Search Los Angeles County Office of Education TEAMS Distance Learning
Student Activities Back To Fast Plants Links Weather Chemistry Earth Processes Festival Heat Fast Plants Electricity Back To Gary's Electronic ClassroomSend Email
Bottle Composting

Teaching Objectives

Beginning concepts

Advanced concepts

Time Required for Exercise

Materials Needed

This exercise requires the following:

  •  40 day-old Fast Plants
  • marking pen
  •   several 2-liter soda bottles
  •   thermometer (optional)
  •  scissors and razor blade/knife
  • pH paper (optional)
  • sharp needles and a candle or a small, fine-tipped soldering iron
  • plant & animal matter for composting along with the dead Fast Plants
  • water

Exploratory Questions

Ask your students questions and discuss ideas they might have such as:


1. Construct a compost column from 2-liter soda bottles.

Figure 1Figure 2Figure 3Figure 4

Figure 5Figure 6 & 7Figure 8

2. Fill the compost column.

3. Observe periodically and record observations.


If you start the compost column/s in the fall, by spring you can use the "humus" to fertilize the plants in your school.

Accompanying Activities

  1. Mix some pieces of plastics along with organic matter (sticks, leaves, etc.) in the compost column. After several months, students can observe that the synthetic material did not decay. What is the position of the synthetic materials within the column now?
  2. Make a second column, identical to the first. Add earthworms or something you want to test and observe the difference between the two.
  3. Measure the total mass (amount) of material added to the column, including liquid. How does the amount of the mass change over a period of time? Does the amount of liquid change?

Background Information for the Teacher

Bottle CompostingIn nature, the recycling of matter produced by living organisms is accomplished by decay organisms, largely bacteria and fungi. A succession of organisms, each group breaking down biodegradable materials into simpler and more usable material, is at the heart of the process. The end product is humus, a dark, crumbly material that then becomes part of the soil.

When people manage the recycling of organic matter, the process is called composting. Often this activity involves putting organic refuse (such as leaves, lawn clippings and garbage) into a compost pile, where the materials decompose. The resulting compost (humus) can be used as a soil conditioner, and as a source of plant nutrients. Almost any plant or animal material or animal material (leaves, grass clippings, straw, newspapers, food scraps or sawdust, for example) can be composted.

Decay organisms use some of the nutrients left in these materials as their food source. As these organisms decompose plant and animal material, energy is released. The organisms use some of this energy, but some is lost as heat. Decay organisms also require a moist environment to grow, so water (or rain) must be added to the compost. Decomposition occurs faster in the presence of oxygen (aerobic) than in its absence (anaerobic conditions). Therefore, good aeration must be provided. This is why gardeners will "turn" a compost file. Composting will occur most rapidly when organic matter is lightly moistened, loosely packed and maintained at temperatures favorable for decay organisms to grow and reproduce.

Different organic materials decompose at different rates. Succulent materials containing water and nutrients, such as fruits and vegetables, decompose more rapidly than fibrous and woody cellulose-containing items. Lignin, the structural material coating cellulose fibers in wood, is very resistant to decay. Only a few microorganisms are capable of decomposing lignin.

As municipal landfill sites become filled with refuse from our throw-away society, composting of all organic wastes becomes increasingly important. Composting is a method of returning organic wastes to the earth in an easily reusable form.


Cochrane, J., Plant Ecology, Bookwright Press, NY, 1987. Chapters 5 & 6.

Schuman, D.N., Living with Plants, A Guide to Practical Botany, Mad River Press, Inc., Eureka, CA, 1980. Excellent introductory chapter for background information entitled, "Introduction to a Plant," as well as other topics such as nutrients, soils and plant hormones.

Spurgeon, R., Ecology (Usborne Science and Experiments), EDC Publishing, Tulsa, OK, 1988. "Building a Compost Heap," p.38.

Fast Plants Index
Gary's Electronic Classroom
TEAMS Electronic Hallway
TEAMS Home Page
LACOE Home Page