Create Your Own Marsh!

For this experiment you will need:

• 4 test tubes
• labels
• aluminum foil
• loamy or finer-textured soil
• organic soil amendment (such as mulch)
• water

Procedure

1. Label the test tubes A,B,C, and D.
2. Place a couple of centimeters of loamy or finer-textured soil in each.
3. Mix in a small amount of soil amendment in test tubes A and B.
4. Cover the soils in tubes A and C with water, then add about a centimeter more water.
5. Cap the test tubes to keep out oxygen.
6. Cover all the test tubes with aluminum foil so that light cannot get in.
7. Let them sit for a day or more.

The wet soils have very little oxygen available. Living things need electron acceptors and a source of carbon. We humans (and other aerobic animals) use oxygen as an acceptor. In environments that are short of oxygen (such as wetlands) organisms (especially microorganisms) that can use other elements as acceptors do so. Alternative electron acceptors include manganese and sulfur. Evidence of the use of manganese and sulfur include precipitation of manganese oxide (the black material) and the formation of hydrogen sulfide gas (which smells like a rotten egg).

Why is there a heightened effect in tube A

What is the purpose of tubes B and D

Do elements that are electron acceptors change from a more negative charge to a more positive charge or more positive to more negative

For more information on this topic, read a chapter on electrochemistry in a chemistry textbook. Also read about anaerobes in a biology textbook. Can you think of other ways to learn more?

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