Mud Shake

What We're Doing

In this activity, you will determine the composition of your soil by separating the soil particles into layers. You will then classify the soil as sand, silt, or clay.

Why We're Doing It

Soil can be made up of different-sized particles. A soil's particle size affects the amount of space available for the air and water needed by the creatures that live there. By separating a soil sample into visible layers, you can estimate the amount of each type of particle and the amount of space that is available for organisms living in the soil.

Making the connection:

Getting Our Hands Dirty

Hypothesize

Is the soil at the field site mostly sand, silt, or clay?

Plan it!

  • Use a measuring cup to collect a sample of about 2 cups of soil from your field site. Put the sample into a Ziplock bag and seal it tightly. If you are doing this activity with the Soil Temperature Test, the Texture Test, the Percolation Test, and the Compaction Test, you should collect the soil from the same place.
  • Make sure you have a good place for your sample to sit undisturbed. You will need to be able to check your results on the day following this activity. If not, you should plan the test for another day.
  • Remove the label from your plastic bottle so that you will be able to see the sample clearly.
  • Use a permanent marker to write your name, or the name of your group, near the top of the bottle.

Do it!

  1. Fill a 2-liter bottle with water until it is two-thirds full.
  2. Add soil from the sample you collected to the bottle, using the funnel, until the bottle is almost full.
  3. Tightly seal the bottle with its cap.
  4. Shake the bottle for 1-2 minutes, or until it is well mixed.
  5. Let the bottle sit untouched for 24 hours.
  6. After 24 hours, observe the layers forming in the bottle. Use the Underground Adventure Field Guide to help identify the different types of soil you see.

Record it!

Remember, be sci-wise!

  • Pour the soil into the funnel slowly. It will take some time for the funnel to empty into the bottle.
  • Make sure your bottle has a tight seal so it doesn't leak while you shake it.
  • Make sure the bottle doesn't move for 24 hours to keep the soil and water from remixing.
  • If you need to move the bottle in order to observe it more easily, move it carefully and try not to shake it.

Thinking About It

  • Which kinds of particles did you see in your sample?
  • Based on the data you gathered here, do you think your hypothesis was correct or incorrect?
  • How did your data compare with those of other students and from other parts of your field site?
  • Which type of particle settled first? Last? Why?
  • Do the results of this activity match the Texture Test results? Did you expect them to? Why or why not?
  • How might the data be different if you used a different soil sample? Why?
  • What other variables might affect your results? How?
  • What would you expect to find if you checked your bottle after a week? A month? A year?
  • Now that you know more about the composition of your soil, would you expect to find many creatures in the soil or just a few? What types of creatures would you expect to see?
  • Looking at the bigger picture, how might the data you gathered here help you to answer your research question?

Still Interested?

If you liked this activity, try this:

  • Calculate the percentage of each soil type in your sample:
    1. Measure the height of the whole sample.
    2. Measure the height of each layer.
    3. Divide the height of each layer by the total height of the sample.
    4. Multiply by 100 to get a percentage.

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