Name:______Date:______

Period:123456

Soil Permeability

Background: In this lab, you will explore how soil and water interact. You will experiment with different soil components, as well as, your local soil, to see how it drains.

Did you know that not all soils are the same? Different soils have different structures depending on what types of particles make up that specific soil.

Granular Soils: Soils that easily break into rounded clumps are called granular soils. They are not packed tightly which means they have a high permeability. Permeability means that things such as water and air can move through the soil. When soil has high permeability it means that water and air can move very easily through the soil.

Blocky Soils: Soils that break into smaller round clumps are called blocky soils. These allow for small pores that will allow for water and air to move through the soil.

Platy Soils: Soils that are tightly packed soil that is found in layers. There is not a lot of space for air to move through the layers in this type of soil.

Answer the questions below from the paragraphs above:

  1. What will you be learning about in this activity?
  1. In your own words, what does permeability mean?
  1. What does it mean to have a high permeability?
  2. Use the information in the background about the different types of soil to predict whether the soil has high permeability or low permeability.Circle your answer
  3. Blocky Soils- high permeability or low permeability
  4. Platy Soils- high permeability or low permeability
  1. Explain why you chose the answers for the above question

Predict:

Why might soil structure and permeability be important to biodiversity?

Soil Permeability

Materials

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  • 4 plastic columns
  • 2 plastic vials
  • 8 1” squares of cheesecloth
  • ruler
  • 4 rubber bands
  • China marker
  • 8 twist ties
  • Timer
  • 500-mL beaker
  • Small measuring cup
  • Tap water
  • Sand sample
  • Clay sample
  • Humus sample
  • Collected soil sample
  • Paper towels

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Prelab Questions:

  1. What goes into each of the 4 columns? ______

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  1. How far do you fill each column?______
  2. How much water is poured into each column?______
  3. What is the first piece of data that is collected?______

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  1. What is the last piece of data that is collected?______

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Procedure

  1. Put two pieces of cheesecloth at the bottom of each of the plastic columns.
  2. Secure the two pieces of cheesecloth to the bottom of the plastic columns with one rubber band.
  3. The cheesecloth should cover the end of the plastic column.
  4. Using a china marker, label the columns
  5. Sand
  6. Clay
  7. Humus
  8. Soil
  9. Lay the columns side by side.
  10. On each column make a mark 7cm up from the bottom of the plastic column where the cheesecloth is.
  11. The mark should be the same level on each column.
  12. Pour some clay on to a paper towel and carefully crush/remove any rocks or clumps.
  13. Pour some soil onto a paper towel and crush/remove any rocks or clumps.
  14. Fill each column with the correct type of soil
  15. Fill the Sand column to the mark with Sand.
  16. Fill the Clay column with Clay to the mark.
  17. Fill the Humus column with Humus to the mark.
  18. Fill the Soil column with Soil to the mark.
  19. Use the twist ties to suspend the columns in the vials.
  20. Thecheesecloth end should be about 3cm above the bottom of the vial.
  21. Put 10mL of water in the measuring cup.
  22. Designate one member of the group as the timekeeper and one as the recorder. When everyone is ready pour the 10mL into the Sand column.
  23. The timekeeper will times how long it takes the first dropof water to come out of the bottom of the column.
  24. Record this time in the data table.
  25. Watch the column until there is no more water standing on top of the column of sand and no more water is dripping through the column.
  26. Record the time it took for the entire sample of water to move through the sand.
  27. Repeat steps 16-20 for each of the rest of the columns, doing one column at a time.
  28. Record all results in the data table provided.

Data:

Determination of Soil Permeability

Sample
Time for First Drop / Time for Entire Sample
Sand
Clay
Humus
Soil

Soil Permeability

Analysis:

  1. Which particle type had the highest permeability? How do you know?
  1. Would soil with high permeability be good for growing crops? Explain.
  1. What is an advantage for building on soil with low permeability?
  1. Considering the results from the last experiment where we determined the size of particles, do the results of the permeability of the local soil match what you would expect? Why or why not?
  1. How would soil permeability influence the rate of erosion on a hillside? (look up erosion if you don’t know what it means!)

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