Digging Into Soil

Activity Source: 

American Geophysical Union. Adapted with permission from “Soils Sustain Life,” AGI.

Materials

  • Piece of heavy duty PVC pipe about one inch in diameter and 10 inches long
  • Piece of wood doweling that will fit inside the PVC pipe
  • Hammer
  • Wood block
  • Leather garden glove
  • Hand lens or microscope
  • Non-toxic marker
  • Large sheet of white posterboard
  • Six clear plastic sandwich bags
  • Plastic knife
  • Tools for separating soil, such as tweezers, tongue depressor, drinking straw
  • Paper towels (for clean up)

Procedure

 1. Choose a spot to investigate the soil on publicly owned land, such as your school’s property. Have an adult make sure the selected spot is safe to use.

 2. Place one end of the PVC pipe on the ground, set the block on top, and hammer it into the soil.

 3. Move the pipe gently in a circular motion to loosen it. If the pipe is stuck, use gentle side taps with the hammer to free it. Carefully pull the pipe out of the ground, making sure the soil remains inside the pipe.

 4. Insert the dowel into the open end of the pipe and carefully push the core of soil out onto a flat surface.

 5. Trying not to break the soil core apart, record your observations of the core. Make note of anything interesting, especially:

  • How the core is different at the top than at the bottom
  • Any color changes along the core
  • Different types of material in the core, including size, color, and shape
  • Any living things in the core

 6. Draw a picture of the core sample in the middle of your posterboard, using colored pencils and markers. Include and label all parts and objects you observe.

 7. Cut the core down the center with the plastic knife. Note any new materials or interesting items you uncover, and mark them on your drawing.

 8. Using the tools you have, pull the core apart. Separate different materials into groups. You'll probably find at least four or five groups. Think about how you decided to group, or classify, these materials.

 9. Look at each material using the hand lens or microscope. Record information in a data table like the one below. If possible, take a close-up image of each object. Create a table with the following information for each object or material.

  • Column A: Image or Sketch
  • Column B: Type of Material
  • Column C: Color
  • Column D: Size
  • Column E: Location (Where it appears in the core in centimeters from the surface)
  • Column F: Name (Try to figure out what these materials might be)

 10. After you identify all materials in the soil, place each group in a clear plastic bag. Arrange the plastic bags around your drawing of the core sample to create a display. Draw arrows from each material to the part or parts of the core sample from which most of that material came.

 11. Repeat this activity at a different times of the year and compare your notes. You may consider doing this before, during and after droughts, spring and fall, or once per month. What has changed? What has stayed the same? Why?

NGSS Connections

Science & Engineering Practices - Planning and carrying out investigations

Disciplinary Core Ideas - Earth’s systems: Biogeology; Earth materials and systems

Crosscutting Concepts - Stability and change; Cause and effect