Soil Study

Overview

Students will conduct a soil study by investigating pH and water absorption.

Objectives

Students will learn:

• How to describe the composition of soil and explain how it forms.
• That soil is made up of tiny particles of rock, plant, and animal matter.
• How to determine whether a solution is acidic, basic, or neutral.
• How scientists classify soils.
• That erosion is controlled by how well the soil retains water.

Lesson Preparation

Procedure for pH probeware

1. Hand out 3 soil samples per group in lidded glass jars (approximately 2 tablespoons of soil).
2. Students write a description of each sample on their data table.
3. Students pour 50mL of distilled water into each jar.
4. Close jar and shake well 30 times.
5. Let the soil sample settle for 3 minutes.
6. Repeat steps 4 and 5 for each soil jar.
7. Rinse the pH probe with the rinse bottle of distilled water.
8. Place the pH probe in the liquid part of the soil and water mixture and briefly swirl.
9. When the reading stabilizes, record the pH value in your data table (approximately 3 minutes).
10. Recap the jar. Rinse the pH probe with the rinse bottle.
11. Repeat steps 8 and 9 for each soil jar.
12. Rinse the pH probe a final time and place cap on probe.

Procedure for Water Absorption

1. Students place 3 tablespoons of soil on a piece of filter paper.
2. Student 1 places filter paper/soil into the container with holes in the bottom
3. Student 2 holds this container over a beaker.
4. Pour 100mL of tap water through the soil, collecting the water in the beaker.
5. Let the sample drip for 1 minute.
6. Use the 100mL graduated cylinder to measure the amount of water in the bottom container. Record on your data table.
7. Repeat steps 1 through 7 for each soil sample.

Analyzing your Data

1. Have students complete the portion of the worksheet below the data table.
2. Have a class discussion.

Extension

1. Students can collect soil samples from home to bring in for testing.
2. Students can graph their results on graph paper or using Excel's graphing feature.
3. Students can research soil conservation.

Assessment

The teacher will use the group discussion and worksheet as an assessment.

Credits

Cristina Solis