Exploring Soil Sandwiches
The soil beneath your feet all looks the same, doesn’t it? Surprisingly, soils in different locations actually have different components. In this science project, you can examine the layers that make up various soil samples and think about why the samples are so different from each other.
All soils are made of four components: clay, loam, sand, and silt. This science project identifies the differences between soils from different environments and attempts to figure out why those differences exist.
How does soil from various locations differ?
- Soil from various locations
- Several glass jars
- Masking tape and marker (for labeling)
- Turkey baster
- Magnifying glass
- Identify at least three sites that you think might have different types of soil, such as a playground, a backyard garden, a riverbed, and a wooded area. These sites should all be public property in which is not forbidden to dig (or your own personal property).
- Hypothesize how the soil from these locations might differ from one another.
- Dig up some of the soil from one location, and fill a jar with about two inches worth of the soil. Label the jar with a description of the location.
- Write down some of the plant and animal life you see around the location.
- Repeat this process with each of the other sites you chose.
- Fill each jar to the top with water. Twist each lid on tightly, and shake vigorously for thirty seconds.
- Leave the jars for about an hour, making sure that all of the soil has completely settled. Check on the jars every fifteen minutes or and take data on what each jar looks like each time you check. Which soil sample settled first? Last?
- Take the lid off each jar. Squeeze the bulb of the baster and insert it into the first jar. Release the bulb to suction the water into the baster, and discard the water. Repeat this process several times which each jar until you have removed as much water as possible.
- Look at each sample under a magnifying glass. Draw a diagram of each soil sample, pointing out each layer of soil (clay, loam, sand, and silt) and anything else that differentiates between the samples.
- Consider why you found these differences, and how they could be related to the conditions surrounding each location.
Warning is hereby given that not all Project Ideas are appropriate for all individuals or in all circumstances. Implementation of any Science Project Idea should be undertaken only in appropriate settings and with appropriate parental or other supervision. Reading and following the safety precautions of all materials used in a project is the sole responsibility of each individual. For further information, consult your state’s handbook of Science Safety.