Analyzing Soil Composition
Lesson 7 of 18
Objective: SWBAT calculate the percentage of each component of soil given a soil sample and draw a conclusion based upon their findings.
This lesson is the conclusion of the Predicting Soil Composition lesson.
Before I passed out the jars, which I had kept covered to build suspense, I explained that jars would need to be treated gently so that the soil does not get mixed back together.
I gave students a few minutes to look at their samples and make observations. I also encouraged them to look at other tables jars to provide an opportunity to compare and contrast samples.
Next I asked each table to share what they noticed. This gave an opportunity to practice using the correct scientific vocabulary in context. In the following video, I use a comment from a student about layers to explain why the sediment always forms layers when it settles.
I explain that because the formation of layers is consistent, geologists can use the layers to determine what components of soil are present. I then have students glue Analyzing Soil Composition into their science notebooks. I have them follow these procedures to determine the percentage of each component in their soil sample.
Once tables have completed measurements, done the calculations, and verified that everything adds up, I ask them to consider what type of soil they have, and think about what type of plant might grow well where their soil came from. These answers should reflect what they know about soil components, such as "Cactus would grow well here because they grow in sand and the sand wouldn't hold very much water for other plants."