Soil Science

Third graders are engaged in an exciting new study of soil.

Over the course of the unit students will observe different types of soil and learn about soil composition. Classes have already done experiments and made observations about two different types of soil.

This is a tube of local soil. It has lots of organic material floating at the top and the water is cloudy.

Students were given soil collected from a nearby park and noticed that it contain many different elements. Mountains student Levi said, “I saw that it had rocks, dirt, pebbles, silt, and twigs.”

Victoria said “I was surprised by how much organic matter there was in the sample.” Students found bits of small leaves, twigs, and branches in their soil samples.

Students looked at the parts of soils and mixed them together.

After observations were made, students did an experiment to see what would happen when the sample was mixed with water. Tate noted that, “The first sample became yellowish brownish. All the organic matter floated to the top.”

Can you tell if this is the local soil or the sandy soil?

After shaking the tube up classes noticed that the soil settled into discrete layers. Larger particles and rocks fell to the bottom, while small particles like silt and clay settled on the top.

Student keep track of their predictions and observations in their science packet.

The classes then worked with another soil sample. Right away students were able to identify that this sample was different.  Kira said that the soil was “way sandier and had lots more rocks”  She also said it felt softer and predicted that the “water would settle faster.”

The example of the sandy soil has much clearer water

Indeed the second soil sample did settle much faster. Students were amazing by how quickly the water cleared compared to the first sample.

Our unit will continue though December and students will experiment with more types of soil.