It's Not Just Dirt!

Our study of soil began by closely examining the three types of soil: sand, clay, and humus.

We determined that sand had the largest particles and was the least sticky. Clay had the smallest particles. We made soil columns for each type of soil and found that water went through sand very quickly. However, clay, with its much smaller particles, held the water for a long time.

We took apart rotting logs and found the creatures living in them that were causing them to decompose into humus. We captured and photographed some of them so that we could identify them. Then we released them back into nature and tried to identify them from their pictures.

We made our own clay and sand by shaking rocks with water in a bottle. As you can imagine, there was a whole lot of shakin' going on....and it was fun!

After learning how important it is to have a mix of the three kinds of soil in order to grow plants, we found that soil can be moved by wind and water in a process called erosion. Since we want to protect our important soil, we tested bare soil and soil covered with grass to see which would better prevent erosion. The grass held the soil in place, while the bare soil easily eroded. Not only does soil help plants, but plants help soil by holding it in place.