Soil horizons might seem straightforward at first glance—just layers of dirt, right? But dig a little deeper (pun intended), and you’ll find a complex story about Earth’s surface, full of chemistry, biology, and time. Over the years, I’ve noticed students often underestimate the importance of understanding soil profiles, which can lead to shaky foundations in later topics like agriculture, water quality, and biogeochemical cycles. To help clarify things, I use a graphic organizer/coloring sheet that encourages students to visualize and internalize what’s happening beneath their feet. It’s one of those topics that deserves extra attention because misunderstandings here tend to echo throughout the course.
Link to Download Coloring Sheet
Implementation
I always include a filled-in version of the notes I create. Sometimes I use the template I created to look at and just throw a blank copy under the documentary camera and lecture while filling in a blank copy in front of the class. Alternatively, if you do not want to lecture, this short youtube video could serve as a good source to take notes from.
Even though many high school students don’t find coloring a page interesting, many students find it cathartic.
Avoid These Common Misconceptions
1. Students often think every soil has a perfect A-B-C horizon structure, when in reality, some horizons may be missing or poorly developed depending on the environment, parent material, and soil age.
2. Some diagrams they see about the soil horizons may not include all of the layers or be missing some in comparison to this coloring sheet. Just because a diagram they see does not specify where the “E” horizon is, they need to know that, if it were to be present, it would be located in the subsoil layer.
3. Students may picture the horizons as evenly spaced layers, like cake layers, without understanding that their thickness varies widely due to climate, organisms, topography, and time. One of my favorite activities to dispel this misconception is creating an edible soil profile based off of the characteristic soil profiles of different biomes. I regularly use this one in class.
