Name ____________________________________
Date ___________________
Edible Soils Lab
Purpose: What is the makeup of a soil horizon (profile)?
Hypothesis: If I use the appropriate ingredients in the correct order, then I will construct an accurate
representation of the soil horizon (profile).
Experiment: Construct an edible soil profile as follows.
Step 1 Horizon R: In a plastic cup, place Oreo cookie in the bottom of the cup. Answer the following
questions.
1A. Why do you think we are using an Oreo to represent horizon R?
Bedrock is solid rock. Parent material is formed from the bedrock after a long weathering process. There are
two basic ways that weathering can happen.
1B. What are the two main types of weathering? _________________ and ________________.
Step 2 Horizon C: Place a small layer of chocolate chips on top of the Oreo cookie. Answer the following
questions.
This is the C horizon in a soil profile. It is called the parent material because it is the weathered rock and
partly weathered soil from which the soil layers above are formed.
2A. How do the crumbled Oreos represent horizon C?
2B. What influences does the parent material have on the other horizons?
Step 3 Horizon B: Place a layer of vanilla pudding on top of the chocolate chips
3A. Horizon B is also known as ___________________________.
3B. Why is it lighter in color than the A or O horizons?
Step 4 Horizon A: Place a layer of chocolate pudding on top of the vanilla pudding.
4A. Horizon A is also known as _________________________.
This is the top layer of soil. Nutrients, bacteria, fungi, and small animals are abundant. Plants thrive in it
because of the nutrients in it.
Step 5 Horizon O: Place a layer of chocolate sprinkles.
The sprinkles represent the organic matter. This layer is usually less than an inch thick. Litter decomposes
into nutrients that enrich the soil. In areas where the temperature is lower, the composition of organic
matter is slower.
5A. The decomposed litter will become _____________________________.
Step 6: DO NOT EAT UNTIL GIVEN PERMISSION TO. You MUST draw your diagram and
answer ALL questions above first!
Analysis and Conclusion:
1. Draw, color, and label the horizons of your “edible soil”.
2. Discuss the use of ………. (Why did we use these materials to represent each layer?)
Material
Chocolate Pudding
Horizon
Why?
Vanilla Pudding
Oreo
Sprinkles
Chocolate Chips
3. What would cause the horizons to become mixed?
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