Dirt Pudding to demonstrate Soil Horizons and Profiles

Edible soil profiles show the layers – horizons – in a soil.

Changing the ingredients alters the appearance, just as happens in actual soil profiles.

First, what are horizons? Then PUDDING!

Horizons are layers that run roughly parallel to the soil surface.

The layers share properties such as color, structure (the shape of the aggregates, what you might call clods) , and texture (not easily visible).

I selected these three profiles because of the obvious differences in color and structure. From left to right, they are from Northern Illinois, Northwest Arkansas, and the one on the right is from the Texas High Plains.

The first thing most people notice in a soil profile is color.

There are distinct color differences in the first two profiles. The structure differs in the third profile – aggregates that look like little blocks at the top and the huge vertical crack at the bottom.

The lines on each of these profiles approximate the boundaries between the horizons: 4 horizons on the left, 5 horizons in the middle and 3 on the right.

So, how do you make pudding look like soil?

First, make the pudding

Basic Recipe
(Prep time: 10 minutes for the basic version.  It certainly takes me longer, but I am slow in the kitchen, and I design the profiles as you see below.)
– 3½ cups cold milk
– 2 pkgs. (4 serving size) JELL-O® Instant Pudding
– 1 tub (12 oz)COOL WHIP® Whipped Topping, thawed 
– 1 pkg. (16 oz.) Chocolate sandwich cookies, crushed
HINT: Crush cookies in zipper-style plastic bag with rolling pin
or in food processor.
– MAKE pudding as directed on package using 3½ cups milk; let stand 5 minutes.
– STIR 3 cups of the whipped topping and ½ of the crushed cookies into the pudding OR alternate layers of crushed cookies and pudding/whipped topping.
– SPOON into 13″ x 9″ dish. Sprinkle with remaining crushed cookies.
– Refrigerate 1 hour.
Dr. Dirt’s modifications:
– Use a glass bowl to allow the profile characteristics to show.
– Mix coconut flakes with green food coloring for grass on top
– Use a variety of food items to get different colored layers (horizons): 
  – crushed vanilla sandwich cookies
  – crushed vanilla wafers, 
  – crushed graham crackers
  – Grape-Nuts
– Use nuts, raisins, chocolate or butterscotch chips, etc for rock fragments
– Use gummy worms or the like to add animal life
– Put a flower in the top

A soil profile is a vertical cross-section, often revealed in a pit dug by hand, by a backhoe, or in a road cut.  This allows you to see the layers of the soil, called horizons. 

  • The A horizon is the surface mineral horizon, also known as topsoil.
  • A few soils have an O horizon at the surface, an organic horizon of partially to mostly decomposed organic matter. Sometimes an A horizon is below the O horizon.
  • Some soils have an E horizon, usually lighter in color and clay content than the layers above and below. An E horizon may be under an A or an O horizon.
  • The B horizon is what is generally known as subsoil. There are many kinds of B horizons, depending upon the soil forming processes that have been at work: accumulations, transformations, translocations and/or losses.
  • The C horizon is the parent material, the stuff in which the soil formed. Depending upon the age of the soil and those processes, the profile may or may not have a C horizon.
  • Some soils have an R horizon – a solid layer of bedrock. But away from mountains, most soils do not have an R horizon. Many soils form in materials deposited by wind, water, ice or gravity, and the soil did not form in weathering bedrock.

This represents a young soil that only has an A horizon over a C horizon (parent material)

This represents a soil with an A horizon and a B horizon over the parent material (C horizon).

Many soils that form in grasslands have these horizons in their profile.

This profile represents a soil with a A, E and B horizons over parent material (C horizon).

Many soils that form in forests have these horizons in their profile.

However you choose to build your soil profile, it will be yummy!

Enjoy it!

Try this recipe for individual servings.

2 cups cold milk
1 pkg. JELL-O® Vanilla flavor Instant Pudding
1 tub(8oz.)COOL WHIP® Whipped Topping, thawed
1 pkg. (16 oz.) Chocolate sandwich cookies, crushed
8 – 10 (7 oz.) Plastic cups – Clear cups work best if students are “creating” a soil
Gummy Worms and frogs
POUR milk into large bowl, add pudding mix.  Beat until well blended.  Let sit 5 min.
STIR in COOL WHIP® and ½ of the cookies
PLACE 1 Tbsp. Cookies into cups. Fill cups ¾ full with pudding mixture. Top with remaining cookies.  Refrigerate 1 hr.
DECORATE with gummy worms and frogs, candy flowers or chopped nuts