Dirt Pudding for teaching about soil horizons and profiles
Vertical and Horizontal Stratification Dirt pudding Recipes and Pictures

Vertisols: Slickensides and gilgai

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 at the left.)
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 Jello OR alternate layers of crushed cookies and Jello/whipped topping.
SPOON into 13" x 9" dish. Sprinkle with remaining crushed cookies.  Refrigerate 1 hour.
dirt pudding in trifle dish
Robinson's modifications:
Use a glass bowl to allow the profile characteristics to show.
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 coconut mixed with green food coloring for grass.

Put the pudding mixture in the center and the dry ingredients around the outside.
I often make one for eating and one for display.  The display versions are drier.

Use raisins, chocolate chips, etc. for rock outcrops.
Gummy worms, frogs, etc. add animal life.  Some will put a flower in the top.

ochric horizon example in dirt pudding A soil profile is a vertical cross-section.  This allows you to see the layers of the soil, called horizons. 

The A horizon is the surface horizon, also known as topsoil.

An ochric A horizon is low in organic matter.  To get this effect, mix some crushed vanilla wafers or vanilla sandwich cookies with the crushed chocolate sandwich cookies.

The C horizon is the parent material, or the material in which the soil forms. 

This profile represents a soil in early stages of development.  The subsoil (B horizon) has not yet formed.

Soils with this characteristics are classified as Entisols.

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The A horizon in this picture used crushed chocolate sandwich cookies because a mollic horizon has more organic matter, and will be both darker and thicker than an ochric horizon.

The B horizon, or subsoil, was made of a mixture of crushed chocolate and vanilla sandwich cookies.  The B horizon is a subsurface zone of accumulation. It may be enriched with organic matter or minerals, and will have color and/or structure changes when compared to the parent material.

The C horizon, or parent material is located under the B horizon.  The darker colors in the B horizon are due to the accumulation of organic matter from plant roots and animal activity.

The C horizon shows no change in color or structure (arrangement of individual particles) from the original condition.

Soils with a mollic horizon are usually classified as Mollisols.

mollic horizon example in dirt pudding
albic horizon example This A horizon is dark (crushed chocolate sandwich cookies), but it is not deep enough to be classified as mollic, so it is an ochric horizon.

The E horizon is a zone where minerals have been removed by leaching.  This removal of minerals bleaches this layer, so it is lighter than the layer above and the layer below.  This sandwich appearance (dark-light-dark) is characteristic of albic horizons.  They most often occur in forest soils, but are found in some grassland soils.

Notice the layers vary in thickness and depth.  This mimics actual soils.

The mineral and chemical composition of the B horizon determines the classification.  Some possibilities with this profile sequence are Alfisols, Ultisols, or Spodosols.
 

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The A horizon at left is thin, so it is an ochric.

The E horizon, as above, is an albic.

The red horizon (red food coloring on coconut) represents a spodic horizon. 
This is a subsurface horizon enriched in iron and organic matter.

Soils with a spodic horizon are usually Spodosols.

spodic horizon example
subsurface horizon variability This profile is done to show the variability that can exist in natural soils and the underlying geologic layers.
 
 



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This recipe allows for individual servings.  
JELL-O® PUDDING DIRT CUPS
2 cups cold milk 1 pkg. (16 oz.) Chocolate sandwich cookies, crushed
1 pkg. JELL-O® Vanilla flavor Instant Pudding   8 - 10 (7 oz.) Plastic cups - Clear cups work best if students are "creating" a soil
1 tub(8oz.)COOL WHIP® Whipped Topping, thawed 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

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