Living Root Garden School • Soil & the Underground • Name: ______________________
🔍 The Case
The case of the underground cake — the ground under your feet is stacked in layers. Dig one pit and read them.
The top layer is O, the crunchy topping: a blanket of dead leaves and twigs that is future soil, not soil yet. Under it sits A, the dark topsoil where almost all the action happens — roots, worms, and billions of microbes. Its dark color comes from humus, fully rotted plant stuff, and it can take hundreds of years to build just one inch of it.
Below that, B is the subsoil basement: denser, often redder or more orange, because that is iron rust. Clay lives here, and clay grabs nutrients and holds on like a magnet. C is the crumbly foundation of broken-up rock, and R is solid bedrock — the floor of the world that roots cannot get through.
Rule out the lookalikes with your fingers: sand feels gritty and falls apart, silt feels smooth like flour, and clay feels sticky enough to roll into a wiggly snake. A soil that is a mix of all three, plus humus, is called loam — the gardener's dream.
Not every soil has all the layers — the pale, washed-out E layer is optional, like the middle seat of a couch. Rain washes tiny clay and mineral bits down out of it, which scientists call eluviation.
Ask: Which layer in your pit will be the darkest, and which will be the thickest? Write your guess before you dig.
Try: Dig one trowel-deep pit, sketch the layers exactly as they lie, and measure how deep the dark topsoil goes with a ruler.
Stretch (Teens & Growers ready for more): Run the jar test: fill a clear jar one-third full of soil, add water until it is nearly full, shake it, then set it down. Sand sinks in seconds, silt settles next, and clay stays cloudy the longest. Come back in a day, measure the settled bands, and work out whether your soil is mostly sand, silt, or clay.
Tell: Fill in the log below — date, how deep each layer was, what surprised you — then finish this sentence in words or a labeled drawing: “The darkest layer was ___ because ___.”
Date
What I saw
What surprised me
Date: ____/____/____
Date: ____/____/____
Date: ____/____/____
Date: ____/____/____
🛠️ Build It
Draw the layers of your pit as they actually looked — color each layer the color you saw in the ground.
🗣️ Be the Teacher
Show someone your pit drawing and tell them why gardeners protect the topsoil like treasure — in your own words, no reading off the packet.
🏅 I can…
☐ I can read a soil profile like a cake.
Portfolio check
☐ Guide read
☐ Case solved
☐ Ask, Try, Tell done
☐ Build It filed: Profile sketch + measurements
☐ Taught someone
☐ Badge earned: I can read a soil profile like a cake.
Living Root Garden School • livingrootgarden.com/homeschool/ • Free — print as many copies as you like. File this sheet with your portfolio log. Sprouts do the Read, the Case, and Build It; Growers try the Ask, Try, Tell stretch when ready; Teens do the whole packet — including teaching it back.