Compost Champions Workbook
Upper Elementary Earth & Life Science Page 1 of 4
Compost Champions Workbook
Investigating Decomposition, Organic Cycles, and Living Soil
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1
The Magic of Rot: What is Composting?
In nature, nothing goes to waste. When leaves fall or plants die, they don't vanish—they undergo decomposition, breaking down into dark, crumbly organic matter called humus (often called "black gold"). Composting is the human-guided process of recycling organic scraps into nutrient-rich soil that feeds new life!
1. Organic Scraps Food waste & plant leaves
2. Decomposer Work Eaten & broken down
3. Living Soil Nutrients returned to plants
2
Meet the F.B.I.: Nature's Cleanup Squad
The 3 Big Decomposers
F
Fungus
Molds, yeasts, and mushrooms. They send out tiny threads (hyphae) that secrete enzymes to break down tough woody fibers that other organisms cannot digest.
Key Role: Tackles tough, dry cellulose & lignin.
B
Bacteria
Microscopic single-celled powerhouses. Billions live in every handful of compost, eating easy sugars and starches. Their intense activity creates heat in the pile!
Key Role: Fast digestion & heat generators.
I
Invertebrates
Animals without backbones like red wiggler earthworms, sowbugs, millipedes, and mites. They chew, shred, and poop out nutrient casts while tunneling air channels.
Key Role: Physical shredders & aerators.
3
Decomposition Check: Think Like a Biologist
1. Why do plants need the humus ("black gold") created by the F.B.I. decomposers? What happens to the nutrients in old leaves?
2. An earthworm (invertebrate) eats through a layer of leaves. Describe two different ways that earthworm helps the compost pile thrive:
Compost Champions Workbook • Unit 1: Decomposition Science Turn to Page 2 for Greens vs. Browns ➔
The Science of Pile Chemistry Page 2 of 4
The Compost Recipe: Greens vs. Browns
Balancing Nitrogen and Carbon for the Perfect Pile
Ideal Golden Ratio: 2–3 Browns : 1 Green
"Greens" = Nitrogen (N)
What they do: Provide protein, amino acids, and fuel for rapid reproduction of bacteria. They are usually moist, soft, and fresh.
Examples: Vegetable scraps, fruit peels, grass clippings, coffee grounds, tea leaves.
⚠️ Too many greens = Stinky, slimy, ammonia-smelling sludge!
"Browns" = Carbon (C)
What they do: Provide energy for microorganisms and create physical air pockets in the pile so oxygen flows freely.
Examples: Dry fallen leaves, shredded plain cardboard, straw, twigs, egg cartons.
⚠️ Too many browns = Pile breaks down at a super slow crawl!
Activity 1: The Great Scrap Sort
Classify each item: Green (G), Brown (B), or NO Way (X)
Item From Home or School Classification Scientific Reason Why
1. Used coffee grounds & paper filter [ ] Surprise! Rich in Nitrogen despite brown color.
2. Dry crunchy autumn leaves [ ] High carbon, traps oxygen in the pile.
3. Leftover cheese pizza slice [ ] Dairy/oils attract rats, raccoons & rot smells.
4. Fresh green lawn mower clippings [ ] High moisture, very fast burst of nitrogen.
5. Shredded plain brown shipping box [ ] Plant fiber cellulose, high carbon structure.
6. Plastic single-serve yogurt cup [ ] Synthetic polymer; bacteria cannot digest it.
Activity 2: The "Lasagna Method" Layering Challenge
Master composters build bins in alternating strata like a lasagna. Label the diagram layers below using: Base Twigs/Sticks, Brown Layer, Green Layer, and Finished Compost/Garden Soil Cap.
Top Layer (Cap):
Layer 3 (Bulk):
Layer 2 (Moist):
Layer 1 (Carbon):
Ground Base:
Critical Thinking:
Why must you always cover fresh fruit and veggie scraps with a thick layer of dry brown leaves or finished soil?
Compost Champions Workbook • Unit 2: The Compost Recipe Turn to Page 3 for The Decomposition Lab ➔
Pile Ecology & Diagnostics Page 3 of 4
Inside the Heap: The 4 Essentials & Troubleshooting
What Makes Microbes Happy, and How to Fix a Sick Compost Pile
The Four Pillars of Active Composting:
1. Greens Nitrogen for microbe cell growth
2. Browns Carbon for energy & structural airflow
3. Moisture Damp like a wrung-out sponge
4. Oxygen Aerobic microbes breathe oxygen!
Science Spotlight: Why Does Compost Get Hot (130°F–150°F)?
As billions of thermophilic (heat-loving) bacteria rapidly consume sugars and nitrogen, their cellular respiration gives off massive amounts of thermal energy. This natural heat sterilizes weed seeds and kills harmful plant pathogens!
Compost Doctor: Diagnose & Treat the Pile
Read each symptom and prescribe the cure!
Case A: "The Swamp Monster" Symptom: Smells like rotten eggs & slimy
What went wrong?
Compost Doctor's Cure:
Case B: "The Frozen Desert" Symptom: Cold pile, bone dry, no breakdown after 3 months
What went wrong?
Compost Doctor's Cure:
Case C: "The Pest Playground" Symptom: Flies everywhere and animals digging holes
What went wrong?
Compost Doctor's Cure:
Compost Champions Workbook • Unit 3: Ecology & Diagnostics Turn to Page 4 for Scrap Audit & Action Plan ➔
Community & Stewardship Page 4 of 4
Waste Not, Soil A-Lot: My Compost Action Plan
Tracking Waste, Calculating Real Impact, and Taking Action
Part 1: 3-Meal Waste Audit Log
Record items from breakfast, lunch, or dinner
Meal Item Tossed / Scrap Can It Be Composted? Green or Brown?
Breakfast
YES / NO GREEN / BROWN
Lunch
YES / NO GREEN / BROWN
Dinner
YES / NO GREEN / BROWN
Part 2: Environmental Math Challenge
An average classroom discards approximately 5 pounds of fruit rinds and sandwich crusts each school day. There are 180 school days in an academic year.
A. How many total pounds of food waste would one class divert from a landfill in a full school year?
Answer:
lbs
B. If 5 classrooms participate together, what is the combined total weight of waste saved?
Answer:
lbs
Part 3: Reflection & Soil Steward Pledge
Final Mission
When food scraps are buried in a plastic landfill bag without oxygen, they produce harmful methane gas instead of soil. How does composting help protect our atmosphere and planet?
"As a certified Compost Champion, I promise to feed the soil, honor nature's decomposers, and prevent food waste!"
Champion Signature:
Date Certified:
Compost Champions Workbook • Unit 4: Action & Stewardship Workbook Complete! 🏆
