Composting 101: Building Cold-Climate Piles

🖥️ Walkthrough Slides (6) 🔬 Virtual Lab 📝 Take Quiz 🗂️ Vocabulary 📖 Curriculum Guide

Interactive Digital Curriculum

Interactive Walkthrough Slides

Step through the complete digitized curriculum deck with illustrated concepts, step-by-step procedures, teacher tips, and interactive knowledge checks.

Slide 1 Soil Regeneration

Transforming Village Scraps into Living Organic Fertilizer

Composting is the aerobic biological decomposition of organic waste into rich, dark, earthy humus.

In sub-arctic Tyonek, building hot thermal compost piles allows growers to turn kitchen vegetable scraps, cardboard, and fish waste into premium organic fertilizer for community greenhouse crops.

🔥
Microbial Furnace: Billions of thermophilic bacteria generate heat up to 150°F inside the pile!
♻️
Zero Waste: Diverts tons of organic matter away from village disposal sites.

Slide 2 Biochemical Balance

The Golden Ratio: 30:1 Carbon to Nitrogen

Balancing "Browns" and "Greens"

Compost microbes require both Carbon (for energy) and Nitrogen (for protein and cell division). The ideal recipe has a Carbon-to-Nitrogen ratio of 30:1 by weight.

Browns (High Carbon): Dry birch leaves, straw, shredded cardboard, sawdust (C:N 60:1 to 400:1).

Greens (High Nitrogen): Kitchen food scraps, green grass clippings, coffee grounds, fish waste (C:N 15:1 to 25:1).

⚡ Quick Knowledge Pulse Choose 1 answer

If a compost pile starts smelling like rotten ammonia, what does it have too much of?

Slide 3 Thermal Microbiology

The Temperature Zones of a Compost Pile

Mesophilic to Thermophilic Succession

Phase 1 (Mesophilic, 68°F–110°F): Common soil bacteria rapidly consume soluble sugars and starches.

Phase 2 (Thermophilic, 115°F–155°F): Heat-loving bacteria (Actinobacteria) take over, breaking down complex proteins and fats. Temperatures above 135°F kill weed seeds and pathogens!

Phase 3 (Cooling & Curing): Fungi and earthworms move in, converting residues into stable dark humus.

Slide 4 Management Practice

Pile Aeration & Moisture Management

Oxygen is the Breath of Living Soil

Compost organisms are strictly aerobic—they require oxygen to breathe. Without air, anaerobic bacteria take over, turning the pile cold, slimy, and putrid.

Turning the pile with a pitchfork once a week injects fresh oxygen, restarting the biological furnace. The moisture level should feel like a damp wrung-out sponge: moist, but not dripping.

Slide 5 Winter Strategy

Sub-Arctic Winter Compost Protection

Keeping the Biological Engine from Freezing Solid

When outside temperatures drop to -15°F, small compost piles freeze solid and go dormant until May.

To maintain winter heat, Tyonek growers build large piles (minimum 4x4x4 feet), wrap bins with straw bales or recycled insulation foam, and feed the core with warm vegetable mashes.

Slide 6 Application & Review

Applying Finished Compost at Tyonek Grown

From Rotting Waste to Crisp Golden Vegetables

Finished compost is dark brown, crumbly, and smells like fresh forest rain. It is rich in mycorrhizal spores, humic acids, and slow-release nutrients.

Spreading a 2-inch layer over greenhouse raised beds triples soil water-holding capacity, helping Tyonek produce award-winning heads of cabbage and sweet carrots.

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Official curriculum guide preview for Composting 101: Building Cold-Climate Piles

📄 Composting-101-2.pdf

Essential Inquiries & Learning Targets

Core Essential Questions:

What biological balance of Carbon (browns) and Nitrogen (greens) creates optimal thermophilic decomposition?
How do aerobic bacteria generate high core temperatures (130-155°F) that kill weed seeds and pathogens in cold sub-arctic climates?
How can rural communities incorporate clean fish waste and garden residues into rich organic humus without attracting wildlife?

Student Learning Objectives:

Calculate a balanced 30:1 Carbon-to-Nitrogen (C:N) ratio using available local feedstock.
Track compost temperature curves through mesophilic, thermophilic, and curing phases.
Evaluate how Tyonek Grown replaces expensive imported chemical fertilizers with closed-loop community compost.

Interactive Experiment

Virtual Laboratory Simulator

🔬 Hands-on Virtual STEM Lab Regenerative Soil Builder

30:1 C:N Pile Balancer & Thermal Simulator

Mix carbon browns (birch leaves, cardboard, sawdust) with nitrogen greens (garden scraps, salmon waste, coffee grounds) to achieve the 30:1 sweet spot and reach 140°F core heat.

Feedstock Recipe (Pounds Added):

Dry Birch Leaves (60:1 C:N)

Shredded Cardboard (350:1 C:N)

Tyonek Garden Greens (18:1 C:N)

Salmon Fish Scraps (5:1 C:N)

Calculated C:N Ratio: 29.4 : 1

Core Temperature: 142°F (Thermophilic)

Decomposition: Optimal Pasteurization ✓

♨ 142°F ♨

Soil Biology: A 29.4:1 ratio hits the exact microbial sweet spot. Bacteria multiply exponentially, generating 142°F core heat that neutralizes weed seeds while converting fish proteins into rich dark humus.

Self-Grading Assessment

Comprehension Mastery Quiz

Test student understanding of scientific principles, local Alaska ecology, and problem-solving scenarios from the lesson guide. Earn the Regenerative Soil Builder credential!

What is the scientifically optimal Carbon-to-Nitrogen (C:N) ratio for rapid, hot aerobic composting?

Terminology & Dena’ina Context

Specialized Vocabulary Flashcards

🗂️ Interactive Vocabulary Deck Card 1 of 3

Click the card or press Space to flip. Use arrow keys to navigate.

Term Click to flip ↷

Carbon-to-Nitrogen (C:N) Ratio

Definition & Context Click to flip ↶

The chemical ratio of carbon-rich energy materials (browns) to nitrogen-rich microbial protein building blocks (greens). The biological sweet spot is 25:1 to 30:1.

Alaska Context:

Too much carbon slows decomposition to a crawl; too much nitrogen creates smelly anaerobic ammonia gas.

Educator Guide

Curriculum Standards & Activity Protocol

📚 Standards Alignment (NGSS & Alaska Cultural Standards)

5-LS2-1

Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.

NGSS

MS-ESS3-3

Apply scientific principles to design a method for monitoring and minimizing human environmental impact.

NGSS

Cultural Standard E.2

Culturally-knowledgeable students understand the ecology and geography of the bioregion they inhabit.

Cultural

🏔️ Local Alaskan & Tebughna Context

Shipping bagged synthetic fertilizer from the Lower 48 to Tyonek across Cook Inlet is expensive and carbon-intensive.
Subsistence salmon filleting and high tunnel vegetable harvests generate large volumes of nutrient-dense organic waste.
Careful pile management (aeration, brown carbon cap layers, bear-safe fencing) turns salmon carcasses into rich, weed-free garden compost.

📦 Required Materials & Classroom Setup

✓ Long-stem dial compost thermometer (18-24 inch probe)✓ Brown carbon materials (shredded cardboard, dry leaves, clean wood shavings)✓ Green nitrogen materials (vegetable trimmings, coffee grounds, clean fish scraps)✓ Garden pitchfork and water hose / watering can

🔬 Step-by-Step Hands-on Activity Guide

Step 1: Layer Browns and Greens
Build alternating lasagna layers: 4 inches of dry carbon browns, followed by 1-2 inches of green nitrogen waste. Moisten until damp like a wrung-out sponge.

💡 Instructor Tip: Always cap fish waste with at least 8 inches of clean dry leaves or sawdust to trap odors.
Step 2: Insert Probe and Log Temperatures
Insert the thermometer probe into the dead center of the pile. Record temperature daily at 9:00 AM.

💡 Instructor Tip: Within 48-72 hours, aerobic bacteria will drive temperatures past 130°F!
Step 3: Turn and Aerate
When core temperature begins dropping below 110°F, turn the pile inside-out using a pitchfork to re-introduce oxygen.

💡 Instructor Tip: Notice steam rising from the center even on a brisk morning.

💬 Wrap-Up Discussion & Evidence of Learning

Discussion Questions:

How does composting fish scraps close the nutrient loop in Tyonek?
Why is synthetic fertilizer worse for soil microbiology than living organic compost?

Evidence of Learning Rubric:

Student can categorize feedstock into "Browns" vs "Greens".
Student can graph a compost heat curve through all three phases.

District Geographic Information System

2025 TTCD Annual Report

20 Years of Tribally Directed Conservation

Paid Summer Youth Internships

Composting 101: Building Cold-Climate Piles

Interactive Walkthrough Slides

Complete Lesson Slides Outline (6 Slides)

Composting 101: Building Cold-Climate Piles

The Golden Ratio: 30:1 Carbon to Nitrogen

The Temperature Zones of a Compost Pile

Pile Aeration & Moisture Management

Sub-Arctic Winter Compost Protection

Applying Finished Compost at Tyonek Grown

Essential Inquiries & Learning Targets

Core Essential Questions:

Student Learning Objectives:

Virtual Laboratory Simulator

30:1 C:N Pile Balancer & Thermal Simulator

Feedstock Recipe (Pounds Added):

Comprehension Mastery Quiz

What is the scientifically optimal Carbon-to-Nitrogen (C:N) ratio for rapid, hot aerobic composting?

Correct!

Certificate of Scientific Mastery