Lesson Q1 L1 – What Makes Soil Alive? Launching S.O.I.L.
Lesson Overview
Quarter 1 · Unit 1A: Outdoor Science Routines · Week 1 · Grades 6–8 · Lesson length: 50 minutes
Essential Question: Is the ground beneath our school garden alive, and how could we find out?
Lesson Focus: Students meet the garden as scientists: they dig a small soil pit, record what they see, and sort their observations into living, once-living, and never-living parts of soil.
Why It Matters: Middle school science starts with careful observation. Sorting soil into biotic and abiotic parts launches the year’s big idea: soil is a living system that we can measure and improve.
Source: New lesson written for this series (2026).
Standards & Learning Targets
Standards Alignment
NGSS Middle School Performance Expectations: MS-LS2-1 — Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem
Science & Engineering Practices / Crosscutting Concepts: Asking Questions and Defining Problems; Analyzing and Interpreting Data; Systems and System Models (CCC)
Student Learning Targets
Learning Targets — students will be able to
Distinguish biotic (living or once-living) and abiotic (never-living) parts of a soil sample
Record observations in a field notebook with date, location, sketch, and labels
Ask at least two testable questions about the garden soil
Key Vocabulary
soil · biotic factor · abiotic factor · organic matter · observation · inference · field notebook · testable question
Materials & Teacher Prep
| Materials Needed | Teacher Prep Checklist |
|---|---|
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Low-Cost Option: No hand lenses? Use phone cameras zoomed in, or a clear water-filled plastic bottle as a magnifier. No garden? Bring two bags of soil (potting mix and schoolyard dirt) and compare them on trays.
Safety: Soil digging in the Phoenix area: mist the soil lightly before digging to keep dust down, and do not dig on windy or dusty days, because the fungus that causes Valley fever lives in desert soil. Gloves on. Use the trowel to tip over boards, pots, and rocks before reaching near them (scorpions and black widows hide there). Clean any cut or scrape with soap and water and report it. Everyone washes hands with soap. See Appendix I.
Equipment Procedure — Hand lens and soil sampling
- Hold the hand lens close to your eye, then bring the sample up until it is in focus; do not move the lens toward the sample.
- Dig a trowel-deep (about 10 cm) sample only at your flagged spot and place it on the tray.
- Mist the sample lightly with the spray bottle so small organisms become active and colors show.
- Spread the sample with a craft stick; never touch your face with gloved hands.
- Return the soil and any organisms to the hole within 15 minutes and wash hands with soap.
Lesson Flow & Timing
| Engage · 7 min | Explore · 18 min | Explain · 10 min | Elaborate · 10 min | Evaluate · 5 min |
|---|---|---|---|---|
| Is the ground alive? | Soil pit sort (Find Someone Who) | Biotic vs abiotic | Notebook entry + questions | Exit ticket |
Phase 1 · Engage — The Hook
Teacher Talk
PCM: Curiosity. Hold up a jar of garden soil and a jar of sand. “One of these jars contains more living things than there are people on Earth. Which one? How could a scientist prove it without a microscope?” Students write a prediction and one reason. Introduce soil and observation briefly now so the discussion stays precise; the formal definitions come in Explain.
Ask Students
“What do you think lives in soil?” “How could something be ‘once-living’?” “What would happen to a garden if all the soil life disappeared?”
PCM Differentiation
Thinker Students: A teaspoon of healthy soil can hold hundreds of millions to billions of bacteria. What observations today could count as evidence that soil is alive, even if we cannot see bacteria?
Harmonizer Students: The garden is shared by our whole school. Write one way the living things in soil help the people who eat what we grow.
Phase 2 · Explore — Kagan Cooperative Activity
Cooperative Structure
Kagan structure: Find Someone Who. Students circulate to compare samples from four different spots, so every student gathers evidence beyond their own team’s tray (See the Teaching Reference for the structure’s steps.) Before teams start, introduce the term inference so students can use it accurately; Explain gives the formal definition.
Step-by-Step
- Step 1 — Dig and observe (6 min): Each team digs its flagged spot, places the sample on a tray, and records color, moisture, and anything it sees moving or growing.
- Step 2 — Sort (4 min): Team sorts observations into Living, Once-Living, and Never-Living on the workbook table.
- Step 3 — Find Someone Who (6 min): Students circulate to find a classmate from another spot who can name (a) a living thing, (b) a once-living thing, (c) a never-living thing, and (d) a difference between the spots; record names and answers.
- Step 4 — Return (2 min): Teams return soil and organisms to the pit and wash hands.
Teacher Moves During Explore
Ask, “Is that root living or once-living? How can you tell?”
Push for inferences labeled as inferences: “I think… because…”
Note which spot had the most life and ask teams to explain why
Phase 3 · Explain — Direct Instruction
Mini-lesson — Soil as a living system. Teacher move: Draw a soil “pie” on the board: about 45% minerals, 25% water, 25% air, 5% organic matter and organisms; label biotic and abiotic parts.
Biotic factors: living or once-living things such as roots, worms, insects, fungi, bacteria, and dead leaves
Abiotic factors: never-living things such as sand, clay, rock, water, air, sunlight, and temperature
Organic matter: material from once-living things; it darkens soil, holds water, and feeds soil organisms
Observation vs inference: an observation is what you sense directly; an inference is an explanation you build from observations
Testable question: a question you can answer by measuring or counting, such as “Which spot has more earthworms per shovel?”
Key Message: Soil is a system of living and nonliving parts that interact. Scientists study it by observing carefully, separating observations from inferences, and asking questions they can test.
Check for Understanding — Ask Students
“Is a dead leaf biotic or abiotic? Why?” “What is the difference between an observation and an inference?” “Turn this into a testable question: “Is the garden soil better?””
Phase 4 · Elaborate — Student Product & Differentiation
Student Product
Each student writes a notebook entry: date, location, labeled sketch of the sample, the three-column sort, one inference, and two testable questions.
Differentiation
| Grade 6 focus | Grade 7 focus | Grade 8 focus |
|---|---|---|
| Identify biotic and abiotic factors and record observations with labels. | Explain how one biotic and one abiotic factor interact in the soil (for example, water and roots). | Compare two spots using evidence and propose a testable question that names what to measure. |
Support (scaffolded entry): Provide a picture word bank (root, worm, pebble, leaf, ant) and the frame “I observed ___. I infer ___ because ___.”
Challenge Extension: Design a quick sampling plan to compare the number of visible organisms in the four spots fairly. What must be kept the same?
Multilingual Learners: Pair words with real objects on the tray; post Spanish cognates: orgánico/organic, observación/observation, inferencia/inference.
Phase 5 · Evaluate — Closure, Exit Ticket & Assessment
Exit Ticket
- Name one biotic and one abiotic part of your soil sample.
- Write one observation and one inference about your sample.
- Write one testable question about the garden soil.
Answer Key / Look-Fors: (1) Biotic: root, worm, ant, fungus thread, dead leaf; abiotic: sand, rock, water, air. (2) Observation uses the senses (dark brown, damp); inference explains (it is damp because it is shaded). (3) A question with something measurable: “Does the bed or the path have more organisms per sample?”
Grade-Level Practice Items
Grade 6. Which item in a soil sample is a biotic factor?
A) sand grain B) water droplet C) fungus thread D) pebble
Answer: C — Fungi are living organisms, so a fungus thread is biotic; the others never lived.
Grade 7. A student finds more earthworms under mulch than in bare ground. Which statement is an inference, not an observation?
A) Twelve worms were under the mulch. B) The bare ground felt dry. C) Worms prefer mulch because it keeps soil moist. D) Three worms were in the bare ground.
Answer: C — Explaining why worms are there goes beyond what was sensed; it is an inference to be tested.
Grade 8. Which question is the most testable?
A) Is our garden soil healthy? B) Does adding compost increase the number of earthworms per 1-liter sample? C) Why is soil important? D) What is the best soil?
Answer: B — It names a variable to change (compost) and a measurable outcome (worms per liter).
Grade-Level Short Response (for quizzes and tests)
Grade 6. List two biotic and two abiotic factors you would expect in a garden soil sample.
Look-for: Biotic: roots, worms, insects, fungi, dead leaves. Abiotic: sand, clay, rock, water, air.
Grade 7. Explain how one abiotic factor in soil affects one biotic factor.
Look-for: Example: more water (abiotic) lets roots and worms survive; dry soil reduces them. Must state cause and effect.
Grade 8. Two soil samples have different numbers of organisms. Describe what you would keep the same to compare them fairly.
Look-for: Same sample size and depth, same time of day, same tool, same observation time, several samples per spot.
Expanding Circles
How does this connect to… Self — What living things depend on you every day? • Classroom — What will our class garden need from us this year? • School — Where on campus would you expect the most soil life? • Community — Who in Phoenix depends on healthy soil (farmers, parks)? • World — How does soil health affect food for the whole world?
Formative Assessment
Formative Assessment (to sort students, use the soil notebook entry with its labeled sketch and three-column sort, the exit-ticket observation and inference, and the grade-level practice items)
Meets (3): Sort is accurate; entry includes a labeled sketch, an inference marked as an inference, and two testable questions.
Approaching (2): Sort is mostly accurate but questions are not testable or the sketch lacks labels.
Not Yet (1): Confuses living and nonliving; reteach with a hands-on sort of five real objects.
Extend & Looking Ahead
Recap video (about 1 minute): Grade 6; Grade 7; Grade 8.
Extension: Start a “Soil Life Log” on the classroom wall where teams add organisms they find all year.
Looking Ahead: In Lesson 1.2 we set up the research teams and outdoor routines that make garden science safe and fair.