Authentic Lessons for 21st Century Learning

How Does Your Garden Grow? (MS-LS2-3)

Conservation, Ecosystems, and Soil Health

Heather Shaffery, Kellie Pettitt, Mariah Warren | Published: July 20th, 2022 by K20 Center

  • Grade Level Grade Level 6th, 7th, 8th
  • Subject Subject Science
  • Course Course
  • Time Frame Time Frame 4-5 class period(s)
  • Duration More 300 minutes

Summary

This lesson is a middle school adaptation of the high school "How Does Your Garden Grow?" lesson. Students will explore soil health principles, soil chemistry, nutrient cycles, and environmental impacts of soil quality. Students will construct models that demonstrate the flow of matter and energy in their local ecosystem, including between living and non-living parts of the environment.

Essential Question(s)

Why should we care about soil health?

Snapshot

Engage

Students will view pictures of healthy and unhealthy soils and crops and speculate on what has caused the difference in the images.

Explore

Students will test soil samples from a variety of locations to evaluate their nutrient levels and pH. Additionally, students will explore several sources to determine properties of healthy soil and practices that support it, followed by a whole-class discussion.

Explain

Students participate in a digital breakout to gather information about soil chemistry and nutrient cycles. The class will collaborate to make connections between soil health, management practices, and nutrient cycling.

Extend

Students will construct models that demonstrate the flow of matter and energy in their local ecosystem.

Evaluate

Students further develop their ecosystem models to show where specific nutrients move between living and non-living parts of the system.

Materials

  • Soil samples

  • Gloves

  • Paper towels and/or disinfectant wipes

  • Mineral-free water (e.g., DI water)

  • Soil test kit or chemical test strips

  • Devices with internet access

  • Sticky notes

  • Posters, markers, etc. for creating presentations and for Anchor Charts

  • Lesson slides—How Does Your Garden Grow?

Engage

Show slide 5. Show the series of photographs of soil and plants in different soil conditions:

  • Healthy harvested wheat fields;

  • Bare field;

  • Plants growing in healthy soil;

  • Plants growing in unhealthy soil.

Have students complete a Photo/Picture Deconstruction strategy. Ask students to reflect on (a) what they have observed in each of the four (4) photographs; (b) the potential causes for differences they notice; and (c) what the healthy plants might have that the unhealthy plants do not.

Show slide 6. After the discussion, ask students to summarize what they think they know about the images in one sentence. Instruct them that their summaries will capture the “big takeaway” each student got from the conversation.

Explore

Have students collect soil samples from possible garden sites around campus. Encourage them to collect soil from multiple sites, including samples from home, to use as comparison.

Show slide 8. Preparing the Soil Samples: Have students prepare the soil solution at least a day in advance of the soil testing.

  1. Have the students create a soil solution by adding 100 mg of soil and 200 mL of water to a beaker or other container.

  2. Have the students use the stirring rod or sticks to blend the mixture.

  3. Ensure that students clean the stirring rod thoroughly or use a different stirring utensil for each soil sample.

Show slide 9. Testing the Soil Samples: Once students understand that soil is important to plant health, have them test the soil types to determine the level of the nutrients present.

  1. Provide each group with the Soil Investigation handout OR have each group create their own data table (see Sample Soil Test Table below).

  2. Based on the specific directions for the soil test kit you have purchased, review the procedure for soil testing with your students.

  3. Have students document their process and results using tablets or their phone cameras if it is a ”Bring Your Own Device” (BYOD) approved environment. These pictures can be incorporated into their final presentation.

Soil Sample Data Table

Show slide 10.

  1. Have students clean up any soil and water messes and wash up surfaces as necessary.

  2. Have students dispose of trash and soil water in regular trash and sink unless the testing materials have specific disposal instructions.

  3. Advise students to consult SDS sheets for proper disposal if any chemicals were added to the water samples. Do not pour any chemicals down the drain.

  4. Advise students they should not pour any water that still has soil/sediment in it down drains, or the sinks will clog.

  5. Demonstrate the proper way to remove gloves by turning them inside out.

  6. Goggles should be wiped clean/disinfected before being put away.

Show slide 12. Provide any class-specific instructions for conducting the research regarding soil and soil health to students or groups in this slide.

Show slide 13. Have students work in groups to gather information about general soil science, soil health, and soil functions.

  • Give students the Window Notes handout.

  • Have each student record important details in a Window Notes graphic organizer.

  • Ask them to leave the Nutrient Cycle box empty for now.

Have students summarize key points about soil and soil health to create an Anchor Chart for each Window Notes box:

  1. Soil Properties

  2. Soil Health

  3. Soil Chemistry

  4. Nutrient Cycles (hold for further instructions).

Show slide 14. Ask students to use these questions for discussion in whole class.

  • What is soil? How do we describe it?

  • What criteria factor into soil health?

  • What are the benefits of having healthy soil?

  • What soil management practices or strategies improve soil health?

Explain

Show slide 15. Have students link to How Does Your Garden Grow? Breakout. Add the information from this page to the Nutrient Cycles Window Note box and make additional notes in the other "windows" as necessary.

Show slide 16. Explain Three Sticky Notes strategy to students. Pass out sticky note pads to student groups.

Show slide 17. Ask students to use the Three-Sticky Notes strategy in their small groups or individually to complete the final box of the Window Box strategy: Nutrient Cycles.

Show slide 17. At this point have students only complete the Word = ___, and Phrase = ____ notes.

Repeat the process you used for the previous anchor charts to develop one for Nutrient Cycles. Ask students to share out their words and phrases as part of the summary conversation. If necessary, add any new information students discover to the other three charts as well.

Show slide 18. Ask students to connect the conceptual pieces for themselves.

Ask students to write a single Summary Sentence. Advise them that their sentence should emphasize the connections among the information they've gathered during the Explore and Explain activities and discussions.

Guide students to make the following connections:

  • The relationship between nutrient cycles and soil health (e.g., how cycles support healthy soil, how unhealthy soil might disrupt cycles);

  • How soil management practices support or supplement natural nutrient cycles;

  • The impact of soil management practices on soil health.

Several alternatives to class discussion or a written assignment for this portion of the Explain are suggested below.

Extend

Show slide 22. Use the following steps to explain the purposes of different types of organisms in an ecosystem.

  1. Have students develop a list of functions performed by different types of organisms in an ecosystem based on prior knowledge and any information collected during the previous parts of the lesson (e.g., decomposers break down organic material to release carbon and nitrogen, producers take in carbon and give off oxygen during photosynthesis, etc.).

  2. Have students include three tropic groups: (a) decomposers; (b) producers; and (c) consumers.

Show slide 22. Have students indicate which ecosystem earlier soil samples came from.

Show slide 23. Hand out copies of the Ecosystem Model - 6th handout. Ask students to construct model food webs of their school or neighborhood ecosystem on their handout.

Show slide 24. Use the following guidelines to create the model food web:

  • Have students use arrows between organisms to show the direction that matter and energy flow.

  • Have students indicate what process causes matter and energy to flow.

    (e.g., consumers eating producers and bacteria fixing nitrogen in the soil are both causes of matter and energy flow).

  • If soil samples were not taken from the school, then use the sample location's ecosystem instead.

  • For another resource on soil food webs, click here.

Evaluate

Show slide 25. Once students have created food web models, have them add environmental elements to them to construct "ecosystem webs."

Show slide 26. Give your students the following guidelines to expand their food web models into ecosystem webs.

Have students select one key nutrient from their soil tests as a focus.

  • Ask students to use a new color and add arrows showing the flow of their nutrient into and out of both the living and non-living parts of the system.

  • Have them indicate what causes the nutrients to flow from one place to another. (For example, carbon is taken from the air into plants during photosynthesis and it enters the air and soil during decomposition.)

Resources