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, environmental impacts of soil quality, and human influence on soil health. Students will create public service announcements (PSA) supporting the benefits of maintaining soil health or consequences of current soil health threats.
Essential Question(s)
Why should we care about soil health?
Snapshot
Engage
Students view pictures of healthy and unhealthy soils and crops and speculate on what has caused the difference in the images.
Explore
Students 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 their understanding of soil health, management practices, and nutrient cycling.
Extend
Students research the impact of human population growth on soil health.
Evaluate
Students create a PSA detailing a specific impact of human population growth on soil health and practices to mitigate the threat.
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
Engage
Show slide 4. Review learning objective with students: Construct an evidence-based argument that explains how an increase in human population affects our consumption of natural resources and impacts soil health.
Explain the Photo/Picture Deconstruction strategy to students. Ask students to examine the photographs in next two slides and 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 slides 5-6. 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. Advise them that they will capture their responses in a single sentence.
Show slide 7. 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 to use as a comparison. Students may even bring soil samples from home to test.
Show slide 9: Preparing the Soil Samples:
Have students create a soil solution by adding 100 mg of soil and 200 mL of water to a beaker or other container.
Have the students use the stirring rod or sticks to blend the mixture.
Ensure that students clean the stirring rod thoroughly or use a different stirring utensil for each soil sample
Let the soil and water mixture sit overnight.
Show slide 10. 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.
Hand out the Soil Investigation handout.
Provide each group with a Soil Test Data Sheet OR have each group create their own data table (See sample Soil Test Table below).
Based on the specific directions for the soil test kit you have purchased, review the procedure for soil testing with your students.
Have students document their process and results using tablets or their phone camera if it is a ”Bring Your Own Device” (BYOD) approved environment. These pictures can be incorporated into their final presentation.
Show slide 11. This slide contains information about clean-up for the Soil Chemistry Investigation. Add any material- and classroom-specific instructions you may have to this slide.
Show slide 13. This slide is a place for you to provide any class-specific instructions for conducting the research regarding soil and soil health.
Show slide 14. Pass out the Window Notes handout. Have each student record important details in a Window Notes graphic organizer. Instruct them to leave the Nutrient Cycle box empty for now.
Show slides 15-16. Some questions to guide the summary discussion could include:
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 would improve soil health?
Explain
Show slide 17. Have students should work together to complete the How Does Your Garden Grow? Breakout. Have them summarize the information they learn in the Nutrient Cycles Window Note box. Remind them to make additional notes in the other "windows" as necessary.
Show slides 18-19.
Ask students to use the 3-Post It Notes strategy in their small groups or individually. Have them complete only the Word = ___, and Phrase = ____ notes. Instruct students to repeat the process they used to create the previous Anchor Charts to develop one for Nutrient Cycles window.
Ask students to share out their Words and Phrases as part of the summary conversation. If necessary, add any new information students discovered to the other three charts as well.
Show slide 20. Help students synthesize the conceptual pieces for themselves. Have them complete the Sentence part of the 3-Post It Notes activity. Ask them to emphasize the connections between the information they have gathered during the Explore and Explain activities and discussions in their sentence. 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
Have students compare the change in human population size to changes in land use to determine the impact of human population growth on soil health. Ask them to identify any threats to soil health and research the cause(s), impact(s), and potential solution(s).
Show slide 24.
Give students the H-Chart handout. Have students watch two videos: (1) the World Population video (population simulation begins at 0:44) and (2) the Global Land Cover Change video.
Show slide 25. Ask students to explain how the two videos relate to one another (e.g., "As population increases, we use up more natural land.") using the H-Chart strategy. Instruct students to take notes on the first video on the left side of the H-Chart. Instruct them to take notes on the second video in the right side of the H. Ask them to connect the two videos to one another on the middle part of the H. Have students share out their conclusions to the whole class.
Show slide 26. Have students brainstorm about how increased population size and land use might impact soil health. Once they have brainstormed, have them select a potential threat to soil health from either their notes, a list you provide to them, or through their own independent research. Several useful sources include the following:
Food and Agriculture Organization of the United Nations. (2015, Aug. 26). Our soils under threat. [Infographic]. http://www.fao.org/resources/infographics/infographics-details/en/c/326257/
Food and Agriculture Organization of the United Nations. (2015, Feb. 11). Soils help to combat and adapt to climate change. [Infographic]. http://www.fao.org/resources/infographics/infographics-details/en/c/340783/
Food and Agriculture Organization of the United Nations. (2015, Mar. 3). Soil is a non-renewable resource. [Infographic]. http://www.fao.org/resources/infographics/infographics-details/en/c/278954/
USDA. Natural Resources Conservation Service. (n.d.). Understanding soil risks and hazards. https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/use/?cid=nrcs142p2_053956
Show slide 27. Hand out the Threat Research handout. Give students sufficient time to research their threat of choice in order to answer the following questions:
How does the threat damage soil health?
What causes the threat?
How can the threat be avoided, mitigated, or eliminated?
Evaluate
Show slide 28. Ask students to create a Public Service Announcement about the dangers posed to soil health. Have them draft an outline/plan for the PSA.
Show slide 29. Have students create their PSA to demonstrate a stance advocating for either (a) the benefits of improved soil health or (b) highlighting the threat of not protecting the soil from their particular threat.
Show slide 30. Remind students to support their PSA with the following:
Evidence and science concepts from their research
Information recorded on their Window Notes handout.
Remind students to include the following in the PSA:
Characteristics of healthy soil
Cause of their chosen threat
Effects of chosen threat
Ways the threat can be avoided, mitigated, or eliminated
Resources
ARVE Research Group. (2011, Jan. 20). Global land cover change from 8000 BP to -50 BP. [Video]. YouTube. https://www.youtube.com/watch?v=gBTlIaf12-4
Food and Agriculture Organization of the United Nations. (2015, Aug. 26). Our soils under threat. [Infographic]. http://www.fao.org/resources/infographics/infographics-details/en/c/326257/
Food and Agriculture Organization of the United Nations. (2015, Feb. 11). Soils help to combat and adapt to climate change. [Infographic]. http://www.fao.org/resources/infographics/infographics-details/en/c/340783/
Food and Agriculture Organization of the United Nations. (2015, Mar. 3). Soil is a non-renewable resource. [Infographic]. http://www.fao.org/resources/infographics/infographics-details/en/c/278954/
Girl Scouts of Texas Oklahoma Plains. (2012, Apr. 17). How to make a PSA. [Video]. YouTube. https://www.youtube.com/watch?v=eywBa0xfQFw
Hirst, K. (2019, Jan. 25). BP: How do archaeologists count backward into the past? ThoughtCo. https://www.thoughtco.com/bp-how-do-archaeologists-count-backward-170250
How Does Your Garden Grow: Breakout. (n.d.). https://sites.google.com/ou.edu/gardengrowbreakout/home
K20 Center. (n.d.). Cognitive comics. Strategy. https://learn.k20center.ou.edu/strategy/198
K20 Center. (n.d.). Concept card mapping. Strategy. https://learn.k20center.ou.edu/strategy/123
K20 Center (n.d.). How does your garden grow. Lesson. https://learn.k20center.ou.edu/lesson/203
K20 Center (n.d.). Metaphorical thinking. Strategy. https://learn.k20center.ou.edu/strategy/146
K20 Center. (n.d.). Paired texts H-chart. Strategy. https://learn.k20center.ou.edu/strategy/132
K20 Center. (n.d.). Photo or picture deconstruction. Strategy. https://learn.k20center.ou.edu/strategy/140
K20 Center. (n.d.). Two minute documentaries. Strategy. https://learn.k20center.ou.edu/strategy/177
K20 Center. (n.d.). Window notes. Strategy. https://learn.k20center.ou.edu/strategy/189
Population Education. (2015, March 26). World population [Video]. YouTube. https://www.youtube.com/watch?v=khFjdmp9sZk&t
Public Service Announcement. (n.d.). In Penn State teaching and learning with technology. https://mediacommons.psu.edu/2017/02/14/public-service-announcement/
USDA. Natural Resources Conservation Service. (n.d.). Understanding soil risks and hazards. https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/use/?cid=nrcs142p2_053956
