Soil Biology Respiration

Overview

Lesson Name: Soil Biology Respiration

Grade Bands: 6-8, 9-12

Lesson Objective: Use a simple test to detect carbon dioxide in the soil. Develop an explanation about where the CO2 comes from and how it connects to the global carbon cycle

Keywords: Earth's systems, Earth and Human Activity, Ecosystems: Interactions, Energy, and Dynamics, Weather and Climate, carbon cycle, respiration

Time: 2 Periods

Materials and Media

• Solvita Soil Kit (1 jar per 2-4 students, 4 jars per kit)

• Soil from the outdoors.

• Scale. Must measure in grams.

• Trowel, shovel. 1 per team of 2-4 students suggested. Can be shared among teams.

• Carbon Cycle Game Cards and Game Board

  • Digital Version: Game Cards Edit View Game Cards Presentation View

  • PDF Version: Game Cards (Download to print or use on computer w/ no internet)

  • Game Board (print only)

• Habitat Earth. California Academy of Science. YouTube video.

Lesson Outline

Background

Even though soil is literally under our feet, it is easy to overlook as one of the Earth's interconnected systems. Soil is not just mineral matter weathered from parent material or deposited from erosion, nor even just decayed organic matter. Rather, soil is a habitat teeming with mega, macro and microscopic organisms, many of which act in symbiosis with the plant communities that soil physically supports.

In this activity, students will discover that soil emits carbon dioxide using a simple color change test kit and develop an explanation for where that carbon dioxide comes from (hint: it has to do with respiration of below-the-surface organisms). Students will then apply their knowledge about soil and carbon dioxide in a carbon cycle mapping game, where they will see that soil CO2 is just one part of a larger, interconnected carbon cycle. 

More resources on Soil Respiration

• University of Nebraska Lincoln Cropwatch: Soil Respiration ppt Powerpoint

• USDA Soil Health - Guides for Educators: Soil Respiration (2014) PDF

Preparation

• Find a safe, accessible site for soil collection. Obtain permission to collect soil. Ideally, soil is tested at the time of collecting. If soil has to be collected beforehand by the teacher in a large bucket, keep moist and covered.

• Prepare the Carbon Cycle Game Cards and Game Boards. 

  • Electronic version. Carbon Cycle Game Cards can be shared electronically and played with or without internet. If played without internet, students will need a ten sided dice. If played with internet, students may need access to the site https://www.online-dice.com/roll-dice/1/d10/. Students will need a print version of the Game Board for tracking their path as a carbon atom through air, water, soil, plants and animals.

  • Print version. Carbon Cycle Game Cards can be printed out and placed around the room with a ten sided dice at each Game Card station. Students will need their own copy of the Game Board for tracking their path as a carbon atom through air, water, soil, plants and animals.

  • Note that physical ten sided dice go from 0 to 9. If you are using physical dice instead of the online one, tell students if they roll a 0 (zero) that is the same as rolling a ten for the purposes of the game.

Engage (Period 1)

• Have students collect and process soil samples from the outdoors using the Solvita kits. They will collect 90 grams of soil. Tell students they are measuring the carbon dioxide in soil. (Instructions for using Solvita kits are included. See this YouTube video for a demonstration.)

• As a class, discuss carbon dioxide and soil. Prompt them with discussion questions such as do you think there is a lot of CO2 in the soil? Use turn-and-talk, think/pair/share or other academically productive discussion method for students to make their thinking visible about carbon dioxide and soil. Debrief as a class. 

• Make note on students' thoughts on what the levels of the soil CO2 might be using qualitative words (high, low, nonexistent). Note: results from Solvita test takes 24 hours.

Explore (Period 2)

• Analyze the results of the color change. Compare with their expectation. Introduce the question: why is there CO2 in the soil?

• Tell the students they are going to watch the video Habitat Earth to learn a little more about soil that has clues that will help them develop an explanation. Prompt them to reflect what do they notice about the soil and what do they wonder while watching the video.

Explain

• Using Notice/Wonders from video, reflect on the question why is there CO2 in the soil?

• Points to highlight

  • Plant and animal organisms in the soil respirate, taking in oxygen and releasing carbon dioxide.

  • The soil structure, the spaces between the soil particles, allow space for organisms, as well as water, oxygen, carbon dioxide.

  • Plants can also release carbon in the form of sugar in their roots to attract beneficial organisms. 

• Have students respond to the question of why is there carbon dioxide in the soil by making a diagram or writing an explanatory sentence. 

Apply

• Tell students that they are going to do an activity to apply their understanding of soil carbon as part of the carbon cycle.

• Present the Carbon Cycle Game to have students map their carbon cycle. 

  • Orient students to the Game Cards (electronic or print).  

  • Explain the concept of pools and fluxes. Pools are the locations where carbon is found on Earth (Atmosphere, Terrestrial Life, Surface Ocean, etc). Fluxes are the processes (e.g. respiration, photosynthesis, decomposition) by which carbon moves from pool to pool.

  • Orient students to the process of rolling the dice, finding the number on the chart and moving to the new pool and drawing a flux line or staying in their pool.

  • Orient students to the Game Board. Show them how to make tally marks on the Board to map their visit.

  • Allow students to play for 10-15 minutes.

• After game play review the student Game Board. Review how soil is connected to the other parts of the carbon cycle.

Assess and Reflect

Ask participants for questions. Ask participants to recap the activity.

Written Assessment

Ask students to draw or write an explanation of where the carbon dioxide in the soil comes from.

Note

This lesson can be condensed into one period if the teacher collects and tests the soil sample. The discussion about soil carbon dioxide can be conducted as students are analyzing the color change.

Extension

Mystery of the Missing Undies

Students observe underwear buried in biologically active soil and develop an explanation for the condition of the garment. They compare a second pair buried in less biologically active soil and develop an explanation for its less consumed state. They create a model of soil impacted by tilling as a partial explanation for the underwear condition.

The full lesson is available here.

Note: Materials necessary for this activity can be borrowed through the SD Discovery Center's kit loan program. Please email soileducation@sd-discovery.org for more information.

Research Connection

The Dakota Lakes Research Farm conducts research on soil husbandry. Plan a virtual or in person visit to learn more about Dakota Lakes and what is a research field station.

Additional Resources

GLOBE E-training: Soil

South Dakota teachers who complete the GLOBE E-training for Soil and Soil Temperature are eligible to receive minigrants for a classroom set of GLOBE materials or Solvita kits. To complete GLOBE E-training, sign up for a GLOBE teacher account and then complete the GLOBE protocol e-training. This is a three part training which consists of Intro to GLOBE, Intro to a Sphere, and Protocol. Please select pedosphere (soil) and soil temperature for the sphere and protocol.