Skip to main content

Testing Conditions that Promote Decomposition

Unit Plan: Decomposer DynamicsLesson: 5 Time: Session 1 (40 min), Session 2 (40 min), Session 3-5 (40 min), Session 6 (1 hr) Setting: Classroom
3-5, 6-8Schoolyard Ecology
icon quick tip

Use the filter to limit your results.


Students test factors that promote the growth of microbes, then use their findings to make compost.


Students will be able to: Understand that invisible spores of microbes are in the air, water, and on all non-sterile surfaces, discover that certain physical conditions, such as moisture and warmth, help microbes grow, explain the connection between the growth of microbes on dead plants and decomposition, refine their experimenting skills



For the Class:

  • 2.5 gallon (30x15x17 cm) plastic animal cage with cover (or a similar clear plastic container to use as a decomposition chamber)
  • clear plastic bag large enough to line the decomposition chamber
  •  6 cups of alfalfa hay
  • 6 cups of hardwood shavings
  • materials to vary conditions for growing microbes

 Session 1

For each pair of students

  • copy of "Research Proposal"

Session 2

For the class

  • miscellaneous containers

For each pair of students

  • 4 sandwich-size ziplock bags
  • masking tape or permanent marker

Session 3-5

For the class

  • measurement and observation tools

For each pair of students

  • 2 hand lenses
  • copy of "Science Fair Story #3"
  • copy of "Science Fair Story #4"
  • copy of Science Fair Story #5

See Lesson Resources for further details.

Lesson Files

Testing Conditions that Promote Decomposition

Benchmarks for Science Literacy

5D Interdependence of Life, 5E Flow of Matter and Energy, 12C Manipulation and Observation

NYS Standards

MST 4- Physical setting, living environment and nature of science, MST 7- Problem solving using mathematics, science, and technology (working effectively, process and analyze information, presenting results)
Next Generation Science Standards

Science and Engineering Practices

Asking questions and defining problems, Planning and carrying out investigations, Analyzing and interpreting data

Cross Cutting Concepts

Patterns, Cause and effect

Disciplinary Core Ideas

LS2A: Interdependent Relationships in Ecosystems, LS2B: Cycles of Matter and Energy Transfer in Ecosystems
New York State Science Learning Standards

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., MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.

Hogan, Kathleen. Eco-Inquiry: A Guide to Ecological Learning Experiences for the Upper Elementary/Middle Grades. Kendall/Hunt Publishing Company, PO Box 1840, 4050 Westmark Drive, Dubuque, IA 52004-1840., 1994.