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Are Soil Microorganisms Important for Plant Health?

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Areas of Science
Time Required
Very Long (1+ months)
Material Availability
Readily available
Very Low (under $20)
Adult supervision is required when using the oven. Use caution when handling and disposing of mold. Treat molds according to the same safety rules as outlined for bacteria in the Microorganisms Safety Guide.
*Note: For this science project you will need to develop your own experimental procedure. Use the information in the summary tab as a starting place. If you would like to discuss your ideas or need help troubleshooting, use the Ask An Expert forum. Our Experts won't do the work for you, but they will make suggestions and offer guidance if you come to them with specific questions.

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Soil may look like a bunch of dirt, but good quality soil is actually a complex mixture of dirt, nutrients, microorganisms, insects and worms. What type of benefit do these microorganisms offer a growing plant? You can test this by baking soil in the oven to sterilize and kill the microorganisms. Do plants grown in sterile soil do better than plants in unsterilized soil? What about adding worms to one plant, but not to the other. Will the plant with worms grow better? Some insects are bad for plants, and others are good for plants. Can you design an experiment to figure out which is which? What about mold and fungus? Try adding moldy bread to soil to see how this affects the growth and health of the plant. (VanCleave, 1993, 9-20; Vecchione, 2001, 168-169)


  • VanCleave, J. 1993. Janice VanCleave's A+ Projects in Biology. New York, NY: John Wiley & Sons, Inc.
  • Vecchione, G. 2001. 100 Award-Winning Science Fair Projects. New York, NY: Sterling Publishing.
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Global Connections

The United Nation's Sustainable Development Goals (UNSDGs) are a blueprint to achieve a better and more sustainable future for all.
This project explores topics key to Zero Hunger: End hunger, achieve food security and improved nutrition and promote sustainable agriculture.


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MLA Style

Science Buddies Staff. "Are Soil Microorganisms Important for Plant Health?" Science Buddies, 20 Nov. 2020, https://www.sciencebuddies.org/science-fair-projects/project-ideas/PlantBio_p031/plant-biology/are-soil-microorganisms-important-for-plant-health. Accessed 21 Sep. 2023.

APA Style

Science Buddies Staff. (2020, November 20). Are Soil Microorganisms Important for Plant Health? Retrieved from https://www.sciencebuddies.org/science-fair-projects/project-ideas/PlantBio_p031/plant-biology/are-soil-microorganisms-important-for-plant-health

Last edit date: 2020-11-20
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