The 77th Osaka City Junior High School Science Research Conference (Presentation Division): “The Story of Soil Told by Saprotrophic Fungi - Ability to Decompose Specific Materials”

Today (September 13), the conference was held at facilities of Osaka Kyoiku University in Teradacho.
From our school, three projects were nominated for the Presentation Division and nine for the Exhibition Division.
Here is a brief report on one presentation: “The Story of Soil Told by Saprotrophic Fungi - Ability to Decompose Specific Materials.”

What the presentation covered
Students investigated saprotrophic fungi in school soil using everyday materials. They buried Someiyoshino cherry twigs for about six months from winter to spring at depths of 5 centimeters, 10 centimeters, and 20 centimeters behind the school in a shady, damp area. During summer, they buried Houttuynia cordata leaves at the same depths for about two months. After recovery, they observed appearance and smell, and split the twigs to check for discoloration near the bark.

The twigs showed little change on the surface; inside, slight discoloration appeared near the bark, and the smell was earthy rather than woody. The leaves were not found at any depth, and an ant nest was noted nearby. The students concluded that clear twig decay was not demonstrated within the short period, while the leaves may have been broken down by saprotrophic fungi and or insects and molds. They also noted that warmer seasons, longer burial time, and the type of material affect the pace of decomposition.

Principal’s reflection
I was impressed by the idea of testing decomposition with familiar soil and plant matter. I felt the careful observations and safe handling showed steady growth. Next time, I would like to see a longer duration, additional plant types and depths, and records of soil moisture, temperature, and acidity, as well as control plots and fixed-point photo records to make the results even clearer.

Keywords: Hokuryo Junior High School / science research / saprotrophic fungi / wood-decay fungi / Someiyoshino / Houttuynia cordata / burial test / soil ecology / decomposition / inquiry-based learning

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