Science Buddies: "Ask an Expert"

My daughter completed the Trash to Biogas experiment and qualified to go to Regional Science Fair. The school judges commented that she should have done cow manure alone, mashed bananas alone, and vegetable peelings alone. Can you please give me a scientific explanation for why the cow manure is needed in all the bottles so she can be better prepared for regionals?

Hi Reganweaver,

Bacteria in the digestive systems of cows naturally turn biomass into methane, which is the central component of natural gas. If the cow manure was not in all of the bottles, then the bananas and vegetable peelings would not produce as much gas on their own as they would be lacking the methane that the manure provides.

Hope this helps,
Lili

Yes it does! Thank you so much!