Science Buddies: "Ask an Expert"

I’m wanting to test how/if different types of earthworms affect the soil in my yard specifically for science fair. For example, I would dig in the same area of my yard, fill 3-4 containers, add different earthworms to each container, observe which would best benefit my yard. Is this controlled enough for testing?

Hi!
This seems like a great experiment but I would give two main suggestions. Firstly, make sure that you have a control group, this could be a container with no worms at all. This will give you a baseline to make comparisons to. Secondly, make sure you know what you're testing about the soil. Is it plant growth? Soil pH? Of course, make sure all other things are constant such as amount of soil, light exposure, number of worms etc. Good luck!