What Are Some Interesting Soil Topics?

[SierraeAlphaeMikee]

I need an interesting soil topic to do research on for extra credit in my soils science class.

 

[boredstiff8]

how many earth worms ar in an acre of soil? would there be any soil with out earth worms?

 

[pickmefirstplz]

what ph the soil is and how does it impact growing