Dear Curiosity Journal,
A curious wave of calm comes over me when I enter the greenhouse in the spring and inhale the scent of thawing soil. I shed a layer of tension from my body, take deeper breaths, and come rushing into the present moment. I can’t help but reach my fingers into the fertile earthy goodness and take a whiff. Often visitors comment on the pleasant aroma when they step into the hoop houses. Why does the smell of soil have this effect on us? Research is finding that contact with soil, particularly the bacteria Mycobacterium vaccae sparks the release of serotonin in our brains. Studies also show that dopamine is released during harvesting causing a state of bliss or mild euphoria. Scientists hypothesize that this response evolved during our years as hunters and gatherers. However, this mental boost only happens with chemical-free soil. A study in 2008 discovered that glyphosate, the active ingredient in Roundup, depletes serotonin and dopamine levels in mammals. Yikes. So, if you need a reason to start planning your garden, do it for the serotonin and dopamine.