Emotional Well-being & the Scent of Soil

by Jade Shutes

The Soothing Scent of Soil: How the Earthy Aroma of Soil Can Reduce Stress

It’s gardening season here in North Carolina, and I have become keenly aware of the impact this has on my emotional well-being. This impact is due primarily to the aromas emitted from the soil itself as I prepare our garden for cold weather crops.

There’s something primal and comforting about the scent of fresh soil. That earthy, damp fragrance seems to have an innate soothing effect, transporting us back to childhood days playing in the dirt. Or, for me, gardening with my mother. But could there be more to this aroma than mere nostalgia? Emerging research suggests smelling soil could actually help relieve stress and anxiety. Robin Wall Kimmer explains in the book ‘Braiding Sweetgrass:

“The smell of humus exerts a physiological effect on humans. Breathing in the scent of Mother Earth stimulates the release of the hormone oxytocin, the same chemical that promotes bonding between mother and child”.

The Science Behind the Aroma of Soil

The chemical compound primarily responsible for the distinctive smell of soil is called geosmin. Secreted by bacteria common in soil and some plants, geosmin is what gives beets their earthy flavor.

Humans have an extremely sensitive sense of smell when it comes to detecting geosmin. We can perceive it even at very diluted concentrations.

Interestingly, many species seem able to recognize geosmin, implying this ability has ancient evolutionary origins. Detecting geosmin may once have helped animals identify environments rich in essential microbes.

So, what happens when we breathe in geosmin emanating from the soil? Like other scents perceived by our sense of smell, the scent of geosmin travels directly to the brain’s emotion and memory centers. This helps explain why smells often trigger emotional reactions and vivid recollections of past experiences better than our other senses can.

Smelling soil can, therefore, tap into powerful neurological pathways closely linked to mood, stress levels, and autonomic nervous system functions. Even brief exposure to the scent of soil has been found to lower heart rate, marking increased parasympathetic nervous system activity. The parasympathetic system is part of the autonomic nervous system that counters stress and triggers broad relaxation responses.

The Effects of the Scent of Soil

While folklore has long touted the benefits of forest bathing and “grounding,” scientific studies on the health effects of smelling soil remain limited. However, early findings are promising.

In one Japanese experiment, after smelling soil for just one minute, participants’ self-reported levels of comfort, relaxation, and tranquility rose. Meanwhile, feelings of nervousness, hostility, tension, anger, and confusion diminished.

Intriguingly, those most soothed by the soil scent experienced the greatest drop in heart rate, hinting at a physiological basis behind soil’s psychological impacts.

Memories triggered by soil smell could partially explain this phenomenon. Nearly two-thirds of participants associated the scent with happy childhood memories of playing outdoors and sensory impressions of forests or rice fields near their homes. By rousing nostalgic recollections and connections to nature, soil scent could, therefore, radically reduce stress and its impact on health and emotional well-being.

Applications for Anxiety and Stress Relief

So, can purposefully sniffing soil help tackle anxiety or decompress from stress? As stated earlier, preliminary studies indicate this could very well be the case, though more research is needed. Nonetheless, experiencing the scent of soil firsthand is easy and costs nothing. And given the risks chronic stress and anxiety pose to health, doing so may be worth a try.

Next time you’re outside walking, gardening, or simply lying in the grass, pause and take a deep whiff of the ground beneath you. Notice how the smell makes you feel. Be aware of any memories or emotions it stirs up.

Breathe slowly and deeply to draw the earthy aroma into your nostrils, lungs, and nervous system.

Spend five, ten, or fifteen minutes bathing your senses in the comforting perfume of the soil.

You could also collect a small sample of clean soil in a jar. At home, after a long, tense day, open the container and breathe in the geosmin-rich air to unwind. However, never sniff questionable soil sources that are possibly tainted with hazardous contaminants.

For those lacking easy outdoor access, another option is to sniff beets or certain essential oils with an earthy component, like vetiver. Certain fungus species also produce geosmin, so the forest mushroom and truffle aromas used in some natural spa therapies could offer stress relief. Just taking off your shoes indoors and digging your bare feet into a plant pot filled with soil may also do the trick.

The scent of soil holds promise for moderating anxiety or panic attacks, easing everyday worries, slowing racing thoughts, and promoting rest. Used as an adjunct stress management tactic or emergency grounding technique, purposefully smelling soil or its geosmin aroma could support one’s mental health.

Considering the gravity of global anxiety and depression rates, exploring the stress-busting power of sniffing soil certainly seems worthwhile.

References:

 1. Morisawa, T. , Hanyu, K. , Mori, H. and Tamura, K. (2017) Physiological and Psychological Effects of Scent of Soil on Human Beings. Open Journal of Soil Science, 7, 235-244. doi: 10.4236/ojss.2017.79017.