Soil 101

Recently I had the opportunity to give my “Soil 101” presentation, via Zoom, to my local chapter of Florida Native Plant Society.

Giving this presentation for the first time since the pandemic shutdown, I was reminded of how essential it is to get the word out about soil conservation. So I’m making you a post to highlight some of the main ideas, and share the sources I used.

• Soil consists of sand, clay, and silt in varying proportions, plus a substantial amount of air and water, plus organic matter (decaying leaves, microorganisms, etc.). Sand, clay, and silt are just names for rock particles, pulverized to varying degrees of fineness over time.

• A single teaspoon of healthy soil contains more soil microorganisms than there are people living on earth.

• Plants literally suck heat out of the air! That’s because photosynthesis (the process by which plants make food from sunlight) is an endothermic reaction. So the reason why you feel cooler when you walk past a clump of trees isn’t just because of the shade they create.

• Bare soil is exothermic (releases heat). In one experiment in a field on a 67-degree day (Fahrenheit), the temperature of a leaf surface was 59 (yes, cooler than the air temp); the temperature of a piece of paper was 89, and the temperature of bare soil was 138! Bare soil and pavement both contribute to heat-island effect.

• In addition to emitting heat, bare soil also releases carbon into the atmosphere (from decomposition of organic matter), and loses moisture over time. Allowing soil to remain bare (as opposed to covered by plants, mulch) leads to desertification. Up to 40% of rainfall comes from local evapotranspiration of water by plants (this is known as the “small water cycle”). When we denude the soil, we disrupt rainfall.

• Most of us, when we think about ways to mitigate climate change or extreme weather, the first thing that comes to mind is planting trees. While trees and other vegetation are great carbon sequesterers, the soil is even better at it. The pedosphere (the ground under our feet) sequesters four times as much carbon as the biosphere (vegetation and other living things). The great thing about working on soil is that, unlike planting and maintaining trees, it doesn’t require a green thumb, any money or even necessarily any outdoor space of your own!

• Got crappy soil? Super sandy, or mucky clay? No worries; the “fix” for poor soil is always “Add organic matter.” And the best way to do that is by composting. Which is super simple. See my previous post “Compost Basics.”

My Soil 101 presentation is available by Zoom, Facebook Live, or other channel of your convenience. I tailor it to your group’s goals and circumstances.

Further Exploration


– Betsy Ross presentation handout: “Living Soils: Bringing Dirt To Life. Soil Biology Impact on Soil Health, Pollution Control, and Plant Health.”

NRCS: visually appealing 2-page info handout “Soil Health Nuggets”


– “Soil Is the Climate Solution” – Soil Advocate training webinar by Finian Makepeace (sometimes available for free by special offer; I paid the regular rate of $99 which I felt was well worth it. You get permanent access to all course materials including slideshow which you can edit to your needs).  Empowers you with the info & ideas to get out and be an advocate for soil restoration.

– Soil-Food Web: Foundation Courses by Elaine Ingham short course I took last year was free; this one is $5,000! Obviously not the same course. I will keep my eyes open for the link to the short, free course I took with her. But for now, this page gives you a feel for her courses.) 

– Soil-Food Web Consultant Training Program by Elaine Ingham (professional training including period of remotely-supervised hands-on training; price $3,000) (seems like a great potential career path; one would always be in demand and be helping the earth)