Look Down, Soil!
When you walk outside, and step off the concrete or asphalt path, have you ever taken the time to think about what you are stepping on? Or what is hiding below the concrete or asphalt? As a human, it is easy to forget to think about other parts of nature, but without what looms below our feet, life would not be as we know it!
When asked this question many people would say, “dirt” and others may say “soil”. Depending on where one is standing either answer may be correct. What is the difference? Dirt is defined as soil that has been taken out of its natural environment. When you track soil in from outside on the bottom of your boot, you have created dirt, and a mess to clean up! Some people also classify dirt as “dead soil”, it is material devoid of nutrients and other things required for life. Soil, on the other hand, is where it is supposed to be, serving as a loose top layer of earth made up of small rock pieces, humus (organic component of soil formed from decomposition of leaves and other plant materials by soil microorganisms), and inorganic (non-living) and organic (living) components. Soil provides nutrients, minerals, microorganisms, water, and other essential elements needed to sustain growth. The quality of soil can vary greatly due to pH, chemical makeup, structure, color, and texture, but one thing that is true for all soils is that soil is essential to life!
Human factors, like tracking soil on our boots or tires, are not the only factors that lead to a displacement of soil. Natural processes like erosion and volcanic eruption can affect and move soil causing it to become dirt. The good news is that dirt can become soil again. From a quick sweep and return to nature to adding back important, life-giving components, via the output of composting and other organic additions, dirt can once again return to glorious state of soil.
The amazing thing about soil, like so many other things in life, when one really starts to study the topic there is a lot to be learned! People spend their whole life studying soil, it is a passion and a career for many. There are four basic types of soil, based on the size of particles contained: clay, silt, sand, and loam. The smallest soil particles are clay, and the largest sand. Loam soil consists of clay, silt, and sand.
While there are highly technical ways to classify soil, a great experiment you can do anywhere, and the next time you are outdoors, is to take a pinch of the soil that is under your feet and roll it between your thumb and forefinger. Take note of what you feel. Is it smooth? Gritty? Does it form into a tube or fall apart? You can also put some in your palm and drop some water on it. What do you notice? Clay is usually smooth and a bit sticky, where sand is gritty and course. Take a few steps, or in a few miles, do this again and compare your results! Soil types can change very quickly. The surface of the earth is anything but simply consistent.
As you begin to explore what is beneath your feet, you will probably be surprised by the variety you find and the things you feel. You may also begin to be become more aware of different plant life associated with different soils, there is a correlation! Without healthy soil, microorganisms and plants cannot grow, and without microorganisms and plants, well, humans are goners. We may have the biggest brains, but we rely on the smallest organisms for life. With this new found respect for what is under your feet, get outside, it is good for humans everywhere.