Living in a developed nation, we have a tendency to take too many things for granted. We can just turn on the faucet and fill a glass with water. When illness occurs, antibiotics are often prescribed. Looking for a warm weather gift – what about cotton flannel pajamas or a wool cap? Drive down to the nearest store and a near mind-boggling array of food products greets you.

What do all of these things have in common? They are all affected by the soil and its properties. Among its functions, soil regulates the flow of water. Will it soak in and replenish groundwater tables or run off carrying valuable topsoil and nutrients? Many do not know that the soil contains millions of species of microbes that produce many unique substances including the antibiotic, streptomycin. Cotton and flax plants are used to make clothing. Sheep and alpacas graze on forage plants growing in the soil. Their fleece is spun into wool yarns. Whether vegan or omnivore, the vegetables, fruits and grains we consume, or feed eaten by livestock raised for meat or dairy products are grown in soils.

Winter squash in basket

Winter squash. Photo by dmp.

Soils not only sustain life both above and below the ground but they store and recycle nutrients. As plant or animal debris falls to the soil surface, microbes decompose these remains releasing essential elements for themselves and other organisms. Soil plays a large role in the nitrogen, phosphorus and sulfur nutrient cycles. These nutrients are held on both organic and inorganic soil particles, and in the bodies of soil dwellers and eventually made available to both plants and animals.

While the uninformed may think of the soil as an inert substance, those familiar with working the soil and getting their hands ‘dirty’ can almost feel and often smell the life in every handful of healthy soil. That earthy odor that emulates from soil stirred or walked upon after a rainstorm is that of geosmin. It is a volatile organic compound produced mostly by soil organisms called actinomycetes. Scientists do not know what purpose it serves other than to clue us into the fact that the soil smells healthy.

Soil is a complex, dynamic living ecosystem. It is the soil organisms that give the soil life and upon which we also depend, whether we realize it or not. These tiny creatures have co-evolved with plants over billions of years and formed symbiotic relationships. In its simplest sense, plants feed the microbes and the microbes feed the plants. It is hard to fathom but in the top 6 inches of an acre of healthy soil, there may be anywhere from 1000 to 5000 pounds of soil organisms!

bare soil

Bare soil is subject to loss by erosion. Photo by dmp.

Aside from providing plants with nutrients and other essential life substances, certain microbes exude a sticky substance called glomalin. This substance is key to good soil structure as tiny particles of sand, silt, clay and organic materials are bound together to form soil aggregates. The aggregates give soil a granular or crumb structure with spaces for air and water and roots to travel. Well-aggregated soils allow more water to infiltrate them, are less compacted, have less runoff and erosion and encourage plant growth.


Exudates from roots and microbes result in soil aggregates. Photo by dmp.

For microbes to do their jobs, they need food just like we do and microbes love organic matter. Our soils in many situations need organic matter too. Several sources have documented world soil organic matter levels declining over the years due to poor soil management. Not only is organic matter essential for soil microbes but it benefits the planet as it serves to sequester carbon. As some of the organic matter is processed by microbes, it is turned into complex, humus compounds that are very resistant to decay so carbon can be stored in them for years.

wood mulch

Bark mulch on perennial bed. Photo by dmp.

Carbon is at the forefront of many discussions and research projects in regards to its contribution to climate change. As most people are aware, carbon and oxygen together form carbon dioxide (CO2) which is known to be a greenhouse gas meaning it has the ability to hold heat. The more greenhouse gases in the atmosphere, the more heat it can hold with the result being changing weather patterns often bringing with them unprecedented weather events such as hurricanes and droughts.

The carbon cycle is fairly simple. Carbon cycles through the atmosphere, the soil and living creatures be they plants, animals or humans. We can’t make more carbon. There are the same number of carbon atoms on the planet now as there was when it was formed. Carbon just moves through these three storehouses. The reason there is more carbon in the air is because it is being removed from the ground by the burning of fossil fuels (the remains of carbon containing plants and animals), deforestation, the conversion of solid carbon in the soil into gaseous carbon dioxide because of poor soil husbandry and other land management practices or decisions.

Increasing the amount of organic matter in soils, whether they be in your backyard or a farmer’s field or on natural sites, is one way to keep carbon where it belongs – in the ground. Leave the grass clippings on the lawn, use mulch or cover crops in garden beds, compost kitchen and yard wastes and consider using natural fertilizers. Yes, these are tiny efforts when compared to what is needed on a global scale, but every measure helps. Support larger scale initiatives to manage soils sustainably.

mulched bed

Keep soil covered. Straw mulch in vegetable bed. Photo by dmp.

The Earth has 58 million square miles of land area but only about 11 percent is considered arable. When this is divvied up by the number of people living on this planet now, somewhere in the neighborhood of 7.5 billion, it means that there is about one-half an acre of arable land per person. Think about that for a moment. Perhaps this realization will find more people wanting to learn about creating healthy soils. It really is time to stop treating our soils like dirt!

Dawn P.