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Life underground

The surprising science of soil and why you should care

In May, volunteers in the Villages of Urbana planted a 3,500 square foot pollinator garden with 900 native plants and shrubs in an area that had been grass for many years. The garden is already serving as a place for insects to live out their life cycles, as a shelter and food source for birds, and as a beautiful spot for us to enjoy nature.

If you helped us plant the garden, you experienced first-hand the poor state of the soil. The ground was very hard and difficult to break apart, and there were no earthworms or other noticeable creatures living there. Sure, we all have tough clay in this region, but that doesn’t mean the soil in our yards can’t be a thriving underground ecosystem, which can benefit all of us. Healthy soil can even sequester carbon dioxide and improve the quality of our water.

Soil is comprised of three components: the physical component, which is the texture and ability to hold water and nutrients; the chemical component, which is its pH level and presence of elements like nitrogen and phosphorus; and the biological component, which is essentially the living universe existing in the soil, such as (from smallest to largest) bacteria, actinobacteria, fungi, protozoa, nematodes, enchytraeids, arthropods and earthworms.

We know that we can improve the physical and chemical components by amending the soil with natural fertilizers and compost, but scientists are just starting to understand how we can help the biological components’ restorative power.

Fascinating new science

Scientists have learned a great deal about the biology of soil and the interactions among all the living things in the soil; they call it the soil food web.

One of the most fascinating aspects of the soil food web is the many roles fungi play in soil health, plant and species survival—and even our own physical and mental health! Fungi are part of the cycle of natural decay of plant and biological matter; they have evolved entirely to clean up and regenerate Earth.

One of the most extensive, but digestible, books on the subject is Entangled Life: How Fungi Make our Worlds, Change our Minds & Shape our Futures, by Merlin Sheldrake. Sheldrake explains that when you see mushrooms, you’re actually seeing fruit. Underneath the mushroom is the rest of the organism, called mycelium. Mycelium grows underground in vast networks, sending nutrients and water over large distances. These networks carry nutrients, improve soil, and support the structure and nutrient supply of all the plants around them. Mycelium even carries chemical messages warning plants about aggressive predation or environmental stress. Believe it or not, plants can adjust chemical compounds in their leaves in response to the warning coming through the mycelium channels, making themselves less appetizing to animals eating the leaves.

Encourage natural processes

Once you have an understanding that plants, insects, animals, fungi and microbes all evolved together and are intricately supportive and collaborative with one another, you can get a feel for the right things to do in your own yard.

Avoid pesticides

Stop using pesticides and herbicides in your yard, as these interfere with soil’s natural processes and the soil food web. Consider other practices for weed control, such as manually removing them or using organic herbicides in a targeted approach. This might mean shifting your perspective on how your yard looks—back to before corporations convinced Americans that a lawn was meant to look a specific way.

Help fungi

Let fungi do the work for you! Leave the leaves to promote fungi. If you’re concerned about leaves on your grass, rake them and place them in a compost pile or garden bed so the countless insects preparing for winter in their cocoons can use the fallen leaves as nesting sites. Let some fallen branches lie and decay if they can be safely piled away from the foundation of the house, or layer them at the bottom of your raised garden beds. There’s a practice called Hügelkultur that is all about taking advantage of the natural decay of sticks, logs, wood chips, etc. to build robust, nutrient dense raised beds for food, trees, shrubs, etc.

Plant native

Another excellent practice is to plant native plants, shrubs and trees in your yard. These are the plants that co-evolved with the local wildlife and weather conditions in a particular region and so are well suited to the local climate and soil. Native plants encourage the growth of microorganisms below ground and provide food and shelter for animals above ground. They also develop deep root systems, do not need synthetic fertilizers and help aerate the soil.

We’ll practice all of these methods in the VOU Pollinator Garden, and we’ll be able to witness firsthand the transformation from lifeless dirt to rich soil! For additional resources on soil, please check out our Resources and the Green Team Urbana Facebook page.

Kim Leahy is a founding member of Green Team Urbana and a Master Gardener.

Further Reading


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