The world under our feet

Living in our urban and suburban world, we most often think of the ground under our feet as a surface to put buildings and roads on, dig canals, and foundations and ponds, meanwhile plopping a few plants hither and thither to create what we think of as “landscapes.”

The “ground” as many of us call it is part of something much greater…part of our living planet, just as much as our dwindling forests, the air we breathe, and the plants and animals we eat…and interestingly, it plays a large part in all those as well.

For the “ground” is soil. It provides habitat for countless beings (there are more living things in a shovel full of soil than there are humans living on this planet). It is, as the Swiss Confederation reported recently, “the connecting element between the atmosphere and the groundwater.”

Our understanding of soil is just beginning to emerge as perhaps one of the 21st century’s greatest scientific breakthroughs.  Soil is the basis for food production, the habitat for innumerable organisms, a water filter and a natural store for carbon and water.

Here in North America, rock, ground down by glaciers, wind, water and other natural events, flowed down streams and rivers, deposited by floods and changing river beds, spread and deposited across the land.

In some places, large inland seas left huge deposits of organic material, as well as rocks and sand.

Sun, rain, frost and soil organisms worked together symbiotically in weathering the rock material, ultimately breaking it down into smaller and smaller particles. Slowly, soil took form. And in that form, plants and land animals began to thrive.

All the living beings that reside in the soil, all the minerals and elements that lay inside that structure, form not just a self-contained ecosystem which exists under our feet, but a truly ancient and rich ecosystem, tied inexorably to all the other ecosystems on the planet.

Are you connected to Earth’s Natural Internet?

Are you connected to Earth’s Natural Internet?

By Bob Dailey

There is a fungus which grows in the soil on and around plant roots that is absolutely essential for plant health. In fact, this fungus is so important that some plant species cannot exist without it. Named mycorrhiza, which literally means “root fungus,” this organism creates a symbiotic relationship with plants. The amazing properties of this root fungus has prompted scientists to call it “Earth’s natural internet.”

If one digs into leaf mold, or into really good soil, tiny white filaments resembling spider webs can be seen spreading through the soil or leaves. This is mycorrhiza. Though deceptively small, a teaspoon of good soil can have eight or nine feet of the tiny strings.

Mycorrhizal fungi create a symbiotic relationship with plant roots, taking in minerals from the soil and delivering it to the plant, in exchange for sugars produced by the plant. Plant biologists have estimated that 95 percent of the plants investigated are either partially or completely dependent on these fungi- a testament to their importance. Orchids, for instance, are so dependent on mycorrhiza that even their seeds cannot germinate without it.

Once attached to plant roots, this fungus sends out tiny threads which extend out much further than the roots can extend.  Though they look like plant roots, these white filaments are what absorb nutrients. Since they have a great deal more range than the plant roots themselves and have significantly more surface area, they are able to find and take in significantly more water and nutrients than the plant roots can. Scientists have also discovered that mycorrhiza can store up nitrogen when it is plentiful, and then release it to the plant when there is a lack of nitrogen in the soil.  These fungi can also store water, which it releases to the plant in times of drought.

Plants that are not aided by these fungi may not be able to take up important nutrients such as phosphate or iron – which can lead to iron chlorosis or other plant deficiencies. Mycorrhiza can also play a protective role for plants in soils with high heavy metal concentrations, such as acidic or contaminated soils. These fungi are also suited for colonization of barren soils.

Soil-borne diseases (such as take-all patch and brown patch) are also serious problems for plants. Unfortunately, many residents are quick to apply fungicides at first signs of take-all or brown patch. While these fungicides will kill the bad fungi, it will also kill the mycorrhiza. A better method may be to inoculate the lawn with organic material that has high concentrations of mycorrhiza.

Studies are showing that plants colonized by mycorrhizal fungi are much more resistant to these and other diseases.  Scientists have also now determined that mycorrhizal fungi can also transport nutrients and water from plant to plant through extensive underground networks.

Operations like tilling can also kill mycorrhiza, although aeration prior to adding organic matter will do relatively little damage to it.  For floral or vegetable gardeners, many experts are recommending “no-till” methods.