Soil Microbes and their importance

Benefits of Soil Microbes

SMALL WORLD

"The further you enter into it; the deeper it becomes", Dante
   Imagine if you will, having been shrunk down to a microscopic size. You are now smaller than an ameba, but larger than a bacterium. You live in the ground, in a microscopic world of one celled and larger creatures. Some of them are living in the thin film of moisture around the soil particles. As you roam around, knee deep in the water layer around a large grainy sand particle, you see in the water film a multitude of animals and algae floating around in the tiny currents in this small world of water. Some of these small microscopic creatures are animals, catching the algae and bacteria and eating them. Some of the bacteria are dining on algae, and also the dead bodies of the animals that live in this film of water clinging by static action to the sand grain.
   You however are large enough to leave this film of water and venture to another particle nearby. This one is up against the sand grain; it is a particle of compost. This particular piece is so decomposed that it is not possible to distinguish what it once was. But now it is a piece of humus, decomposed plant or animal matter. It is a fluffy segment larger than the sand particle. As you get closer to it you see that is so open and porous, its many cavities and cracks are full of tiny organisms. Some are the same as were around the sand, and some are different. This piece also has water in and around it, but since it is so porous it has soaked up water in mush the same way a sponge would. Its' many cracks and fissures are full of water, in fact this piece of detritus is carrying more water than its' own weight. And in all this water and organic matter there is a veritable colony of organisms at work, digesting the organic compounds of the compost, as they work at it their own waste products are released into the water in the particle. These compounds are worked upon in turn by even smaller creatures, and some substances from them form acids that help to etch the soil particles and hasten the breakdown of the material.
   There are some creatures that have the ability to convert naturally occurring compounds and chemicals into food for themselves. They do this by directly eating the naturally occurring compounds, and sometime they secrete enzymes that help them break the compounds down for digesting. These creatures are called 'autotrophs'. The rest are generically referred to as 'heterotrophs', they dine on the autotrophs, or their waste products. These are basically the plants and animals of this microscopic world. On them the rest of life depends, because these creatures form the base of the food pyramid. With them the decomposition of all organic materials begins. And in turn, the renewal of all energy given to us by the sun is continued. Also from the recycling of organic compounds, chemicals, and other materials that is constantly being renewed into new life in a large cycle known as 'The Cycle of Life'.
   Going around to the other side of this spongy mass teeming with microscopic life you see a large root near the organic matter. This root is actually a very small feeder root, but as it is larger even than the sand particle or the compost it seems overly large in this tiny world. The root is inhabited by a multitude of small fungi called mycorrhizae that live in conjunction with the root in a process called symbiosis. This means that each depends on the other for help, and each releases something that is a waste product to them but useful to the other. In this way they help each other out without any harm to themselves and receive benefit from their mutual co-operation. The bacteria in this case are releasing a substance that is a food for the root; the root is giving up sugars that the mycorrhizae and other little creatures depend upon. Each exchange on this sub-atomic level is a chemical exchange that involves swapping of one atomic neutron for another. This tiny change signifies a chemical change in itself, and helps both life forms grow.
   Much of this chemical exchange is a result of positive for negative electron swapping, and happens only in the presence of sufficient water to carry the electrical charge across the gap between soil and root. In this same way water (hydrogen) is carried into the roots and transported through the plant.
   Unexpectedly the ground near you rumbles and heaves, suddenly the head of an earthworm moves into view, squeezing its' way between the soil particles, and swallowing the bits of organic debris which have made their way down into this soil from the surface, or left over bits of rotted roots from dead plants. As it moves the worm makes a small tunnel that will serve as a passageway for tiny creatures, air and water. It will also serve as a handy highway for the plant roots to move through the soil quickly and easily. This traveling composter leaves a trail of castings (earthworm manure) in the tunnels it creates. These castings are a nutrient rich source of food for many of the micro-composters such as bacteria that colonize these bits of organic debris. These little critters take advantage of the fact that organic material such as this has been pre-digested by a higher animal, it makes the job of reducing it much easier for them once it is already shredded, and half broken down increasing its' surface area. As the plant roots invade the tunnels they take up the rich nutrients from both the castings and the colonizers in it.
   This tiny land is so full of algae, bacteria, viruses, protozoa, fungi and mites that a single shovel full can contain over one thousand separate species, and each gram of rich soil can have millions of individuals. In fact the amount of biomass in the soil is so very high that there is generally (in a fertile non-polluted soil) a larger weight of mass than on the soil surface. For instance an acre of soil might contain 130 pounds each of Algae and protozoa, 890 lbs. of insects, nearly 900 pounds of earthworms and about 2,000 pounds each of bacteria and fungi as well as a larger weight of plant roots than the above-the-ground plant parts. One can see on this small level that the soil is like a jungle with its scavengers feasting on the dead bodies of every creature in the ground, as well as the detritus from above the soil line. There are predators that catch their prey with sticky pads, and others that ensnare unwitting victims in microscopic lassos of tiny filaments. It is a bacterium eat virus world, and it all goes on continually in the ground beneath our feet. It is influenced by outside weather, too much cold or heat can affect the balance of populations in this small soil world. Too little or too much water, or the acidity level of the soil can initiate large-scale die-offs, and this can in turn be influenced by soil temperature alone. So it is easy to see how small things people do to the soil can influence how the soil behaves. Turning the soil when it is too wet can compact the soil, causing the air spaces between soil particles to become packed together, this will reduce the airflow and the soil moisture between particles to become reduced. This in turn will influence the movement of water and air through the soil. PH and microbial action will be impacted, resulting in the potential for a 'sour' (highly acidic) soil. Such a soil might take a year of careful attention to correct this imbalance.
   So be thoughtful of the little critters in the soil. Soil is more than the mineral earth that comprises the majority of the weight of a soil; it is also this small world of animals and plants that convert the raw mineral earth into the rich soil upon which all life depends. When gardening organically it is this world we are seeking to cause to flourish, in this world are the things that will cause a soil to become biologically alive, and able to cause the plants we grow to become resistant to disease and better able to withstand the rigors of life in the above-the-ground world. E-Mail

Rivenrock Gardens
Organic Philosophy