Beneath the Surface
In my a recent blog (Five tips to quality Gardening), I mentioned that there is a difference between dirt and soil. Dirt is basically varying amounts of sand, silt and clay. Dirt in and of itself contains no minerals, nutrients nor the living organisms that makes up soil. Dirt lacks the texture and structure that is needed to produce the life that comes from soil.
Soil on the other hand is a living by product of its many components. Soil that is well balanced will have a relationship with the plants that live in it. Its balance comes from a mixture of things that are seen and not seen with the naked eye. Things such as, bacteria, Nematodes, Protozoa, Anthropoids and earthworms. These along with good water quality and air flow become the basis for a healthy soil.
How do these affect plant growth?
Bacteria is a one cell organism that has the ability to change or modify compounds in the soil to make it accessible for absorption in the plant. Due to their small size, a teaspoon of soil can contain between one hundred million and one billion bacteria.
Bacteria falls into two general groupings, Aerobic and Anaerobic. Now is one of these better than the other and the answer depends on what you are needing to accomplish. Anaerobic bacteria work in low oxygen environments and help in the decomposition process. When it comes to soil life, we want to stay away from Anaerobic bacteria and the best way to do that make sure that you have a well aeriated soil.
Aerobic bacteria on the other hand help transform components in the soil into plant absorbing components. One of the better known and can see the result of is the nitrogen fixation bacteria. These bacteria, along with their counter parts are able to take the nitrogen out of the atmosphere and turn it into a useable plant product. You can see the result of these at work when you pull up alfalfa or bean plant in the form of white spheres along the plants roots.
Fungi are also another microscopic cell organism. Unlike bacteria who primarily work as a single unit that attaches to other bacteria, fungi form long threads called hyphae. These hyphae can last just a few cells in length to several yards.
It has been observed that where there are fungi, the water dispersion is better, as the hyphae act like a drain pipe. These fungi also work as a chemical factory that can aid in the reduction of attacks from various insects. Because of this internetworking of fungi, it is one reason that no-dig gardening produces healthier crops. The thought for this is, in the no-dig process the network of they hyphae are not disrupted as in with tilling and plowing. So, when it comes to the intricacy of how fungi work, there is still a lot to learn.
Nematodes are some of the most numerous microscopic worms, with at least 20,000 known types. These non-segmented worms typically range in length of 1/500th of an inch in length. Nematodes are divided into four basic groups; Bacteria feeders, fungal feeders, predatory nematodes and root feeders. Due to this character, the decomposition process and the breaking down of organic matter is possible.
The last of the microscopic entities on this list is the Protozoa. Because of their genetic makeup, protozoa are often considered “Animal-like”. The reason for this classification is because of their carbon and energy must be obtained by consuming organic compounds that are derived from other living organisms.
When it comes to gardening, earthworms are the most notorious. These animals are the major consumers of decomposing material in the soil. The earthworm is divided into twenty-three distinct families. They can range in length from one inch up to twenty-two feet in length and can be found in varying depths of soil.
Maintaining a healthy soil, and thus the natural biology that makes it up can be easily done by simply supplying organic material to the soil. It is by this simple process not only do we provide the benefits for the micro-organisms that live there, but they in return provide what our plants need.