A Garden Amongst The Weeds

A Garden Amongst The Weeds

Sunday, May 29, 2011

What makes good soil?

Compost! What is compost? It's a gardeners goldmine if done right. Everyone that gardens, even badly, has some knowledge of rot. The basis of any good garden soil begins with the minerals and trace elements. Oxygen, nitrogen, silicon, aluminum, iron, calcium, magnesium, potassium, phosphorous and sodium along with many others can be found in a handful of soil. Particle size also makes a big difference. Depending on your location, clay, sand, or silt may be the basis of your garden soil. Particle size makes a huge difference on how a plant will grow and thrive.

Clay contains very small sized particles. These particles tend to trap oxygen, nitrogen and water and hold it away from plant roots. If a plant is unable to obtain the minerals it needs for growth, the plant will not thrive. Rich soil must contain humus which is decayed plant material. This is often overlooked. Without decomposition, plants cannot thrive. Clay can be amended with humus to make a healthy environment for plant growth.

All plants need the basics for survival. Sun, air, water and nutrients. In basic biology class, it is taught that all plants need carbon, hydrogen, oxygen and nitrogen to survive. While this is true, there is much more going on, much more fascinating things happen beneath the soil surface, as a plant lives. As we live. Without plants, none of us would survive. This natural circle of rot, growth and regeneration are what makes the plant world so very fascinating.

Back in the 1800's a theory was formed that plant roots ate humus. This theory was proven to be true but for the wrong reasons. Plants do not eat anything, as they do not have teeth. They do however, break down these trace elements into a form that plants can absorb and utilize. Before chemical fertilization became popular, the world longed for sources of nitrogen. They found that bird guano was a fantastic source of rich nitrogen and it was harvested by the millions of tons from ocean islands. Since it was no longer available to the millions of tiny, hungry plankton in the oceans, they ceased to reproduce. This caused a huge drop in the plankton and algae population. They could no longer eat or breed and began to die off. As the lowest on the food chain started to drop off, fish and bird populations also dwindled.

With the advent of chemical fertilizers and the unavailability of bird guano, the popularity in chemical fertilizers increased. The birds were left to poo where they may, the algae levels and plankton levels restored, the bird and fish populations increased and a natural balance began once again. Man avoided an ecological disaster, by sheer luck!

That's not to say that I approve of dumping chemical fertilizers on plants. Quite the opposite. I garden as organically as I possibly can. The problem with chemical fertilizers is that although a plant may produce more or grow larger because you are spoon feeding it day-glo blue chemical fertilizers this year, when you go to plant the next year and in the years following, if you don't continue to feed your plants these chemicals, no plants will survive in the soil. If you were to then test a handful of soil, after using chemical fertilizers for a few years, you'd find that while many of the trace elements are still contained in the soil, the plants roots cannot utilize them readily. Without the bacteria that causes natural breakdown of plant materials contained in humus, the soil becomes inert. Useless to organisms that depend on bacterial growth and decomposition to survive.

To begin composting, you need an area that has good drainage and good air flow. My best recommendation is that you place it somewhere that is readily available to your kitchen area. Almost all of your kitchen refuse can be utilized to make healthy garden soil. Egg shells, vegetable and fruit peelings, coffee grounds, even the left over flour you used to cook dinner with can and should be dumped into the pile. Good compost is a mixture of dead and decomposing matter, air circulation and moisture. Dried leaves should be added to your pile as often as possible. Green grass trimmings as well. Stirring your compost pile a few times each season will keep the moisture content under control. It's a balance. Not too wet, not too dry.

While the 1800's theory of plant roots eating humus was incorrect, bacteria, which lives amidst plant roots do in fact consume humus. Bacteria break down decaying matter, allowing plant roots to utilize the nitrogen contained in humus. When we think of bacteria, we naturally think of germs and sickness but that's not all that is going on here. Most bacteria is actually helpful. Plant roots excrete carbon dioxide, the microorganisms are attracted to this carbon dioxide, latch onto certain types of plants and actually bond to the plants roots. You can see this for yourself if you pull up a pea or bean vine. Little white nodules form on the roots of the plants and are slowly released, allowing the plants to take up as much nitrogen as is needed. The bacteria give the plant the nitrogen that it needs and in turn, the plant feeds the bacteria in the form of carbon dioxide and protection that the bacteria needs to survive. They have a symbiotic relationship. This is why crop rotation is so very important.

The magical world of plants is amazing in that each plant benefits from another's demise. This whole circle of life thing goes on above and beneath the earth's surface every day. It's brutal and messy. If all of this is going on, how can a plant defend itself against rotting roots? We all know that dead roots decompose, but why then do healthy roots not succumb to disease and eventually rot?

Plants have developed an uncanny ability to protect themselves. Cucumbers for instance, produce a deadly (to plants) gas called, ethylene to kill fungi and ward off an attack. This also lets the other plants nearby know that they could be in jeopardy too. Obviously plants cannot produce these gasses all of the time. Much in the same way as our bodies produce antibodies to ward off an infection. Energy becomes depleted over time and either they get well or they succumb to disease and perish.

These gasses are also sometimes emitted by plants in competition with their neighbors. If you grow the aforementioned cucumbers too close together, what you will get will not be just smaller plants, but sickly smaller plants with yellowing leaves, and a tendency for the vines to rot and in the end, a bunch of dead plants.

When seeds sprout, deadly gasses are also emitted. (This time, deadly to fungus) Anti fungal gasses are produced, allowing a tiny seedling to break through the soil, reach the sunlight and get off to a good start. This is where your humus rich soil benefits your plants. If the soil is loose and pliable, the seedling will emerge from the soil, find the sun and begin to collect its energy and fungal fighting properties, as only so much is stored within each seed. If that plant is unable to break through the soil surface, it succumbs to rot and dies. Such is the circle of life in good garden soil.

There is no need to add bacteria, or in my opinion, beneficial insects to your soil. If you allow the natural processes to do what nature intended, the beneficial bacteria, insects and all the rest will, in time return to the soil in the form of humus and benefit all living things.

Instead of adding chemicals to your gardens, try instead adding composted soil, sea kelp, dried plant materials and a shovel or two of good old manure.

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