The Importance of the Soil's Biological Terrain, Soil Composition and Humus Soil Depth on Plant Growth
No Conference Call this week in celebration of the holiday
Effects of the Biological Terrain, Soil Composition & Humus Soil Depth on the Development of Plants
The biological terrain refers to the balance of microbial life, vermiculture (worms), pH, and active nutrients within a soil (or a human body for that matter), along with levels of pollution or cleanliness.
Soil composition, which is a more narrowed definition of the terrain, referring to the balance of humus matter, clay, sand, earthen minerals, and other components essential to the growth of plants.
Depth of soft humus-rich soil before hitting a clay or granite-type hardpan is another component affecting soil health by limiting or lengthening the ability of roots to reach the greater depths for nutrient access.
In this year's garden I found sunflowers to be an excellent gauge of soil health. I learned a great deal about how successful I was at improving my soil's quality from observing how tall the sunflowers got, how many flowers the multi-flower versions produced, how large the seed head of the single flower versions got, and whether or not the sunflower was able to hold up the weight of the flower(s) without falling over (indicating the presence of adequate silica in the soil).
Below are a few pictures which demonstrate the sunflower's ability to visually display the health of your garden soil.
Most of what you will see below are volunteers from a layer of compost/worm bin material added between layers of our new garden soil blend. All three photos below were taken on the same day, and all three sunflowers were volunteers in the garden from either birdseed (the 3rd photo) or last year's sunflowers that were placed into my compost pile (found in the new garden soil).
The first picture is actually our youngest sunflower volunteer (it took us most of the summer to build up our garden soil again, starting from scratch, so volunteers were exposed to the surface soil at different times).
This sunflower is an example of getting it right in all three areas responsible for soil health: biological terrain, soil composition, and humus soil depth (close to 18 inches). The flower reaches 11 feet in the air and holds close to 50 budding flowers throughout its infrastructure (common to the species). The stem is over 2 inches in diameter revealing the high silica presence in the soil (from Silica Rich Pyrophyllite Clay).
Here is an example of a sunflower grown in soil that contains a moderate amount of biological additives, a mixture of poor soil and beneficial mineral/nutrient additives, and a shallow humus soil depth (less than 8 inches) before hitting a decomposed granite base. Even though this sunflower sprouted long before the one pictured above, it is just now beginning to flower. These less than ideal conditions promoted slower plant growth, later blooming and a thinner stalk. Even though the plant is healthy due to the few biological and mineral additives, the shallow humus soil depth and poor original soil composition detered its development.
Below you see an example in which all three components responsible for soil health, the soil's biological terrain, composition, and humus soil depth, were ignored, being grown in pure decomposed granite (a volunteer from winter bird seed). The shiny object at its base is a quarter. For some reason my camera would look right past the tiny frail flower to the larger background for its focus, so the image is not very crisp, but the point is clear - soil quality matters when it comes to growing quality plants and produce!
Clearly, the biological terrain (bacteria, fungi, worm presence, pH, etc.), the soil composition (mineral/nutrient content, humus/clay/sand, etc), as well as the soft humus depth available for extended root development play significant roles in the growth rate, size and health of a plant.
Many blessings of health and success,
Enjoy the simple gifts from Nature!
