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Humus, Humics, Fulvics and Liquid Sunlight

What exactly are humics and fulvics? To begin to answer this, lets look at a few definitions that are frequently confused. Humus is the material that is like gold in the soil- in fact, some experts refer to humus as stored sunlight. It is what is left after organic material in the soil has been broken down and decomposed through the various microbial and environmental actions that come into play. Scientists don't know exactly what it is. We do know that it is an extremely stable substance made of very complex carbon chains. Humus is amorphous and has no cellular cake structure characteristic of plants, micro-organisms or animals- it is so degraded that one cannot tell what the original organic matter it derives from. It has no determinate shape, structure or quality, yet may last in the soil for millennia. It is largely composed of carbon, hydrogen, oxygen, and a small amount of nitrogen.

Humus does not contain active bacteria or microbiotic life This makes it a stable substance because it will not decompose any further. Humus contains both humic and nonhumic material. Humic acids are the acid radicals found in humic matter and are separated by alkaline extraction. These are dark black/brown in colour and are often seen when water is run through a batch of well composted material- it is what makes the water dark brown.

Current scientific studies show that the fertility of soil is determined to a very large extent by the content of humic acids. They are stimulants for microbes and food for worms. Their high cation-exchange capacity (CEC), the oxygen content as well as the above average water holding capacity are the reasons for the high value of using humic acids for improving soil fertility and plant growth. The most important feature of humic acids lies in their ability to bind insoluble metal ions, oxides and hydroxides, and to release them slowly and continually to plants when required.

Fulvic acid has a much lower molecular weight than the humic substances. Because of this, it is a golden yellow colour, unlike the darker brown/black humics. Its smaller molecular size permits it to penetrate the leaf cells and even the mitochondria of the cell. This is very valuable, as this alone makes it very efficient used with foliar sprays and root drenches, whereas humic acids are better as soil conditioners when dry broad cast onto the soil.

This ability to move through the cell walls allows it to pull or transport mineral ions through the plant membranes, delivering them exactly where they achieve the greatest benefit. For instance, if you have sick clones, then try a fine mist of fulvic acid mixed with a bit of liquid kelp at a 5:2 ratio. This will provide stress release and stimulate root growth in a very short time.

Humus, the degraded form of organic material, is fairly common and found in almost all soils. Generally, humus distinguishes itself from organic matter because all the sugar, fiber, cellulose, lignin, gums and proteins have been decomposed, rendering the parent material no longer identifiable and resistant to further decomposition. This decay process broke the organic matter down into reasonably simple molecules, which were then acted upon by the soil fungal microbiology and built up into very complex, larger carbon chains. At this point, it is called humic substance. These larger carbon chains are very stable in the soil and can last for many years.

So now we get down to the really interesting part. We all know that plant health and soil fertility are directly impacted by beneficial soil organisms, such as algae, bacteria, fungi, mycorrhizae, and nematodes. As an example, it is bacteria that release organic acids which play a role in the break down of the mineral elements in the soil. There are fungi that are responsible for releasing compounds called glomalin that help to create soil crumbs, giving the soil a desirable structure. Mycorrhizae assist with the uptake of water and trace minerals in the root zone.

But these soil organisms are unable to capture the energy from the sun directly, due to their lack of photosynthetic functions. They therefore must obtain their energy by taking up residual carbon that is found in the soil. The carbon that is taken from the residual soil carbon is now considered biological or living carbon. Biological carbon distinguishes itself because the energy that is stored within the carbon bonds of these humic substances sustain the organisms and their metabolic processes. This is why it is referred to as liquid sunshine. A healthy, fertile soil sustains the billions of microscopic life forms only when it contains sufficient carbon containing compounds. Reduce the available carbon and humus in the soil and you reduce the energy source of these soil organisms. Reduce the soil organisms, and you reduce the available nutrients and organic compounds that crucial plant health and growth depend on.


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