Humus formation Process
Plant residues contain mainly lignin, carbohydrates, and protein. All of which are very high molecular weight, large size compound and are also chemically bound to one another. Microorganisms produce extra cellular enzyme which breaks down this macro molecule to smaller units. The Microorganisms are as who, a part of it is Oxidized to CO2 and the rest is exuded in the form of different waste product (phenols/quinines) through by the transformation. Polyphenols of the quinines appear to be common molecular waste which is find little use as a food (energy) sources by Microorganisms. Such compound therefore, accumulating soil. Phenol polymerization takes place under the influence of certain enzyme (phenol exuded) by Microorganisms. Phenols may also complementize with nitrogenous compound (amino acid), sugar and other degradation products in soil. As a polymerization proceeds, the compound become dark brown or black and gets precipitated and huming polymers of various sizes are form.
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