Humus, that rich organic matter found on forest floors, is actually a giant organic solar battery, storing and converting the sun’s energy into plant and animal food, and completing the cycle of life and death and back to life.
Plants create organic matter through photosynthesis. When they die and decompose, that organic matter feeds the macro- and micro-organisms in the soil. These in turn change the organic matter back into plant food, nutrients for other organisms and into humus.
Essentially, humus is the partially decomposed residue of plants and animals that has been ‚”eaten” by micro- and macro-organisms, such as earthworms, smaller insects and arthropods, and finally by microbes (bacteria and fungi), which is basically the process of decay.
A good analogy is that the process of creating humus is like a giant, organic digestive system.
Organisms eating the plant material create byproducts, such as urea, water and carbon dioxide. Undigested matter is excreted. When these organisms die, they also contribute their tiny bodies to the already rich mixture.
This is the lower part of the food chain. When the microbes finally get to the plant and animal residue, they break it down into sugars, starches, protein, cellulose, and other carbon compounds to use for their own existence.
Humus is extremely rich in nutrients, and small amounts can convert large areas of ‚”dead” soil into a rich growing environment for plants, and the energy, nutrients, mineral salts and other elements stored in humus can be converted by plants into food, which completes the process of rebirth.
Agricultural scientists have found out that one acre of soil, enriched by a mere four percent of humus, contains enough energy as 20 to 25 tons of anthracite coal. Five percent of humus can transform lifeless rock dust which is found in many desert areas, into rich, fertile loam.