Healthy soil and sustainable growing

[Nancy Babbitt <nbabbitt2003@adelphia.net>]

Paul,

Is it likely then, that composting (allowing microbes to decompose the plant material) before it's applied to the soil, can have a negative effect on humus formation.  What I mean is that if less plant material is is present in the final compost, than before composting, and that lesser amount is added to soil, then there is less to potentially become humus.

Is it possible also that the anaerobes assist in the humus formation, and they're not the ones doing the decomposing in a hot pile?

Nancy

On Jun 30, 2006, at 12:26 PM, TradingPostPaul wrote:

Let me try that again easier to read. Point being, it appears that the

initial composting process is not humus formation; that occurs in the soil.

paul, tradingpost@riseup.net

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from Humus - Understanding the Soil Processes

http://www.petrik.com/PUBLIC/library/ups.html#humus

The production of humus is a complex process. In general cyclic substances

like phenol groups and also other like organic acids and vitamins (humus is

also related to crude oil) are polymerized with help of enzymes,like phenol

oxidase. These cyclic compounds are both from plant parts(like lignin) and

are also produced by the microorganisms. Mostly fungi, actinomycetes

(Streptomycets) seem to be responsible for humus formation. Aspergillus,

Pisolithus, Rhizoctonia, Streptomycets are only but a few examples of

microorganisms actually capable of synthesizing cyclic(aromatic) compounds

and form them into humus from non-cyclic materials.

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from Humus: Still a Mystery

http://www.nofa.org/tnf/humus.php

Humus is essentially a massive storage battery containing energy that was

originally derived from the sun. Researchers in England discovered that an

acre  (furrow slice) of soil with 4 percent organic matter contains as much

energy as 20-25 tons of anthracite coal. Another researcher in Maine

equated the energy in  that amount of organic matter to 4000 gallons of #2

fuel oil. This organic energy, which is stored as carbon compounds, was

originally derived from the sun  by autotrophic organisms such as plants

that can extract carbon from atmospheric carbon dioxide. About one percent

of the energy from the sun that  reaches plant leaves is used to

photosynthesize carbon compounds. During the  plants' life much of the

energy that is absorbed from the sun is utilized for growth, foliage

production, flowering, seed production and other functions.

About 10 percent of the absorbed energy, initially from the sun, is left

available to a consumer, e.g. an animal that eats and digests the plant.

Like the plant, the animal uses most of the energy it consumes for

functions such as growth and sustenance but can offer about 10 percent of

the energy it derived from plants to the next consumer in the food chain.

Humus in the soil has more real value than money, real estate, stocks or

bonds. Its value doesn't fluctuate; it doesn't become scarce in a

recession; it's worth can't be depleted by inflation and it can't be

stolen. It is the direct or indirect source of sustenance for all life on

earth. It can sometimes be lost by environmental changes but more often,

its demise is from either the apathy or the inadvertent errors of the

steward who tends it.

Humus is a renewable resource. Its presence in the soil can be maintained

indefinitely. Unfortunately, many agricultural and horticultural practices

are essentially mining humus. Like other mined products, such as coal,

minerals and oil, the natural resource can eventually be exhausted.

The popular scientific definition of humus is "A more or less biologically

stable, dark, amorphous material formed by the microbial decomposition of

plant and animal residues". It is difficult to visibly differentiate humus

from organic matter in other stages of decay. Compost, well rotted manures

and peat are not necessarily humus. However, at some hard-to-define point,

all of these organic materials will contribute immeasurably to the humus

content in the soil.

It is not realistic to think that one can quantify or qualify humus

production from contributions of organic matter to soil. There are too many

factors that control its formation and existence in the soil environment.

One can only assume  that cultural practices that both minimize the

depletion and contribute to the formation of humus will maintain the best

possible level of soil humus for each individual environment.

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