[permaculture] Sheet Mulch
Lawrence F. London, Jr.
lfl at intrex.net
Thu Mar 27 01:58:34 EST 2003
Kevin email wrote:
> Guess I need to have my say too. I have also opted for sheet mulching as my
> primary method of fertilization. If it is thick and has received moisture in
> the last 100 days, the soil interface zone is moist. There is no nitrogen
> tie up (or bondage) if there is a humus layer between the carbonaceous mulch
> and the soil proper. Moisture is necessary to get the humus developed from
> the sheet mulch over several months if bare dirt is the original substrate.
> Inoculate the sheet mulch with composting green waste or animal manures. I
> use my chicken made compost/mulch or bunny poop. The extra bacteria are what
> does the trick. It also encourages fungi and slime molds. Once there is a
> healthy biological community established, water will be retained by all the
> mucilaginous exudates. I think glomalin my be the largest water sink, but
> this is only conjecture on my part. I hope I have not been too repetitive,
> but remember: Mulch, moisten and inoculate, then wait.
On glomalin; results of a Google search:
STORY LEAD: Glomalin: The Real Soil Builder
ARS News Service Agricultural Research Service, USDA Don Comis, (301) 504-1625, comis at ars.usda.gov February 5, 2003
"An Agricultural Research Service scientist now has more proof that she has found a key ingredient responsible for the well-known benefits
of soil organic matter.
Sara F. Wright, a soil scientist with the ARS Sustainable Agricultural Systems Laboratory in Beltsville, Md., discovered glomalin in 1996
and named the substance after Glomales, the taxonomic order of the fungi that produce the sticky protein. Recently, she used a nuclear
magnetic resonance imager to show that glomalin is structurally different from any other organic matter component, proving it is a distinct
The fungi live on most plant roots and use the plants' carbon to produce glomalin. Glomalin is thought to seal and solidify the outside of
the fungi's pipelike filaments that transport water and nutrients to plants.
As the roots grow, glomalin sloughs off into the soil where it acts as a "super glue," helping sand, silt and clay particles stick to each
other and to the organic matter that brings soil to life. It is glomalin that helps give good soil its feel, as smooth clumps of the
glued-together particles and organic matter flow through an experienced gardener's or farmer's hands.
Glomalin was long lost in humus, the organic matter that is often called "black gold." When it did turn up in humus measurements, it was
thought to be a contaminant.
Glomalin is not just the glue that holds humus to soil particles, it actually does much of what humus has been credited with. Because there
is so much more glomalin in the soil than humic acid, an extractable fraction of humus, glomalin stores 27 percent of total soil carbon,
compared to humic acid's eight percent. It also provides nitrogen to soil and gives it the structure needed to hold water and for proper
aeration, movement of plant roots and stability to resist erosion."
ARS is the U.S. Department of Agriculture's chief scientific research agency.
Glomalin: Hiding Place for a Third of the World's Stored Soil Carbon
"A sticky protein seems to be the unsung hero of soil carbon storage.
Until its discovery in 1996 by ARS soil scientist Sara F. Wright, this soil "super glue" was mistaken for an unidentifiable constituent of
soil organic matter. Rather, it permeates organic matter, binding it to silt, sand, and clay particles. Not only does glomalin contain 30 to
40 percent carbon, but it also forms clumps of soil granules called aggregates. These add structure to soil and keep other stored soil
carbon from escaping.
As a glycoprotein, glomalin stores carbon in both its protein and carbohydrate (glucose or sugar) subunits. Wright, who is with the
Sustainable Agricultural Systems Laboratory in Beltsville, Maryland, thinks the glomalin molecule is a clump of small glycoproteins with
iron and other ions attached. She found that glomalin contains from 1 to 9 percent tightly bound iron."
I remember something about chitin and that it exists, maybe in great quantities, in farm soils. Perhaps it is also a water sink.
a Google search produced this info on chitin:
"Chitin is a complex molecule, AKA a polymer. Chitin can be found in crustaceans, such as crabs, lobsters, and shrimp. It can also be found
in insects, worms, and fungus, or mushrooms. The thing about chitin is that it is a natural polymer, which means that it is found in nature.
In the creatures where chitin is found, it is in different percentages depending on the place. As you can see from the chart of all the
creatures, crabs contain the largest percentage of chitin. (Muzzarelli: All numbers are approximate)
Water Beetle 37%
Silk Worm 44%
Hermit Crab 69%
Edible Crab 70%
The structure of chitin is very similar to cellulose"
"Chitin is the second most abundant polysaccharide in nature (after cellulose). At least 10 gigatons of chitin are synthesised and degraded
each year in the biosphere. Chitin mainly consists of the aminosugar N-acetylglucosamine, which is partially deacetylated. The mostly
deacetylated form of chitin is called chitosan. Chitin is present in nature usually complexed with other polysaccharides and with proteins.
Chitin is a renewable resource and is isolated from crab and shrimp waste. It is used for waste water clearing, for cosmetics and for
medical and verterinary applications."
"Chitin is a polymer that can be found in anything from the shells of beetles to webs of spiders. It is present all around us, in plant and
animal creatures. It is sometimes considered to be a spinoff of cellulose, because the two are very molecularly similar. Cellulose contains
a hydroxy group, and chitin contains acetamide. Chitin is unusual because it is a "natural polymer," or a combination of elements that
exists naturally on earth. Usually, polymers are man-made. Crabs, beetles, worms and mushrooms contain large amount of chitin.
Chitin is a very adaptive material for a creature. Insects and animals with chitin coats usually shed these coats, or molt, at least once a
year. Chitin is a very firm material, and it help protect an insect against harm and pressure. Depending on its thickness, chitin can be
rigid or yielding. Often, insect coats contain thick, stiff layers of chitin. The areas around legs and face contain very thin, pliable layers.
In addition to being a naturally-occurring molecule, chitin is also notable for the process in which it is broken down. Because many sea
creatures shed shells of this material every year, one would expect the ocean to be full of chitin. This is not so. There are tiny bacteria
in the ocean that can sense small chains of sugars sent from a discarded chitin shell. Once these bacteria (Vibrio furnisii) have determined
that they have found a shell, they begin to create enzymes that can be used to break down the shell. In a series of nine steps, these
bacteria reduce chitin to chains of simple sugars and ammonia. The implications that this holds are great. Using this process, scientists
may be able to trigger breakdown and responses in other materials besides chitin. They may also be able to trigger an immune responses in
plants, using the molecules that chitin releases when shed.
A spinoff of chitin that has been discovered by the market is chitosan. This is a man-made molecule that is often used to dye shirts and
jeans in the clothing industry. Chitosan is formed by a process called "N-deacylation." Chitosan can be used within the human body to
regulate diet programs, and researchers are looking into ways in which it can sure diseases. Chitin and Chitosan are only slightly different
on a molecular level. Chitosan contains an amine group, or a group without carbons bonded to oxygen, whereas chitin contains an amide group,
where this is the case.
Chitin itself is the subject of exciting medical experiments. When applied to human wounds and surgical cloths, it accelerates the skin
healing process. An acidic mixture of chitin, when applied to burns, also accelerates the healing process. Left on for a few days, it can
heal a third-degree bun completely. It has been shown to support the immune system during certain kinds of illness-blocking procedures.
Chitosan, chitin's spinoff, has been known to aid plants' immune systems while they are growing. When placed on a seed, it induces
protective measured within the growing plant."
"In the wild world where multi-cellular creatures first began to evolve, plants were the first to break away from the herd and start to
become something distinct. Fungi and animals seem to have continued together for a while before diverging into their present distinct
states. One consequence of this is that although fungi have cell walls, like plants, so they don't need a skeleton to support themselves,
their cell walls are made of chitins, the same class of compounds that compose the exoskeletons of insects and crustaceans.
Chitins are polymers of glucosamine, with an acetyl group attached to a variable number of the individual glucosamine molecules (making them
acetylglucosamine). A polymer composed totally of acetylglucosamine is called chitin, and one composed totally of glucosamine is called
chitosan. These polymers and those made up of a mixture of glucosamine and acetylglucosamine are known collectively as glucoaminoglycans."
lfl at intrex.net
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