permaculture

["Lawrence F. London, Jr." <venaurafarm@bellsouth.net>]

On 12/29/2010 1:08 PM, Beginning Farmers wrote:
> Speaking of microorganisms and phosphorus...
>
> In the late 1980's researchers at Michigan State did a simple experiment
> with white clover grown in the presence of mycorrhizae (which is extremely
> important in phosphorus uptake by plants). In the experiment they used some
> soil that was phosphorus deficient, and some that had plenty of available P.
> What they found was that the P deficient plants were colonized by the
> mycorrhizae at much higher levels than the plants that had plenty of
> phosphorus.
>
> A curious result. But that's not where the story ends. Based on this result
> it was postulated that the plants were actually sending out a 'signal' when
> they were under P stress that 'told' the mycorrhizae 'we need help'. Another
> researcher, Muralee Nair, was able to isolate a compound called formononetin
> - an isoflavanoid (think soybeans) that was responsible for the signal.
> Formononetin was present in such small quantities that Nair didn't believe
> the results at first. But after isolating and synthesizing the compound, he
> consistently got significant increases in not only mycorrhizal colonization
> but also rhizobial nodulation (associated with nitrogen fixation) in
> legumes. You can get the paper for free here:
> http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.1991.tb00568.x/abstract
>
> When I was working with them testing the product, we were able to get
> significant increases in plant growth and production by applying
> formononetin at levels as low as 30 grams (yes, grams) per acre! I tested
> this product on plants all over the country with mixed yield results (I
> never saw significant decreases, but sometimes didn't get increases) - which
> I attribute to the fact that conventional farmers typically apply so much
> phosphorus that increased mycorrhizal colonization doesn't always result in
> increased yield.
>
> Just another example of the beautiful complexity of nature, the wonders of
> symbiotic convolution, and the importance of healthy living soils for
> optimal plant growth.

Is the research described here related to the work you did?

-
From niemirab@student.msu.edu Fri Mar  3 21:38:31 EST 1995
Article: 5512 of bionet.plants
From: niemirab@student.msu.edu  (Brendan A. Niemira)
Newsgroups: bionet.plants
Subject: Re: Mycorhizzae vs. Fertilizer
Date: Thu, 02 Mar 1995  11:04 est
Organization: Michigan State University

In Article <3j30kl$s12@vixen.cso.uiuc.edu> "egrunden@prairienet.org 
(Eric Grunden)" says:
> If a person was to isolate a fungus that would form a
> mycorhizzae relationship with an agronomic crop, would
> innoculation of that fungus into the field (once it
> became established) be an effective method for reducing
> the need for commercial fertilization? Wouldn't the
> "strength/abundance" of the fungi grow exponentially with
> the passing of years?

For agronomic crops, you're talking about vesicular arbuscular 
mycorrhizae (VAM), a symbiotic endomycorrhizal fungus.  These are 
ubiquitous anyway, and not very host-specific, so there is very little 
need to inoculate the field in order to introduce them.  The big trick 
is getting them to colonize your crop plant to such an extent that 
fertilizer inputs can be reduced.  You can a) build up the population in 
the soil such that even moderately active fungi result in heavy 
coloniazation, b) put something in the soil to stimulate the activity
of smaller populations to get heavy colonization.

Crop rotations have been shown to have a definite impact on the 
population dynamics of VAM, and work is currently being done (by me, 
among others) to determine how the different crop plants differentially 
select for certain species of VAM among all that are availible in the soil.

Other workers have shown that certain natural, plant-produced chemicals 
can stimulate the existing VAM to higher levels of activity.  These 
chemicals were originally derived from red clover, a popular sequence in 
crop rotations.  This may shed some light on why rotations are effective 
w/regard to VAM.

Good luck.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Brendan A. Niemira           |   "You know your Shelley, Bertie." 

Dept. Botany and Plant Path  |   "Oh, am I?"
Michigan State University    |       P.G. Wodehouse
niemirab@student.msu.edu     |       *The Code of the Woosters*
        All opinions expressed are entirely my own.

<>

Some related information from my archives at:
http://www.ibiblio.org/ecolandtech/orgfarm/mycology/

Glomalin:

http://www.ibiblio.org/ecolandtech/orgfarm/mycology/High.CO2.Stimulates.Soil-Building.Glue
STORY LEAD:
High CO2 Stimulates Soil-Building "Glue"
ARS News Service
Agricultural Research Service, USDA
Don Comis, (301) 504-1625, dcomis@asrr.arsusda.gov
August 12, 1999
In the first examination of the effects of high atmospheric carbon 
dioxide levels on soil structure, an Agricultural Research Service 
scientist and cooperators found that the gas stimulates soil-dwelling 
fungi to produce more of a unique protein that greatly amplifies a 
soil's ability to store carbon. The study's results are described in a 
letter published in the August 12 issue of Nature magazine. One of the 
letter's authors, ARS soil scientist Sara F. Wright, previously 
discovered the protein and named it glomalin. She suspects it may be the 
primary glue that holds soil together. Now it appears that a little of 
this glue goes a long way toward helping soils keep carbon out of the 
atmosphere in the form of carbon dioxide.

Chitin:

http://www.ibiblio.org/ecolandtech/orgfarm/mycology/chitin.txt
Date:         Fri, 11 May 2001 08:18:07 -0500
Sender:       Sustainable Agriculture Network Discussion Group
<SANET-MG@LISTS.IFAS.UFL.EDU>
From:         "Wilson, Dale" <WILSONDO@PHIBRED.COM>
Subject:      Chitin in laymans terms

Two basic strategies for mechanical support are found among living 
things, bones/muscles and tough, hard shells.  Plants, fungi, insects, 
spiders, and crustaceans (including lots of tiny, tiny soil creatures) 
have shells or cell walls.  Most of these exoskeletons and walls are 
made of sugar molecules spun together to make long chains.  The sugar 
molecules are connected by a kind of linkage or bond that is very 
resistant to breakdown (unlike starch, which is easily broken into 
sugar). The plants make cell walls mainly out of cellulose, the main 
constituent of cotton and wood.  The animals (and most fungi) that make 
cell walls and exoskeletons make them out of a substance very similar to 
cellulose called chitin, also fiberous and hard to break down.  It is 
almost identical chemically to cellulose, except the sugar molecules 
have an amino group (contains N) stuck on the side.

The fact that chitin contains all this nitrogen has important
implications ecologically.  Nitrogen is a scarce resource in most 
systems (well, not if you apply 200 lb/a!), and chitin is an important 
source of N, and sugar in many systems.  There has been great pressure 
for the evolution of organisms that can exploit this resource.  In soils 
with a large currency of chitin (soils with a lot of fungi) there are 
also many organisms that eat chitin for breakfast.  In such situations, 
chitin is less effective as armor plate. It so happens that nematodes 
use chitin as armor plate, and of course most fungi do to.  Soil with a 
high rate of formation and breakdown of chitin is less hospitable to 
nematodes and fungi.  Flora must spend more energy
defending itself.  Plants have ways of exploiting this situation at the
root/soil interface.  It is all wonderfully complex and, well, 
miraculous (also very violent on a tiny scale).

Dale

<>

http://www.ibiblio.org/ecolandtech/orgfarm/mycology/fungi-mycorrhizae.faq

<>

Date: Tue, 28 Mar 2000 09:51:57 -0500
To: ARS News List <ars-news@ars-grin.gov>
Subject: Adding Microbes to Transplant Mix
STORY LEAD:
Adding Microbes to Transplant Mix Helps Increase Crop Yields
ARS News Service
Agricultural Research Service, USDA
Jesus Garcia, (301) 504-1627, jgarcia@ars-grin.gov
March 28, 2000
Tomato and pepper farmers can now add microbes along with their 
transplant mix to the arsenal of production practices used to reduce 
yield losses caused by soilborne pathogens--including root-knot 
nematodes. The microbe-amended transplant mix is being developed by 
Agricultural Research Service scientists at the U.S. Horticultural 
Research Laboratory in Fort Pierce, Fla., led by Nancy K. Burelle, in 
cooperation with Gustafson LLC of Plano, Texas. The transplant mix, 
called BioYield 213, is amended with two naturally occurring soil 
microorganisms--Paenobacillus macerans and Bacillus amyloliquefacien.

<>