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  • From: "Lawrence F. London, Jr." <venaurafarm@bellsouth.net>
  • To: permaculture <permaculture@lists.ibiblio.org>, Market Farming <marketfarming@lists.ibiblio.org>
  • Subject: [permaculture] Fwd: Re: [SANET-MG] Soil solution concentrations of phosphorus
  • Date: Thu, 30 Dec 2010 16:45:17 -0500

-------- Original Message --------
Subject: Re: [SANET-MG] Soil solution concentrations of phosphorus
Date: Thu, 30 Dec 2010 16:19:36 -0500
From: James Kotcon <jkotcon@WVU.EDU>
To: SANET-MG@LISTS.IFAS.UFL.EDU

Here in West Virginia, both VAM and ectomycorrhizal fungi ARE ubiquitous. We typically find 10-20 species/100 cc in most agricultural soils, and will even find several species on reclaimed mineland soils. These are "soils" that are literally created from mine spoil out of crushed bedrock. It appears that they are inoculated from several sources, including previously colonized transplants brought in for re-seeding, as well as wind blown spores. Within a few years after reclamation, the soils are loaded.

It is true that root colonization tends to be very limited in agricultural soils, largely due to inhibition by large amounts of phosphate in heavily fertilized soils.. Hence high levels of root colonization tend to occur only in phosphorus deficient soils, or in native ecosystems. But low root colonization is not the same as "wiping out" the species. In our experience, although root colonization can be reduced, anything short of broad spectrum biocides (e.g., methyl bromide) is unlikely to wipe them out.

Given the low host specificity and the functional similarities of many VAM species, we have found it difficult to demonstrate a benefit of VAM inoculation except in fumigated nursery beds or similar special situations. Of course, there are species-specific differences associated with things like induction of disease tolerance in infected crops, but it is difficult to make broad generalizations because these vary among crop, VAM species, and plant pathogen.

Perhaps others know how to make them work, but I have rarely seen consistent benefits from field inoculations, except where soils are low in phosphorus or similar elements.

Jim Kotcon

Elaine Ingham <soilfoodweb@AOL.COM> 12/30/2010 1:30 PM >>>
I have to STRONGLY object to this statement from.....

From niemirab@student.msu.edu Fri Mar 3 21:38:31 EST 1995

Article: 5512 of bionet.plants

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.



Most chemical agriculture fields do NOT have mycorrhizal fungi colonizing the root system.

It is NOT TRUE that mycorrhizal fungi are ubiquitous.


If toxic chemicals have been applied, as in inorganic fertilizers, rock powders, pesticides, or herbicides, the mycorrhizal fungi were significantly reduced, if not lost.
Addition of high numbers of Trichoderma spores to a compost tea will also usually seriously reduce a huge portion of the mycorrhizal fungi colonizing your roots.


Don't imagine for a second that mycorrhizal fungi are "ubiquitous". Work by Mike and Eddie Allen, Jim Trappe, Bob Lindeman, Mike Amaranthus and a host of others have proven that many disturbances wipe out mycorrhizal fungal colonization of plants. Gosh, four or five other folks that have showed similar losses of VAM colonization, or ecto-mycorrhizal colonization following common agricultural management just came to mind....... but the ones I listed above are probably adequate for most people to get started.



Elaine R. Ingham
President, Soil Foodweb Inc.




-----Original Message-----
From: Lawrence F. London, Jr. <venaurafarm@BELLSOUTH.NET>
To: SANET-MG <SANET-MG@LISTS.IFAS.UFL.EDU>
Sent: Wed, Dec 29, 2010 10:23 pm
Subject: Re: [SANET-MG] Soil solution concentrations of phosphorus




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?



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.



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