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.
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