Lon:
Excellent piece. Good show.
Bruce Hansen, FD
Member Nafex
Mid Michigan Zone 5
From:
nafex-bounces@lists.ibiblio.org [mailto:nafex-bounces@lists.ibiblio.org] On Behalf Of Lon J. Rombough
Sent: Tuesday, October 25, 2005
11:20 PM
To: NAFEX
Subject: [NAFEX] Microflora and
soil pH
I did some inquiring about the possibility of mycorrhizal fungi being
able to affect the pH of soils. Dr. Robert Linderman, who has been working with
soil microflora for 40 years or so had a very interesting reply:
"
Interesting that you ask the question you did just now as I am writing another
paper for a presentation in Denmark
on the mycorrhizosphere. As it turns out, the real story about weathering
mineral rock to release nutrients is that bacteria live in association with the
mycorrhizal fungal hyphae, and they are the source of acid that can etch the
rock, solubilizing it for uptake by the mycorrhizal fungus and on to the
plant. Pretty neat, huh? C. Y. Li, now retired from the Forest
Service here in Corvallis,
was the scientist who documented that fact. He was able to isolate the
bacteria from the hyphae and show that they could dissolve even marble with the
acids they produced. It is the bacterial association with the mycorrhizal
fungal hyphae that perform many functions previously attributed to the
mycorrhizae. I call this phenomenon the “mycorrhizosphere effect”.
We have shown that the fungi selectively increase populations of bacteria that
can do many things as part of a team, even help suppress diseases (the subject
of my own research). So I have described a new paradigm for the
mycorrhizosphere wherein the host plant associates with the mycorrhizal fungi
and the soil bacteria (certain ones) associate with the mycorrhizal fungus,
making a marvelous microbial team that has been a winner for some 460 million
years!! By the way, we have shown that some of the bacteria can produce
acids, some ammonia; both can change the pH around them. I really do
think it can account for the way ericoid mycorrhizal fungi function on
blueberries; that is by changing the pH in order to allow their proteinases to
break down organic substrates. Those enzymes require very low pH to
function at a maximum."
-Lon J.
Rombough
Grapes,
writing, consulting, my book, The Grape
Grower, at http://www.bunchgrapes.com Winner of the Garden Writers
Association "Best Talent in Writing" award for 2003.
