Re: soil microbes

From: Elaine Ingham (Soilfoodweb@AOL.COM)
Date: Mon Dec 23 2002 - 01:28:31 EST


I have a hard time with the generalities in Dale's (nosliwelad@YAHOO.COM)
post.

Let me give you some data, something I'm much more comfortable with than the
suppositions that some people have about what is or is not present in ag
soils.

When we assay healthy soils from native grasslands, or assay agricultural
soils that don't need pesticides or fertilizers, we see 600 million or more
bacteria per gram of soil.

Ag fields treated with high levels of pesticides, fertilizers, etc, we only
see 1 million bacteria OR LESS per gram.

Maybe, just maybe, an inoculum of the missing beneficial critters would be a
good idea.

Healthy soil - as defined for example, by very little disease, few weeds, low
requirement for fertilizer - has 150 to 300 micrograms of a good mix of
fungal species. If soil only has say 5 to 10 micrograms of fungal biomass,
based on the testing we've done with corn, wheat, potato, etc, then disease
is significant or fungicides, insecticides and nematicides are needed,
herbicides are needed, and fertilizers are required.

So, let's not make generalities about agricultural soils, ok? Some fields
have good biology, some don't. Don't make statements that do not
differentiate healthy soil from not-healthy.

Inoculation of beneficials into soils lacking beneficial organisms clearly
improve bio-control.

Inoculation of soils that already have beneficial species doesn't necessarily
help. Also, if the foods those "bio-control" organisms need to eat are not
present, no amount of addition of individuals is going to help. For example,
think about dropping people into the middle of the Sahara, with no food or
water. Not going to build a city, no matter how many individuals you drop
in.

In a great deal of our agricultural soils, we have "blown off" the foods for
those organisms. If the organic matter of the soil is less than 1%, the
foods to feed the beneficial, bio-control organisms just aren't there.

So you have to add the organisms AND the foods to feed them. You have to
re-establish the habitat for the organisms to return and do their jobs, as
Joel Gruver said.

So, if in the past you have added beneficial, bio-control organisms to soil,
and did not check to see if they were there already, or if you did not add
foods to feed those beneficial organisms, and did nothing to make sure their
habitat was appropriate, then there may be a perfectly reasonable explanation
for why they did not perform as you expected.

Some pre-testing to determine the soil's condition before adding some set of
organisms is needed.

Elaine Ingham
President, Soil Foodweb Inc.
www.soilfoodweb.com


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