Re: nitrogen fixing bacteria / soil tea

From: Elaine Ingham (Soilfoodweb@AOL.COM)
Date: Tue Jan 14 2003 - 00:53:31 EST


Given the right conditions in a soil tea or compost tea, you can grow certain
of the free-living N-fixing bacteria. The inocula are available from:

holmesenviro@attbi.com

Testing to make certain that the bacteria are functioning properly are
available as well. What rate of N-fixation is occurring? That can be
determined and reported back to you. How much N will be fixed? How much can
you lower your fertilizer inputs?

The N-fixing symbionts require a host to grow, I believe, so not likely to
get Rhizobium growing in a compost pile, or in tea. Some research could be
tried, however, to see if they could be grown in tea. Not just survive,
right? But grow, or increase in number.
----------
Why the advocacy for aerobic conditions in tea? One reason is so you don't
get the human pathogens growing. I don't dislike anaerobes, some of my best
friends are..... Sorry, I couldn't resist.

When we have to deal with the EPA and USDA, folks, we have to exclude E.
coli, and all the human pathogens, such as Salmonella, Shigella, Listeria,
Yersinia, etc. Maintaining aerobic conditions is a simple way to do that.

AND, plant roots do not tolerate anaerobic conditions. We are trying to grow
plants, correct?

This is not a laboratory exercise. The point is to grow plants in field
conditions.

Fermentative anaerobes are not the bacteria that roots need. Roots do not
tolerate the soil habitat that anaerobes produce.

Anaerobic conditions select AGAINST the beneficial, aerobic fungi. Most of
the beneficial fungi are STRICT aerobes.

Anaerobic conditions select FOR the disease causing fungi - like Rhizoctonia,
Pythium, Phytopthora, Cylindrocarpon, Fusarium oxysporum, etc.

Anaerobic conditions kill the nutrient cyclers your plants require.
Flagellates and amoebae in soil are nearly strict aerobes. Cilates tolerate
reduced oxygen levels, but do not survive truly anaerobic conditions.

If you are ever going to get away from having to add inorganic fertilizer to
keep plants growing, you cannot have anaerobic conditions in your soil that
kill the N-cyclers.

It is not just bacteria that we are concerned with.

We need THE WHOLE FOOD WEB.

Don't forget the reason we're doing this. We're trying to set the conditions
up in the soil to grow the plant you want to grow - and that means the right
ratio of bacteria to fungi. Otherwise you get to go through succession, and
most of us don't have the time to let that occur so we can grow bluegrass, or
blueberries, or whatever.

Maximize diversity of bacteria and fungi - so your plant can choose to feed
the bacteria or fungi it needs. But we set the stage by making the soil
habitat correct for the ratio of bacteria and fungi that plants need.

The biochemical information from the existing bacteria and fungi is picked
up by the plant, and that causes the plant to alter the exudates the plant
puts out, and thus changes the bacteria and fungi that grow.

Maximize the number and types of protozoa and nematodes, and microarthropods.
    That way nutrient cycling will occur no matter what the weather. BUT THE
NUTRIENT CYCLERS ALL NEED AEROBIC CONDITIONS.

If nature does something truly out-of-the-ordinary, then the critters you
need may have been hammered and possibly lost, so then you add back what may
have been killed.

OK? Our role as caretakers of plants is to maximize diversity. But we had
better maximize the diversity of the organisms that grow in the same
conditions as the desired plant needs to grow. Aerobic, well-structured soil
is what plants need.

Hum, aerobic.

Ever tried growing plants in sour kraut? Fermentative bacterial species are
what produce sour kraut. Not putrefactive, maybe not losing ammonia or
making the rotten egg smell. Maybe not losing nutrients, which is what we
were talking about before.

But still, fermentative anaerobic conditions are not the right conditions for
plants to grow.

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


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