Re: [compost_tea] Re: Sticky Gooey .

From: <soilfoodweb_at_aol.com>
Date: Tue, 9 Nov 2004 16:02:01 EST

In a message dated 11/9/2004 12:32:50 PM Pacific Standard Time,
bnbrew_at_yahoo.com writes:
Elaine - Would the slick slime also permit roots to penetrate the soil to go
deeper. Ever get down there to see what is going on? Earth worms leave a
trail of slime as they travel. Rain probably re-fills this slime to absorbe
and hold water in the same tunnels that let water go deep in the soil. Bob of
Bob's Brewers
Soil structure is what allows roots to grow deeper, because roots must have
air in order to grow. The most phytotoxic material in soil is simple alcohol,
because this compound solubilizes cell membranes. If soil lacks oxygen, then
anaeorbic bacteria grow, produce alcohol, some low pH organic acids,
volatilize nitrogen, sulfuer and phosphorus, and thus reduce soil fertility.

Lose the N, P, S, and roots don't grow there. Have some seriously anaerobic
growth occur, and roots die.

To resuscitate this, you need to re-from structure, which means aggregates
have to be formed, and preferably water-stable aggregates, so the structure
doesn't go away the next time it rains. Or you irrigate.

Aggregate formation is done by the biology, and the biology alone. Chemicals
will floculate clays, and may ephemerally result in cohesiveness, but they do
not form water stable aggregates.

Slime is involved in anything bacteria do. Gels hold water. No bacteria, no
gels. No bacteria, no earthworms. Bacteria form micro-aggregates in soil,
if the clays have been adequately floculated. So, soil chemistry and soil
biology work together to form the basic building block of soil structure.

Fungi then build the larger macroaggregates, wihch results in holding water
in small soil pores. The larger critters, like protozoa, nematodes, worms, and
microarthropods form the bigger soil pores, which result in holdling even
more water in the soil.

I've written a fair amount about soil aggregate structure, but the folks at
Univeristy of Georgia have probably written even more. The work in Iowa at
the Tilth lab is important to understand in assessing the interactions between
soil chemistry and soil biology.

So, I could go on for several days about this, but if you want roots to grow
deep into soil, you have to have hte biology form air passageways, hallways,
room structures in order that roots will have the air they need.

Tillage will fluff soil, but that fluff colapses as soon as you get water
moving through the soil. And then compaction happens, and you can't get roots
into the soil, and you have to then use fertilizers to get the plants to grow.

If you have straight sand, you typically start out with air passages, but we
compact sand all the time with large machinery. So, you may start out with
roots going deep, but over time they get shorter and shorter, until disease and
stress results in sever problems. You have to have biology to build the dams
and rooms to hold water. Or it just whooshes through and you have to water
every hour.

If you have straight clay, you have to make aggregates to let air or water
pass through the soil and not puddle. .

But, that's enough for now. Untl the participants in this discussion want to
define the soil they are dealing with, and not just trade verbiage, this is
about it from me.

Elaine R. Ingham
Soil Foodweb Inc., Corvallis, Oregon
Soil Foodweb Inc., Port Jefferson, New York
Soil Foodweb Institute, Lismore Australia
Soil Foodweb Institute Cambridge, New Zealand
Laboratorios de Soil Foodweb, Culiacan, Mexico
Soil Foodweb Inc., Jerome, Idaho
Soil Foodweb Inc., South Africa







Received on Tue Nov 09 2004 - 18:09:59 EST

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