Healthy soil and sustainable growing

["Tradingpost" <tradingpost@lobo.net>]

Good. I located more of Lowenfels at
http://blog.oregonlive.com/kympokorny/2010/04/jeff_lowenfels_talks_about_the.html
 .
That's one fellow I wasn't familiar with. Interesting about the need for 
different kinds of mulch.

paul tradingpost@lobo.net


*********** REPLY SEPARATOR  ***********

On 8/24/2010 at 3:12 PM yarrow@sfo.com wrote:

>I went to a talk by Jeff Lowenfels, author of Teaming with Microbes: A
>Gardener's Guide to the Soil Food Web, this spring. If you haven't come
>across this information on *why* organic gardeners say "feed the soil
>not the plants," and why to avoid chemical fertilizers and pesticides
>and rototilling, here's a very brief summary. For details, see the
>book.
>
>As Lowenfels described this elegant system, 60 to 70 percent of a
>plant's energy goes to producing exudates that it drips out through
>its roots to attract bacteria and fungi, who in turn attract
>nematodes and protozoa to the root zone. To get carbon, the protozoa
>eat bacteria, and the nematodes eat bacteria, fungi, and other
>nematodes, and poop out the rest, which feeds the roots. The plant
>can change the exudates it produces if it wants different foods!
>That's because different exudates will attract different bacteria,
>fungi, nematodes, and protozoa. The huge diversity of soil biota
>helps the good guys keep the bad guys in check.
>
>A common way to destroy the microbiology in the soil is to add salts
>(nonorganic fertilizers). The salts kill the bacteria and fungi by
>dehydrating them, with the result that the plant can no longer feed
>itself and becomes dependent on its fert fix. In addition, without
>bacteria and fungi, the other parts of the food chain start dying off
>as well.
>
>The soil food web is also responsible for soil structure. Bacteria
>create slime that glues soil particles together, and fungi weave
>threads to create larger soil aggregates. Larger fauna in the soil,
>such as mites and earthworms, create pathways for air and water.
>(Lowenfels called worms taxicabs for bacteria and fungal spores,
>distributing them through the soil.) To destroy soil structure, the
>most common methods are rototilling and using pesticides.
>
>To bring soil back to life, you can do the following:
>1. add a quarter inch of good quality compost
>2. use appropriate mulches -- dry leaves for perennials, shrubs, and
>trees (which prefer the form of nitrogen produced in soils where
>fungi predominate; tomatoes are a perennial and prefer a
>fungal-dominated soil), or straw/grass clippings for annuals (which
>prefer the form of nitrogen produced in soils where bacteria
>predominate)
>3. use properly prepared aerated compost tea, made with good quality
>compost
>4. apply mycorrhizal fungi, especially in a new garden that's been
>rototilled or chemically fertilized (but note that brassicas are
>nonmycorrhizal).
>
>(also, try to avoid walking on the root zone. Lowenfels said palm
>trees were dying in Hawaii and redwoods were dying in Calif. because
>tourists were walking all over the root zone, which kills fungi)
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