[permaculture] humas

souscayrous souscayrous at wanadoo.fr
Thu Mar 7 14:59:20 EST 2002


Mark, can't disagree with you there, though I don't think Lemieux should be
dismissed out of hand for overstating his case. Here's what I paraphrased,
in his own words (from Agroforestry Today Vol 8 no 3), titled "New Ideas on
Soil Formation and Soil Fertility":


'Most of the worlds agricultural land was originally covered by forest, with
the exception of the Asian
steppes, the South American pampas and the central prairies of
North-America,' writes Gilles Lemieux,
professor in the faculty of forestry and geomatics at Laval Univertsity in
Quebec, Canada. The steppe
ecosystems, says Lemieux, are primarily grass growing in a rather dry
climate forming deep soils.
However, the soil that have been used in agriculture have been formed over
hundreds of millions of years
under forests.



He continues later in the same article:


This hypothesis. says Lemieux, is supported by the idea that the basic
biologial processes responsible for
soil fertility and productivity have been developed under forest cover. So,
if forests are destroyed, soil
fertility and productivity could eventually disappear. And if chemicals, as
fertilizers, are used in
large amount, the soil structure can be badly damaged and mineral
deficiencies as well as parasites and
diseases could eventually increase. According to Lemieux, throughout the
world where hardwood forests
have been cleared to make way for agriculture, the soils have deteriorated.
One efficient way of restoring
some of the original fertility and productivity of these soils is to
incorporate RCW (ramial chipped wood), to help maintain
biological processes in the soil, the nutrient cycling and the soil
structure.




Souscayrous

-----Original Message-----
From: permaculture-admin at lists.ibiblio.org
[mailto:permaculture-admin at lists.ibiblio.org]On Behalf Of Mark
Sent: Thursday, March 07, 2002 7:31 PM
To: permaculture at lists.ibiblio.org
Subject: [permaculture] humas


>
>The underlying premise of Lemieux's work is that all fertile soil comes
>originally from climax hardwood forests and that without renewal of climax
>hardwood breakdown products this soil will eventually become exhausted.

I'll put our midwestern grassland prairie soils (or pampas soils in SA) up
against the best of the forest soils.  I'll grow just as good a crop but
won't have to pull stumps to do it ;<)
Furthermore I'll take burned out farm land and graze it for 10 years and
get similar results to 100 years of reforestation, plus I get to eat
beef.  Dogmatism is a barrier to progress, I'd advise folks not to get
sucked in by nonsense like only forests making humates.
Mark


Mark P. Ludwig
Poultry Research Lab
University of Wisconsin -Madison
608-262-1730 WK
608-846-7125 HM

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