From: "Lawrence F. London, Jr." <venaurafarm@bellsouth.net>
To: permaculture <permaculture@lists.ibiblio.org>
Subject: Re: [permaculture] Double-dug?
Date: Sat, 12 Dec 2009 23:48:25 -0500
Jeff wrote:
Just curious, can someone give me an explanation or a how to on double
digging a plot for biointensive plantings?
The essence of it is that you invest a lot of effort and materials up
front, inverting the soil, fragmenting the crumb structure, with
associated temporary disruption of soil life and soil structure,
oxidation of organic matter and release of co2 through exposure of humus
to air. You remove much of the soil in the bed, add organic matter and
mineral based soil amendments to it, homogenize these materials then
return the amended, enriched soil mix to the bed. This is done in
increments of one (typical short (42" to 48") English D-handled) digging
spade blade width wide and one spade blade length deep for the width of
the bed (38-50" wide depending on the gardener's height).
After this process is completed you need never again turn your soil,
except to a depth no greater than is necessary to control newly emerging
weeds, break crust and create a fine, loose seedbed. You now have
biointensive no-till, permanent raised beds.
This technology has been around for centuries and it works.
There is a very big net gain for soil, its inhabitants and the environment.
See John Jeavons books, Alan Chadwick's literature and lectures (links
on my website) and Aquatias' "Intensive Culture of Vegetables, French
System".
Double digging is as essential and indispensible to gardening anywhere
in the world, where the climate does not mandate other methods, as grain
is to bread.
I'll work up a complete description of the method with variations next.