permaculture

["Jara" <jara@otenet.gr>]

Lisa,

Bentonite can indeed be used to retain water in sandy soils. Mix 5-10% 
bentonite with your sandy soil (bentonite and soil must be as dry as 
possible. Calcium bentonite differs from sodium bentonite in that it swells 
much less ie holds less water than sodium bentonite. Neither the sodium nor 
the calcium in the bentonite is available to the plants because it is bound. 
In addition Bentonite is a clay and so soil micro-organisms and bacteria 
cannot metabolize it so nutrients or sodium build up is not really an issue. 
Btw, Bentonite is also used as a detox food supplement for the above reason. 
Finally, on the whole heavy metal content is neglible in the source that I 
use - Greek and Bulgarian bentonite. I can't speak for bentonite sourced 
elsewhere.

> Message: 4
> Date: Tue, 20 Jun 2006 15:17:13 -0500
> From: "Lisa Rollens" <rollens@fidnet.com>
> Subject: Re: [permaculture] Bentonite
> To: "permaculture" <permaculture@lists.ibiblio.org>
> Message-ID: <008101c694a6$85866fe0$0559e5d8@yourw92p4bhlzg>
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> reply-type=original
>
> Does anyone know anything about using Bentonite in garden soil to increase
> the water holding capability?  I have lots of SAND, and live in a droughty
> area and have been thinking about Bentonite to hold water.  Didn't know
> there was calcium and sodium bentonite.  The calcium one would probably be
> the best idea, in terms of nutrients.  However, when used like this would
> the calcium be "used up", and the effect negated?  How is the calcium held
> in the bentonite and how soluble is it?  Anybody have any experience???
>
> Thanks,
>
> Lisa, in the Ozarks of MO, USA