permaculture

[Dennis Argall <dennisargall@bigpond.com>]

On 13/03/2005, at 9:21 AM, Toby Hemenway wrote:

> And as noted, it is mostly gypsum, which is good at lightening clay  
> soil.
> Gypsum (CaSo4) also releases dilute sulfuric acid when mixed with  
> water, so
> it will acidify soil considerably (and is used as such in ag--the  
> opposite
> of lime)
>
> Toby
> www.patternliteracy.com
Hi Tony and thanks for correcting my remembered expectation of raising  
pH. ... You sent me googling gypsum soil pH though and the results from  
that tend to suggest that the effect is pH neutral.

There is a good piece here on using gypsum to treat saline soils.
http://virtual.clemson.edu/groups/turfornamental/ 
Irrigation%20Water%20Quality/overcoming_high_sodium.htm

I agree entirely with the idea of breaking it up, not using as sheet.

You mentioned the longevity of carpet as mulch. I would also note that  
some some small herb growers in Australia many years ago went into  
using old carpet, only to discover to their horror that the old carpet  
importation had brought unacceptable levels of long lasting pesticides  
into the garden.

cheers

Dennis
www.aplaceof.info