In article ,
Jane Yeoman wrote:

Has anyone used expanded sale to improve clay soil? I read of a study
by Texas A&M which indicated it is a permanent solution to improving the
air and drainage properties for gardening.

Has anyone used it?

No I haven't, but I have serious doubts about it being the single answer
to your soil's problems. As part of a strategy, it seems like a good
idea.

http://www.highplainsgardening.com/?q=content/physical-soil-composition
If you have tight compacted clay and caliche soil, you should add a mix
of organic matter with one of the newer inorganic amendments. I
recommend adding an inorganic amendment for heavy clay soil, such as
Turface® (calcined clay), Tru-Grow® (expanded blue shale), Ecolite�
(zeolite) or Axis® (diatomaceous earth) and Profile� for sandy soil.
Expanded blue shale is also available from Soil Mender and is called
natural expanded shale. These are a few of the better inorganic
amendments that retain water and nutrients, in addition to creating more
spaces for air and water.
Other inorganic amendments with much more limited ability to retain
water and nutrients are crushed granite, granite and lava sand,
greensand, glass sand, and finally, regular sand. If your clay soil
develops cracks during summer droughts, please consider adding the
inorganic as well as organic amendments.
--
- Billy
³When you give food to the poor, they call you a saint. When you ask why the poor have no food, they call you a communist.²
-Archbishop Helder Camara

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