Pelletized gypsum is an excellent product to add to the soil when it is hard
clay. I would not suggest you use powdered gypsum. The addition of sand may
work, but usually only if accompanied by a thick layer of mulch, otherwise the
small particles of clay stick to the significantly larger sand particles and can
cause some very hard soil, as you now can see. Mulch is really important in
that it continues to nourish the soil with active organisms which help break
down the mulch and shades the soil to keep it cooler, thus the earthworms come
higher to the surface and drag down the organic matter to ingest and process, as
well as aerating the soil. Worm castings will then be present in the soil,
which will introduce other aerobic organisms, which further break the soil down
into more friable particles.

Leaving clay with added sand in hot open sun will give you something on the
order of concrete. It will change the minute you mulch. On areas where
aesthetic is not an issue, I will use alfalfa hay to suppress weeds and feed the
soil organisms. It keeps the soil cool and moist, which is how clay(s) develop
from hardpan into workable soil.

It's a process which is well worth it. It can take about three years for soil
to truly come alive and be self sufficient enough where you only need to add
organic matter to maintain the levels of micro and macro organisms which in
turn, do all the work. A soil should only need to be tilled mechanically once.
Then it should be left alone to recover and develop a fungal mat where you will
smell frankincense in the soil. It smells sweet and has great texture and
structure. Clay is a lot easier to do this with than sand since the clay
already has body, it just needs to be nurtured and given organic matter to
develop. If you add anything, add finished compost, preferably with active
actinomycetes, which is a fungus and will help develop active soils.

For information about soil and how to get it alive, take a look at:

http://www.soilfoodweb.com/phpweb/to...ex.php?tid=153

or start at their home page:

www.soilfoodweb.com

Victoria


On Tue, 10 Jun 2003 07:44:54 -0500, Carl e Roberts wrote:

15 yrs ago I added 24 cu yds of white sand to my yard (here in Memphis).
(The neighbors thot I was building a beach). We are on the downward side
of a slight slope and this sand definitely has helped with drainage and
has improved our soil overall. Recently this spring we tilled about
400sq. ft of new flowerbeds and I was amazed at the variety of soil
types in various locations of the yard. Some in full sun, partial shade,
the "upside" of our yard, and the "downside" all with different types of
soil. (I am going to take a small break from this sand issue to say for
the benefit of some-I have also added other "amendments" to the soil
such as lime,compost,organic matter,etc. ). Here (finally) is the issue:
The area where we have a small garden after tilling and planting this
spring is showing signs of hard packed soil. The sand is still mixed
with the clay but the clay still "hardpacks" after a good rain. I have
two compost piles "working" and intend this fall to incorporate large
quantities of organic matter (grassclippings/shredded newspaper) into
this garden spot. My question is this: I am wondering whether to add
more sand to help with the breakup of the clay or maybe gypsum is the
answer here- I am not very familiar with this product what exactly is
"gypsum" and how/when is this product added? where can gypsum be
purchased?