[Arid_gardener] Gypsum

[Tyler Storey]

Gene, good morning,

While gypsum is one of the substances most often recommended for home soil
improvement, in truth it's generally not necessary or desirable in Southwest
soils.  The great benefits of gypsum are actually something of a myth.  

Gypsum cannot alter the texture of a heavy clay soil, and it doesn't work at
all well on caliche, or layered and compacted soils.  Gypsum is calcium
sulfate, and our soils already have more then enough calcium in them.

If you have done a soil analysis and found that you have very salty soil,
then gypsum will help in flushing the salts from the soil.  But if you don't
have proven salty soils, then it won't help, and may contribute to the
leaching of iron and manganese, both necessary nutrients.  

As you mention adding sand, I'm guessing you have clay soils.  As difficult
as clay soils can be to get going, consider yourself lucky: clay soils are
the very best for water and nutrient retention and in the long run will give
you the finest garden.

Do consider omitting the sand from your improvement mix; rarely can we add
enough sand to make a real difference, and you also run the risk of making
"dirt concrete."  Also, sand can interfere with the natural water-holding
capacity of your soil.

To best improve your soil for a vegetable or flower garden, use copious
amounts of organic material, such as compost or manure, digging a 6-inch
layer into the top 12 inches of your soil.  At the same time, dig in a
sprinkling of soil sulfur at the rate of 2.5 to 5 pounds per 100 square
feet; that will help to lower the alkalinity of your soil much better than
gypsum.  Top-mulch your plants with an organic mulch that you can dig in
later, and continue to amend the soil with compost, manure, and sulfur every
time you plant, digging in a few inches deeper each time.

Follow that recipe, and you will have wonderful improved garden soil in
short order -- and for less money that if you added gypsum and sand.

I hope that's useful,

Tyler

tyler at tylerstorey.com
http://tylerstorey.com
602-738-2978


-----Original Message-----
From: arid_gardener-bounces at CALS.arizona.edu
[mailto:arid_gardener-bounces at CALS.arizona.edu] On Behalf Of
Geneack at gmail.com
Sent: Sunday, September 30, 2007 4:20 PM
To: arid_gardener at Ag.arizona.edu
Subject: [Arid_gardener] Question from Home-Hort WWW page

Gene Ack
85373
Geneack at gmail.com

I plan to start a new garden in Sun City. I will add compost and sand to the
soil. How much Gypsum would you recomend? I don't want to add too much.
Thanks!


_______________________________________________
Arid_gardener mailing list
Arid_gardener at CALS.arizona.edu
http://CALS.arizona.edu/mailman2/listinfo/arid_gardener