[Arid_gardener] Question from Home-Hort WWW page

[Dick]

Caliche,  a river bottom aggregate bonded together like concrete with a clay 
compound is a very effective water barier.  If the vein is six inches or 
less you may be able to hack holes through to act as vents that will allow 
water to go on through. If you can make the holes, fill them with rounded 
river rock and/or river sand to avoid rapid re-clogging. I found that 
crushed granite was very temporary. Otherwise, as you well know, the plant's 
roots setting in wet, airless soil without oxygen will die quickly.

In a San Diego property, I had a thick layer of caliche to deal with. Water 
setting in a trench for a week would only penetrate the clay a quarter inch 
or less. The vents, although getting through the vein without a jack hammer 
was backbreaking work, it was well worth the effort. I tried to disolve the 
bonding agent with sulfuric acid but found the treatment to be totally 
inadequate and expensive except, perhaps in a very, very limited area and 
working with strong acids made me nervous. Battery acid I found to be too 
weak to be ineffective.

If you can't get through the layer, the only option left is to plant 
everything in raised beds and containers or sell your house and move to a 
faster draining landscape.

To test your soil, dig one or more holes 12 inches deep and fill them with 
water. When empty, fill them again and again. When you find them still full 
the day after, you will have exceeded the drainage limit of your soil.  That 
is a point you must not reach when irrigating.  A slow drip can overcome the 
problem until evaporation without any flushing action will concentrate 
alkalines in the root zone and eventually kill your plants anyway in a slow, 
painful, agonizing demise but you might get a little fruit in the meantime. 
A drip systen can be tweaked to compensate but salt accumulation from water 
evaporation may eventually become a bigger problem.

In El Centro, farmers routinely flooded fields for days to reduce the saline 
content built up in the soil.

Dick Gross, Master Gardener Volunteer
University of Arizona Maricopa County
Cooperative Extension

Dick Gross, Master Gardener Volunteer
U of A Maricopa County
Cooperative Extension

----- Original Message ----- 
From: "Chris Trask" <christrask at earthlink.net>
To: <d.morg at netzero.com>; <arid_gardener at Ag.arizona.edu>
Sent: Saturday, February 16, 2008 6:31 AM
Subject: Re: [Arid_gardener] Question from Home-Hort WWW page


> >
>> Is there any thing to soften calechie. I've hand dug
>> about three feet two of the bottom feet are calechie.
>> I want to plant a tree but every where I dig in the
>> yard I can only get about a foot of soil. What do you
>> sugest shot of a back hoe. Thanks
>>
>
>     Go to a grodery store and buy a few gallon jugs of the cheapest white 
> vinegar you can find.  Dig a shallow pit in the caliche and pour in one of 
> the jugs of vinegar, then fill the remaining hole in the caliche with 
> water.  Wait 24 hours, then you my be able to scoop it out with your bare 
> hand.  Continue doing this until you've completed the hole or the grocery 
> store runs out of vinegar.
>
>     Don't bother with gypsum.  The only long-term solution for caliche is 
> excavation.
>
>
>
> Chris Trask
> Outings Leader, Sierra Club (1981-1991)
> Palo Verde Group Outings Chair, Sierra Club (1985-1988)
> Grand Canyon Chapter Outings Chair, Sierra Club (1988-1991)
> Member, Arizona Native Plant Society
> Member, Arizona Governor's Advisory Council on Invasive Species 
> (2005-2006)
> Member, Central Arizona Weed Management Area
>
> http://www.home.earthlink.net/~christrask/wildflowers.html
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