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Roger Weller, geology instructor
by Casey Fuller
Caliche: Bane of the Desert Homeowner
Have you ever tried to dig a hole through concrete? It is
doubtful that you have. The very idea is rather absurd. Really, who would try
something that foolish? Surprisingly, many people have tried, usually in vain,
to dig through concrete. However, the material is not called concrete: it is
called caliche. Also known as hardpan, caliche is a naturally occurring concrete
found in arid environments, and inexplicably,
in many frustrated homeowners’ yards. But, what makes caliche so hard, what
value does caliche posses, and what can a person do to get rid of the nasty
stuff? Caliche is a very interesting material that can be hard to get rid of,
with the right tools and advice, anybody can stop caliche from ruining his or her backyard garden plans.
Illustration by Roger Weller
As previously stated, caliche is a naturally occurring soil that is
cemented by lime (Weller). The creation of caliche is a fascinating process.
Caliche is found in many different varieties and places.
Photos of sand and calcite by Roger Weller
Nevertheless, the basic ingredients that are needed to make caliche are the
same. Calcite (lime), gravel, clay, sand, and silt are the most common
substances found in a typical caliche, with lime being the constant ingredient
(Caliche). These materials are the content of every type of caliche, but the
presence of these materials alone does not create caliche. A very specific
process must be completed before caliche is created.
In order for caliche to form, several steps need to occur. The first
step that must happen is the leaching of the top layer of soil (Caliche).
Leaching is the process where mineral and organic materials filter down through
the top layer of soil (the A Horizon). The materials subsequently deposited in
the next layer of soil (the B Horizon) are used in the process of creating
caliche (Leaching). Leaching is essential because it brings minerals like lime
do to the gravel, sand, and other types of materials that are not found in the A
Horizon. The lime then slowly starts growing crystals, which in turn merge with
the surrounding in many frustrated homeowners’ yards. But, what makes caliche so
hard, what value does caliche posses, and what can a person do to get rid of the
nasty stuff? Caliche is a very interesting material that can be hard to get rid
of, but with the right tools and advice, anybody can stop caliche from ruining
his or her backyard garden plans.
The final form of caliche. Photo by Roger Weller
There are two major uses for caliche. The first use is the
harvesting of the caliche for its lime content. Because caliche is an excellent
source of lime, caliche is used to make cement. It is rather interesting that
this naturally occurring cement is used to make synthetic cement. Besides being
used to make cement, caliche has another economic use. Caliche is used in the
refining process of sugar. Again, this is because of the high lime content in
caliche. Even though caliche is not made exclusively of lime, it is cheaper to
refine the caliche, rather than purchase other sources of lime, such as
limestone (Caliche). Still, even though caliche does have some economic uses,
what can a desert homeowner do to get rid of caliche in his or her yard and
To any person who has dealt with caliche, the hardness of the
material is fully understood. Because of the difficulty in removing caliche, it
is not recommended that a gardener try to remove all of the caliche in the
garden (Conquering). This is would be very time consuming and difficult work.
Yes, caliche is that hard. Photo by Encefalus.com
Unfortunately, there no magical ways of making caliche disappear or soft. However, where there is a will, there is a way; there are some helpful hints are available for the removal of caliche.
The best way to get rid of caliche is to do it in a scientific manner. This means that there should be a plan attack before ever picking up a pickaxe or crowbar. First, one should decide how large of a hole needs to dug (Conquering). After the planning stages are over, it is time to actually go and dig a hole. Depending on the depth of the top layer soil, digging a hole can be easy or difficult. For example, if the top soil is deep, then a gardener may only have to dig a chimney for drainage purposes. Digging a chimney simply means that a small tube like hole needs to be dug through the caliche. Placing the chimney close to the hole where the plant is will allow for proper drainage around the plant (Carefree Gardener). However, if the top soil is shallow, then the only option is to dig a hole into the caliche layer. It is very necessary to replace the caliche with good gardening soil. Reusing the broken caliche for planting would not be good for the plants (Conquering). While these steps may not be easy to accomplish, they are the best way of efficiently removing caliche from a future garden.
Caliche is a very interesting material. The process from which it is
formed demonstrates how unique this material is. It is also incredible how
something so seemingly useless could have economic value. However, caliche still
is an enormous irritant to any desert homeowner and gardener. The very thought
of removing it can be daunting. Nevertheless, the successful removal of caliche
is still possible. Caliche is a formidable opponent in the battle for the
backyard, but with the right tools, gumption, and energy, this fascinating,
natural cement can be conquered by any desert homeowner.
Photo by Roger Weller
"Caliche." Wikipedia. Web. 20 Apr. 2010.
"Caliche." The Carefree Gardener. The Carefree Gardener. Web. 21 Apr.
"Conquering Home Yard Caliche." Master Gardener Manual. University of Arizona. Web. 21 Apr. 2012. http://cals.arizona.edu/pubs/garden/mg/soils/caliche.html
"Leaching." Wikipedia. Web. 21 Apr. 2010.
Weller, Roger. "Chapter 5."
Roger Weller, 5 Nov. 2009. Web. 20 Apr. 2010. http://skywalker.cochise.edu/wellerr/GLGP-illvocab/GLGP-05.htm
Index of Photos Used
Opal’s Pals: http://skywalker.cochise.edu/wellerr/VGM/opals-pals/054.htm
Caliche 1: http://skywalker.cochise.edu/wellerr/GLGP-pict/ch5/caliche1.htm
Atomic Explosion: http://encefalus.com/wp-content/uploads/2008/07/atomic_bomb_explosion.jpg
Caliche 2: http://skywalker.cochise.edu/wellerr/GLGP-pict/ch5/caliche2.htm