Thursday, June 17, 2010

Drip Irrigation: A New Take on Old Technology

Out of the ground to show its shape, an olla (pronounced 'oy-ya' or 'oh-ya') sits waiting to be installed and then filled with water. 

One more of our 'modern' technologies has been proven to be but an updated petrochemical based revision of an earlier, more earth friendly, idea from some civilization regarded as backward by most Western peoples over the past several hundred years.

Ollas are simple. They are only unglazed terra cotta jugs.  Once it is planted in the ground with only the flare of the neck sticking out, plants are planted around the olla - at different distances depending on the water needs of the plants and the texture of the soil - the olla is filled with water.  For most efficient operation, cover the open top with a non-porous pot, cup or even a flat rock or a plate, to prevent water from being wicked up into the atmosphere.  Depending on your soil and your crops, a large olla like this ought to not empty out in a week or so.  However, please note:  The real test of whether you need to fill the olla is NOT whether or not it is empty - it is the amount of water in the soil around the olla!  Remember, the olla is only the transit point for water in the soil.  

This low tech system of watering has no moving parts and no electricity usage.  You can use it when you go away on a vacation and it is much more efficient than even drip irrigation.  Some of the plus points over drip:
       * no plastic petrochemical production
       * no moving parts to break 
       * even less water lost to evapo-transpiration  
       * no constant upkeep or broken parts, cut water lines to fix or replace
       * not one single drop of electricity  

On the other hand.... they are fragile and somewhat pricey.  This little guy cost me $30 (from Path to Freedom's Shop), and I picked mine up myself.  I actually broke one of two when I picked the first one up and the second rolled into it, breaking its neck.  They were good to me and replaced the beheaded one.  While they won't be as likely to be damaged once in the ground by humans, woody roots (like woody perennials or trees have) could crack the terra cotta.  Other than that, they seem to be relatively maintenance free.  

They do require monitoring and refilling, however.


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