Wednesday, February 14, 2018

sahara




 
 
This needs to be integrated with those water harvesting ponds with nets.  The ponds can be a simple cast bowl partially filled with sand and holding vertical canes  suspending a mono - filament net.   This draws dew out of the atmosphere at night and the water drops into the sand to be protected.
 
The surplus moisture can then be distributed into the surround while a planting can grow in the cast pond.  As this matures and acreage expands it will become possible to grow  an adjacent tree as well to increase the soil's holding capacity.

In that way we produce an intact shallow water table able to support a complete agricultural system.  What makes it really work is that all moisture drawn from the atmosphere is recycled over and over again as this tech advances into the desert.
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These are incredible examples of sustainable agriculture systems that are created by harmonizing with the natural patterning effects of wind and sand.

By enhancing the edge effect of pressure between different medias, in this case, wind and sand, the extension pattern creates the dish form that then shelters the plantings at the lowest point. It shelters them from the wind itself and from the extended shade in the lower position closer the water table. Combined this reduces evaporation, extends productivity, and reduces input requirements.

These systems can be permanent with no reduction in fertility if the scale and order of the appropriate pattern size relationship is carefully observed and applied as the guiding principles of design, implementation, establishment and permanent maintenance.

This is classic permaculture design :-)

George Steinmetz


January 25 at 8:32am ·

Photograph by George Steinmetz @geosteinmetz One of the last great examples of pit agriculture in a remote part of the Algerian #Sahara. Here the water table is just below the surface, and is drawn up by hand and donkey to sustain date #palms in the midst of a sea of mobile sand dunes. This ancient method of cultivation was once found throughout the Middle East, but increasing population and electric pumps are causing the water table to drop. 
 

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