When will it rain? Drylands irrigation - Biodesign N/L December 29, 2010

When will it rain?   Drylands irrigation

 

I have been seeking ways for those who live in a dry climate, or where they expect it to get drier, to produce food despite a shortage of water.

 

It has been disturbing to discover that the only technique on offer in most places is drip irrigation which is not only expensive but unreliable. Even where this is affordable one advice offered is

“...drip systems are easily vandalized and expensive to repair. I recommend using drip systems only in situations where routine inspection and maintenance is readily available.”

There are alternatives! 

 

I have prevously mentioned porous pots, which several contacts are testing, but an even more promising technique is wick irrigation.

Unfortunately only one person in the whole world seems to have done any real testing of this and he is now retired. Here is what he wrote 20 years ago:  

Wick irrigation systems have been used in India in conjunction with buried clay pot irrigation (Mari Gowda 1974). A hole or series of holes is punched in the buried clay pot and a porous wick is inserted in the hole(s). The material wicks the water from the container into the soil and provides a slow, steady source of moisture to encourage root development and plant growth.

We tried a small field test of wick irrigation on a very dry, east-facing slope at the Travertine site <In the USA!> where we compared mesquite (Prosopis glandulosa) transplants irrigated with wicks and others irrigated by hand watering. We found that wick- irrigated mesquite survived longer and grew faster than the hand-watered transplants. We did not calculate the water consumption precisely, but it appeared to be about 4 teaspoons (20 ml) per day.

www.scribd.com/doc/3136855/alternative-irrigation

This small water consumption is due to the fact that the root hairs of all plants grow towards any source of water and wrap themselves around the wick so drawing out only the amount the plant needs!