permaculture

["Marjory Glowka" <forestgarden@austin.rr.com>]

Hello Everyone,

We have a large rain-water collection system on top of a hill which gravity
feeds an orchard a bit down the hill.  The water pressures we get at the
orchard vary a bit from 4.3 - 8 psi.  We sucessfully tested and have been
using some drippers that worked well enough even though they are not spec'ed
at that low of a pressure.

Our soil is very sandy and we've notice that drippers only cause a stream of
water to drip pretty much straight down - the water does not soak around and
spread like we had hoped - probably because of the soils low organic matter.
So we are now thinking about perhaps using a sprayer jet instead of
drippers.  I know we won't get much of a 'spread' with only 4 psi, but it
seems anything would be better than nothing.

Does anyone have any experience with low pressure gravity fed irrigation
systems?  Can you recommend a source for emitters/sprayers that works under
low pressure situations?

We are considering buying a solar pump and pressure tank to get the psi up,
but we are trying to keep the whole project as 'low tech' as possible, so I
am hoping to find another solution.

Any help or suggestions greatly appreciated.

Cheers,

marjory.