Subject: Re: Water_conductivity

From: [email-masked] (LodiCraig)
Date: 10 Jul 1994 14:26:02 -0400

In article <[email-masked]>, [email-masked]
([email-masked]) writes:

>I am watering, my greps with a water with a very high conductivity, I am 
>looking for a way to destruct this conductivity, and get a water with a
low 
>level of conductivity. Thankyou.

Hi, I'm a grape grower in Lodi, California.  

What you call high conductivity is referred to here as high EC for
electrical conductivity.  It is a cheap measurement that means nothing
more than the fact that you have high salts in your water.  What is really
important is what salts are in your water.  High E.C. (conductivity) is
not a problem by itself, but an indicatior of potential problems.

If you are high in sodium and chlorides, then you will have some problems
to overcome.  Gypsum and maintaining a higher moisture level in your soil
will be part of your solution..

If you are high in bi-carbonates, then you will have to acidify your water
if you want to use drip.

If you are high in calcium, potassium, sulphates, nitrates, and other
'good' elements, then you won't have to fertilize as much, but excess
vigor may lead to rot and other quality problems if not dealt with.

I am sorry to inform you that the only economical way to lower salt levels
in your water is to get water from a different source.  Don't even think
about using a salt type water conditioner:  they simply replace calcium
with sodium.  Reverse osmosis water conditioning could help, but it is
very expensive and wasteful of water.  Your most economical solution will
be to balance the salts if that is possible.

I suggest you contact a local agricultural lab.  The problems and
solutions vary widely depending on the nature of your salt load and the
type/condition of your soil.  High salt in your water is not the end of
the world, but you do have to take the appropriate measures to mitigate
the negative impacts.

If you could post the results of a composit soil test ( .2 through 1.5
meters) and a water analysis including macro and micro elements I am sure
you could get some very specific and workable solutions to your problems. 
Be sure to include carbonates, bi-carbontes, sodium, and chloride levels
in your test ... more expensive but very revealing.

Also, what problems are you having with your grapes:  Are you getting
chloride burn?, are you getting draught stress even though you water a
lot?  Are you having problems with the metal parts of your irrigation
system?

Good luck.
Craig Thompson