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Phoenix, AZ

Based upon my soil report, my Ca was through the roof (in an area that I had not ameneded at all yet). Based upon this, I assume I have lime in the soil. Plenty of magnesium also. Currently my PH is 7.3 in this virgin area.

Everyone talks about using sulfur to reduce the PH, but I have understood if you have existing lime in your soil, it will not help. Calcium just ends up making gypsum which will not reduce your PH. Just what I read.

Instead, has anyone used Citric Acid? Just wanted some opinions.

Thanks all.
Ben

12/9/2004 11:11:56 AM

Utah

I don't have an answer to your question...
I haven't used Citric acid...

but experience has shown me that 7.3 is fine to grow in. I grew my 906 this year in soil with a 7.8 pH.

12/9/2004 12:08:04 PM

Menomonie, WI (mail@gr8pumpkin.net)

7.3 would be fine to me also..If I was to try and lower the PH a couple clicks I would add a few cubic hard of peat moss.

12/9/2004 1:13:52 PM

Menomonie, WI (mail@gr8pumpkin.net)

yards..dang I have to proof read what I write before hitting enter.

12/9/2004 1:14:37 PM

I'm with Gordon... GO UTES!

If you have calcium and add sulfer, I guess you can create
calcium sulfate, which is gypsum. And they say, gypsum
doesn't lower pH, nor does it raise it. I don't know if
by-products are released in this reaction...

Another approach is to add lots of organic matter. As it
breaks down it will lower pH a little.

Three years ago my pH was 7.8. I've been adding sulfur,
gypsum, and organic matter... although only the organic
matter has been "heavy"... Then last year my pH was 7.5.
Since then I've added LOTS of organic matter... I'll
probably get a new test after this coming season.

12/11/2004 12:35:21 AM

San Diego, Ca.

The reason gypsum (calcium Sulfate) does not lower pH is because the sulfur in the gypsum is in the sulfate form.
Soil sulfur is broken down by soil organisms causing an acid reaction thus lowering the pH. As the soil organisms break down the soil sulfur it is converted into sulfate sulfur which no longer has any acidifying power.
I'm with Linus, add peat moss. 3 or 4 inches should lower your pH a few clicks. From what I have read, the acidifying effects of peat moss can last from 6-10 years. Another benefit is added organic matter.

12/11/2004 2:59:43 AM

Roanoke Il

A slightly alkalinity can be curedsometimes with a littlle borax and manganese, It doesn't take much boron to kill a plant so be careful. calcium sulphate will also help. 2 pounds of sulfur per 100 square feet will lower your ph about one unit.this is proably the easiest whay to bring your ph down. The best way and proably the best for your patch is by adding oak leave, oak bark, oak saw dust this will help bring up your organic mater in your soil. hope this helps... mark

12/12/2004 8:04:41 PM

Phoenix, AZ

Thanks all for the replies. I have in the last few weeks added probably 20% OM from my original 1%. Lets see what that does to my January test.

Mark, How I would love to add oak leaves...sure wish those grew down here in Phoenix. We grow things like Bouganvilleas which you cannot use since the leaves are toxic. Fun huh?

Ben

12/13/2004 7:19:45 AM

Ctpumpkin@optonline.net

Sulfur converts into sulfuric acid which lowers the pH. No Oaks? How about Pine Needles? Compost them part way first.

Citric acid is used to adjust the pH of irrigation or spray tank water. The amount needed to alter soil pH would be cost prohibitive if effective at all.

Peat Moss is the greatest bang for the buck when % OM is low.

12/13/2004 7:52:10 AM

Phoenix, AZ

Ahhh Steve, I knew you would straighten me out!

Yeah I have read citric acid breaks down very quickly once it hits soil microbes.

HA, Pine trees? Help me out and give me an analysis of palm trees, OK?

I should post a pic of what our surrounding vegitation consists of.

Hey, I think because of the challenge, I picked pumpkins to try and grow. Remember, if I am able to grow anything over 200lb, that would be considered amazing here in our climate. Had someone down here grow one to 176lb few years back and he says he got a dollar a pound for it. Can't confirm, but just what he told me.

Ben

12/13/2004 5:44:01 PM