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Soil Preparation and Analysis

Subject:  Gypsum, how much?

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Creekside

Santa Cruz, CA

My son reminded me this morning that we need to get going on amending our patch soil for next year. He's right. Once the rain starts, we won't be able to back our dump truck into the patch and add what is necessary. Here's our plan. What do you think?

We will be adding: manure, calcium and gypsum. Tremor suggested, after looking at our soils test, that we add 150-200 lbs of calcium per 1000 sq ft tilled in 9". Would that be calcium carbonate? High- cal lime? Some other type? Jim Falls suggested Gypsum for the high sodium levels in the soils test. How much should I add per 1000 sq ft tilled? Is there just one type of gypsum? Also do you till the calcium, manuer and gypsum in now or just lay it down on top of the soil with the manuer over it and till it in in the spring? Sorry for so many questions...I'd like to get it as close to right as I can.

If you go here you can see the soils test results. http://www.bigpumpkins.com/msgboard/ViewThread.asp?b=20&p=135833 Thanks for the help and suggestions - Creek and son

11/2/2005 11:34:27 AM

MontyJ

Follansbee, Wv

The gypsum is what provides the calcium. They are one and the same. Use agricultural grade gypsum, available at most decent gardening centers. Don't use any lime with a pH of 7.0 in the mound area. The 6.1 pH could benefit from a light lime application. 20-40 pounds of lime per 1000 sq feet depending on the type of lime used. With an OM level of 6.5% you can get away with a slightly lower than normal pH, so I would recommend 30 pounds of calcitic lime for 1000 sq. feet and re-test in the spring.

11/2/2005 1:38:36 PM

Creekside

Santa Cruz, CA

Thanks Monty! One more question, do we till this all in now? or wait until spring?-Creek and son

11/2/2005 5:23:30 PM

Tremor

Ctpumpkin@optonline.net

Gysum is Calcium Sulfate & does supply soluble Calcium without altering the pH.

11/2/2005 5:29:15 PM

JMattW

Omaha, NE (N41-15-42 )

I would put the gypsum in now. Maybe add some Calcium Nitrate in the spring before planting if your soil test is still low.

11/2/2005 7:17:29 PM

CowD

Jaffrey NH

I would add as much gypsum as you can afford into the soil. Sure, I only had an 810 pounder and a 726 pounder, but they went quite heavy. The insides of the pumpkins were very nice, no cracks, even where there were dill rings. Last year I had all my pumpkins go under the charts. This year was the complete opposite.
DK

11/2/2005 8:09:36 PM

MontyJ

Follansbee, Wv

Till it all in now Creek. That way it has the winter to react in the soil. It takes time for the lime to neutralize the acids in the soil.

11/2/2005 10:11:08 PM

Creekside

Santa Cruz, CA

Hi Everyone, Thanks for all your advise I am working on implementing it. Ok, I talked to our local garden center and this is what they have. Should I use this or keep looking:

1. They sell gypsum (not noted agricultural grade on package) for $6.99 for a 50lb bag. We have 3,000 square foot patch area so I was going to order 600lbs worth. Should I get more?
Is this the right type?

2. They don't carry Calcitic lime noted that way but they do carry agricultural lime (Dolomite?) and Oyster shell lime. Would one of these work well or should I keep looking? I was going to order 90lbs of it and spread it on the non-mound part of the patch and till it in.

It started to rain here today but It's probably only a sprinkle and not too late to add amendments. -Creek and son

11/4/2005 12:32:23 PM

anaid_tecuod

SF Bay Area, California

I've gotta kick in with a few comments. One be careful of overdosing the soil with gypsum. My sources recommend 50 pounds per 1000 square feet for a single application. I think you could probably double that with no problem given your soil condition but 200 pounds per 1000 square feet is too much in a single application. I would recommend that you back off to half of what you are planning at this time and then follow up in the spring with 50 pounds per 1000 square feet when you do your final patch prep only if it is still indicated in your spring soil test.

Secondly, lime should only be used where the PH is under 7 as it raises ph. So if you use lime use it only in your mound area where the ph is low. I would be sure not to use Dolomite as it will bump up your magnesium which is at the top of (or somewhat over) the optimum range already.

Oyster shell lime if it is not ground to a fine flour is slow acting. I would look for Oyster shell flour or mined limestone... stay away from Dolomite or you will be adding gypsum next year to leach out the excess magnesium.

These amendments should be spread evenly and tilled in. The winter rains will then do their magic.

best of luck, vince

11/4/2005 10:40:19 PM

Big Kahuna 25

Ontario, Canada.

Monty and Steve are right Cristine. We are starting to hone these soils test results a bit better than in past years. Gypsum will not affect the ph but organic soils do require somewhat lower ph levels for maximum uptake of calcium into the roots. IMHO soils higher than 10% OM chould be lower than 6.5

Gypsum, Is often used in my area to increase the size and quality of potato crops grown in my region.

My 3 soil tests have come back recently with ca ppm in excess of 3500 and A & L labs has recommended a further application of 20 pounds of ag gypsum per 1000 sq.ft.

11/5/2005 8:31:53 AM

Creekside

Santa Cruz, CA

Hi Everyone,
We got the gypsum and a small amount of lime in today and the patch is all cleared and tilled. It looks so good. We'll be adding in the manure next week and planting the 3,000 sq ft with favas.

One more question what does IMHO soils mean?

Thanks everyone for you help...we feel more confident in our soil now and can't wait for spring. -Creek and son

11/11/2005 10:27:49 PM

Stan

Puyallup, WA

I-In
M-My
H-Humble
O-Opinion

11/11/2005 11:23:58 PM

Total Posts: 12 Current Server Time: 9/2/2024 7:15:25 PM
 
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