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Spokane,WA

Hi all. I was wondering who had luck using gypsum in their soil. My patch is about 800 sq. ft.I have heavy clay that last Spring I added about two loads of free 5 year old cow poop, and about ten bags of maple leaves. I have been looking at adding about 25 lbs of gypsum and tilling it in the spring. Any advice would be appreciated.

Darren

2/8/2006 3:59:49 PM

Norton, MA

The stuff is super cheap, at least here, so I'd put on a bunch if you're going to. It deffinately will raise your Ca alot! I did have consistently somewhat heavy pumpkins last year, while the year before (without gypsum) they were both light. I added 400 lb. to 1200 sf. last spring, will do at least that this spring. I put it on in the spring because I hear it leaches out alot. AleX Noel.

2/8/2006 7:24:28 PM

Mill Bay, British Columbia

Darren, agricultural gypsum is wonderful stuff that will do alot in all types of soil. I don't have very much clay in my soil but add gypsum every year anyways. From what I have read (and witnessed in my patch) the tilth and overall health of your soil will improve with the addition of gypsum on a regular, yearly basis.

Search the site here and you will find all the details you need.

2/8/2006 9:34:37 PM

Simi valley, ca

I ADD EVERY YR 500-600 LBS FOR A 2000 SQ PATCH!! IV ALREADY ADDED THAT MUCH THIS YR & WILL PROBLY ADD MORE IN SPRING ,, FOR 800 SQ IT WOULD BE GOOD TO PUT ATLEAST 200 LBS ON NOW & 200 MORE IN SPRING

2/8/2006 10:15:47 PM

SF Bay Area, California

If your soil is a heavy sticky clay, it most likely will benefit from the application of gypsum. The element that makes clay's sticky and harden like concrete when dry is excess magnesium. Heavy clays are also typically low in calcium. The gypsum will increase the calcium level and also helps unlock and leach the excess magnesium out. This leaching action works best in the winter when there is lots of moisture to move it through the soil layers.

However, you can overdo it and put your soil totally out of balance by using too much gypsum. Literature that I've read suggests not to use more than 5 pounds per 100 square feet in a single application. That would be 40 lbs for your 800 square foot patch. I have used twice this level in some cases. I never recommend more than 10 pounds per 100 square feet even when a soil is really out of wack.

You can, however, apply gypsum more frequently than once a year if your soil needs it. It can be applied first in the fall and then again in the spring and tilled in. Later in the season, it can be spread on the surface, raked and then watered in. However, I have to recommend you take a soil test to determine if you need it at all. If the soil test reads low in calcium, high in magnesium, go for it... but at most 10 pounds per 100 square feet and tilled in throughly.

Gypum will also liberate and help leach other necessary elements out of your soil such as potasium. Overuse of gypsum will result in a soil that is deficient in magnesium and potasium, and is overly high in calcium and sulfer.

vince

2/9/2006 11:00:32 AM

Midwest

Darren

I'm no expert but, I've learned alittle about Gypsum. Gypsum is a very good source of Calcium. Gypsum will work down through the soil and will make several nutrients more soluable. Gypsum allows the soil to aggregate, increasing oxidation. It is ideal if it is broadcast on the surface and NOT tilled it in. Vince is correct that you can apply it more than one time a year. I was told you can apply it during seeding with no problem. A good ratio of Ca:Mg is 3.3:1. The presence of soluable Calcium is more important than a correct ph. There are scientific studies that point to soluable Calcium determining higher yields. In addition to Gypsum, add ammonium sulfate. If the soil environment is balanced, the biological activity will thrive. I have much info on this if you need it.
Greg

2/9/2006 3:06:51 PM

Spokane,WA

Thanks everyone. I did a google search also and found some really good stuff also, but it didn't tell me how much pumpkins love the stuff. Like you all have experienced. Not too much longer and I will find out for myself.

Darren

2/9/2006 9:56:26 PM