Calcium Products - Andrew Hoiberg, Ph.D.
Calcium Product 98G


Andrew Hoiberg, Ph.D.

Andrew Hoiberg, Ph.D.

Carboxylic acid . . . is it worth the price?

Carboxylic acids are added to some gypsum products to act as a ‘complexing agent.’ One of the claims is that these acids make the calcium ‘more available’ for plant uptake.

For the calcium and sulfur to be plant available it needs to be in the soil solution. Using a simple test, one can determine how soluble a product is. Our research has shown that SuperCal SO4 is more soluble than products containing expensive carboxylic acids.



Soil acidity

Within any given soil, there are two states of acidity that need to be accounted for before liming recommendations can be made. First is the active acidity, which indicates the current pH status of the soil. Active acidity accounts for the H+ ions in the soil/water solution that the laboratory measures. What active acidity doesn’t account for, however, is the reserve, or potential acidity. Think of a swimming pool that has a few people in it, those people represent the active acidity. Now, imagine that there are more people outside the pool, just waiting to jump in after some of the others leave. Those folks represent the potential acidity. When we determine how much lime we need to neutralize the acidity in the soil, it is really the potential acidity that needs to be accounted for. To neutralize the active acidity is easy and requires little lime, but the potential acidity can be a major problem to neutralize if it warrants such action.


Blending SO4 with fertilizers

We got a question today on Twitter about blending calcium sulfate with other fertilizers so we're sharing the answer with everyone....

Our SuperCal SO4 gypsum (calcium sulfate) is compatible with any standard fertilizer. You should blend it to meet our application rate on the bag. Target your application at roughly 10-20 lbs of our product per 1000 square feet. 

Our calcium sulfate is analyzed at (0-0-0-21Ca, 17S), so for each 100 lbs of product, there is 21 lbs calcium and 17 lbs sulfate. That means in 10 lbs of product, there would be 2.1 lbs calcium and 1.7 lbs sulfate applied over the 1000 square feet.

Example, if you have a fertilizer that is 10-10-10 and you are targeting 1 lb of N per 1000 square feet, you need 10 lbs of that fertilizer to accomplish that. If you want to blend in our product to supply Ca and S for that same area, you should blend 10-20 lbs of our product in with the 10 lbs of standard fertilizer. If you want to make it simple and blend a whole 50 lb bag with our product, you can assume, at that targeted rate, you'll cover 5000 square feet with a 50 lb bag of 10-10-10, so you'll want to add 50-100 lbs of our product with that fertilizer.


More questions? Email me!

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