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


Andrew Hoiberg, Ph.D.

Andrew Hoiberg, Ph.D.

Nitrogen leading to acidic soil?

Many farmers do not consider nitrogen fertilizers as contributing to soil acidity but it is actually THE largest factor in soils becoming more acidic. Areas in western Kansas are now dealing with acid soils, even in areas where alkaline soils are common, thanks to nitrogen applications.

We think this article from Kansas State University explains this very well.

And if you're ready to fix acidic soil, you'll want our SuperCal 98G!


Gotta get that feeling...

I was watching the Super Bowl over the weekend and, of course, the commercials. I was struck by how many commercials had little or nothing to do with the product or service they were selling. Well-known companies with simple, straight-forward products. Yet these companies paid millions for the 30- or 60-second spot. They paid a lot of money to actors, writers, special effects people—some were like mini movies. Why?

Advertisers know people don’t buy a “thing,” they buy a feeling. They buy the feeling that “thing” can do for them or what feeling they would miss if they didn’t buy.

At Calcium Products, we have some great things to talk about, but maybe we spend too much time talking about the “thing.” It’s easy to do—98% calcium carbonate, pellets instead of powder, pounds instead of tons per acre, etc., etc.

However, farmers who buy 98G talk about seeing better, more even crops and can prove it with their yield monitor. After spending thousands of dollars on “precision agriculture,” they feel better knowing what they needed to apply actually ended up where it was needed and not blown into the neighbors’ field. They know this year’s application of 98G helps this year’s nitrogen, potash, phosphate, seed and chemicals work better this year, to pay off this year’s operating note at the bank this year. That may even leave extra money in the bank to remodel the kitchen this year.

I don’t think you will see a Calcium Products advertisement on next year’s Super Bowl broadcast, but if you purchase SuperCal 98G this year, you’ll get that much advertised feeling of elation this year.


Let's talk about pH

When thinking about soil pH, it’s easy to get confused with all of the terminology involved. Simply stated, the acidity or basicity of any solution, e.g. soil and water, is defined by its pH. Technically, pH is the negative logarithm of the ionic concentration of H+ (hydrogen) in the solution. As the hydrogen ion concentration increases, the resulting pH number decreases. The reason logarithms are used is because the concentration of H+ is actually very small, even when the soil is very acidic. For example, when the pH of a soil solution is 4.0, the actual concentration of hydrogen ions is 0.0001 moles per liter (one mole is equal to the number of hydrogen atoms in 1 gram of hydrogen).

The true meaning of the lowercase ‘p’ in pH has been purported to stand for different things throughout history. Some suggest that it stands for “power;” others claim “potential,” or even the Latin term pondus hydrogenii, potential hydrogen. In chemistry circles, the lowercase ‘p’ stands for decimal cologarithim of, and the capital ‘H’ is the chemical symbol for hydrogen.

Hard to wrap your head around, isn’t it? Luckily, you aren’t the only ones and long ago, some scientists decided to take the negative logarithm of numbers like 0.0001 moles per liter and change it to a simple number to understand: 4 on the pH scale. One numerical step in the pH scale represents a 10-fold increase or decrease in acidity. So, pH 5 is 10 times more basic than pH 4 and 100 times more basic than pH 3. Therefore, a pH of 1 is ten trillion times more acidic than a pH of 14.

Now that we have a more thorough understanding of what pH really represents, the following are ways soils can become acidic:

1)     Soil parent material. Soils formed from parent material low in carbonates (both calcium and magnesium) are usually acidic, as are soils formed from sandstone and shale.

2)     Climate. Soils that form under high rainfall are subject to extensive chemical leaching and weathering, which removes essential basic cations (Ca2+, Mg2+, K+, Na+), and allows acidic cations (H+ & Al3+) to occupy the empty cation exchange sites.

3)     High yielding crops. Harvested plant parts take a lot of basic cations with them.

4)     Acidifying fertilizers. Ammoniacal fertilizers can contribute greatly to the acidity of soil. This is due to left over H+ ions after microbes transform ammonia and ammonium into nitrate, which plants prefer for uptake, in the natural process of nitrification. Also, as plants uptake ammonium, which they will, even though they preferentially uptake nitrate, they secrete H+ ions into the soil solution to maintain a balance of chemical charges.

Fertilizers that have the highest potential for acidifying soil are: ammonium sulfate (AMS – 21-0-0) and mono-ammonium phosphate (MAP – 11-52-0), both of which are very commonly used in agriculture.

Another issue with acidic soil conditions, namely below 5.5, is that Al and Mn becomes increasingly available for plant uptake and that uptake can quickly cause toxicity within the plant, while excess Al in the soil solution will inhibit root growth and function, and also restricting uptake of certain nutrients like Ca and Mg, which further compounds problems.

With all the inputs farmers have to balance, one issue often pushed to the back burner is pH. Generally speaking, farmers might decide to apply lime every 3-5 years. What other soil amendment or farm input is treated in such fashion? Why take a reactive approach to managing pH when you can be proactive about the problem and not have to worry about a corrective measure every 3-5 years when yields start to suffer? At Calcium Products, we believe farmers should be more proactive about measuring, monitoring and correcting pH on their farms. With the advent of precision agriculture in every aspect of farming, there is no reason we should exclude lime application and pH correction from that process. Yearly applications of SuperCal 98G at rates much lower than with agricultural limestone should be part of your soil management regimen.

As acidity continues to increase, corrective measures to bring back optimal conditions for crops are harder to achieve. Act now to help the soil help your bottom line!

In the next article, I will take a closer look at how acidity works and what characteristics of soil lead to different levels of acidity, and how the current recommendations for lime-based pH correction work.


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.
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