5 Myths to Know About Liming


MYTH #1: Pell-lime is just a quick fix

When it comes to increasing soil pH, some agronomists and growers view pell-lime as a quick fix, often used on rented acres, while aglime is used as the long-term solution. It is true that 98G works quickly, changing soil pH more rapidly than aglime. However, research completed at Iowa State University in 2018 showed 98G resulted in more rapid and sustained pH correction than calcitic and dolomitic aglimes.*

MYTH #2: All pell-lime is the same

Pell-lime is a nickname used to refer to pelletized limestone. Pell-limes vary widely in raw material and manufacturing quality. 98G is made from 98% pure calcium carbonate limestone and is ground to an ultra-fine powder before it is pelletized, maximizing its reactivity. Many pell-limes are manufactured from dolomitic limestone and are slow to react just like their parent material.

MYTH #3: Aglime will work better long-term

Aglime takes about two years to correct soil pH. While soil pH slowly returns to optimal levels in the first one to two years, yield suffers. After the third year, soil pH drops below optimal levels and yield suffers again. This pH roller coaster is depicted in the line graph above and is not a long-term solution. In order to maximize yield potential every year, soil pH should be maintained at a consistent level.

MYTH #4: 98G pelletized limestone is too expensive

When comparing 98G to aglime on a per ton basis, 98G can look like an expensive option. A better cost comparison is to evaluate pH correction on a per acre basis and in a variable rate application scenario. Generally, 98G’s application rate for correcting soil pH is considerably lower than aglime, reducing the per acre application cost. After soil pH is corrected, we recommend an annual or biennial maintenance rate of 98G (200-300 lbs/acre) be included in the dry fertilizer mix to offset acidity created by nitrogen fertilizer. Using lower rates to maintain soil pH results in a smaller annual investment vs. requiring a larger investment in aglime every five years.

MYTH #5: Light colored or white aglime means it is “hi-cal” lime

The color of a liming material does not indicate its chemical composition. Dolomitic aglime means it contains more than 5% magnesium. The higher the magnesium content in a liming material, the slower it corrects pH and the more material you need to make that correction. 98G is 36% calcium and less than 0.5% magnesium.

98 G vs Aglime Reactivity Curves 1200x630

* Jones, J.D. and A.P Mallarino. 2018. Influence of source and particle size on agricultural limestone efficiency at increasing soil pH. Soil Sci. Soc. Am. J. 82:271-282.