Education

Optimize your Crop Yield by Applying 98G Pelletized Limestone with your Phosphorus Fertilizer

There is an old anecdotal story that limestone and phosphorus (P) fertilizer should never be applied together.  While the origins of this are unknown, it is a question that still occurs. With the help of Dr. Fred Below and his team at the University of Illinois, the possibilities of applying P fertilizer with Calcium Products 98G Pelletized Limestone were investigated.

For years, it has been thought but never proven that applying limestone for pH correction at the same time as your Phosphorus fertilizer would diminish the effectiveness of the P fertilizer’s availability for the next growing crop. Previous research done in areas with more weathered, acidic soils saw great results through co-applications as increasing soil pH (with a liming material) led to the mineralization of organic P to inorganic P, making it available for plant uptake and increasing soil test P levels. However, how would this co-application behave in younger, higher organic matter soils at pH levels near neutral?

University of Illinois Study (2021-2023)

A study comparing phosphorus fertilizer (MAP) and 98G Pelletized Limestone + phosphorus fertilizer was conducted in Illinois to document the effects of co-application. It is important to note that these soils had an average soil pH of 6.5 and organic matter levels of 3.4% at the beginning of the experiments. Several key findings are listed below.

1. Increased P Availability: In nearly all treatments, soil test P increased with the addition of 98G vs. MAP fertilizer alone.
2. Enhanced Yield: Grain yield increased significantly when lower P rates (40lb P₂O₅/acre as MAP) and 98G (200 lbs/acre) were applied vs. MAP alone. Yield increases were also observed with standalone applications of 400 lbs/acre of 98G without additional P fertilizer.
3. Improved P Uptake: Compared to P fertilizer alone, the addition of 98G to the P fertilizer improved the overall nutrient P concentration of the plant tissue and grain, meaning co-application improved P uptake into the corn plant.
4. Stabilization of soil pH: Nearly all applications of MAP alone slightly lowered soil pH while MAP applications that included 98G maintained or slightly increased soil pH.

The findings of this recent research prompted Calcium Products to further investigate these types of co-applications through additional research in 2024 and the results were similar. Co-applications of P fertilizer (MAP) and various rates of 98G tended to increase corn grain yield vs. the same rate of MAP alone. In several cases, the yield increases from co-application exceeded 10 bushels per acre.

Advantages of Co-Application

Combining phosphorus fertilizer with 98G Pelletized Limestone can offer synergistic benefits, including:

1. Enhanced Nutrient Availability: Applying 98G pelletized limestone can help improve phosphorus availability, reducing the risk of fixation by aluminum and iron at low pH (<5.5), or calcium compounds at high pH (>7.5).
2. Improved Phosphorus Uptake: Research has shown that when soil pH is optimized between 6.5 and 7.0, phosphorus uptake can increase by 30%.
3. Efficient and Accurate Application: Applying both 98G and P fertilizer together saves time and labor as well as ensuring a uniform distribution of both products vs. regular aglime applications.
4. Increased Grain Yield: See study results above. Applying maintenance level rates (~250 lbs/acre) of 98G has been shown to increase corn and soybean yields by 9.4 bushels per acre and 3.1 bushels per acre respectively through regional research with third-party researchers.

When, Where, and How to use 98G Pelletized Limestone?

When: Due to the product’s initial quality and fineness of grind prior to pelletizing, 98G Pelletized Limestone reacts much quicker than other liming materials to correct or maintain your soil’s pH. These factors make 98G a great choice for either fall or spring applications.

Where: 98G should be used in situations where acidic soil pH levels need to be corrected, or more neutral pH levels want to be maintained. It is OMRI certified for organic use and offers high calcium (36%) and low magnesium (<0.5%).

How: 98G can be blended with other dry fertilizer products making it easy and efficient for your operation to apply. 98G is a great choice for either pH correction or a pH maintenance approach to offset acidity from nitrogen fertilizer application.

For more information about 98G Pelletized Limestone, contact your local Territory Sales Manager today!

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