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Use of Gypsum for Corn Production
Corn is a plant that needs a few basic soil requirements for optimizing growth and maximizing yield potential. Although corn can tolerate a range of pH, it performs best in a slightly acidic soil. A pH range of 5.8 to 6.2 is ideal; however, when we drop below that level, the availability of calcium (Ca) and sulfur (S) can be reduced.
In most North-Central region soils, the relative pH levels are over 7; therefore, Ca and S levels are often adequate. But, the addition of Ca and S is still beneficial in many instances. Thus, the need for liming in corn production is often a topic for winter discussions. Do I need some on my farm? Let’s talk about why that is important for your soils and your corn crop.
Properly limed soils have improved nutrient availability, microbial activity, and overall soil productivity.1 The normal sources are calcitic or dolomitic limestone. In states that produce sugar beets, a lime byproduct is produced during the process to remove impurities from the sugar. The byproduct has a lower acid neutralizing value than other agricultural limes; therefore, the per acreage rate should be higher.1 There are many manufactured sources of both Ca and S available in the industry. Mined gypsum, the common name for calcium sulfate is also common across North America.2
- Gypsum has several agricultural uses as a soil amendment including:3
- Being used to reclaim sodic soils (soils high in sodium).
- Improving soil aggregation, which in turn can increase water percolation.
- Reducing soil crusting and runoff.
- Decreasing soil pH in high-pH soils (greater than pH 8.5).
- Increasing soil pH in aluminum dominated soils (less than pH 4.5)
- Decreasing iron chlorosis in some soils.
- Being used as a source of fertilizer S and Ca.
With the ability to do so many things, it may seem like the ‘miracle' cure for all soil ailments. However, you need to know exactly what your soil needs and why it needs it. So, the best recommendation is to annually soil test, interpret your results, and discuss with your agronomist what the addition of gypsum may be able to do for you.
1Battel, B. 2017. Use of byproduct lime on agricultural soils. Michigan State University Extension. https://www.canr.msu.edu/.
2Dick, W.A. 2018. Crop and environmental benefits of gypsum as a soil amendment. Presentation at annual meeting of American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. https://scisoc.confex.com/scisoc/2018am/meetingapp.cgi/Paper/111261
3Franzen, D., Rehm, G., and Gerwing, J. 2006. Effectiveness of gypsum in the North-central Region of the U.S. SF-1321. North Dakota State University Extension Service. https://library.ndsu.edu/.
Channel Technical Agronomist