There are some farmers who are considering growing more soybeans next year and may have some continuous soybean rotations. There are a few management considerations to think about as you make your seed purchases for next year:

Don’t plant the same variety in the same field. Even if it ends up being your top yielding variety in 2014. Each variety is susceptible to some disease. It could be brown stem rot, white mold, Sudden Death Syndrome (SDS), phytophthora, downy mildew, charcoal rot, or a host of other diseases. If you plant the same variety, the risk of having that disease be a problem will be much higher.

Make sure your fertility is good, especially potassium. Soybeans need more potassium (K) than corn so be sure that you replace it. On average, soybeans remove about 1.5 lbs. of K per bushel so a 60 Bu./A. crop needs 90 lbs. or the equivalent of 150 lbs. of 0-0-60. In addition, soybeans are more sensitive to pH than corn so be sure that your pH is in the mid six range.

Plant moderate to moderately short soybeans with strong standability. Soybeans are a legume and fix their own nitrogen, and they will provide more nitrogen to the subsequent crop. Nitrogen causes more vegetative type growth, so they will grow taller and have more of a tendency to lodge.

Plant varieties with good disease tolerances. There will be a higher likelihood of disease and the more tolerant varieties you plant the better off you will be.

Make a note of any weed issues in this year’s crop and make herbicide adjustments. I have noticed many fields this year with marestail escapes as well as giant ragweed. If you use the same herbicide program as last year, you will have the same weed escapes. If you haven’t tried Liberty soybeans, then you may want to use them for Roundup resistant weeds.

Will continuous soybeans yield less than a corn/soybean rotation? The research is mixed on this. Wisconsin and Minnesota report about an 8 percent reduction when compared with continuous corn, while research in Iowa showed no reduction. If you follow the practices above I believe yield losses can be minimized.

For more Beck’s Illinois Agronomic Soybean News, please visit the IL Agronomy page at

NE Illinois agronomy questions can be sent to Chad Kalaher, CCA

NW Illinois agronomy questions can be sent to Craig Kilby, CCA

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About the Author: Bob Beck

Dr. Bob Beck is a WinField agronomist out of central Illinois. Feel free to contact him with any questions at