Michigan Late Soybean Planting Recommendations

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KEY POINTS

  • Excessive rains can delay soybean planting, but proper management can help maximize yield potential and reduce the risk of frost damage.
  • Soybean maturity, row spacing, weed control, planting rates, and insurance options should be considered in late- planted soybeans

What to Consider

Yield decreases can occur when late-planted, full-season soybean products do not reach adequate height for setting pods, or frost damages plants before maturity. Michigan State University reports that yield losses due to delayed planting increase from 0.4 bushel per acre per day until June 1st to 1 bushel per acre per day on July 1st.1 In addition, for every 3 to 4 days that planting is delayed, soybean maturity can be delayed by 1 day. Switching soybean maturities at the appropriate time can help alleviate some of these physiological disadvantages and help maximize yield potential at later plantings.

Soybeans can have the ability to compensate when planted late. Michigan State University reports that adapted full-season soybean products can yield better than shorter maturing products when planted in June because they produce a larger crop canopy before beginning to flower.1 The risk of frost damage to full-season products may lead some growers to switch to a shorter-season product too early, resulting in short plants with low yield potential. When growers feel the season is getting late, decisions to switch products and maturities can sometimes bring confusion on what is the best option. Some recommendations are to switch to a shorter maturity (Michigan State University suggests switching to a product that is 0.5 to 1.0 shorter in maturity after June 15th1), while others recommend staying with the same maturity originally planted, or even increasing the maturity to ensure plant height and continued growth. Using the same or later maturities during later plantings or even double-crop will allow the soybean plant to grow later in the season, produce adequate foliage and still fill the pods. Work with your local agronomist to determine which decision is best for your operation.

Management Options

Weed Control. Weed management is a priority for late-planted soybeans due to the potential for the lack of a canopy to compete with weeds. Starting clean with a good burndown, using a preemergent herbicide, and a timely post program is critical for managing the rapidly growing weeds that will compete with the crop. Always follow pesticide label directions when making applications.

Row Spacing. Plant soybeans in narrow rows (less than 30-inches) or with a drill to help increase canopy closure, sunlight interception, and biomass accumulation.

Seeding Rates. Seeding rates should be increased in late-planted soybeans. Increase seeding rates by 15% during the first half of June, and by 20% when planting in the last half of June.1

Soybean Aphid Management. Late-planted soybeans can be more susceptible to aphid feeding compared to earlier planted soybeans. Michigan State University recommends frequently scouting less mature soybean fields for soybean aphids.1

Other Considerations

Plant back restrictions. When a field originally intended for corn is being switched to soybeans, it is important to know the plant back restrictions for the specific herbicides that may have already been applied. Herbicide plant-back restrictions found on labels should be followed to prevent any carryover damage from further delaying the crop.

Insurance Options. The “final planting date” for soybeans in Michigan is June 15. The “late planting period” is 25 days following the final planting date.1 Contact your local insurance agent for insurance coverage and options. The USDA Risk Management Agency has developed the following web page of fact sheets and examples: www.rma.usda.gov/news/currentissues/prevented/index.html​

Sources: 1Staton, M. 2017. Late-planted soybean recommendations. Michigan State University. http://msue.anr.msu.edu/. Hicks, D. and S. Naeve. 2013. The soybean growers field guide for evaluating crop damage and replant options. University of Minnesota; Pedersen, P. 2008. How late can soybeans be planted? Iowa State University, Integrated Crop Management. Web sources verified 5/22/18