If forecasts call for early fall frost and you still have soybeans in the field, don’t panic. Soybean frost damage can prove costly at the grain elevator, but mitigation strategies can lessen the risk. Find out how to adjust your equipment, storage and drying procedures to minimize the impact from frost damage to soybeans.
Soybean frost damage: Facts at a glance
- Risk of frost damage to soybeans begins when temperatures drop below 32 F. At this temperature, damage is typically reserved for leaves, but temperatures below 30 F for an extended time may damage stems, pods and seeds. Below 28 F is considered a killing freeze.¹
- Signs of frost damage in soybeans vary and when damage leads to beans shrinking when dried, their extractable oil content is reduced.
Tips for harvesting, handling and storing frost-damaged soybeans
Stay aware of soybean shatter
Wetting and freezing patterns can increase the likelihood of shattered pods and lost seeds. Insect pests like spider mites can also make pods more susceptible to shatter. If you face these risk factors, timing your harvest based on moisture levels and adjusting equipment accordingly can help reduce shatter.
For example, severely frost-damaged soybeans dry down more slowly, leading to increased shatter risk, but adjusting drying times can help. Electronic moisture meters can underestimate the moisture content of green and immature frost-damaged soybeans. As a rule of thumb, add 1 to 1.5 percentage points to moisture meter readings when testing frost damaged soybeans at all stages of maturity. ²
If only the upper leaves were damaged by frost, allow the beans to mature and dry to 14% to 15% in the field if possible, rechecking the moisture content after drying a couple of days.³
Reduce combine concave clearance
After a frost, soybeans are usually wet and more difficult to thresh. Reducing your thresher’s concave clearance can help reduce losses without damaging grain. If that doesn’t help, increasing your cylinder/rotor speed may improve threshing efficiency. Always make adjustments incrementally and check your progress after each change.
Separate frost-damaged soybeans from normal grain
Since frost-damaged grain can resist field dry-down and maintain excessive moisture levels through harvest, it’s best to harvest unaffected areas of your field first. Harvesting separate loads can help you avoid storage risk and dockages at the grain elevator, where green and immature soybeans may be refused.
Since air and drying can help reduce green discoloration over time, dockages can often be reduced by separating out the small beans and drying the rest to 12% moisture, storing these beans in aerated bins for several months.⁴
How you dry down matters
Soybeans are more fragile than corn when it comes to artificial drying. If drying is necessary, keep temperatures under 130 F for continuous-flow dryers and under 110 F for batch dryers. Ensure relative humidity stays above 40% to curb seed coat issues and splitting.⁵ Optimizing soybean moisture content is key to protecting your harvest.
Experts are available to help you make your decisions. Reach out to your seed retailer, a nearby extension office agent or a seed company professional like your regional BASF representative.
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Endnotes
- Anderson, Eric. “Harvesting and handling frost-damaged soybeans.” MSU Extension, Michigan State University, 26 Oct. 2023, www.canr.msu.edu/news/how_to_manage_frost_damaged_soybeans. Accessed 3 Sept. 2026.
- Hurburgh, Charles, et al. “Frost Damage to Soybeans.” Knox County Agricultural News | OSU Extension, The Ohio State University, 10 Oct. 2019, u.osu.edu/knoxcountyag/category/weather/frost/. Accessed 3 Sept. 2026.
- Anderson. “Harvesting and handling frost-damaged soybeans.”
- Anderson. “Harvesting and handling frost-damaged soybeans.”
- Anderson. “Harvesting and handling frost-damaged soybeans.”
