Think Different: Luck or Genetics
Drought stricken soybeans that pushed yield records had several advantages:
- Perfectly timed August rains.
- Reproductive resilience. While corn has only one chance to develop an ear and tassel, soybeans can abort many flower flushes and still produce more. Soybeans can compensate if environmental conditions change.
- Normal August day and night temperatures.
- Deep roots; some reported at 5, 6, 7 and even 9-ft. depths to find moist soil.
- Drought suppressed pests and disease.
While the drought ravaged many Midwestern corn fields in 2012, soybeans in many of those same areas broke yield records. Field averages of 70, 80 and 90 bu. with spikes well above that were reported throughout the upper Midwest. Extension crop specialists contacted by Corn & Soybean Digest credit the ever-resilient soybean's response to late-season rains. And to the role the hot dry weather played in reducing insect and disease pressure.
"The 2012 season was the most unusual I have seen in 32 years of Extension work in Illinois and Michigan due to the heat and the drought," says Ned Birkey, Spartan Agricultural Consulting and former Michigan Extension educator, field crops. "This was our seventh year for Michigan soybean yield contests and the first where we documented a 100-bushel yield. We had three yields in the 90 to 99 bu./acre range and six in the 80 to 89 bu./acre range."
While the top three yields were on irrigated acres, non-irrigated Group 2 beans came it at 90.1 bu./acre; Group 3 non-irrigated dropped to 67.6 bu. Birkey points to an 8-in. variation in rains across the 15 counties with entrants. He also points to an absence of insect pests aside from an early spider mite infestation. Disease was also down, though Birkey gives much credit here to expanded fungicide use in recent years.
“To go from ankle-high in July to an average of 60.2 bushels at season end is pretty phenomenal,” says Laura Lindsey, Ohio State University assistant professor, soybean and small grain production. "When I visited our Henry County location in early July, the soybeans were only ankle high. However, they got 6.5 in. of rain in August, well above average, and soybean performance trials there averaged 60.2 bu./acre, with a high of 74.6 bushels and a low of 39."