Frost nipped northern soybeans hard
Though it didn't cause much of a stir in the grain markets, last week's frost and freeze in the northern Corn Belt had a little more of an effect on the region's soybean crop than earlier guessed.
Monday's USDA-NASS Crop Progress report showed around 10% drops in soybeans rated good-to-excellent in South Dakota, North Dakota and Minnesota. Losses were fewer just to the south, but it's still clear the crop was nipped pretty hard by the frost and freeze, says Freese-Notis Weather, Inc., meteorologist Craig Solberg.
"The corn and soybean markets showed no reaction whatsoever to the freezing temperatures that were recorded last week, but crop progress and crop condition data this week suggests that indeed that was a significant event," Solberg said Tuesday morning. "With more than a third of the soybean crop in South Dakota and more than half of the crop in Iowa, Minnesota, Wisconsin, and North Dakota not dropping leaves as of this past Sunday, that was all immature soybean acreage that could have been affected by the cold."
The frost and freeze damage isn't spotty, either, says one north-central Iowa farmer and Agriculture.com Marketing Talk veteran contributor. "Between us and Minneapolis, you can hardly find a bean field not affected by the frost," Mike M2692830. "The tops are burned off. That has to have an effect on yield."
So, what kind of yield loss will affected farmers find when they start combining soybeans this fall? There's not a ton of research on the topic, says University of Minnesota Extension soybean agronomist Seth Naeve, but the research that's out there -- namely one study he's conducted over the last 3 years -- shows planting date is the key variable to take into account when assessing frost damage.
"When soybeans of all three maturities were planted late, early frost had a large yield effect. Frost in late September affected both the long-season variety as well as the adapted one. As expected, frost had a much larger effect on yields of late-planted soybeans," Naeve says of 2009 field study results. "Early planting did not benefit soybean yields in the absence of frost, except in the case where the soybean variety planted was of a much later than normally adapted maturity. Late planting primarily affected yield through increased losses due to early frost."
Looking ahead, though, Naeve says even if your bean yields slump because of frost damage this year, don't always opt for shorter-season beans in an effort to avoid frost losses in the future. "While short-season soybeans are virtually 'frost-proof,' only the very earliest frost date tested reduced yields of the full- and long-season varieties below those of the very short-season variety," he says. "Short-season soybeans are not a good risk-management strategy unless planting dates get pushed back to the end of May."