Wet and/or cold spring weather always causes headaches for farmers. But volatile weather this past winter into spring could affect the crop long after the planters are back in the shed, with ramifications that stretch all the way to harvest.
“If we look at the history of corn yields since we started keeping records in the 1860s, we have had four 25-year periods of highly variable corn yields because of variability in the weather,” says Iowa State University climatologist Elwynn Taylor. “I believe what we’re seeing is the beginning of a period of variable yields and weather.”
Weather volatility back in December may already affect 2015 yield outcomes, even before a single seed is planted, notes Kurt Seevers, technical services manager with Verdesian Life Sciences.
“Increased temperatures allow soil bacteria that contribute to nitrogen loss to be active for longer periods of time,” he says. “Variability in rainfall may also play an increasing role in nitrogen loss if we see heavy rains like we’ve had in some areas of the country the past couple of years. A combination of these factors could increase the likelihood of nitrogen loss.”
Seevers says up to half of nitrogen applications can be lost either through leaching, volatilization or denitrification. More farmers are turning to nitrogen stabilizers to protect their fertility investment, he says.
Fertility isn’t the only aspect of crop management that farmers should investigate following volatile winter weather, either. Warm December and January temperatures have also boosted winter weed activity in many areas, setting the stage for big populations this spring and summer.
“For example, in the High Plains, you can drive by miles and miles of fences already bound up with windblown kochia,” says Abe Smith, market development specialist at Dow AgroSciences. “And in many areas, there are really good conditions for weeds to germinate early. That means you should be scouting early this year.”
Early season weed identification is critical, Smith says. That’s because the sooner a farmer identifies what weed mix is in his or her fields, the more control options will still be on the table. Don’t underestimate the impact wind, wildlife and even migratory birds can have on even previously weed-free fields.
“Not all the problems you encounter are due to your own management,” he says. “It reinforces the need for scouting and understanding how outside influences can affect weed populations.”
Don’t forget about the pests you had last year, says Jeff Hartz, director of marketing at Wyffels. Winter may knock pests back, but it doesn’t knock them out entirely. If your field has a history of a particular weed, disease or insect, chances are you’ll see it again, he says.
“For example, rootworm pressure came on a little late in Iowa last year, but those pests are still there, and we could have a storm on our hands for 2015,” he says.
Disease pressure also has the potential to be high in 2015, adds Bond McInnes, fungicide manager with DuPont Crop Protection.
“If you had a lot of disease pressure last year, there will be a high pathogen population in the soil this year, so early outbreaks are possible,” he says.
McInnes’ advice echoes what other crop protection specialists have been recommending for the 2015 season – scout early, scout often. Chances are, Mother Nature has been setting up plenty of potential problems all winter long.