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Planting corn early? Watch treatment timing

With all the talk of early planting lately, the idea of early fieldwork has almost taken a backseat. But, just as the wrong conditions later on in the spring could doom an early-planted crop, bad timing can rob your fertilizer and herbicide applications' efficacy, too.

A lot of farmers had time to get fertilizer applied last fall. That was good news then, but it's not such good news now. With the warm late winter and early spring in much of Illinois, any nitrogen that was applied prior to "the last several days" is probably no longer in the field where it's needed and has been converted to the ammonium to nitrate form of nitrogen "because of increased soil temperatures as a result of the unseasonal warmth," says Dave Mowers, agronomist with Agricultural Information management in Toulon, Illinois.

"With the nitrogen being in the nitrate form means that it is vulnerable to be lost. There are 2 ways it can be lost: By leaching or runoff following a flushing rain, or by denitrification following a period of water-saturated soil conditions. Because it has been dry up to this time almost everywhere, nothing has happened yet," Mowers says.

If you haven't gotten your nitrogen applied, it's far from time to worry just yet, Mowers says. "If you have not applied Nitrogen yet for the 2012 crop, you can still get this work done this spring. Better yet, if you are thinking about fall application of Nitrogen after this year’s soybean crop, you can do it this spring and have prescriptions ready to go right to the field and apply fall N," he adds.

What about herbicide? If you're getting ready for planting -- or already have corn seed in the ground -- the advanced age of the crop later in the season won't do much to help out your weed control, especially if you have to apply herbicides early too, says Purdue University Extension weed specialist Bill Johnson.

"We normally start our planting operations in the middle of April, but with all the fieldwork being done right now we're running 2-4 weeks ahead of schedule," Johnson says. "That means that we're potentially adding 1 month onto the growing season. And for producers using what we call reduced or setup herbicide rates, they may find their herbicide programs running out 2-4 weeks early as well."

Simply buying more herbicide and adding a later application won't necessarily help. But, if you do find yourself putting down herbicide well before you usually do, adding to your usual application may help.

"If you're using setup rates with a planned post-emerge treatment, I would strongly consider using full rates instead," Johnson says. "Or, when you make your post-emerge treatment, use some of your residual herbicide with your post-emerge treatment."

Another way to make sure any herbicide you do put down earlier than normal does what it's supposed to is to use products with multiple modes of action for grasses and broadleaf weeds. "You want products that are pretty robust in what they control," Johnson says.

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