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Sunday, May 1, 2016

Timely rains needed for 2013 growing season

Friday, February 1, 2013

Two weather extremes, heat and drought, dominated crop production in Plymouth County in 2012.

The moisture situation hasn't improved since farmers finished harvesting last year's crop, according to Joel DeJong, Iowa State University (ISU) Extension crop specialist.

"We have less water in storage in the soil in Iowa than we had at this time last year," he said.

Last fall was dry, and there hasn't been much moisture this winter, he points out.

"We need spring rainfall, we need timely rainfall during the growing season," DeJong said. "We can get that, but we have less margin for error going into this year."

Crops need approximately 20-21 inches of water during the growing season to prevent water from being a limiting factor in production, he said.

Soil samples last fall showed a range of 1.5-4.5 inches of moisture.

The western part of Plymouth County has less soil moisture going into the 2013 growing season than the eastern part of the county, DeJong said.

"So we're kind of similar to what we were last year, maybe a shade worse, in general," he said.

Optimistically, the ISU Extension agronomist said average rainfall would provide adequate moisture for the 2013 crop season.

Using Sioux City records, the average rainfall between May 1 and Sept. 1 is a little more than 14 inches of water, he said.

"If we have 6 or 7 inches of moisture in the soil on the first of May, then maybe there's a decent chance if we get pretty good spring precipitation we could be getting closer to having enough water in storage," DeJong said.

The opposite is true if precipitation is below average.

Another hot year?

July 2012 was one of the hottest ever and the timing of the temperatures impacted the corn crop.

"You don't expect a record every year," DeJong said. "If we can moderate some of those temperatures, it is going to be a benefit."

As he listened to Harry Hillacker, state climatologist, speak at an ISU Extension crop production update, in Le Mars this week, DeJong said a couple of Hillacker's records stood out.

The first indicated rainfall hasn't been average across the state after a drought year.

"That concerns me because we need average to better than average rainfall if we aren't going to limit our crop potential," he said.

The state climatologist's records also indicated temperatures in the year after a drought are typically "a shade hotter than normal," DeJong said.

"I don't want temperatures to be record-setting, but a little hotter than normal probably isn't going to hurt us as much as a lot hotter than normal," he said.

Managing risk

Citing the potential for a higher risk year, DeJong said crop insurance is a risk management tool.

"I think the big issue is what level and what rate of crop insurance will producers look at to protect the long-term integrity of their operation," he said.

Producers have a March 15 deadline to purchase crop insurance for this growing season, according to Marty Pippett, AmBank Insurance, in Le Mars.

Some producers are considering a shift from corn to soybeans for the 2013 crop, DeJong said.

"But the economics are on the corn side," he said.

A few people may grow more soybean acres because they also recognize if it stays dry the first half of the growing season, corn is likely to suffer more than soybeans, DeJong said.

"I see some acres going one way, some going the other but I don't see a big shift in this part of the state," he said.

Hot dry conditions are favorable for spider mites, according to DeJong.

"We had a big outbreak of spider mites in soybeans last year," he said. "Perhaps we're at a little higher risk if the scenario continues."

Wet conditions, which can kill corn rootworm larvae in June, were absent from the 2012 growing season.

"We probably had more adult root worms laying eggs this past year," DeJong said.

In high risk fields, rotating from a corn crop to soybeans is the best way to manage the pest, he said.

DeJong said he is still being an optimist about the 2013 growing season.

"I don't think you can farm without being somewhat of an optimist and so you can't plan for failure -- you've got to plan for some success," he said.

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